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The effects of anxious arousal on fear, fear reduction, and the return of fear Flessati, Eugene William 1990

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THE EFFECTS OF ANXIOUS AROUSAL ON FEAR, FEAR REDUCTION, AND THE RETURN OF FEAR By EUGENE WILLIAM FLESSATI B.Sc. (Honours), The University of Calgary, 1981 M.A., The University of B r i t i s h Columbia, 1986 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (PSYCHOLOGY) We accept t h i s thesis as conforming to the reguired standard THE UNIVERSITY OF BRITISH COLUMBIA July 1990 © Eugene William F l e s s a t i , 1990 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada DE-6 (2/88) ABSTRACT The purpose of t h i s investigation was to examine the a p p l i c a b i l i t y of several habituation models to fear processes with special reference to the e f f e c t s of anxious arousal on fear, fear reduction, and the return of fear. The e f f e c t s of anxious arousal on s e l f - e f f i c a c y expectations were also explored. Seventy-six female undergraduate students who reported a fear of snakes and met a minimum c r i t e r i o n of fear on a Behavioral Approach Test participated i n the study. Subjects viewed a videotaped fear reduction program under eith e r control or anxious arousal conditions. Fear and s e l f -e f f i c a c y expectations were assessed repeatedly during the f i r s t session. During a follow-up session one month l a t e r , subjects were re-exposed to the feared stimulus under eith e r control or anxious arousal conditions. Although anxious arousal did not a f f e c t fear l e v e l s within-session, experiencing anxious arousal during fear reduction impeded reduction of subjective fear and, paradoxically, resulted i n less heart rate response upon exposure to the feared stimulus following fear reduction. Return of subjective fear was experienced by a l l of the subjects except those who experienced fear reduction while in an anxious state and follow-up assessment i n a calm state. These subjects experienced a substantial decrement i n self-reported fear at follow-up. There was a f a i l u r e to f i n d a r e l a t i o n s h i p between anxious arousal and s e l f - e f f i c a c y . The r e s u l t s were interpreted i n terms of several habituation models. I t was concluded that the r e s u l t s are better understood i n terms of emotional processing models of fear. Novel findings include evidence that: anxious arousal during fear modification impedes the return of fear, and that assessment i n a calm state, following fear reduction while i n an anxious state, blocks the return of fear. These findings are t h e o r e t i c a l l y and c l i n i c a l l y important. The implications of the r e s u l t s to s e l f - e f f i c a c y theory were discussed. The c l i n i c a l implications of the findings were also explored with special reference to relapse. Table of Contents Abstract i i L i s t of Tables v i L i s t of Figures v i i i Acknowledgements ix INTRODUCTION 1 OVERVIEW 1 MECHANISMS OF FEAR REDUCTION 2 HABITUATION 8 DUAL PROCESS THEORY OF HABITUATION 12 CORTICAL MODEL THEORIES OF HABITUATION 15 EFFECTS OF AROUSAL ON HABITUATION 2 2 Comparison of normal subjects who d i f f e r with respect to t h e i r l e v e l s of s e l f -reported t r a i t anxiety or neuroticism 26 Comparison of normal subjects with subjects who are diagnosed as c l i n i c a l l y anxious 27 Comparison of subjects who d i f f e r with respect to t h e i r resting physiological l e v e l 30 Experimentally inducing d i f f e r e n t i a l l e v e l s of arousal 30 A b i l i t y of the habituation models to explain the influence of arousal 3 3 THE EFFECTS OF AROUSAL ON FEAR REDUCTION AND THE RETURN OF FEAR 4 0 SELF-EFFICACY AND AROUSAL 49 STATEMENT OF PURPOSE 53 Hypotheses 55 Overview of Method and Design 57 Predictions 58 METHOD 69 SCREENING 69 MEASURES 69 FEAR REDUCTION PROGRAM 7 2 FEAR REDUCTION SESSION 73 V FOLLOW-UP SESSION 78 RESULTS 7 6 EVALUATION OF THE EXPERIMENTAL MANIPULATION 76 ANALYSIS OF THE EFFECTS OF ANXIOUS AROUSAL ON FEAR 88 ANALYSIS OF THE EFFECTS OF ANXIOUS AROUSAL ON SELF-EFFICACY 106 DISCUSSION 115 EVALUATION OF THE EXPERIMENTAL MANIPULATION 115 EFFECTS OF ANXIOUS AROUSAL ON FEAR 117 Ef f e c t s of anxious arousal on within-session changes i n fear 118 Ef f e c t s of anxious arousal on fear reduction 122 Ef f e c t s of anxious arousal on the return of fear 12 6 EFFECTS OF ANXIOUS AROUSAL ON SELF-EFFICACY EXPECTATIONS 131 THEORETICAL IMPLICATIONS 137 CLINICAL IMPLICATIONS 14 6 CONCLUSIONS 149 REFERENCES 156 APPENDICES 174 APPENDIX A: FEAR SURVEY SCHEDULE 17 5 APPENDIX B: MOOD SCALE 177 APPENDIX C: SELF-EFFICACY SCALE 179 APPENDIX D: CONSENT FORM 181 APPENDIX E: RESIDUAL GAIN SCORE ANALYSIS 183 v i L I S T OF TABLES TABLE 1 P r e d i c t i o n s r e g a r d i n g t h e e f f e c t s o f a n x i o u s a r o u s a l p r i o r t o a n d d u r i n g f e a r r e d u c t i o n on f e a r 64 TABLE 2 P r e d i c t i o n s r e g a r d i n g t h e e f f e c t s o f a n x i o u s a r o u s a l d u r i n g f e a r r e d u c t i o n a n d a t f o l l o w - u p on t h e r e t u r n o f f e a r 65 TABLE 3 P r e d i c t i o n s r e g a r d i n g t h e e f f e c t s o f a n x i o u s a r o u s a l on s e l f - e f f i c a c y e x p e c t a t i o n s 68 TABLE 4 R e s p o n s e s o f t h e s u b j e c t s on t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 1 82 TABLE 5 R e s p o n s e s o f t h e s u b j e c t s on t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 2 84 TABLE 6 R e s p o n s e s o f t h e s u b j e c t s on t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 3 86 TABLE 7 R e s p o n s e s o f t h e s u b j e c t s on t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 4 88 TABLE 8 R e s p o n s e s o f t h e s u b j e c t s on t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 5 89 TABLE 9 R e s p o n s e s o f t h e s u b j e c t s on t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 6 91 T a b l e 10 Mean i n i t i a l h e a r t r a t e , h e a r t r a t e r e s p o n s e , a n d h e a r t r a t e r e s p o n s e a d j u s t e d f o r i n i t i a l h e a r t r a t e a t t i m e 1 94 TABLE 11 Mean i n i t i a l h e a r t r a t e , h e a r t r a t e r e s p o n s e , a n d h e a r t r a t e r e s p o n s e a d j u s t e d f o r i n i t i a l h e a r t r a t e a t t i m e 2 96 v i i TABLE 12 Mean i n i t i a l heart rate, heart rate response, and heart rate response adjusted for i n i t i a l heart rate at time 3 97 TABLE 13 Mean i n i t i a l heart rate, heart rate response, and heart rate response adjusted for i n i t i a l heart rate at time 3 and time 4 100 TABLE 14 Mean i n i t i a l heart rate, heart rate response, and heart rate response adjusted for i n i t i a l heart rate at time 4 and time 6 for subjects who were i n the control and anxious arousal groups at follow-up 103 TABLE 15 SUDS scores at time 4, time 6, and residual gain SUDS scores for subjects i n the four groups 107 TABLE 16 Proportion of subjects i n each of the four groups who showed return of fear 108 TABLE 17 Mean s e l f - e f f i c a c y scores at time 4 and time 6 of subjects i n the control and anxious arousal groups at follow-up 114 v i i i LIST OF FIGURES FIGURE 1 Habituation and s e n s i t i z a t i o n processes 14 FIGURE 2 Mean SUDS scores at time 4 and time 6 for subjects i n the control group and anxious arousal group at follow-up 102 FIGURE 3 Mean SUDS scores at time 4 and time 6 for subjects i n congruent and incongruent states of anxious arousal during session 1 and session 2 105 FIGURE 4 Mean adjusted heart rate responses at time 4 and time 6 for subjects i n congruent and incongruent states of anxious arousal during session 1 and session 2 110 ix ACKNOWLE DGEMENTS F i r s t and foremost, I wish to thank my supervisor, Dr. Jack Rachman, whose support, advice, and guidance i n matters of science, l i f e , and wine have been invaluable and much appreciated. This research could not have been conducted without the generous assistance of K e r r i Fraser, Debbie MacNamera, and Annabel Webb i n c o l l e c t i n g the data on which t h i s thesis i s based. I also wish to thank my committee members, Dr. Dim i t r i Papageorgis and Dr. A. Ralph Hakstian, for t h e i r suggestions regarding the design and presentation of t h i s t h e s i s . I would also l i k e to thank the "Anxiety Research Team", Debbie Samsom, Cindy Lopatka, Richard Booth, Maureen Whittal, and Steve Taylor, for t h e i r constructive feedback during the past several years. F i n a l l y , I wish to thank my friends. They have stuck by me, been an enormous source of emotional support, and taken me out to play. They have made my l i f e much r i c h e r and happier as a r e s u l t of knowing them. Special thanks to L o r i , Kevin, Mike, Sonya, Angela, Karen, Geoff, Nancy, Andrea, Risha, Michelle, Melanie, Kelly, Cam, Joy, (and Je s s i c a ! ) , Scott, John, and John. 1 OVERVIEW Exposure-based techniques of fear reduction are e f f i c a c i o u s i n reducing fear but there i s s t i l l no acceptable explanation of t h e i r e f f i c a c y . A notable attempt i s the habituation model of fear (e.g., Lader & Mathews, 1968; Lader & Wing, 1964, 1966). The habituation model of fear, as well as theory and research from several other sources, have suggested that heightened arousal during exposure may impede fear reduction and f a c i l i t a t e the return of fear. The purpose of the present study was to examine the a p p l i c a b i l i t y of several habituation models to fear reduction with special reference to the ef f e c t s of anxious arousal on fear reduction and the return of fear. The r e s u l t s of t h i s study are relevent for the understanding of habituation processes, fear reduction, and the return of fear. Ultimately, t h e o r e t i c a l and c l i n i c a l benefits may be derived from t h i s research. The l i t e r a t u r e review begins with a discussion of processes postulated to underlie fear reduction. Common to these postulated processes i s an emphasis on the r o l e of repeated exposure to the feared s t i m u l i . Given the s i m i l a r i t y between fear reduction and habituation, i t i s suggested that an examination of the theories and data of habituation w i l l aid i n the understanding of fear reduction. Consequently, an overview of habituation i s presented. Research that has a bearing on the ef f e c t s of arousal l e v e l on habituation to neutral and feared s t i m u l i i s discussed. The r e l a t i o n s h i p 2 between anxious arousal and s e l f - e f f i c a c y i s then explored. F i n a l l y , a statement of the problem and a series of predictions based on the theories and data are made. MECHANISMS OF FEAR REDUCTION A number of therapeutic procedures are e f f i c a c i o u s i n reducing fear and anxiety. The most common of these procedures include systematic desensitization, graduated exposure, modeling procedures, and exposure and response prevention (e.g., Emmelkamp, 1982a, 1982b; Masters & Rimm, 1987; Mavissakalian & Barlow, 1981; Rimm & Masters, 1979). Although i t i s impossible to make unqualified statements regarding the r e l a t i v e e f f i c a c y of the d i f f e r e n t therapeutic procedures, i t can be stated that they a l l show a degree of success i n reducing fear and anxiety (for example, see reviews by Barlow & Beck, 1984; Emmelkamp, 1982a, 1982b; Linden, 1981; Marks, 1975, 1978; Mathews, 1978; Rachman & Wilson, 1980). These methods vary procedurally on such variables as whether the fear inducing stimulus i s presented i n an i n vivo or imaginal manner, the length of each exposure duration, and the degree of arousal induced i n the i n d i v i d u a l during exposure. Although these treatments d i f f e r , they a l l include repeated exposure to the feared stimulus. This has led a number of researchers,to the conclusion that the c r i t i c a l element determining fear reduction i s repeated exposure to the feared stimulus (e.g., Barlow, 1988; Barlow & Beck, 1984; Barlow & Mavissakalian, 1981; Foa & Kozak, 1985, 1986; Leitenberg, 1976; Marks, 1975, 1978, 1987; Wilson, 1982). 3 Exposure i s also often a component of non-behaviorally based therapies and i s recognized i n c l i n i c a l l ore as important. For example, Sigmund Freud understood the importance of exposure as an aid to anxiety reduction: One can hardly ever master a phobia i f one waits t i l l the patient l e t s the analysis influence him to give i t up ... one succeeds only when one can induce them through the influence of analysis to go about alone and to struggle with t h e i r anxiety while they make the attempt. (Freud, 1924; c i t e d i n Leitenberg, 1976, p. 400) Although fear reduction can occur i n the absence of exposure to the feared stimulus, exposure i s the most e f f e c t i v e procedure for reducing fear (Bandura, 1977; Boyd & Levis, 1983; de S i l v a & Rachman, 1981, 1983; Foa & Kozak, 1986; Rachman, 1990). Exposure i s a descriptive term for what occurs i n treatment and does not explain the process whereby exposure i s e f f e c t i v e i n reducing fear. Several explanations of fear reduction have been suggested. E a r l i e r single-process explanations have included re c i p r o c a l i n h i b i t i o n (e.g., Wolpe, 1958, 1982), s e l f - e f f i c a c y theory (e.g., Bandura, 1977), extinction (e.g., Levis & Hare, 1977), and habituation (e.g., Rachman, 1978). There i s currently l i t t l e agreement regarding the extent to which these explanatory mechanisms account for fear reduction (e.g., Borkovec, 1978; Levin & Gross, 1985; Rachman, 1978, 1984, 1990; Wolpe 1978). Although i t i s parsimonious to postulate a single explanatory mechanism of fear reduction, t h i s may be u n r e a l i s t i c a l l y s i m p l i s t i c given the complex nature of fear (e.g., Hodgson & Rachman, 1974; 4 Lang, 1968, 1977b; Rachman, 1978, 1990; Rachman & Hodgson, 1974). Later theories of fear reduction have responded to t h i s challenge and attempted to integrate findings i n l i n e with the m u l t i f a c t o r i a l nature of fear and fear reduction. These theories include Lang xs (e.g., 1977a, 1979, 1985) bio-informational model of fear, Rachman's (1980) theory of emotional processing, and Foa and Kozak's (1985, 1986) emotional processing model of fear reduction. Each of these models w i l l be summarized. Lang (1977a, 1979, 1985) suggested that information about fear i s pr o p o s i t i o n a l l y coded i n the form of associative networks i n memory. In the associative network of memory: An event i s represented i n memory by a c l u s t e r of desc r i p t i v e propositions. These are recorded i n memory by establishing new associative connections among instances of the concepts used i n describing the event... The contents of consciousness are the sensations, concepts, and propositions whose current a c t i v a t i o n l e v e l exceeds some threshold. A c t i v a t i o n presumably spreads from one concept to another, or from one proposition to another, by associative linkages between them. (Bower, 1981, p. 134) The associative network defining a s p e c i f i c fear includes information about properties of the stimulus (e.g., "Spiders are h a i r y " ) , response to the stimulus (e.g., "heart pounds", "run"), and meaning information that elaborates on the stimulus and response information (e.g., "Spiders are dangerous"). The degree to which the elements comprising the network defining the feared stimulus are activated determines the l i k e l i h o o d that a fear response w i l l occur. Lang hypothesizes that r e l a t i v e to non-fearful i n d i v i d u a l s , the associative networks defining feared s t i m u l i i n f e a r f u l 5 i n d i v i d u a l s have a higher degree of associative strength, and a c t i v a t i o n of fewer elements of the feared stimulus are necessary to cause a fear response. Lang suggests that a l t e r a t i o n i n the network defining a feared stimulus r e s u l t s i n behavior change. In t h i s view, exposure i s e f f e c t i v e to the extent that i t accesses the c o g n i t i v e - a f f e c t i v e network that defines the stimulus. This i s congruent with the finding that greater fear reduction occurs when there i s greater phy s i o l o g i c a l arousal i n response to i n i t i a l stimulus exposures, which presumably r e f l e c t s accessing of the network representing the feared stimulus (Dyckman & Cowen, 1978; Glenn & Hughes, 1978; Lang, Melamed, & Hart, 197 0; Levin, Cook, & Lang, 1982; Marshall, 1988; Stern & Marks, 197 3; Vermilyea, Boice, & Barlow, 1984). Lang does not focus attention on the s p e c i f i c mechanisms of behavior change. Fear reduction i s said to occur as a r e s u l t of a weakening of the associations between the stimulus, meaning, and response elements of fear, and the development and elaboration of other non-fearful associations. Lang's (1977a) analysis of fear imagery was the impetus for Rachman's (1980) theory of emotional processing. Rachman noted that the origins of emotional processing can be traced to Freud's well known case of Anna 0. Freud argued that because of circumstances Anna O. was forced to suppress emotion over the i l l n e s s and death of her father. This emotional suppression was supposedly responsible for the wide range of neurotic symptoms experienced by Anna 0. Emotional 6 processing refers to, "a process whereby emotional disturbances are absorbed and decline to the extent that other experiences can proceed without disruption" (Rachman, 1980, p. 51). The core concept of emotional processing derives from findings i n d i c a t i n g that fear reduction i s enhanced by the experience of emotion during exposure to the feared stimulus (e.g., Lang, Melamed, & Hart, 1970). Rachman suggested that reductions i n fear w i l l not be maintained i f emotional processing i s not complete. Direct indications of unsatisfactory emotional processing include undue persistence of fear, unprovoked return of fear, and the incubation of fear. A large number of possible factors that may f a c i l i t a t e or disrupt emotional processing were suggested by Rachman. Notable among the state factors that: may influence emotional processing are high arousal and dysphoria, which may hinder emotional processing; and relaxation, which may f a c i l i t a t e emotional processing. Foa and Kozak (1985, 1986) extended Rachman's notion of emotional processing and more f u l l y integrated Lang's (e.g., 1985) bio-informational theory into t h e i r model of emotional processing. Their d e f i n i t i o n of emotional processing d i f f e r s from Rachman's (198 0) i n that they suggest that the term refers to the incorporation of any new information into the fear structure regardless of i t s e f f e c t s on fear. Central to t h e i r explanation of fear reduction are two processes: fear reduction within-session and between-session. They suggested that within-session fear reduction i s the r e s u l t of 7 habituation of autonomic responsiveness. Within-session fear reduction i s postulated to have two causes: d i s s o c i a t i o n of the fear response from the stimulus and the incorporation of more adaptive responses; and a decrease i n the p r o b a b i l i t y and valence of perceived threat associated with the feared stimulus. The second habituation process, between-session habituation, i s dependent on durable changes i n cognition. S p e c i f i c a l l y , the meaning ascribed to the feared s t i m u l i must change i n order for between-session habituation to occur. These changes are accomplished through the process of within-session habituation. The most common b e l i e f s that are necessary to be modified include the b e l i e f that the fear response w i l l l a s t i n d e f i n i t e l y , and the fear of fear (e.g., Clark, 1986). Foa (1979), and Foa and Kozak suggest that between-session habituation of fear i s dependent on within-session habituation; however, the occurrence of within-session habituation does not ensure between-session habituation. In other words, i n t h e i r model within-session habituation i s a necessary, but not s u f f i c i e n t , condition of long term habituation. Failures i n emotional processing can occur either as the r e s u l t of a f a i l u r e of the stimulus exposure to s u f f i c i e n t l y activate the fear structure underlying the feared stimulus, or because of a f a i l u r e of the stimulus exposure to allow information that disconfirms the threat. The importance attached to repeated exposures to the feared stimulus by a l l of the above theories of fear reduction suggests that habituation, which i s defined as a decrease i n 8 responding as the r e s u l t of repeated stimulus presentation, may be a v i a b l e explanation of the fear reduction process. There are consistent data in d i c a t i n g that the process of exposure-based fear reduction occurs i n a manner akin to habituation i n the subjective report and autonomic components of the fear response (e.g., Connolly, 1979; Foa, 1979; Foa & Chambless, 1978; Klorman, 1974: Lande, 1982; Lang, Melamed, & Hart, 1970; Parkinson & Rachman, 1980). The f i r s t attempt to consider fear reduction as an habituation process was made by Lader and Wing (1964, 1966) and l a t e r elaborated by Lader and Mathews (1968). Although the s i m i l a r i t y between the fear reduction process and habituation has not gone unnoticed by l a t e r researchers i n the area of fear reduction, with very few exceptions (e.g., Rachman, 1978, 1990; Watts, 1979) they have not considered the mechanisms hypothesized to underlie habituation that have been developed i n other areas of psychology. Given that the roots of behavioral approaches to fear reduction are derived from experimental psychology, i t seems appropriate to consider the data and theories of habituation. I t i s l i k e l y that an examination of t h i s research and theory w i l l allow an integration of habituation theory into the area of fear reduction. This should r e s u l t i n an increased understanding of the fear reduction process HABITUATION Habituation can be defined most simply and generally as a decrease i n responding as the r e s u l t of repeated stimulus presentations (e.g., Harris, 1943; Thompson, Berry, R i n a l d i , & 9 Berger, 1979; Thorpe, 1963). Response decrements due to extremely rapid stimulation (which may r e s u l t i n sensory adaptation or motor fatigue), trauma (Harris, 1943; Hinde, 1970; Thompson & Spencer, 1966), or drugs (Thompson et a l . , 1979) are excluded from the d e f i n i t i o n of habituation. Habituation has been recorded at a l l phylogenetic l e v e l s ranging from s i n g l e - c e l l e d organisms to humans, and across responses ranging widely i n function and complexity. The vast majority of research has examined habituation i n nonhuman animals. Habituation research with humans has been almost li m i t e d to studies of physiological response to auditory tones. The ubiguitousness of the habituation phenomenon does not denote that i t s underlying mechanisms are s i m i l a r across species or responses (Mackintosh, 1987; Petrinovich, 1984; Thompson, Groves, Teyler, & Roemer, 1973). Habituation can be considered as a form of conditioning (Kimmel, 1973; Stephenson & Siddle, 1983) and may provide further understanding of more complex v a r i e t i e s of learning (Groves & Thompson, 1970; Stephenson & Siddle, 1983). Although most studies have examined r e f l e x behavior, the term habituation can also c o r r e c t l y be used to r e f e r to decreased responding of conditioned responses (Thompson & Spencer, 1966; Thorpe, 1963). Although studies of habituation t y p i c a l l y present the subject with s t i m u l i i n the form of a series of discrete t r i a l s , uninterrupted stimulus presentations can also be used to study habituation (Hinde, 1970). 10 H i s t o r i c a l l y , response decrement due to habituation has been considered as a phenomenon that spontaneously recovers i n a very short period of time following stimulus termination ( i . e . , within minutes). Although most studies neglect the assessment of long term habituation, even phylogenetically simple animals can exhibit s i g n i f i c a n t response decrement over much longer periods. For example, Carew, Pinsker, and Kandel (1972) reported s i g n i f i c a n t maintenance of habituation of the siphon withdrawal r e f l e x i n Aplysia (a bivalve mollusk) over a period of three weeks. Leaton and Jordan (1978) found evidence of continued habituation of EEG a c t i v i t y i n rats i n response to tones 32 days following habituation. Habituation and extinction are s i m i l a r processes to the extent that they are both characterized by a gradual decrease in response followed by a degree of spontaneous recovery (Kling & Stevenson, 1970). Also, both occur as a r e s u l t of experience and can be r e l a t i v e l y stable and context-specific (Peeke & Petrinovich, 1984) . Beyond t h i s , however, i t i s very d i f f i c u l t to compare these two processes as they are procedurally d i f f e r e n t . Extinction refers to response decrement i n learned responses as the r e s u l t of repeated presentations of a conditioned stimulus without i t s unconditioned stimulus (in c l a s s i c a l conditioning), or repeated occurrences of an operant response that are not followed by p o s i t i v e or negative reinforcement (in instrumental conditioning). Habituation t r a i n i n g involves repeated presentations of the same stimulus and i s a simpler 11 p r o c e d u r e t h a n e x t i n c t i o n . A l t h o u g h h a b i t u a t i o n i s t y p i c a l l y s t u d i e d w i t h u n c o n d i t i o n e d s t i m u l i , l e a r n e d r e s p o n s e s a r e n o t e x p l i c i t l y e x c l u d e d from t h e d e f i n i t i o n o f h a b i t u a t i o n . There i s n o t p r e s e n t l y s u f f i c i e n t e v i d e n c e t o unambiguously e s t a b l i s h t h e e x t e n t t o which e x t i n c t i o n and h a b i t u a t i o n r e f l e c t t h e same p r o c e s s . The f i n d i n g t h a t e x t i n c t i o n may be more permanent t h a n h a b i t u a t i o n i s u s u a l l y r e c o g n i z e d t o be, s u g g e s t s t h a t t h e two p r o c e s s e s may be f u n d a m e n t a l l y d i f f e r e n t . A number o f p a r a m e t r i c p r o p e r t i e s o f h a b i t u a t i o n have been summarized i n r e v i e w s o f t h i s l i t e r a t u r e ( e . g . , Carew, 1984; Hinde, 1970; O'Gorman, 1977, 1983; Graham, 1973; S i d d l e , Stephenson, & S p i n k s , 1983; Stephenson & S i d d l e , 1983; Thompson & Spencer, 1966). A l t h o u g h t h e r e i s a c e r t a i n degree o f v a r i a n c e i n t h e s p e c i f i c p a rameters o f h a b i t u a t i o n a c r o s s r e s p o n s e s and s p e c i e s , f o r t h e most p a r t t h e s e p r o p e r t i e s e x h i b i t a l a r g e degree o f g e n e r a l i t y . S e v e r a l t h e o r i e s have been d e v e l o p e d t o e x p l a i n h a b i t u a t i o n . Two t h e o r i e s o f h a b i t u a t i o n t h a t have s t i m u l a t e d a c o n s i d e r a b l e amount o f r e s e a r c h a t t e n t i o n , and t h a t a r e o f t e n c o n t r a s t e d w i t h each o t h e r , a r e t h e d u a l p r o c e s s t h e o r y d e v e l o p e d by Thompson and h i s c o l l e a g u e s ( e . g . , Groves & Thompson, 1970; Thompson e t a l . , 1979; Thompson e t a l , 1973; Thompson & Spencer, 1966), and a c l a s s o f t h e o r i e s t h a t have as t h e i r common e x p l a n a t o r y element t h e development o f a c o r t i c a l model o f t h e s t i m u l u s ( e . g . , S o k o l o v , 1963; S o k o l o v , 1968; S o k o l o v & V i n o g r a d a , 12 1975; Wagner, 1976; Whitlow, 1975; Whitlow & Wagner, 1984). These theories w i l l be discussed i n the following sections. DUAL PROCESS THEORY OF HABITUATION Dual process theory (Groves & Thompson, 1970; Thompson et a l . , 1979; Thompson et a l . , 1973) was developed i n order to explain the parametric properties of habituation summarized i n Thompson and Spencer (1966). Thompson and his colleagues contended that these properties could not be explained by any single process theory of habituation. Rather, habituation was thought to be the r e s u l t of two processes: the habituation process, which occurs i n the stimulus-response pathways; and the s e n s i t i z a t i o n process, which occurs i n the "state system" and i s analogous to l e v e l of arousal. Groves and Thompson (1970) stated that any stimulus that i s capable of evoking a behavioral response has two properties: i t e l i c i t s a response, and i t a f f e c t s the arousal l e v e l of the animal exposed to the stimulus. Behavioral response i s the r e s u l t of the in t e r a c t i o n of these two inferred processes. Repeated stimulus presentation r e s u l t s i n a decrease i n the strength of the stimulus-response associations (termed the habituation process). This attenuated association between stimulus and response recovers over time. However, i t has a degree of permanence, e s p e c i a l l y a f t e r extended stimulus presentations. Stimulus exposure also r e s u l t s i n s e n s i t i z a t i o n ( i . e . , an increase i n arousal). This s e n s i t i z a t i o n i n i t i a l l y increases and then decreases across stimulus exposures. The degree of s e n s i t i z a t i o n i s a d i r e c t function of stimulus i n t e n s i t y . 13 S e n s i t i z a t i o n i s r e l a t i v e l y t r a n s i e n t a n d d e c a y s s p o n t a n e o u s l y . S e n s i t i z a t i o n h a s a g e n e r a l e f f e c t on r e s p o n d i n g , a n d d o e s n o t o n l y i n f l u e n c e r e s p o n s e t o s t i m u l i b e i n g h a b i t u a t e d . D u a l p r o c e s s t h e o r y a r g u e s t h a t o v e r t b e h a v i o r a l r e s p o n d i n g i s t h e r e s u l t o f t h e i n t e r a c t i o n o f t h e t w o i n f e r r e d p r o c e s s e s o f h a b i t u a t i o n a n d s e n s i t i z a t i o n . U n d e r s t a n d i n g o f t h i s t h e o r y may be a i d e d b y a v i s u a l r e p r e s e n t a t i o n o f t h e s e p r o c e s s e s . A s shown i n F i g u r e 1, b e h a v i o r a l o u t c o m e i s t h e r e s u l t o f t h e i n t e r a c t i o n o f t h e d e c r e m e n t a l h a b i t u a t i o n p r o c e s s a n d t h e s e n s i t i z a t i o n p r o c e s s , w h i c h i s i n i t i a l l y i n c r e m e n t a l a n d l a t e r d e c r e m e n t a l ( i . e . , t h e r e i s h a b i t u a t i o n o f t h e s e n s i t i z a t i o n p r o c e s s i n r e s p o n s e t o r e p e t i t i v e s t i m u l u s e x p o s u r e s ) . A m a j o r i m p e t u s i n t h e d e v e l o p m e n t o f t h e d u a l p r o c e s s t h e o r y was t h e phenomenon o f d i s h a b i t u a t i o n . D i s h a b i t u a t i o n r e f e r s t o t h e c o n s i s t e n t f i n d i n g t h a t a n h a b i t u a t e d r e s p o n s e w i l l r e c o v e r f o l l o w i n g e x p o s u r e t o a n o v e l , o r o t h e r w i s e a r o u s i n g , s t i m u l u s . Thompson e t a l . (1979) s u m m a r i z e t h r e e f i n d i n g s b a s e d on t h e d i s h a b i t u a t i o n p a r a d i g m : b o t h h a b i t u a t e d a n d n o n - h a b i t u a t e d r e s p o n s e s i n c r e a s e i n m a g n i t u d e f o l l o w i n g e x p o s u r e t o a n o v e l s t i m u l u s ; e x p o s u r e t o a d i s h a b i t u a t i n g s t i m u l u s may i n c r e a s e r e s p o n s i v e n e s s o f a n h a b i t u a t e d r e s p o n s e a b o v e b a s e l i n e l e v e l ; a n d t h e d i s h a b i t u a t e d r e s p o n s e s p o n t a n e o u s l y d e c a y s t o i t s p r e v i o u s l y h a b i t u a t e d l e v e l i n t h e a b s e n c e o f f u r t h e r h a b i t u a t i o n t r a i n i n g . Thompson e t a l . (1979) a r g u e t h a t t h e s e r e s u l t s 14 F i g u r e 1 H a b i t u a t i o n and s e n s i t i z a t i o n p r o c e s s e s High Response Amplitude Low * ' , * Sensitization process T 1 Stimulus Presentation Number 1 r n- l n 15 cannot be explained with a unitary explanatory process, but are congruent with dual process theory. Within t h e i r model, the term "dishabituation" i s a misnomer. Instances of response recovery i n the dishabituation paradigm are the r e s u l t of the influence of the superimposed process of sensitization/arousal on the habituation process. The dual process model i s a common-elements model. Generalization of habituation i s regarded as a function of the amount of correspondence i n the elements defining the s t i m u l i . This degree of correspondence i s p a r a l l e l e d i n the central nervous system i n terms of the extent of overlap i n the s p e c i f i c interneurons i n the stimulus-response pathway excited during exposure. CORTICAL MODEL THEORIES OF HABITUATION These models were developed by Sokolov (1963, 1969; Sokolov & Vinograda, 1975), and Wagner and Whitlow (Wagner, 1976; Whitlow, 1975; Whitlow & Wagner, 1984). Sokolov's model focuses on habituation of the orienting response. The orienting response i s a response to novelty or environmental change (Sokolov, 1963). I t i s a non-specific response to s t i m u l i of low to moderate int e n s i t y , and i t s purpose i s to maximize the organism's a b i l i t y to perceive and react to environmental change (Sokolov, 1963). Components of the orienting response include increased receptor s e n s i t i v i t y , modification of s k e l e t a l muscles responsible for d i r e c t i n g the receptors, a l t e r a t i o n s i n general s k e l e t a l musculature, increased electroencephalographic arousal, and autonomic 16 changes (e.g., increased galvanic skin response) (Lynn, 1966). During i n i t i a l exposures to the stimulus, the orienting response i s of a generalized nature. After repeated exposures, however, the orienting response becomes progressively more l o c a l i z e d and s p e c i f i c to the stimulus. Sokolov argues that repeated exposures to a s p e c i f i c stimulus r e s u l t s i n the development of a c o r t i c a l model of the stimulus. This c o r t i c a l model includes stimulus parameters such as stimulus duration, i n t e n s i t y , and time i n t e r v a l between stimulus exposures. With repeated exposures, the c o r t i c a l model becomes increasingly stronger and well-defined. Each stimulus presentation r e s u l t s i n a comparison of the stimulus with the "expected" neural model. A mismatch between the stimulus and the c o r t i c a l model re s u l t s i n c o r t i c a l arousal and, as a r e s u l t , e x c i t a t i o n of the r e t i c u l a r formation, r e s u l t i n g i n an orienting reaction. Given a match between the stimulus and the c o r t i c a l model, the cortex does not send excitatory impulses to the r e t i c u l a r formation and i t i n h i b i t s other impulses from the c o l l a t e r a l afferents descending to the r e t i c u l a r formation. Thus, i n Sokolov's model of habituation, habituation of the orienting response i s the r e s u l t of i n h i b i t i o n of the r e t i c u l a r formation by the cortex as the r e s u l t of congruence between the stimulus and the continually developing c o r t i c a l model of the stimulus. The degree of habituation i s d i r e c t l y proportional to the degree of s i m i l a r i t y between stimulus properties and properties of the "expected" c o r t i c a l model. Sokolov's e a r l i e r writings were vague with respect to the 17 manner i n which the "expected" c o r t i c a l model was d i f f e r e n t i a t e d from the myriad other c o r t i c a l models. He l a t e r postulated the existence of two memory systems: operative memory, "which stores the system of hypotheses that are being v e r i f i e d i n the experiment" (Sokolov, 1969, p. 698), and a long term memory store to explain how the expected c o r t i c a l model was iso l a t e d from the other c o r t i c a l models. Like Sokolov's model of habituation, the model developed by Whitlow and Wagner (Wagner, 1976; Whitlow, 1975; Whitlow & Wagner, 1984) also postulates the development of a c o r t i c a l model as central to the explanation of habituation. However, unlike Sokolov's model, i t i s a general model of habituation, and places greater emphasis on memory processes. The theory uses an associative network model of memory (e.g., Bower, 1981; G i l l i g a n & Bower, 1984; Lang, 1977a, 1979). In the following discussion, the elements defining the stimulus representation i n memory (corresponding to Sokolov's concept of c o r t i c a l model) w i l l be referred to as a memory node. The l a t e s t version of t h i s model (Whitlow & Wagner, 1984) postulates three le v e l s of memory: i n a c t i v i t y , corresponding to the more common term "long term memory"; and two states of a c t i v i t y or short term memory - primary and secondary. When a stimulus i s perceived by the organism, a representation of the stimulus i s stored i n the primary-active memory state. This representation then decays into the secondary-active memory state and f i n a l l y , into the inactive memory state. Both active memory states are of limited capacity and, as t h i s capacity i s 18 approached, more recent or s a l i e n t information displaces the e a r l i e r information from the primary-active memory state to the secondary-active memory state to the inactive memory state. A c t i v a t i o n of the memory node representing a stimulus to the primary-active memory state only occurs to the extent that the node i s i n the inactive memory state at the time of exposure. I f the memory node representing a stimulus i s i n the primary-active memory state at the time of stimulus exposure, t h i s exposure w i l l not have any further e f f e c t on the organism as the representation i s redundant. If the memory node representing the stimulus i s i n the secondary-active memory state at the time of stimulus exposure, the stimulus i s i n e f f e c t i v e i n act i v a t i n g the memory node to the primary-active memory state as memory nodes cannot be r e c a l l e d from the secondary-active to the primary active memory state. The p r i n c i p l e that a memory node cannot be r e c a l l e d from the secondary-active to the primary-active memory state i s the central feature of habituation i n t h i s model. Habituation occurs when a greater than zero number of elements defining the node representing the stimulus are i n the secondary-active memory state at the time of stimulus exposure. Elements that are i n the secondary-active memory state cannot be r e c a l l e d to the primary-active memory state. This r e s u l t s i n a weakened representation of the stimulus being r e c a l l e d to the primary-active memory state. As a r e s u l t of the weakened stimulus representation, the associated response i s also weakened. 19 Whitlow and Wagner contend that there are two ways i n which s t i m u l i can be represented i n the secondary-active memory state at the time of stimulus exposure, thus causing response habituation: 1. Self-generated priming - which occurs as a r e s u l t of a recent presentation (which has not yet decayed from secondary-active memory) of the same stimulus. 2. Retrieval-generated priming - which occurs as a r e s u l t of previously learned associations between the stimulus and the environmental context i n which i t occurred. After repeated associations between the context and stimulus, the context by i t s e l f primes the memory node representing the stimulus to secondary-active memory. In t h i s model, the dishabituation phenomenon i s thought to be the r e s u l t of the interpolated stimulus di s p l a c i n g the representation of the stimulus from the secondary-active to the inactive memory state. As a r e s u l t of t h i s displacement to the inactive memory state, at the next stimulus exposure the memory node representing the stimulus w i l l be avail a b l e for r e c a l l from inactive memory to primary-active memory and, as a re s u l t , there w i l l be recovery of the associated response. Although many studies over the l a s t 25 years have examined the parameters of habituation, few conclusions can be drawn regarding the a b i l i t y of the theories to explain the re s u l t s . Several researchers (Groves & Thompson, 1970; Mackintosh, 1987; Stephenson & Siddle, 1983; Thompson et a l . , 1979) have summarized t h i s research i n the context of these 20 theories of habituation. In l i e u of an expanded discussion of these findings, pertinent comments and conclusions made by these reviewers w i l l be presented. In t h e i r comparison of dual process theory and Sokolov's theory of habituation, Groves and Thompson (1970) and Thompson et a l . (1979) suggested that although the neural mechanisms postulated to underlie habituation d i f f e r e d , the theories were fundamentally s i m i l a r . They argued that many of the apparent t h e o r e t i c a l differences were simply the r e s u l t of differences i n the language used to describe the theories. Although Groves and Thompson are correct i n stating that many of the apparent differences between these theories may be semantically based, i t i s incorrect to assume that they are fundamentally s i m i l a r theories. For example, central to dual process theory i s the notion that dishabituation i s a transient phenomenon that r e s u l t s from s e n s i t i z a t i o n . Conversely, Sokolov (as well as Whitlow and Wagner) view dishabituation as the r e s u l t of a disruption of habituation. I t may be d i f f i c u l t to reconcile these views. Stephenson and Siddle (1983) undertook a thorough review of the habituation l i t e r a t u r e with the goal of evaluating four theories of habituation, including the three theories discussed, and concluded that statements regarding the r e l a t i v e e f f i c a c y of these theories were precluded for several reasons. F i r s t l y , they noted that there i s a dearth of unambiguous and r e l i a b l e data with respect to d i f f e r e n t i a l predictions made by the theories. Secondly, the authors noted 21 a lack of precision i n the theories, e s p e c i a l l y i n the c o r t i c a l model theories. F i n a l l y , the authors noted that because of the semantic differences of the theories i t i s d i f f i c u l t to determine the extent to which they encompass common processes and explanations of habituation. Stephenson and Siddle (1983) were not optimistic that a synthesis of these theories was currently possible: Given the present state of the theories discussed and the inadequacy of the data available, i t remains to be seen whether they can be integrated into a single coherent account of habituation, or indeed, whether such a general theory i s appropriate. (p. 230) Mackintosh (1987) reviewed previous data that had been gathered i n support of Whitlow and Wagner's (e.g., 1984) theory of habituation and as evidence against dual process theory (e.g., Groves & Thompson, 1970). He argued that these r e s u l t s are open to al t e r n a t i v e explanations. S p e c i f i c a l l y , these findings can be explained equally well, and more parsimoniously, within the context of dual process theory. On the basis of his review and re-analysis of these findings, Mackintosh (1987) concluded that: no data or arguments have been advanced which should persuade us to accept t h i s apparently more complex theory, either in the p a r t i c u l a r form proposed by Wagner (1976, 1978) or i n a more general form. In the absence of compelling data or argument, we should either r e j e c t the theory, or acknowledge that i t i s only a re-description, i n more f a n c i f u l language, of the simple S-R theory. (p. 95) In summary, current consensus i s that the available data do not d i f f e r e n t i a l l y support any of the previously described theories. However, given the c l a r i t y and parsimony of dual 22 process r e l a t i v e to the other two theories, i t seems most appropriate at t h i s time to consider habituation within the framework of t h i s model. EFFECTS OF AROUSAL ON HABITUATION Theories d i f f e r i n the emphasis given to the e f f e c t s of arousal on response habituation. Dual process theory (e.g., Groves & Thompson, 1970) stresses the importance of arousal, which i s said to be central to the explanation of habituation. In t h i s conceptualization of habituation, arousal during exposure r e s u l t s i n an increase i n responsiveness. However, because the arousal masks the inferred habituation process, any differences i n the degree of habituation between indi v i d u a l s who are more and less aroused w i l l not be evident except at d i s s i m i l a r l e v e l s of arousal at the time of assessment. In other words, arousal at the time of assessment should influence response, with greater arousal r e s u l t i n g i n greater responsiveness. Although Lader and his colleagues (Lader & Mathews, 1968; Lader & Wing, 1964, 1966) do not have a f u l l y developed theory regarding habituation, they discuss habituation i n the context of treatment of anxiety disorders. They also postulate a central r o l e to arousal i n the process of habituation. In t h e i r model, which postulates a single process of habituation, higher l e v e l s of arousal, above some c r i t i c a l c r i t e r i o n l e v e l , r e s u l t i n a disruption of the habituation process. In t h i s model, heightened arousal r e s u l t s i n an actual impairment of 23 habituation that w i l l be evident on l a t e r assessment regardless of the l e v e l of arousal at that time. The two c o r t i c a l model theories of habituation (e.g., Sokolov, 1963; Whitlow & Wagner, 1984) do not accord any s i g n i f i c a n t r o l e to arousal. However, predictions can be gleaned from t h e i r discussions of the theories. Although Sokolov does not discuss the role of arousal on habituation, he does argue that low l e v e l s of c o r t i c a l arousal r e s u l t i n recovery of an habituated response. This occurs because lowered c o r t i c a l arousal r e s u l t s in an impairment of the c o r t i c a l mechanisms responsible for stimulus-model comparisons. As the c o r t i c a l model of the stimulus i s not well developed with lowered arousal l e v e l s , the cortex exerts less depression of the r e t i c u l a r a c t i v a t i n g system which i s responsible for the orienting response. In an analogous manner, i t can be argued on the basis of t h i s model that higher l e v e l s of c o r t i c a l arousal would allow a better model of the stimulus to be developed i n the cortex, r e s u l t i n g i n a corresponding i n h i b i t i o n of response to the stimulus. On the basis of Whitlow and Wagner's (1984) model of habituation, i t would be predicted that to the extent that arousal r e s u l t s i n a r e - d i r e c t i o n of attention away from the stimulus and toward the environment or bodily symptoms of arousal, arousal may disrupt habituation (Wagner, 1981; Whitlow & Wagner, 198 4). Furthermore, according to t h i s model, to the extent that arousal functions as a cue to prime the stimulus into short term memory, greater maintenance of 24 habituation would be expected with s i m i l a r l e v e l s of arousal at habituation and assessment. This focus on contextual cues i s s i m i l a r to the focus of theory and research that have examined the ef f e c t s of a f f e c t on memory, (e.g., Blaney, 1986; Bower, 1981, 1987; Clark & Teasdale, 1982; Clark, Milberg, & Ross, 1983; Singer & Salovey, 1988; Teasdale, 1983; Teasdale & Fogarty, 1979). The major differences are that Whitlow and Wagner (1984) focus on contextual, as opposed to emotional cues, and focus on habituation, as opposed to memory. Differences i n the type of cue u t i l i z e d - contextual versus a f f e c t i v e - may prove to be of l i t t l e importance. For example, Eich (1989) has suggested that the influence of contextual cues on memory may be the r e s u l t of differences i n the a f f e c t i v e valence associated with the d i f f e r e n t contexts. The rol e of a f f e c t on memory w i l l be b r i e f l y considered. Research on the eff e c t s of a f f e c t on memory has been conducted within the context of an associative network model of memory (e.g., Bower, 1981). The phenomenon of mood dependent r e t r i e v a l "implies that what one remembers during a given mood i s determined i n part by what one learned (or focused on) when previously i n that mood; the a f f e c t i v e valence of the material i s i r r e l e v a n t " (Blaney, 1986, p. 229). This i s thought to occur because re-experiencing the emotion w i l l r e s u l t i n a spread of ac t i v a t i o n i n memory from the elements representing the emotion to the previously learned information. This increases the p r o b a b i l i t y that t h i s information w i l l be rec a l l e d . This e f f e c t has been well 25 documented; however, a number of researchers (Blaney, 1986; Bower, 1987; Eich, 1980, 1989; Overton, 1985) have noted that there have also been a number of f a i l u r e s to document t h i s e f f e c t . These inconsistent findings can be explained i n large part by the presence or absence of other r e t r i e v a l cues i n the environment (Eich, 1980; F i e d l e r & Stroehm, 1986). Mood dependent r e c a l l e f f e c t s are much more apparent when the i n d i v i d u a l i s unable to r e l y on alternate r e t r i e v a l cues. In a related vein', Eich (1989) has suggested that memory for i n t e r n a l l y generated information i s much more s e n s i t i v e to changes i n mood than memory for externally generated information. Within the context of habituation of fear, predictions derived from theory on mood-dependent r e c a l l would be analogous to those based on Whitlow and Wagner (1984). S p e c i f i c a l l y , i t would be predicted that there would be greater memory of the previous fear reduction session given that the i n d i v i d u a l experienced congruent states of arousal during fear reduction and at follow-up. However, consideration of the phenomenon of mood congruence suggests that t h i s p rediction may not be e n t i r e l y supported. The mood congruency e f f e c t assumes that information i s better learned and r e c a l l e d when the a f f e c t i v e valence of the information to be learned/recalled matches that of the individual's current a f f e c t (Bower, 1981). Mood congruency e f f e c t s have been documented i n a number of studies (e.g., see review by Blaney, 1986). 26 As can be seen from the above discussion several d i f f e r e n t i a l predictions regarding the role of arousal on habituation can be made. A number of studies have examined the ef f e c t s of arousal on habituation of the orienting response i n humans. These studies w i l l be reviewed i n the following section. Four d i f f e r e n t paradigms have been used to d i f f e r e n t i a t e more and less aroused subjects: 1. Comparison of normal subjects who d i f f e r with respect to t h e i r l e v e l s of self-reported t r a i t anxiety or neuroticism. The rationale underlying t h i s methodology i s that i n d i v i d u a l s who report higher l e v e l s of t r a i t anxiety and/or neuroticism are more highly aroused than less anxious and/or less neurotic i n d i v i d u a l s . Although t h i s assumption may often be correct i t i s not invariably the case that higher l e v e l s of t r a i t anxiety and/or neuroticism r e f l e c t over-arousal (Eysenck, 1977; Lader, 1975, 1979). 2. Comparison of normal subjects with subjects diagnosed as c l i n i c a l l y anxious. Studies u t i l i z i n g t h i s approach are based on the same assumption as i n 1 above. 3. Comparison of normal subjects who d i f f e r with respect to t h e i r r e s t i n g physiological l e v e l . 4. Experimentally inducing d i f f e r e n t i a l l e v e l s of arousal. Comparison of normal subjects who d i f f e r with respect to  t h e i r l e v e l s of self-reported t r a i t anxiety or  neuroticism 27 At l e a s t eight studies have compared normal subjects who d i f f e r e d with respect to t h e i r scores on s e l f - r e p o r t measures of anxiety or neuroticism. The r e s u l t s of these studies have been inconsistent. While several studies have found s i g n i f i c a n t l y greater habituation of physiological response i n less anxious individuals (Coles, Gale, & Klein, 1971; Jackson & Berry, 1967; McGuiness, 1973; Sadler, Mefferd, & Houck, 1971), other studies have not found any e f f e c t using s i m i l a r measures of physiological arousal (Chattophyay, Cooke, Toone, & Lader, 1980; Katkin & McCubbbin, 1969; Koepke & Pribram, 1966; Neary & Zuckerman, 1976). The e f f e c t of i n d i v i d u a l differences i n t r a i t anxiety or neuroticism among normal ind i v i d u a l s i s not very robust. For two major reasons t h i s i s not surprising. F i r s t l y , given that subjects were selected from a r e l a t i v e l y homogeneous population of u n i v e r s i t y undergraduate students (Chattopadhyay et a l . , (1980) i s the possible exception), there was not l i k e l y a large difference between the more and less anxious subjects. Secondly, and most importantly, subjects' anxiety l e v e l was assessed using measures that purport to measure stable t r a i t c h a r a c t e r i s t i c s . Given that arousal or anxiety l e v e l i s p r i n c i p a l l y a function of current environmental and interpersonal stressors (e.g., Spielberger, 1972), the consistency of the experimental s i t u a t i o n across subjects would l i k e l y overset any differences i n t r a i t anxiety. Assessment of current anxiety or arousal l e v e l s would l i k e l y prove more appropriate. Comparison of normal subjects with subjects who are 28 diagnosed as c l i n i c a l l y anxious Several studies conducted by Lader and h i s colleagues (Chattophyay et a l . , 1980; Lader, 1967; Lader & Wing 1964) and Raskin (1975) have compared the habituation rates of normal subjects and patients with anxiety disorders. The e a r l i e r studies by Lader (Lader, 1967; Lader & Wing, 1974) and Raskin (1975) are consistent i n reporting that anxious patients are more p h y s i o l o g i c a l l y aroused (as assessed by re s t i n g skin conductance l e v e l and the number of spontaneous fluctuations) than normal, nonanxious subjects. The anxious patients' galvanic skin response amplitude habituated more slowly than the normal subjects'. Although the amplitudes of the responses to the i n i t i a l tones were not consistently d i f f e r e n t (Lader, 1967, Lader & Wing, 1964; Raskin, 1975), the normal subjects' galvanic skin resistance response during the l a t e r t r i a l s was s i g n i f i c a n t l y smaller than the anxious patients' (Lader and Wing, 1964), and a s i g n i f i c a n t l y greater proportion of normal subjects were defined as "habituators" based on t h e i r rate of response decrement across t r i a l s (Lader & Wing, 1967; Raskin, 1975). Lader (1967) compared the habituation rates of patients with d i f f e r e n t anxiety disorders. He found that patients with s p e c i f i c phobias had a s i g n i f i c a n t l y lower re s t i n g l e v e l of anxiety, and a faster rate of habituation to neutral s t i m u l i than subjects experiencing more pervasive and generalized v a r i e t i e s of anxiety (e.g., agoraphobia and generalized anxiety disorder). This i s not surprising given that the more generally anxious patients were more l i k e l y experiencing 29 anxiety during the experimental session than the patients with s p e c i f i c phobias who were not l i k e l y being exposed to fear-evoking s t i m u l i at the time of assessment. Hart (1974) and Chattopadhyay et a l . (1980) also compared the responses of patients to a series of auditory tones. Both studies f a i l e d to r e p l i c a t e most of the findings of Lader (1967), Lader & Wing (1964), and Raskin (1975). For example, Hart (1974) found that although anxious patients exhibited a greater number of spontaneous skin fluctuations than normal subjects, t h e i r resting heart rate and skin conductance l e v e l were not d i f f e r e n t . The two groups were not s i g n i f i c a n t l y d i f f e r e n t with respect to galvanic skin response habituation rate or the number of subjects who are were defined as "habituators". The only s i g n i f i c a n t difference between the two groups concerned the habituation of i n i t i a l heart rate deceleration i n response to lower i n t e n s i t y tones. Normal subjects displayed s i g n i f i c a n t habituation of the heart rate decelerative response. Anxious subjects, however, i n i t i a l l y responded with a lesser decelerative response that did not habituate across t r i a l s . Given the vagueness of the diagnostic c r i t e r i a used to define the patient groups, i t i s not possible to determine the extent to which differences i n population c h a r a c t e r i s t i c s may be responsible for differences i n the obtained r e s u l t s . Beyond t h i s , however, there are several other methodological differences that may explain the r e s u l t s (Sartory, 1983). For example, whereas Lader (1967; Lader & Wing, 1964) and Raskin 30 (1975) used the same sti m u l i across t r i a l s , Hart (1974) used s t i m u l i of three d i f f e r e n t i n t e n s i t i e s . Although further research i s necessary to c l a r i f y the parameters of t h i s e f f e c t , i t can be t e n t a t i v e l y concluded that subjects defined as anxiety disordered may be impaired r e l a t i v e to normal subjects with respect to t h e i r rate of habituation to neutral s t i m u l i . The inconsistencies of these r e s u l t s stress the necessity of consistency and completeness i n defining subject samples and method variables. Comparison of subjects who d i f f e r with respect to t h e i r  r e s t i n g physiological l e v e l Several studies have compared the responses of indiv i d u a l s d i f f e r i n g i n t h e i r r esting l e v e l of physiological arousal. Physiological arousal was defined i n terms of the number of spontaneous skin fluctuations (Deitz, 1982; Katkin & McCubbin, 1969; Koepke & Pribram 1966) or r e s t i n g skin conductance l e v e l (Thayer & S i l b e r , 1971). The r e s u l t s of the studies are consistent in finding that although more highly aroused subjects do not d i f f e r from low aroused subjects i n terms of i n i t i a l amplitude of the galvanic skin response, they habituate i n a s i g n i f i c a n t l y greater number of t r i a l s (Deitz, 1982; Koepke & Pribram 1966) and to a s i g n i f i c a n t l y lower amplitude (Katkin & McCubbin, 1969; Koepke & Pribram, 1966). Experimentally inducing d i f f e r e n t i a l l e v e l s of arousal The most commonly used paradigm for examining the e f f e c t s of arousal l e v e l on habituation has modified arousal l e v e l with various experimental manipulations. Procedures for 31 manipulating arousal have included sleep deprivation (Bohlin, 1973), changes i n body po s i t i o n (Goldwater, 1987; Goldwater & Lewis, 1978), exposure to loud sounds (Epstein, 1971), engagement i n motor responses or i n mental/attention tasks (Hulstijn, 1978), threat of examination (Kimmel & B e v i l l , 1985), or threat of shock (Bohlin, 1976; Carrol & Pokora, 1976; Chattopadhayay et a l . , 1980; Gatchel & Gaas, 1976; Gatchel, Gaas, King & McKinney, 1977; Watts, 1975). With the exception of Bohlin (1973), who attempted to manipulate arousal through sleep deprivation, these studies have been successful i n manipulating resting physiological arousal l e v e l . Furthermore, the threat of shock has also been shown to increase the l e v e l of self-reported stress (Briush & Hendrix, 1980; Briush & Schwartz, 1980; C a r r o l l & Podora, 1976; Chattopadhyay et a l . , 1980; Watts, 1975). Because the re s u l t s of Bohlin (1973) suggested that the arousal manipulation was not e f f e c t i v e i n a l t e r i n g arousal level,, the re s u l t s of t h i s study w i l l not be included i n the following discussion. Examination of the remaining studies allows one to make several tentative comments. Although many of these studies have found that arousal has s i g n i f i c a n t e f f e c t s on habituation, the pattern of res u l t s varies both between studies and within the same study when considering d i f f e r e n t assessment measures. For example, with respect to the habituation of the magnitude of the skin conductance response, Bohlin (1976) found that heightened arousal resulted i n a slower rate of habituation, but to the same l e v e l as with 32 lower arousal l e v e l s . On the other hand, Carrol and Pokora (1976) found that aroused and non-aroused subjects responded s i m i l a r l y on i n i t i a l t r i a l s , but that on l a t e r t r i a l s the aroused subjects' responses were of a greater magnitude than the non-aroused subjects'. Gatchel and Gaas (1976) found that aroused subjects i n i t i a l l y responded with higher magnitude skin conductance responses than non-aroused subjects, and habituated to a s i m i l a r l e v e l but at a slower rate, and Goldwater (1987) and H u l s t i j n (1978) found that arousal l e v e l had no e f f e c t on habituation of the magnitude of the skin conductance response. Although a number of studies report that the experimental manipulation of arousal s i g n i f i c a n t l y influences habituation, there are also several notable exceptions. Although there are several methodological differences that may account for these r e s u l t s , the most consistent difference seems to be related to the s p e c i f i c type of manipulation used. With the exception of Chatopadhyay et a l . (1980), a l l of the studies that manipulated arousal using the threat of shock or examination i d e n t i f i e d one or more detrimental e f f e c t s of arousal on habituation. (Unfortunately, the study by Chattopadhay et a l (1980) i s not s u f f i c i e n t l y described to allow comparison with the other studies that manipulated arousal through the use of threat.) On the other hand, the e f f e c t s of the other arousal manipulations are apparently less robust i n t h e i r influence on habituation of physiological responding. Although unqualified statements regarding the differences between the threat of 33 shock or examination and other paradigms cannot be made a t the pre s e n t time, two p o s s i b l e e x p l a n a t i o n s o f t h i s d i f f e r e n c e may be suggested. F i r s t l y , perhaps t h r e a t o f shock or examination e x e r t s a more potent e f f e c t , or a d i f f e r e n t p a t t e r n of e f f e c t s on p h y s i o l o g i c a l a r o u s a l than do the oth e r a r o u s a l m a n i p u l a t i o n s . Secondly, i t i s reasonable t o expect t h a t the t h r e a t o f shock or examination may have ot h e r e f f e c t s on c o g n i t i v e or a f f e c t i v e p r o c e s s i n g t h a t do not occur w i t h other a r o u s a l m a n i p u l a t i o n s . For example, i t seems s e l f - e v i d e n t t h a t the t h r e a t o f shock would be much more l i k e l y t o r e s u l t i n p h y s i o l o g i c a l a r o u s a l and ne g a t i v e a f f e c t than s t a n d i n g (e.g., Goldwater & Lewis, 1978) or p r e s s i n g a dynamometer ( H u l s t i j n , 1978). In f a c t , w h i l e the a r o u s a l generated by the l a s t two t a s k s would be p r i m a r i l y of a p h y s i o l o g i c a l nature, t h r e a t would produce p h y s i o l o g i c a l a r o u s a l because of the mediation of c o g n i t i v e and a f f e c t i v e v a r i a b l e s . Perhaps t h i s i n f l u e n c e on c o g n i t i v e o r a f f e c t i v e p r o c e s s i n g r e s u l t s i n f u r t h e r impairments i n h a b i t u a t i o n . A b i l i t y o f the h a b i t u a t i o n models t o e x p l a i n the  i n f l u e n c e of a r o u s a l In summary, with the e x c e p t i o n of s t u d i e s examining s e l f -r e p o r t e d t r a i t a n x i e t y , t h e r e i s evidence t h a t i n c r e a s e d l e v e l s of a r o u s a l may d i s r u p t h a b i t u a t i o n of p h y s i o l o g i c a l response t o n e u t r a l s t i m u l i . U n f o r t u n a t e l y , u n q u a l i f i e d statements r e g a r d i n g the parameters or s p e c i f i c e f f e c t s of a r o u s a l cannot be made a t t h i s time. Even more i m p o r t a n t l y , w i t h v e r y few excepti o n s , these s t u d i e s have been c a r r i e d out 34 without the e x p l i c i t objective of evaluating s p e c i f i c predictions made by the various theories of habituation discussed e a r l i e r . I t i s d i f f i c u l t to evaluate these theories given the post-hoc nature of the data currently available. Any statements regarding t h i s issue must be made very cautiously. The studies discussed previously suggest that heightened arousal may impede habituation. Although t h i s finding casts doubt on the a b i l i t y of Sokolov's (1963) theory to accurately explain and predict the ef f e c t s of heightened arousal (assuming that the prediction that heightened arousal w i l l f a c i l i t a t e habituation i s congruent with Sokolov's theory), i t does not d i f f e r e n t i a l l y support the theories of Thompson (e.g., Groves & Thompson, 1970), Lader (Lader & Mathews, 1968; Lader & Wing, 1964, 1966), or Whitlow and Wagner (e.g., 1984). In order to d i f f e r e n t i a t e between these theories a more s p e c i f i c examination of the pattern of re s u l t s i s necessary. The main d i f f e r e n t i a l prediction i s with respect to the rate of habituation across repeated presentations. Dual process theory (Groves & Thompson, 1970) would predict that the rate of habituation would not be affected by arousal l e v e l . Aroused subjects should show increased responsiveness to s t i m u l i ; however, t h e i r rate of response decrement should be r e l a t i v e l y constant across arousal l e v e l s . Because habituation rate i s assumed to be a property of the stimulus and independent of arousal l e v e l , the rate of habituation should not vary given presentation of the same stimulus across conditions. On the other hand, Lader's model (Lader & Mathews, 19 68; Lader & 35 Wing, 1964, 1966) would predict that higher l e v e l s of arousal disrupt the process of habituation, r e s u l t i n g i n a lesser rate of response decrement with higher l e v e l s of arousal. Whitlow and Wagner's (1984) model would predict that arousal would disrupt the rate of habituation because of the r e s u l t i n g d i s t r a c t i o n . Re-examination of the studies discussed previously (excluding those that examined in d i v i d u a l differences i n t r a i t anxiety or neuroticism, or that did not determine that the arousal manipulation was e f f e c t i v e i n manipulating resting arousal l e v e l at the time of assessment) provides support for the notion that heightened arousal impedes the rate of habituation to neutral s t i m u l i . Of the 11 studies that examined whether or not there was d i f f e r e n t i a l rate of change across stimulus exposures, seven studies reported that heightened arousal disrupted the rate of habituation (Bohlin, 1976; Carrol & Pokora, 1976; Goldwater & Lewis, 1978; Lader, 1967; Lader & Wing 1964; Neary & Zuckerman, 1976; Raskin, 1975), and one study (Katkin & McCubbin, 1969) reported a disruption i n the rate of habituation with higher, but not lower, i n t e n s i t y s t i m u l i . Of the other available studies, Goldwater (1987) and Hart (1974) f a i l e d to r e p l i c a t e t h i s finding, and Gatchel and Gaas (1976) found that more highly aroused subjects had a greater rate of response decrement. These re s u l t s suggest that increased arousal may disrupt the rate of habituation. Although t h i s conclusion seems incongruent with dual process theory, t h i s incongruence can be 36 resolved with a modification of the theory. I t can be argued that heightened arousal has two e f f e c t s on habituation. Not only does i t r e s u l t i n an increase i n general responsiveness i n the "state" system that i s independent of the habituation process (e.g. Groves & Thompson, 1970), but i t also may have an e f f e c t on the habituation process because i t re - d i r e c t s the indi v i d u a l ' s focus of attention away from the stimulus. I f an in d i v i d u a l i s experiencing heightened l e v e l s of arousal, he or she may search the environment to i d e n t i f y the source of arousal and/or attend to physiological manifestations of arousal. As arousal becomes more s a l i e n t for the i n d i v i d u a l , e s p e c i a l l y i f the arousal i s accompanied by negative a f f e c t , other cues i n the environment w i l l l i k e l y become more s a l i e n t and less attention w i l l be directed to the stimulus. The disruptive e f f e c t s of arousal and anxiety on attention and concentration are well documented (e.g., Eysenck, 1977, 1882; Hockey, 1984 ; Fenz & Epstein, 1965; Fenz, 1965, c i t e d i n Lang, 1985; Wine, 1971, 1980). For example, arousal and anxiety increase the frequency of negatively valenced, r e p e t i t i v e , and int r u s i v e thoughts (e.g., Horowitz, 1975; Parkinson & Rachman, 1981). Further, Rachman and L e v i t t (1987) found that claustrophobic subjects' report of bodily symptoms ("Flushes (hot flashes) or c h i l l s " ; Nausea or abdominal distress") and/or anxiety-related cognitions ("I am going to pass out"; "I am going to lose control") related to anxiety following i n i t i a l exposure to the feared stimulus s i g n i f i c a n t l y predicted the extent to which t h e i r fear would habituate 37 across t r i a l s . S p e c i f i c a l l y , report of these symptoms and/or cognitions was predictive of an absence of l a t e r habituation. Attention to i r r e l e v a n t information increases cognitive processing demands and r e s u l t s i n processing overload (Hamilton, 1980; Tobias, 1986), and may adversely a f f e c t performance at one of three points: attention to relevant environmental s t i m u l i ; encoding and processing of these s t i m u l i ; and selection of the appropriate response (Sarason, 1975). With respect to habituation, the spreading of attention w i l l subtract "processing time" from the immediate task at hand (e.g., Eysenck, 1979, 1982) and r e s u l t i n lessened "functional exposure" (e.g., Borkovec & Grayson, 1980) to the stimulus. Cognitive manipulations have been demonstrated to influence habituation to neutral (e.g., Iacono & Lykken, 1983, 1985) and feared (e.g., Grayson & Borkovec, 1978; Grayson, Foa & Steketee, 1982, 1986) s t i m u l i . As attention i s drawn away from the stimulus, the stimulus-response associations determining response to the stimulus w i l l have less opportunity to be weakened as a r e s u l t of the repeated stimulus presentations. Expansion of the dual process model to consider the influence of attentional and c o g n i t i v e / a f f e c t i v e factors i s consistent with the model and may allow greater explanatory power, e s p e c i a l l y when considering habituation to more complex s t i m u l i i n humans. In fact, Thompson et a l . (1979) acknowledged that although present knowledge does not permit an understanding of how cognitive factors a f f e c t functioning 38 on a neural l e v e l , such influences nonetheless have a s i g n i f i c a n t influence on habituation. In summary, the r e s u l t s of the studies discussed previously suggest that arousal disrupts the process of habituation. This finding i s inconsistent with the predictions based on Sokolov's (1963) theory of habituation; however, i t i s not c l e a r l y supportive of either the revised version of dual process theory just described, or Whitlow and Wagner's c o r t i c a l model theory. A modification of the paradigm used to assess the e f f e c t s of arousal may help to c l a r i f y t h i s issue. The r e s u l t s of a study that assesses the e f f e c t s of arousal during the process of habituation, as well as the extent of habituation at a l a t e r point i n time when a l l ind i v i d u a l s are i n a s i m i l a r state of arousal w i l l r e s u l t i n a set of d i f f e r e n t i a l predictions. Both the revised version of dual process theory and Whitlow and Wagner's c o r t i c a l model theory would predict that heightened arousal may impair the process of habituation. However, the revised version of dual process theory would predict that individuals who are aroused during habituation would manifest a further response decrement ( i . e . , increased habituation) when l a t e r assessed i n a state of reduced arousal. Whitlow and Wagner (1984) and Lader (Lader & Mathews, 1968; Lader & Wing, 1966) would also predict that any e f f e c t s of arousal that were apparent at the time of habituation would be maintained at l a t e r assessment. However, to the extent that arousal i s a s a l i e n t cue to prime the stimulus into short term memory, subjects who were aroused during habituation but not at the time of retest would be expected to show a further response increase ( i . e . a decrease i n habituation) at l a t e r assessment r e l a t i v e to subjects who were not aroused during habituation. 40 THE EFFECTS OF AROUSAL ON FEAR REDUCTION  AND THE RETURN OF FEAR Arousal may impede habituation to neutral s t i m u l i and several studies have noted that arousal also a f f e c t s fear and the fear reduction process. A r e l a t i o n s h i p between i n i t i a l autonomic responsivity to imaginal and i n vivo presentations of feared s t i m u l i and fear reduction has been noted by several investigators (Dyckman & Cowen, 1978; Glenn & Hughes, 1978; Lang, Melamed, & Hart, 1970; Levin, Cook, & Lang, 1982; Marshall, 1988; Stern & Marks, 1973; Vermilyea et a l . , 1984). S p e c i f i c a l l y , responsiveness to i n i t i a l presentations of the feared s t i m u l i i s p r e d i c t i v e of greater fear reduction v i a exposure treatment. These re s u l t s suggest that emotional processing of fear during exposure, as evidenced by an increase i n autonomic arousal i n response to the stimulus exposure, expedites fear reduction. This finding i s central to the previously discussed models of fear developed by Lang (e.g., 1985) Rachman (1980), and Foa and Kozak (1985, 1986). Although autonomic arousal i n response to i n i t i a l exposure to feared s t i m u l i promotes fear reduction, other findings suggest that high basal l e v e l of arousal a f f e c t s fear and hinders the fear reduction process. There are suggestions, based on Lang's associative network model of fear that experiencing increased arousal that i s unrelated to the feared stimulus i n t e n s i f i e s the fear response (e.g., Lang, 1988). Barlow (1988) suggested that baseline anxiety l e v e l i s a 41 "platform" for fear and that the p r o b a b i l i t y of responding f e a r f u l l y upon exposure to a feared stimulus i s increased given high l e v e l s of baseline anxiety. Rachman (1990) used the term "emotional s p i l l - o v e r " i n his discussion of the r e l a t i o n s h i p between general arousal, e s p e c i a l l y anxious arousal, and fear. He argued that increased anxious arousal primes the cognitive networks defining feared s t i m u l i , thus increasing the l i k e l i h o o d that a fear response w i l l occur upon exposure to a feared stimulus. Most of the support for the suggestion that increased arousal a f f e c t s fear and fear reduction i s derived from research on the return of fear. The return of fear refers to "the reappearance of fear that was present e a r l i e r but had undergone a decline" (Rachman, 1979, p. 165). The return of fear should not be confused with the phenomenon of relapse which can take many forms (Rachman, 1987). The return of fear i s a robust phenomenon and has been examined i n circumscribed fears (Grey, Rachman, & Sartory, 1981; Grey, Sartory & Rachman, 1979; P h i l i p s , 1985; Rachman & Lopatka, 1988; Rachman, Robinson, & Lopatka, 1987; Rachman & Whittal, 1989a, 1989b; Samsom & Rachman, 1989; Sartory, Rachman, & Grey, 1982), performance based fears (Craske & Rachman, 1987), and in obsessive-compulsive disorders (Foa, 1979; Grayson, Foa, & Steketee, 1982, 1986; Likierman & Rachman, 1980). Return of fear can be assessed either between sessions of fear reduction or following the completion of treatment (Craske & Rachman, 42 1987). The return of fear more properly refers to p a r t i a l , as opposed to complete, return of fear (Rachman, 1987). Grey et a l . (1979) examined the e f f e c t s of treatment demand on the return of fear. Demand was manipulated by a l t e r i n g the distance that the subject was from the feared stimulus during i n vivo exposure. They found that there was less subjective report of return of fear under conditions of low demand compared with increasing or high demand. Although the findings for the autonomic index of fear (heart rate) were i n the same d i r e c t i o n as those for subjective fear, they were not s i g n i f i c a n t . A follow-up study (Grey et a l . , 1981) attempted to determine the extent to which the d i s s i p a t i o n of arousal that resulted from high or increasing l e v e l s of demand during exposure was responsible for the e a r l i e r r e s u l t s . Subjects were exposed to feared s t i m u l i under conditions of either massed or d i s t r i b u t e d practice. Contrary to predictions, there were no s i g n i f i c a n t e f f e c t s with respect to the return of fear for any of the three indices of fear (subjective report of fear, heart rate, or behavioral approach) assessed either half an hour or one week following exposure. Upon closer examination of the data, however, the authors did f i n d that four subjects i n the d i s t r i b u t e d practice condition who displayed very high heart rates during the i n i t i a l behavioral avoidance t e s t in spite of reports of an absence of fear, also displayed a greater return of subjective fear one week following treatment compared with the other subjects who received d i s t r i b u t e d practice. There was 43 l i t t l e evidence of return of fear using the other two indices of fear. A further follow-up study by Sartory et a l . (1982) investigated the p o s s i b i l i t y that exposure to high i n t e n s i t y s t i m u l i and imaginal rehearsal of the feared s t i m u l i immediately following treatment would r e s u l t i n a return of fear r e l a t i v e to exposure to low i n t e n s i t y fear s t i m u l i and d i s t r a c t i o n following treatment. There were no s i g n i f i c a n t e f f e c t s of the manipulations on the return of fear 30 minutes following treatment ( i . e . , following the distraction/imagination period). The i n t e n s i t y of exposure also did not a f f e c t the subjective report of the return of fear one week following treatment; however, low i n t e n s i t y exposure resulted i n a greater return of fear for minimally, but not maximally, feared s t i m u l i . Contrary to prediction, rehearsal following treatment reduced the extent of the return of fear upon exposure to the medium and high fear s t i m u l i . The authors based t h e i r prediction regarding the e f f e c t s of imaginal rehearsal on the idea that imaginally rehearsing the feared s t i m u l i r e s u l t s in increasing l e v e l s of arousal that i n turn r e s u l t s i n return of fear. This contrary r e s u l t i s not surprising, however, i f rehearsal of the feared s t i m u l i i s conceived of as imaginal exposure to the feared s t i m u l i . This imaginal exposure could contribute further therapeutic benefit in^addition to the i n vivo exposure experienced immediately p r i o r to the imaginal rehearsal period. Once again, the authors noted that there was a subset of subjects who 44 exhibited very high heart rates while reporting an absence of fear upon i n i t i a l exposure to the feared s t i m u l i . Although the e a r l i e r finding of a relationship between high heart rate during i n i t i a l exposure and the return of fear was not replicated, i t was found that i n i t i a l heart rate was p r e d i c t i v e of the return of fear i n subjects who approached the feared s t i m u l i . This e f f e c t was not found i n those subjects who avoided the s t i m u l i . The small number of subjects e x h i b i t i n g high heart rate precluded s t a t i s t i c a l analysis of these r e s u l t s . A study by Craske and Rachman (1987) attempted to more systematically examine the role of arousal i n the return of fear. In t h i s study a population of musicians with performance anxiety were treated and assessed. In addition to examining the e f f e c t s of i n i t i a l autonomic arousal, as indexed by heart rate, the authors sought to examine the e f f e c t s of i n i t i a l l e v e l of perceived s k i l l on the return of fear. Among t h e i r findings were that elevated heart rate was p r e d i c t i v e of greater subjective report of the return of fear at follow-up, and greater report of anxious thoughts at a l l assessment occasions. Post hoc analyses indicated that subjects who exhibited a return of fear at follow-up had a s i g n i f i c a n t l y greater i n i t i a l heart rate, lower i n i t i a l perceived s k i l l , more anxious thoughts, and performed less often during the follow-up period than subjects who did not show a return of fear. A multiple regression analysis which examined the a b i l i t y of i n i t i a l heart rate, i n i t i a l perceived s k i l l , actual 45 s k i l l l e v e l , number of anxious thoughts, and number of follow-up performances to predict the amount of return of fear following treatment was conducted. None of these variables contributed s i g n i f i c a n t l y to the regression equation beyond the variance explained by i n i t i a l heart rate. The combined e f f e c t of a l l the remaining variables also f a i l e d to add s i g n i f i c a n t l y to the a b i l i t y of i n i t i a l heart rate to predict the return of fear. Taken together these four studies suggest that autonomic arousal p r i o r to fear reduction i s p r e d i c t i v e of the return of fear. There are several problems with these data that must temper the conclusion. Most importantly, i n examining the e f f e c t s of arousal on the return of fear a l l studies used groups that were selected on the basis of pre-existing differences i n arousal l e v e l . As a r e s u l t , i t i s not possible to determine the extent to which other subject variables correlated with the l e v e l of autonomic arousal p r i o r to exposure may explain the r e s u l t s . The most obvious a l t e r n a t i v e explanation involves autonomic arousal l e v e l at follow-up. An examination of arousal l e v e l at follow-up i n the Grey et a l . (1981) Sartory et a l . (1982) and Craske and Rachman (1987) studies does not allow r e j e c t i o n of the p o s s i b i l i t y that arousal l e v e l at follow-up determines the amount of return of fear. (Note: The study by Grey et a l . (1979) did not d i r e c t l y examine the e f f e c t s of autonomic arousal on the return of f e a r ) . 46 There are thus at least two possible explanations for the previously obtained r e s u l t s . F i r s t l y , perhaps autonomic arousal upon i n i t i a l exposure to the feared s t i m u l i (and presumably throughout exposure) impedes the process of habituation, as evidenced over the longer term but not at the end of the session. As discussed i n the previous section on the e f f e c t s of arousal on habituation, arousal during exposure to neutral s t i m u l i may hinder habituation. A major difference between those findings and the findings regarding the e f f e c t s of arousal on the return of fear concerns the time i n t e r v a l over which the d e f i c i t i n habituation becomes apparent. The research on the e f f e c t s of arousal on habituation to neutral s t i m u l i indicates that arousal has a detrimental e f f e c t on habituation during the exposure i n t e r v a l . I t i s presently not known what e f f e c t s arousal has on the long term habituation to neutral s t i m u l i as there has not been an assessment of these e f f e c t s . In contrast to t h i s , research on the return of fear suggests that arousal during fear reduction may r e s u l t i n a return of fear even when i t f a i l s to disrupt within-session habituation (Grey et a l . , 1981). It may be that there i s more than one process governing habituation to feared s t i m u l i , and that heightened arousal disrupts mechanisms governing long term ( i . e . , .between-session) but not short term ( i . e . , within-session) habituation. A number of researchers have attempted to garner support for a two-process (within-session and between-session) explanation of habituation. For example, Groves and Lynch 47 (1972) suggested that within-session habituation i s mediated by the r e t i c u l a r formation and between session habituation, "involves elaboration by forebrain structures, most p a r t i c u l a r l y f r o n t a l (or other association) cortex and hippocampus, but probably other forebrain structures as well" (p. 237). Likewise, Whitlow and Wagner (e.g., 1984) discuss the d i f f e r e n t i a l importance of short term and long term memory processes, and self-generated and retrieval-generated priming, i n within- and between-session habituation. Foa (1979) and Foa and Kozak (1985, 1986) postulated the existence of two p a r t i a l l y dependent habituation processes that account for within- and between-session reductions i n fear. Although postulating two processes of habituation may f a c i l i t a t e explanation of the finding that indi v i d u a l s who show return of fear do not d i f f e r from those who do not show a return of fear with respect to within-session fear reduction, i t i s worthwhile to consider the arguments of Mackintosh (1987) i n his i n s i g h t f u l analysis of habituation. He reviewed data that have been used as evidence i n support of the existence of separate short term and long term habituation processes and concluded that although a two process explanation i s congruent with the data, there i s a more parsimonious explanation. S p e c i f i c a l l y , he argued that concepts of incomplete retention across the follow-up i n t e r v a l and differences i n generalization decrements across conditions could equally well account for the r e s u l t s . In a s i m i l a r manner, when considering the habituation of fear responses, i t 48 i s p l a usible that within- and between-session habituation represent a single process, and that disruptions i n the habituation of fear become apparent only i n the long term because arousal disrupts long term retention of the habituated response. The second major explanation for the e f f e c t of autonomic arousal on the return of fear i s that the return of fear i s the r e s u l t of heightened arousal at the time of r e t e s t . The habituation l i t e r a t u r e has documented examples of the e f f e c t s of i n t e r p o l a t i o n of a novel or otherwise arousing stimulus on habituation to a neutral stimulus. S p e c i f i c a l l y , r e s u l t s of several studies indicate that exposure to a novel stimulus r e s u l t s i n a t r a n s i t o r y increased l e v e l of response to the o r i g i n a l stimulus (e.g., Groves & Thompson, 1970; Magliero, Gatchel & Lojewski, 1981; McCubbin & Katkin, 1971,; Rust, 1976; Thompson & Spender, 1966). I t i s not e n t i r e l y clear, however, that t h i s increased l e v e l of responsiveness i s e n t i r e l y due to increases i n arousal (Edwards & Siddle, 1976; Rust, 197 6). Central to the dual process theory of habituation (e.g., Groves & Thompson, 1970) i s the prediction that increased arousal w i l l r e s u l t in a generalized increase i n responding. There are also c l i n i c a l accounts of a return of fear during, or following, treatment as the r e s u l t of the i n d i v i d u a l experiencing increased l e v e l s of stress (e.g. Bilsbury & Morley, 1979; Rachman, 1987). Possibly increased arousal at the follow-up assessment, independent of arousal 49 l e v e l at the beginning of treatment, r e s u l t s i n a dishabituation of the fear response. Rachman and Whittal (1989a) examined the e f f e c t s of increased anxious arousal at follow-up on the return of fear. They found that increased anxious arousal did not r e s u l t i n increased return of fear. However, t h i s finding i s l i m i t e d by the fact that the anxious arousal manipulation that they used did not s i g n i f i c a n t l y increase heart rate compared to t h e i r control condition. In summary, although the previous studies that noted the ef f e c t s of arousal on the return of fear focused attention on the role of autonomic arousal at the time of pretest, i t i s equally plausible that the return of fear i s augmented by arousal at the time of follow-up assessment. Unfortunately, currently available studies do not allow an evaluation of the two p o s s i b i l i t i e s . In order to c l a r i f y the role that autonomic arousal has on fear reduction and the return of fear, i t i s necessary to conduct further research that more systematically controls and manipulates arousal l e v e l . SELF-EFFICACY AND AROUSAL Bandura (1977) formulated the theory of s e l f - e f f i c a c y as an explanation of behavior change. S e l f - e f f i c a c y expectations r e f e r to b e l i e f s of an individual that he or she can successfully behave so as to achieve a ce r t a i n goal or outcome. Bandura argues that reductions i n fear (and more generally, changes in behavior) (Bandura, 1977, 1982, 1986) 50 are mediated by changes i n s e l f - e f f i c a c y . S e l f - e f f i c a c y expectations a f f e c t "people's choice of a c t i v i t i e s and behavioral settings, how much e f f o r t they expend, and how long they w i l l p e r s i s t i n the face of obstacles and aversive experiences. The stronger the perceived s e l f - e f f i c a c y , the more active the coping e f f o r t s " (Bandura & Adams, 1977, p. 287-288). S e l f - e f f i c a c y expectations are based on four sources of information. These sources of information include performance accomplishments, vicarious experience, verbal persuasion, and l e v e l of emotional arousal (Bandura, 1977). Although previous research has demonstrated that s e l f - e f f i c a c y expectations predict fear behavior (e.g. Bandura & Adams, 1977; Bandura, Adams, & Beyer, 1977; Bandura, Adams, Hardy, & Howells, 1980; Bandura, Reese, & Adams, 1982; Bandura, Taylor, Williams, Mefford, & Barchas, 1985; Craske & Craig, 1984; Craske & Rachman, 1987; Kendrick, Craig, Lawson, & Davidson, 1982; Williams & Watson, 1985), i t s status as the primary mediator of behavior has not been established (Borkovec, 1978; Craske & Rachman, 1987; Eastman & M a r z i l l i e r , 1984; Fe l t z , 1982; Wolpe, 1978). Bandura (1977, 1982, 1986) maintains that there i s an inverse re l a t i o n s h i p between arousal l e v e l and expectations of s e l f - e f f i c a c y . He argues that heightened arousal indicates to the i n d i v i d u a l that he or she i s currently vulnerable to stress and anxiety r e s u l t i n g i n a decrease i n expectations of s e l f - e f f i c a c y . Bandura (1982) states that arousal l e v e l a f f e c t s behavior i n d i r e c t l y because of i t s e f f e c t on 51 expectations of s e l f - e f f i c a c y : " I t i s not arousal per se but self - e v a l u a t i v e rumination that i s detrimental to performance" (Bandura, 1986, p. 442). S p e c i f i c a l l y , Bandura would predict that heightened arousal would lower s e l f - e f f i c a c y which would, i n turn, increase fear. Although there do not appear to be any studies that d i r e c t l y address t h i s issue, a finding reported by Craske and Rachman (1987) suggests that arousal l e v e l and l e v e l of perceived competence (a measure s i m i l a r to s e l f -efficacy) are not related (r.=-.10, n=63). Although t h i s finding suggests that arousal l e v e l may not influence s e l f -e f f i c a c y expectations, i t can be c r i t i c i z e d for not adequately addressing t h i s issue. F i r s t l y , Craske and Rachman (1987) assessed perceived competence as opposed to s e l f - e f f i c a c y . It i s not e n t i r e l y clear how these two measures are related to each other. Secondly, the c o r r e l a t i o n obtained by Craske and Rachman (1987) was based on single measures of pre-existing l e v e l s of perceived competence and arousal. F e l t z (1982) and Williams and Watson (1985) also found that pre-existing l e v e l s of arousal and s e l f - e f f i c a c y were unrelated. Conversely, Williams, Dooseman, and K l e i f i e l d (1984) and Williams, Turner, and Peer (1985) found that s e l f - e f f i c a c y and self-reported l e v e l s of performance anxiety were s i g n i f i c a n t l y related i n an inverse fashion. A l l of these studies have examined pre-e x i s t i n g l e v e l s of arousal and s e l f - e f f i c a c y ; i t i s unknown what e f f e c t s changes in arousal l e v e l have on expectations of s e l f - e f f i c a c y . 52 There i s l i t t l e information on the e f f e c t of arousal on s e l f - e f f i c a c y expectations. Research i n t h i s area would allow a further c l a r i f i c a t i o n of the role of arousal on s e l f -e f f i c a c y and behavior change. 53 STATEMENT OF PURPOSE The main purpose of the present study was to investigate the e f f e c t s of anxious a r o u s a l 1 during fear reduction t r a i n i n g and at follow-up assessment on fear reduction and the return of fear. J u s t i f i c a t i o n for t h i s study comes from several sources. F i r s t l y , predictions regarding the ro l e of anxious arousal on fear reduction and the return of fear can be made based on hypotheses derived from the major theories of habituation. Secondly, previous l i t e r a t u r e i n the area of the return of fear has suggested that heightened l e v e l s of physiological arousal has detrimental e f f e c t s on the maintenance of fear reduction. At present, however, s p e c i f i c parameters of anxious arousal on fear reduction and the return of fear are unknown. A second purpose of the present study was to examine the ef f e c t s of anxious arousal on s e l f - e f f i c a c y expectations. Although s p e c i f i c predictions can be derived from s e l f -e f f i c a c y theory, they have been larg e l y untested. The r e s u l t s of t h i s study w i l l be useful i n several ways: f i r s t l y , they w i l l allow a greater understanding of the 1 There i s debate regarding the use of the term arousal (Anderson, 1990; Neiss, 1988, 1990). I t has been argued that the term i s meaningless without reference to the psychological context i n which the arousal occurs (Neiss, 1988, 1990). Arousal produced through d i f f e r e n t means l i k e l y r e s u l t s i n d i f f e r e n t e f f e c t s . For example, arousal that accompanies fear i s not e n t i r e l y the same as arousal r e s u l t i n g from physical exertion or sexual excitement. In the present study, use of the term 'anxious arousal' allows greater d e f i n i t i o n a l s p e c i f i c i t y than the term 'arousal'. Anxious arousal encompasses physiological arousal as well as the cognitive e f f e c t s associated with increased anxious arousal such as worry, apprehension, and d i s t r a c t i o n (e.g., Barlow, 1988; Sarason, 1984, 1985). 54 a b i l i t y of the major theories of habituation to explain fear reduction. Secondly, they w i l l allow greater insight regarding the e f f e c t s of anxious arousal during fear reduction and at the time of follow-up on fear reduction and the return of fear. Thirdly, the res u l t s of the study w i l l allow greater insight into the ef f e c t s of anxious arousal on s e l f - e f f i c a c y . Ultimately, both t h e o r e t i c a l and c l i n i c a l benefit may be derived from these findings. A number of hypotheses and s p e c i f i c predictions regarding the e f f e c t s of anxious arousal on fear reduction and the return of fear can be made based on the revised version of the dual process theory and c o r t i c a l theory (e.g. Whitlow & Wagner, 1984). Within the context of the present study, these two theories lead to several i d e n t i c a l predictions as well as several d i f f e r e n t i a l predictions. Results congruent with predictions that are i d e n t i c a l across theories are useful as they allow a more systematic understanding of, and alt e r n a t i v e explanations of, the ef f e c t s of anxious arousal on fear reduction. D i f f e r e n t i a l predictions are most useful, however, as they not only allow a more systematic understanding of the phenomena under study, but they also allow statements to be made regarding the r e l a t i v e explanatory a b i l i t y of each theory with respect to the eff e c t s of anxious arousal on fear reduction. Hypotheses and predictions based on s e l f - e f f i c a c y theory (e.g., Bandura. 1977, 1982, 1986) w i l l also be presented. 55 Hypotheses Several hypotheses regarding the influence of anxious arousal on fear reduction were based on the revised version of dual process theory (henceforth to be referred to as dual process theory). It was hypothesized, based on dual process theory, that anxious arousal has two major e f f e c t s on habituation: f i r s t l y , the experience of an increase i n anxious arousal r e s u l t s i n an increase i n the s e n s i t i z a t i o n process. Behaviorally, t h i s i s manifested as a r e l a t i v e l y transient increase i n responsiveness (in the case of fear, increased f e a r ) . In other words, as the anxious arousal i s allowed to dissipate, the i n f l a t e d fear response also d i s s i p a t e s . Secondly, the experience of heightened l e v e l s of anxious arousal during habituation t r a i n i n g (in the present study, during fear reduction) impedes the habituation process. Behaviorally, t h i s impediment to habituation i s manifested by a decrease i n the amount of fear reduction during exposure to the feared stimulus. This disruption i s the r e s u l t of re-d i r e c t i o n of the individual's attention away from the feared stimulus. Rather than focussing on the feared stimulus, the i n d i v i d u a l tends to attend to other cues i n the environment and/or bodily sensations of anxious arousal, and/or may be di s t r a c t e d by negatively valenced i n t r u s i v e thoughts. Unlike the postulated e f f e c t s of anxious arousal on the s e n s i t i z a t i o n process, these e f f e c t s are hypothesized to be permanent, representing an impairment i n learning. 56 Several hypotheses regarding the influence of anxious arousal on fear reduction were based on the c o r t i c a l theory of habituation (e.g., Whitlow & Wagner, 1984). F i r s t l y , i t was hypothesized that anxious arousal during habituation (in the present case, during fear reduction) r e s u l t s i n a d i r e c t i o n of attention away from the feared stimulus, r e s u l t i n g i n decreased habituation. In the present study, t h i s i s represented behaviorally as impaired fear reduction. This e f f e c t represents an impairment i n learning and i s permanent. Secondly, i t was hypothesized that long term habituation (represented behaviorally as maintenance of fear reduction) i s determined by the extent of s i m i l a r i t y i n anxious arousal l e v e l during fear reduction and at retest. S p e c i f i c a l l y , experiencing s i m i l a r l e v e l s of anxious arousal during fear reduction and at retest r e s u l t s i n greater maintenance of the fear reduction than re s u l t s given incongruent l e v e l s of anxious arousal during fear reduction and at retest. This was hypothesized to occur because the individual's anxious arousal state serves as a cue that i s used to access memories of the stimulus from long term memory. The extent to which the stimulus i s primed i n memory p r i o r to exposure to the (previously) feared stimulus i s determined i n part by the indivi d u a l ' s anxious arousal state. The extent to which the stimulus i s primed into short term memory determines the extent of maintenance of the habituated response. It was hypothesized based on s e l f - e f f i c a c y theory (e.g., Bandura, 1977, 1982, 1986) that s e l f - e f f i c a c y l e v e l i s 57 d i r e c t l y influenced by anxious arousal l e v e l . S p e c i f i c a l l y , as anxious arousal l e v e l increases, s e l f - e f f i c a c y decreases. When anxious arousal l e v e l i s allowed to return to normal, s e l f -e f f i c a c y shows a corresponding increase. Overview of Method and Design Subjects were female undergraduate students who reported a fear of snakes. Upon the subject's a r r i v a l at the laboratory during the f i r s t session, the i n t e n s i t y of her fear was assessed using a standardized Behavioral Approach Test (BAT). The dependent measures assessing fear included self-reported fear (subjective units of distress) and heart rate response. Subjects who exhibited a minimum c r i t e r i o n l e v e l of s e l f -reported fear were asked to p a r t i c i p a t e i n the rest of the study. Subjects were randomly assigned to one of two groups: anxiously aroused ( i . e . , received a series of randomly timed shocks) vs. control (did not receive any shocks). Once anxious arousal l e v e l was manipulated, the subject's fear l e v e l was again assessed using the BAT. Strength of s e l f - e f f i c a c y was also assessed. The subject then viewed a videotaped fear reduction program under control or anxious arousal conditions. Following t h i s , the subject again p a r t i c i p a t e d i n a BAT and measures of fear and s e l f - e f f i c a c y were taken. Subjects i n the anxious arousal group then had t h e i r anxious arousal reduced ( i . e . , through termination of shock/shock threat). A fourth BAT then occurred. Subjects returned for a follow-up session one month l a t e r . Half of the subjects i n each of the above groups were randomly assigned to conditions of either anxious 58 a r o u s a l o r c o n t r o l c o n d i t i o n s d u r i n g f o l l o w - u p . A f i n a l BAT was used t o a s s e s s f e a r l e v e l s . S e l f - e f f i c a c y was a l s o a s s e s s e d . I n o r d e r t o a s s e s s p r e d i c t i o n s r e g a r d i n g t h e e f f e c t s o f a r o u s a l l e v e l d u r i n g f e a r r e d u c t i o n on f e a r and s e l f - e f f i c a c y , t h e s t u d y used a two by f o u r f a c t o r i a l d e s i g n w i t h r e p e a t e d measures on t h e second f a c t o r . The d e s i g n c o n s i s t e d o f a n x i o u s a r o u s a l l e v e l d u r i n g f e a r r e d u c t i o n ( A n x i o u s l y a r o u s e d v s . C o n t r o l ) by t i m e o f assessment ( P r i o r t o t h e a n x i o u s a r o u s a l m a n i p u l a t i o n {Time 1) v s . Immediately a f t e r t h e a n x i o u s a r o u s a l m a n i p u l a t i o n {Time 2} v s . Immediately a f t e r f e a r r e d u c t i o n {Time 3) v s . F i v e minutes f o l l o w i n g t h e t e r m i n a t i o n o f f e a r r e d u c t i o n - A n x i o u s a r o u s a l e q u a l i z a t i o n {Time 4}) f a c t o r i a l d e s i g n w i t h r e p e a t e d measures on t h e second f a c t o r . I n o r d e r t o e v a l u a t e t h e i n t e r a c t i v e e f f e c t s o f a n x i o u s a r o u s a l l e v e l d u r i n g f e a r r e d u c t i o n and a t f o l l o w - u p , s u b j e c t s i n each o f t h e above two groups were randomly a s s i g n e d a t f o l l o w - u p t o e i t h e r t h e a n x i o u s a r o u s a l o r t h e c o n t r o l c o n d i t i o n . Each o f t h e t h r e e dependent v a r i a b l e s ( h e a r t r a t e r e s p o n s e ( i . e . , maximal h e a r t r a t e d u r i n g t h e BAT, c o v a r y i n g out r e s t i n g h e a r t r a t e i m m e d i a t e l y p r i o r t o t h e BAT), s e l f -r e p o r t e d f e a r , and s e l f - e f f i c a c y ) was a s s e s s e d on each o c c a s i o n . P r e d i c t i o n s P r e d i c t i o n s were made f o r t h e two dependent v a r i a b l e s a s s e s s i n g f e a r ( i . e . , h e a r t r a t e r e s ponse and s e l f - r e p o r t e d 59 fear) based on hypotheses derived from each of the two major theories of habituation. Although the following predictions were made i n absolute terms, i t was not implied that proponents of either theory would not allow for the influence of other factors on fear and the fear reduction process. Given the complex nature of fear and the fact that these theories have been based on the study of organisms, s t i m u l i , and responses that are less complex than those currently under study, i t i s un l i k e l y that any one theory would be able to completely explain fear behavior. Rather, the previously discussed theories are more appropriately considered as "mini models" (Mineka, 1985) that guide research and allow further insight into, but not a complete understanding of, the phenomena under study. The predictions were as follows: 1. E f f e c t s of anxious arousal on pre-exposure l e v e l s of fear. (Fear at time 2). Dual process theory The subjects in the anxiously aroused group would experience s i g n i f i c a n t l y greater heart rate responsiveness ( i . e . , maximal heart rate during the BAT, covarying out rest i n g heart rate immediately p r i o r to the BAT) and s e l f -reported fear r e l a t i v e to the subjects i n the control group. The reason for the anxiously aroused subjects' greater response r e l a t i v e to the subjects i n the control group i s because of t h e i r increased l e v e l of anxious arousal which, 60 according to dual process theory, would increase responsiveness. C o r t i c a l theory (e.g., Whitlow & Wagner, 1984) Although c o r t i c a l theory does not make any s p e c i f i c predictions regarding the eff e c t s of anxious arousal on habituation, i t was argued on the basis of t h i s theory that the subjects i n the anxiously aroused group would be re-exposed to the feared stimulus at time 2 under a d i f f e r e n t l e v e l of anxious arousal compared with time 1. As a re s u l t , the feared stimulus would be less l i k e l y to be cued i n memory p r i o r to the BAT. As a r e s u l t of t h i s , these subjects would show increased heart rate response and self-reported fear r e l a t i v e to subjects i n the control group. Both dual process theory and c o r t i c a l theory made i d e n t i c a l predictions regarding the eff e c t s of anxious arousal on pre-exposure l e v e l s of fear. 2 . E f f e c t s of anxious arousal during fear reduction on fear l e v e l immediately following fear reduction. (Fear at time 3). Dual process theory The subjects i n the anxious arousal group would experience s i g n i f i c a n t l y greater residual fear immediately following fear reduction on the two measures of fear (heart rate response and self-reported fear) than the subjects i n the control group. The reason for t h i s prediction was because anxious arousal r e s u l t s i n an increase i n general responsiveness and 61 d i s t r a c t s attention away from the feared stimulus during exposure. This decreased functional exposure r e s u l t s i n decreased fear reduction. C o r t i c a l theory The subjects i n the anxious arousal group would experience s i g n i f i c a n t l y greater fear on the two measures of fear (heart rate response and self-reported fear) than the subjects i n the control group. The reason for t h i s prediction was because increased anxious arousal d i s t r a c t s attention away from the feared stimulus during exposure. This decreased functional exposure r e s u l t s i n decreased fear reduction. Dual process theory and c o r t i c a l theory made i d e n t i c a l predictions regarding the e f f e c t s of anxious arousal on fear l e v e l s assessed immediately following fear reduction. 3. E f f e c t s of removal of anxious arousal on fear l e v e l . (Change between time 3 and time 4). Dual process theory Upon re-assessment under condition of non-anxious arousal ( i . e . , when not under the threat of shock), the subjects who experienced fear reduction under conditions of anxious arousal would show a decrease i n heart rate response and self-reported fear r e l a t i v e to the control subjects. The reason for t h i s prediction was that as the previously aroused subjects' arousal l e v e l decreased, t h e i r l e v e l of general responsiveness as indexed by heart rate response and self-reported fear would also decrease. C o r t i c a l theory Upon re-assessment under conditions of non-anxious arousal ( i . e . , when not under the threat of shock), the subjects who experienced fear reduction under conditions of anxious arousal would show increased heart rate response and self-reported fear r e l a t i v e to the subjects i n the control group who experienced fear reduction under conditions of non-anxious arousal. This prediction d i f f e r s from that based on dual process theory. The reason for t h i s prediction was that anxious arousal functions as a memory cue and subjects i n the control group would experience a greater degree of congruence i n anxious arousal l e v e l between exposure and the second post-test than subjects i n the anxious arousal group. 4. E f f e c t s of anxious arousal during fear reduction and at follow-up on the return of fear. (Change between time 4 and time 5 ) . Dual process theory The subjects who were anxiously aroused at follow-up would show a s i g n i f i c a n t l y greater increase i n fear scores between exposure and follow-up r e l a t i v e to the subjects who were not aroused at follow-up. The reason for t h i s prediction was that as arousal l e v e l increased, the l e v e l of general responsiveness as indexed by heart rate response and self-reported fear would show a corresponding increase. 63 C o r t i c a l theory The subjects who experienced congruent states of anxious arousal during fear reduction and at follow-up ( i . e . , e ither anxiously aroused on both occasions or non-anxiously aroused on both occasions) would evidence s i g n i f i c a n t l y less return of fear than subjects who experienced incongruent states of anxious arousal on the two occasions. The reason for t h i s prediction was that anxious arousal functions as a memory cue and the subjects who experienced congruent states of arousal during fear reduction and at follow-up would show s i g n i f i c a n t l y less responsiveness. Refer to Tables 1 and 2 for tabular presentations of the predictions regarding the eff e c t s of anxious arousal on fear. Predictions regarding s e l f - e f f i c a c y were made based on Bandura's (e.g., 1977, 1982, 1986) model of s e l f - e f f i c a c y . 1. E f f e c t of anxious arousal on s e l f - e f f i c a c y p r i o r to fear reduction. ( S e l f - e f f i c a c y at Time 2). The subjects i n the anxious arousal group would report s i g n i f i c a n t l y less s e l f - e f f i c a c y r e l a t i v e to the subjects i n the control group. The reason for t h i s decreased l e v e l of s e l f - e f f i c a c y r e l a t i v e to the subjects i n the control group was because of the anxiously aroused subjects' increased l e v e l of anxious arousal which, according to s e l f - e f f i c a c y theory, was a source of information i n d i c a t i n g to the in d i v i d u a l that she was currently vulnerable to stress which may impede coping a b i l i t i e s . 64 Table 1 Predictions regarding the e f f e c t s of anxious arousal  p r i o r to and during fear reduction on fear Predictions derived Predictions from Dual derived from Process Theory C o r t i c a l Theory Ef f e c t s of anxious arousal on HRR: A>C HRR: A>C pre-exposure l e v e l s of fear SUDS: A>C SUDS: A>C Ef f e c t s of anxious arousal HRR: A>C HRR: A>C during fear reduction on fear SUDS: A>C SUDS: A>C le v e l s immediately following fear reduction. E f f e c t s of removal of HRR: A<C HRR: A>C anxious arousal on change SUDS: A<C SUDS: A>C in fear l e v e l s ( i . e . , Fear l e v e l at Time 4 minus fear l e v e l at Time 3) Note: HRR=Heart rate response. . SUDS=Subjective units of di s t r e s s . A=Anxious arousal p r i o r to/during fear reduction. C=Control group. 65 Table 2 Predictions regarding the ef f e c t s of anxious arousal during fear  reduction and at follow-up on the return of fear Fear response at Time 5 minus fear response at Time 4 Predictions derived from Dual Process Theory HRR: (CA+AA)>(CC+AC) (and c o r t i c a l theory predicts that (CA+AA)=(CC+AC)) SUDS: (CA+AA)>(CC+AC) (and c o r t i c a l theory predicts that (CA+AA)=(CC+AC) Predictions derived from C o r t i c a l Theory HRR: (CA+AC)>(CC+AA) (and dual process theory predicts that (CA+AC)=(CC+AC) SUDS: (CA+AC)>(CC+AA) (and dual process theory predicts that (CA+AC)=(CC+AA) Note: CC=Control group - session 1, Control group - session 2. CA=Control group - session 1, Anxious arousal group - session 2. AC=Anxious arousal group - session 1, Control group - session 2. AA=Anxious arousal group - session 1, Anxious arousal group -session 2. 6 6 2 . E f f e c t o f a n x i o u s a r o u s a l d u r i n g f e a r r e d u c t i o n on s e l f - e f f i c a c y f o l l o w i n g f e a r r e d u c t i o n . ( S e l f - e f f i c a c y a t t i m e 3 ) . The s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p w o u l d r e p o r t d e c r e a s e d s e l f - e f f i c a c y r e l a t i v e t o t h e s u b j e c t s i n t h e c o n t r o l g r o u p . The r e a s o n f o r t h i s p r e d i c t i o n was t w o - f o l d : f i r s t l y , t h e s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p w o u l d c o n t i n u e t o e x p e r i e n c e h e i g h t e n e d l e v e l s o f a n x i o u s a r o u s a l d e s p i t e e x p o s u r e t o t h e f e a r e d s t i m u l u s . T h i s c o n t i n u e d a n x i o u s a r o u s a l may r e s u l t i n a d i s r u p t i o n i n d e v e l o p m e n t o f s e l f -e f f i c a c y e x p e c t a t i o n s . S e c o n d l y , e x p e r i e n c i n g a n x i o u s a r o u s a l w o u l d r e s u l t i n d e c r e a s e d f u n c t i o n a l e x p o s u r e t o t h e f e a r e d s t i m u l u s w h i c h w o u l d a l l o w l e s s o p p o r t u n i t y t o i n c r e a s e s e l f -e f f i c a c y e x p e c t a t i o n s . 3 . E f f e c t o f r e m o v a l o f a n x i o u s a r o u s a l on s e l f - e f f i c a c y . ( Change b e t w e e n Time 3 a n d T ime 4 ) . The s u b j e c t s who w e r e a r o u s e d d u r i n g f e a r r e d u c t i o n w o u l d e x p e r i e n c e a s i g n i f i c a n t i n c r e a s e i n s e l f - e f f i c a c y r e l a t i v e t o t h e s u b j e c t s i n t h e c o n t r o l g r o u p . The r e a s o n f o r t h i s c h a n g e i n s e l f - e f f i c a c y r e l a t i v e t o s u b j e c t s i n t h e c o n t r o l g r o u p was b e c a u s e t h e r e d u c t i o n o f a n x i o u s a r o u s a l c o n s t i t u t e d r e m o v a l o f a s o u r c e o f i n f o r m a t i o n t h a t p r o m o t e s d e c r e a s e d l e v e l s o f s e l f - e f f i c a c y . 4 . E f f e c t o f a n x i o u s a r o u s a l a t f o l l o w - u p on s e l f -e f f i c a c y . (Change b e t w e e n Time 4 a n d Time 5 ) . 67 The subjects who were anxiously aroused at follow-up would show a significantly larger decrease in self-efficacy between exposure and follow-up than subjects in the control group. The reason for this change in self-efficacy relative to the subjects in the control group was because the increased anxious arousal constituted addition of a source of information that promotes decreased levels of self-efficacy. Refer to Table 3 for a tabular presentation of the predictions regarding the effects of anxious arousal on self-efficacy. Table 3 Predictions regarding the e f f e c t s of anxious arousal on s e l f - e f f i c a c y expectations E f f e c t s of anxious arousal p r i o r A<C to fear reduction on SEE Ef f e c t s of anxious arousal during A<C fear reduction on SEE immediately following fear reduction E f f e c t s of removal of anxious A>C arousal on changes i n SEE ( i . e . , SEE at Time 4 minus SEE at Time 3) E f f e c t s of anxious arousal at follow-up A<C on changes i n SEE ( i . e . , SEE at Time 5 minus SEE at Time 4) Note: SEE=Self-efficacy expectation. C=Control. A=Anxious Arousal. 69 METHOD SCREENING Undergraduate students i n introductory psychology were administered an abbreviated version of the Fear Survey Schedule (Wolpe & Lang, 19 64) (see Appendix A) i n order to determine t h e i r appropriateness for i n c l u s i o n i n the present study. Female students who indicated that they were "extremely f e a r f u l of" or " t e r r i f i e d of" snakes were then contacted v i a telephone and asked to pa r t i c i p a t e i n the study. It was decided to use only female students i n the current study for two main reasons: f i r s t l y , the incidence of animal phobias i s much more frequent i n women than men (Bourdon, Boyd, Rae, Burns, Thompson & Locke, 1988; Hersen, 1973; Marks, 1969, ci t e d i n Sturgis & Scott, 1984); secondly, i t has been observed that men exhibit greater discordance between s e l f -report and other indices of fear (e.g., behavioral avoidance, physiological arousal) (Hersen, 1973; Lopatka, 1987). I f the subject agreed to pa r t i c i p a t e , the experimenter arranged a convenient appointment time. MEASURES Self-report measures: Several s e l f - r e p o r t measures were used i n t h i s study. The state version of the State-Trait Anxiety Inventory (STAI) (Speilberger, Gorsuch, & Lushene, 1970) consists of 20 statements that focus upon q u a l i t i e s of anxiety, tension, worry, and apprehension. Subjects indicate the extent to which each of the statements describes t h e i r current state. Test-retest r e l i a b i l i t i e s for the state version 70 of t h i s scale range from .16 to .54 across time periods ranging from 1 hour to 20 days. Internal consistency as measured by the K-R 20 ranges from .83 to .92 (Katkin, 1978; Mason-Dreger, 1978). The v a l i d i t y of the scale has been has been empirically validated i n a number of studies (e.g., Katkin, 1978; Kendall, 1976). A mood scale, consisting of s i x 100 mm. v i s u a l analog scales was administered to each subject on a number of occasions. Each scale represents a d i f f e r e n t emotion ( i . e . , anxiety, sadness, agitation, happiness, relaxation, and apprehension) (see Appendix B). Subjects were to indicate the extent to which they were currently experiencing each emotion. This mood scale i s s i m i l a r to scales used i n previous studies of fear and has been found to be sensi t i v e to experimental manipulations of mood (e.g., Rachman & Whittal, 1989a; Samsom & Rachman, 1989; Sutherland, Newman & Rachman, 1982). Subjective units of d i s t r e s s (SUDS) upon exposure to the snake during the Behavioral Approach Test (BAT) were assessed by asking the subject to verbally report how much fear they experienced at the point of closest exposure to the snake, with zero i n d i c a t i n g no fear and 100 in d i c a t i n g t e r r i f y i n g fear. SUDS are very commonly used i n research on fear and are a very s e n s i t i v e measure of changes i n fear (Agras & Jacob, 1981). Strength of s e l f - e f f i c a c y regarding the a b i l i t y to touch the snake was assessed by having the subject indicate on a 100 point v i s u a l analog scale the extent to which she was 71 confident that she could approach a l i v e but harmless snake (see Appendix C). The s p e c i f i c behavior that the subject was asked to evaluate corresponded to the closest approach point to the snake that the subject engaged i n during the i n i t i a l BAT. Heart rate: Heart rate was recorded with a Sanyo heart rate monitor model number HRM-700E. This monitor consists of a photoplethysmograph that i s attached to the earlobe. I t has a d i g i t a l display that i s accurate to within 3 %. During sesion 1, heart rate during exposure to the modeling program was sampled for f i v e second i n t e r v a l s every one minute. The maximum heart rate during each f i v e second i n t e r v a l was recorded, r e s u l t i n g i n 14 samples of heart rate data. During session 2, the maximum heart rate during each f i v e second i n t e r v a l was sampled at one minute i n t e r v a l s for six minutes beginning immediately aft e r the subject was t o l d that she would be exposed to the series of tones (in the control group) or shocks (in the anxious arousal group), r e s u l t i n g i n six samples of heart rate data. Heart rate immediately p r i o r to the BAT was defined as the maximum heart rate i n the f i v e second i n t e r v a l occurring between 2 5 and 3 0 seconds following completion of the sel f - r e p o r t measures. Heart rate response during the BAT was defined as the maximum heart rate during the f i v e second i n t e r v a l immediately following the closest approach point to the snake. Heart rate was chosen as a measure of autonomic arousal as i t i s r e l i a b l e , more highly correlated with other measures of fear than other autonomic 72 measures (Agras & Jacob, 1981; Bellack & Lombardo, 1984; Craske, 1982; Hodgson & Rachman, 1974; Hugdahl, 1989; Lang et a l . , 1970), and i s the autonomic index used i n previous research on the return of fear. FEAR REDUCTION PROGRAM A modeling sequence to be presented to the subjects v i a videotape was developed for use i n the present study. The program, which i s approximately 15 minutes i n duration, depicts two individuals who were i n i t i a l l y f e a r f u l of snakes undergoing fear reduction through the use of graduated pa r t i c i p a n t modeling. A l l four models i n the program (two c l i e n t s and two therapists) are female and appear to be i n t h e i r l a t e teens or early twenties. Three of the four models are Caucasian, and the fourth i s o r i e n t a l . The program depicts both coping (the c l i e n t s ) and mastery (the therapists) models. Throughout the modeling sequence there i s provision of information regarding snakes and how to handle them, and the c l i e n t i s given frequent feedback and p o s i t i v e reinforcement about her performance. The outcome of both t h e r a p i s t - c l i e n t interactions i s clear: the c l i e n t i s gradually able to more competently, and less f e a r f u l l y , handle the snake. In the f i n a l moments, both c l i e n t s are able to handle the snake without assistance while reporting very low l e v e l s of fear. These factors ( i . e . , use of multiple models, s i m i l a r i t y between the models and the subjects, use of coping models, provision of information, feedback, and p o s i t i v e reinforcement) serve to maximize the e f f e c t s of the modeling 73 procedure (e.g., Kazdin, 1974, Kazdin, 1975, Meichenbaum, 1972) . Although videotape modeling i s a less e f f e c t i v e method of fear reduction than participant modeling (e.g., Bandura, 19 69), i t i s nevertheless a robust fear reduction procedure. Furthermore, i t was a more appropriate procedure than pa r t i c i p a n t modeling for use i n the present study as i t allows complete standardization between subjects with respect to amount and type of exposure to the feared stimulus. This degree of standardization cannot be achieved with participant modeling procedures. The use of par t i c i p a n t modeling procedures would l i k e l y have resulted i n systematic group differences regarding the parameters of exposure to the snake. FEAR REDUCTION SESSION Upon a r r i v a l at the laboratory, the subject was escorted to the t e s t i n g room by the experimenter, a man i n his la t e twenties, and seated i n a r e c l i n i n g chair. She remained i n t h i s chair for the duration of the experiment. The heart rate monitor was then shown to the subject and attached to her ri g h t ear lobe. The experimenter then explained to the subject how to complete the mood scale and the state version of the STAI. The subject was then given the consent form (Appendix D) to read and sign. Any additional questions of the subject were answered at t h i s time. The research assistant, who was b l i n d to the hypotheses of the study and the condition of the subject, entered the room and the experimenter was seated by the shock equipment which was behind a screen to the ri g h t of the subject. After a 74 f i v e minute a d a p t a t i o n p e r i o d , t h e s u b j e c t c o mpleted t h e mood s c a l e and t h e STAI, and h e r h e a r t r a t e was r e c o r d e d . The s u b j e c t was t h e n asked t o p a r t i c i p a t e i n a BAT i n o r d e r t o f u r t h e r a s s e s s h e r l e v e l o f f e a r . The r e s e a r c h a s s i s t a n t uncovered t h e c o n t a i n e r h o u s i n g t h e snake w h i c h was 18 f e e t from t h e s u b j e c t . The s u b j e c t was g i v e n t h e f o l l o w i n g i n s t r u c t i o n s : I n s i d e t h e c o n t a i n e r i s a l i v e h a r m l e s s g a r t e r snake. Can you see i t from where you a r e s i t t i n g ? I n a moment I am g o i n g t o ask you t o r e p o r t t h e peak amount o f f e a r t h a t you a r e e x p e r i e n c i n g u s i n g a s c a l e from 0 t o 100, w i t h "0" b e i n g no f e a r and "100" b e i n g t e r r i f y i n g f e a r . I w i l l move t h e c o n t a i n e r toward you and when I r e a c h where you a r e s i t t i n g , I would l i k e you t o p i c k up t h e snake f o r f i v e seconds w h i l e c o n t i n u i n g t o l o o k a t i t . I w i l l t e l l you when t h e f i v e seconds a r e up. I f you a r e u n a b l e t o p i c k up t h e snake p l e a s e l e t me know when t h e snake i s as c l o s e t o you as you can p o s s i b l y t o l e r a t e . I t i s i m p o r t a n t t o do so as q u i c k l y as p o s s i b l e . Do you have any q u e s t i o n s ? I w i l l now move t h e snake toward you. ( E x p e r i m e n t e r s l o w l y moves t h e c o n t a i n e r toward t h e s u b j e c t ) Now I would l i k e you t o r e p o r t t h e peak amount o f f e a r you a r e e x p e r i e n c i n g u s i n g t h e 0 t o 100 s c a l e . The s u b j e c t ' s h e a r t r a t e and l e v e l o f s e l f - r e p o r t e d f e a r were r e c o r d e d a t t h e c l o s e s t approach p o i n t t o t h e snake. The c l o s e s t approach p o i n t was h e l d c o n s t a n t f o r each s u b j e c t f o r subsequent BATs so as t o a l l o w comparison a c r o s s BATs. S u b j e c t s who were a b l e t o t o u c h t h e snake w h i l e r e p o r t i n g a f e a r l e v e l o f l e s s t h a n 70 were e x c l u d e d from t h e s t u d y . Use o f a minimum c u t t i n g s c o r e o f 70 i s c o n s i s t e n t w i t h o t h e r s i m i l a r s t u d i e s o f f e a r and t h e r e t u r n o f f e a r (e.g., Samsom & Rachman, 1988). A f t e r t h e BAT, t h e r e s e a r c h a s s i s t a n t l e f t t h e room and t h e s u b j e c t was randomly a s s i g n e d t o one o f two c o n d i t i o n s : 75 1. Anxious arousal condition - An electrode was attached to the subject's forearm. I t was held i n place by a tensor bandage wrapped around the subject's arm. The subject was given the following instructions: You w i l l now receive a series of b r i e f 0.5 second shocks through t h i s electrode. The shocks are completely harmless and w i l l cause absolutely no l a s t i n g pain or damage. Each succeeding shock w i l l be s l i g h t l y more intense than the previous one. I would l i k e you to t e l l me when you f i r s t experience the shock. You w i l l continue to receive shocks u n t i l you are unable to tolerate any further shocks. At any time during the sequence of shocks, simply saying "Stop" w i l l end the series of shocks. Please do your best to tolerate as intense a shock as possible. Do you have any questions? The subject was then given a series of 0.5 second shocks at 10 second in t e r v a l s i n order to es t a b l i s h the subject's pain s e n s i t i v i t y range - pain threshold to tolerance. Pain threshold was defined as the l e v e l of shock f i r s t discerned by the subject and pain tolerance was the l e v e l at which the subject was not prepared to accept any further increases i n shock i n t e n s i t y . Following t h i s procedure, the subject was given the following instructions: During the rest of the experiment, u n t i l you are t o l d otherwise, you w i l l receive a number of shocks. The shocks w i l l be of various i n t e n s i t i e s and the timing of the shocks w i l l be randomly determined. You cannot do anything to change the i n t e n s i t y or timing of the shocks. Do you have any questions? 2. Control condition - An electrode, d i f f e r e n t i n size and shape from that used for subjects i n the arousal condition, was attached to the subject's forearm. I t was held i n place by a tensor bandage. The subject was given the following instructions: 76 The purpose of t h i s electrode i s to measure your l e v e l of physiological responding. In order to c a l i b r a t e the equipment, I need to assess your physiological response to a series of standardized tones. You w i l l now hear a series of b r i e f tones. I would l i k e you to do nothing but simply l i s t e n to the tones. Do you have any questions? The subject was then exposed to a series of 11 b r i e f tones that were presented at 10 second i n t e r v a l s . This number i s equivalent to the mean number of shocks needed to e s t a b l i s h the pain s e n s i t i v i t y range of subjects i n the anxious arousal group during p i l o t t e s t i n g and served to equate the amount of time that subjects in the two groups were in the laboratory p r i o r to viewing the modeling videotape. Following t h i s procedure the subject was given the following i n s t r u c t i o n s : You are i n the control condition and w i l l not at any time be exposed to shock. There i s absolutely no p o s s i b i l i t y that you w i l l receive a shock. Throughout the procedure please do your best to s i t qu i e t l y . Do you have any questions? At t h i s point any questions of the subject were answered and, i f the subject agreed, the experiment continued. At t h i s point, the subject was asked to not discuss with the research assistant any aspects of the study. The research assistant then re-entered the room. She asked the subject to complete the STAI, the mood scale, and the s e l f - e f f i c a c y scale, and recorded the subject's heart rate. A second BAT was then conducted. The research assistant l e f t the t e s t i n g room and the experimenter gave the subject the following instructions: I would now l i k e you to watch a short videotaped program. You w i l l see two d i f f e r e n t i n d i v i d u a l s who, l i k e yourself, were f e a r f u l of snakes. On the program they w i l l be taught s k i l l s that helped them to become more s k i l l f u l i n handling snakes. Ultimately, they both became r e l a t i v e l y fearless of 77 harmless snakes l i k e the one i n the program. Please pay attention to the program. Subjects i n the anxious arousal condition were then t o l d , "Please remember that you w i l l continue to receive one or more shocks u n t i l you are t o l d otherwise and disconnected from the shock equipment." Subjects i n the control condition were t o l d , "Please remember that you absolutely w i l l not receive any shocks throughout the procedure." Subjects then viewed the modeling program. Subjects i n the anxious arousal group received a series of 10 shocks during the program. The 15 minute program was divided into 10 i n t e r v a l s of 1.5 minutes. Within each i n t e r v a l one shock was delivered to the subject. The i n t e n s i t y of the shocks varied from .50 to .95 of the i n t e r v a l from pain threshold to pain tolerance. Heart rate was sampled for f i v e second i n t e r v a l s every one minute throughout the program. Following the program the research assistant re-entered the room, asked the subject to complete the three scales, recorded her heart rate, and conducted a t h i r d BAT. The research assistant then l e f t the t e s t i n g room. The electrode was removed from the subject's forearm. Subjects i n the arousal condition were t o l d , "You w i l l no longer be exposed to any further threat of shock." Subjects i n the control condition were t o l d , "Your l e v e l of physiological responsiveness w i l l no longer be assessed." 2 P i l o t t e s t i n g was i n i t i a l l y conducted using a shock threat manipulation. The subjects i n the shock threat group were connected to an electrode and informed that they would receive a p a i n f u l shock on one or more occasions during the session. However, they did not actually receive any shocks. It was found that t h i s manipulation did not r e l i a b l y increase either self-reported anxious arousal or heart rate and, consequently, actual shock was used i n order to generate anxious arousal. 78 Subjects were asked to s i t quietly for f i v e minutes and were given a magazine a r t i c l e to read. The purpose of t h i s i n t e r v a l was to allow subjects i n the anxious arousal and control conditions to develop s i m i l a r l e v e l s of anxious arousal. Following the f i v e minute anxious arousal normalization period, the research assistant asked the subject to complete the three scales completed previously, recorded her heart rate, and conducted a fourth BAT. The subject was then thanked for her cooperation and a second appointment, four weeks l a t e r , was scheduled. FOLLOW-UP SESSION The follow up session took place i n the same t e s t i n g room as i n the f i r s t session. The subject was asked by the research assistant to complete the mood scale and the STAI and, a f t e r a f i v e minute adaptation period, her heart rate was recorded. Half of the subjects in each of the two conditions of session 1 were randomly assigned to the anxious arousal group and the remaining subjects were assigned to the control group. The shock s e n s i t i v i t y range of subjects i n the anxious arousal group was established i n an i d e n t i c a l fashion to that used i n session 1. Subjects i n the control group were exposed to a series of tones using the same procedure as i n session 1. Following the establishment of the shock s e n s i t i v i t y range, subjects i n the anxious arousal group were given the following instructions: During the rest of the session, u n t i l you are t o l d otherwise, you w i l l receive a number of shocks. The shocks w i l l be of varying i n t e n s i t i e s and the timing of the shocks w i l l be randomly determined. You 79 cannot do anything to change the i n t e n s i t y or timing of the shocks. Do you have any questions? Afte r exposure to the series of tones, subjects i n the control condition were given the following i n s t r u c t i o n s : You are i n the control condition and w i l l not at any time be exposed to shock. There i s absolutely no p o s s i b i l i t y that you w i l l receive a shock. Please do your best to s i t quietly. Do you have any questions? Any questions of the subject were answered. Subjects i n the arousal condition then experienced a series of 6 shocks over a six minute i n t e r v a l . One shock was received within each one minute i n t e r v a l . The i n t e n s i t y of the shocks varied between .50 and .95 of the subject's pain s e n s i t i v i t y range. Subjects i n the control group were asked to s i t quietly for s i x minutes. Immediately following the six minute i n t e r v a l , the research assistant re-entered the room. The subject completed the mood scale, the s e l f - e f f i c a c y scale, and the STAI, and her heart rate was recorded. The subject then pa r t i c i p a t e d i n a BAT using i d e n t i c a l instructions to those i n the previous BATs. The subject was then debriefed, paid a stipend of ten d o l l a r s , and thanked for her cooperation. 80 RESULTS A t o t a l of 91 subjects attended the i n i t i a l session. Of these subjects, 1 subject refused to p a r t i c i p a t e because her fear l e v e l was too great, and 14 subjects were judged unsuitable because t h e i r i n i t i a l fear l e v e l s were not s u f f i c i e n t l y high. Thus, a l l of the analyses to be presented regarding session 1 are based on the re s u l t s of 76 subjects, 38 i n the control group and 38 i n the anxious arousal group. Of these subjects, 1 subject, who was assigned to the anxious arousal group during both sessions, did not attend the follow-up session. Thus, a l l analyses involving the follow-up session are based on the res u l t s of the remaining 75 subjects. The res u l t s section consists of three subsections. F i r s t , data regarding the e f f e c t s of the experimental manipulation on anxious arousal w i l l be presented. This w i l l be followed by the p r i n c i p a l set of analyses, those concerning the e f f e c t s of anxious arousal on fear. The f i n a l subsection presents the res u l t s regarding the ef f e c t s of anxious arousal on s e l f -e f f i c a c y . EVALUATION OF THE EXPERIMENTAL MANIPULATION Self-reported anxiety (anxiety subscale on the Mood Scale (see Appendix B) and the STAI and heart rate immediately p r i o r to each Behavioral Approach Test (BAT) ( i . e . , r e s t i n g heart rate) were evaluated on four occasions during session 1 and on two occasions during session 2. On each occasion, responses of subjects i n the anxious arousal group were compared with subjects i n the control group. It was hypothesized that 81 subjects who were i n the anxious arousal group during session 1 would exhibit s i g n i f i c a n t l y greater anxious arousal as assessed by the three variables immediately following the anxious arousal manipulation (Time 2) and immediately following the fear reduction procedure (Time 3). I t was hypothesized that they would exhibit s i m i l a r l e v e l s of anxious arousal to subjects i n the control group p r i o r to the anxious arousal manipulation (Time 1) and following anxious arousal equalization (Time 4). I t was also hypothesized that subjects who were in the anxious arousal group during session 2 would exhibit greater anxious arousal following the anxious arousal manipulation (Time 6), but not p r i o r to t h i s manipulation (Time 5). The r e s u l t s of the analyses for each dependent variable on each occasion w i l l now be considered. Session 1: 1. Anxious arousal l e v e l p r i o r to the anxious arousal manipulation (Anxious arousal l e v e l at time 1): The means and standard deviations for the three dependent variables assessing anxious arousal at time 1 are shown in Table 4. A univariate t - t e s t was conducted on each of the three variables assessing anxious arousal l e v e l . The two groups did not d i f f e r on any of these three variables (anxiety subscale of the Mood Scale: t (74) = 0.01, p > .90; STAI: t (74) - 1.41, p >.15; heart rate: t (74) = -0.18, p > .80.). Analyses of anxious arousal l e v e l at times 2, 3 and 4: 82 Table 4 Responses of subjects on the anxious arousal measures at time 1 Group Variable Control Arousal El SD SD Anxiety subscale 42. .5 19.6 42, .4 20 . 8 STAI 1 45. . 1 8.4 42. .2 9.5 Heart rate^ lb. .5 11.5 77. . 0 12.3 Greater values indicate greater self-reported anxiety. Measured in beats per minute. 8 3 u n i v a r i a t e t - t e s t s t h a t c o m p a r e d t h e r e s p o n s e s o f s u b j e c t s i n t h e t w o g r o u p s o n e a c h a s s e s s m e n t o c c a s i o n . H e a r t r a t e i m m e d i a t e l y p r i o r t o e a c h B A T was e v a l u a t e d w i t h a o n e - w a y a n a l y s i s o f c o v a r i a n c e * w i t h r e s t i n g h e a r t r a t e a t t i m e 1 ( p r i o r t o t h e a n x i o u s a r o u s a l m a n i p u l a t i o n ) a s t h e c o v a r i a t e . I n o r d e r t o c o n t r o l T y p e I e r r o r r a t e ? t h e c r i t i c a l l e v e l o f s i g n i f i c a n c e f o r t h e t h r e e a n a l y s e s w a s c a l c u l a t e d u s i n g t h e B o n f e r r o n i i n e q u a l i t y . E a c h u n i v a r i a t e t - t e s t wa s e v a l u a t e d a t t h e . 0 5 / 3 = . 0 1 7 p r o b a b i l i t y I ewe i 2 . A n x i o u s a r o u s a l l e v e l i m m e d i a t e l y f o l l o w i n g t h e a n x i o u s a r o u s a l m a n i p u l a t i o n ( A n x i o u s a r o u s a l l e v e l a t t i m e 2)• R e f e r t o T a b l e 5 f o r a p r e s e n t a t i o n o f mean s c o r e s f o r t h e t w o g r o u p s o n t h e t h r e e m e a s u r e s o f a n x i o u s a r o u s a l a t t i m e 2 . T h e s u b j e c t s who w e r e i n t h e a n x i o u s a r o u s a l g r o u p r e p o r t e d s i g n i f i c a n t l y g r e a t e r a n x i o u s a r o u s a l o n t h e a n x i e t y s u b s c a l e o f t h e M o o d S c a l e C t ( 7 4 ) = - 3 . 1 8 > £ < .DOS ) a n d o n t h e S T A I ( t ( 7 4 ) = - 3 . 7 3 . . £ < . QQD5 > a n d e x p e r i e n c e d s i g n i f i c a n t l y g r e a t e r h e a r t r a t e ( F ( I J 7 3 ) = 1 1 . 6 2 ? £ < .DDD5 ) c o m p a r e d w i t h s u b j e c t s i n t h e c o n t r o l g r o u p . 3 . A n x i o u s a r o u s a l l e v e l f o l l o w i n g t h e f e a r r e d u c t i o n p r o c e d u r e ( A n x i o u s a r o u s a l l e v e l a t t i m e 3 ) : 3 I n i t i a l l y > t h e t w o s e l f - r e p o r t m e a s u r e s o f a n x i e t y w e r e a n a l y s e d u s i n g a n a l y s i s o f c o v a r i a n c e p r o c e d u r e s . T h e r e s u l t s o f t h e s e a n a l y s e s i n d i c a t e d t h a t t h e r e w a s no s i g n i f i c a n t l i n e a r r e l a t i o n s h i p b e t w e e n t h e c o v a r i a t e a n d t h e d e p e n d e n t v a r i a b l e f o r t h r e e o f t h e a n a l y s e s . D e p a r t u r e s f r o m l i n e a r i t y r e d u c e t h e e f f i c i e n c y o f a n a l y s i s o f c o v a r i a n c e a n d r e s u l t i n b i a s e d e s t i m a t e s o f t h e t r e a t m e n t m e a n s ( K i r k ? 1 9 8 2 ; U i n e r . . 1 9 7 1 ) . C o n s e q u e n t l y . ' i t w a s m o r e a p p r o p r i a t e t o a n a l y s e t h e s e d a t a w i t h a n a l y s i s o f v a r i a n c e p r o c e d u r e s . T a b 1e 5 R e s p o n s e s o f s u b j e c t s o n t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 2 G r o u p V a r i a b l e C o n t r o l A r o u s a l d SD SD 1 A n x i e t y s u b s c a 1 e 31 . . 5 2 3 . 7 4 8 . 6 2 3 . 6 S T A I 1 4 0 , . 3 ? . • 4 8 . 8 1 0 . 6 H e a r t r a t e ^ 7 2 . . 0 8 . 8 7 7 . 5 1 2 . 1 H e a r t r a t e a c j j 7 2 , .2 7 7 . 3 G r e a t e r v a l u e s i n d i c a t e g r e a t e r s e I f - r e p o r t e d a n x i e t y . M e a s u r e d i n b e a t s p e r m i n u t e . 8 5 R e f e r t o T a b l e 6 f o r a p r e s e n t a t i o n o f t h e mean s c o r e s f o r t h e t w o g r o u p s o n t h e t h r e e v a r i a b l e s a s s e s s i n g a n x i o u s a r o u s a l a t t i m e 3 . T h e r e w a s no s i g n i f i c a n t d i f f e r e n c e b e t w e e n t h e t w o g r o u p s r e g a r d i n g t h e i r r e s p o n s e s o n t h e a n x i e t y s u b s c a l e o f t h e M o o d S c a l e <t ( 7 4 ) = - 2 . 2 6 > £ = . 0 3 ) ; h o w e v e r . * t h e s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p r e p o r t e d s i g n i f i c a n t l y m o r e a n x i o u s a r o u s a l o n t h e S T A I (jt ( 7 4 ) = -4 . 53 . » £ < . QD01 ) a n d e x p e r i e n c e d s i g n i f i c a n t l y h i g h e r h e a r t r a t e ( F ( I J 7 3 ) = 2 3 . 9 7 . . £ < . 0 0 1 ) t h a n d i d s u b j e c t s i n t h e c o n t r o l g r o u p . A s a f u r t h e r c h e c k o n t h e e x p e r i m e n t a l m a n i p u l a t i o n . , h e a r t r a t e was s a m p l e d on 14 o c c a s i o n s d u r i n g t h e f e a r r e d u c t i o n p r o c e d u r e . T h e s e d a t a w e r e s u b j e c t e d t o a t w o ( G r o u p : C o n t r o l v s . A n x i o u s a r o u s a l ) b y 14 ( T i m e ) a n a l y s i s o f v a r i a n c e ? w i t h r e p e a t e d m e a s u r e s o n t h e s e c o n d f a c t o r . I t w a s f o u n d t h a t t h e r e w a s a s i g n i f i c a n t m a i n e f f e c t o f g r o u p ( F (l.> 7 4 ) = 1 3 . 3 8 . . £ < . 0 0 1 ) . T h e s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p h a d a s i g n i f i c i a n t l y g r e a t e r h e a r t r a t e (M = 7 9 . 8 ) t h a n t h e s u b j e c t s i n t h e c o n t r o l g r o u p (M = 7 1 . 9 ) . I n e v a l u a t i n g t h e e f f e c t o f t i m e a n d t h e i n t e r a c t i o n o f t i m e a n d g r o u p . , t h e d e g r e e s o f f r e e d o m w e r e a d j u s t e d u s i n g t h e p r o c e d u r e r e c o m m e n d e d b y K i r k ( 1 9 8 2 ) . T h i s p r o c e d u r e c o n t r o l s f o r v i o l a t i o n s o f t h e s p h e r i c i t y a s s u m p t i o n a n d i n v o l v e s a d j u s t i n g t h e d e g r e e s o f f r e e d o m f r o m ( k - 1 ) a n d ( n - 1 ) ( k - 1 ) ( w h e r e k i s t h e n u m b e r o f t r e a t m e n t s a n d n i s t h e n u m b e r o f s u b j e c t s ) t o ( k - 1 ) a n d ( k - D ( n - l ) r e s u l t i n g i n . 4 8 1 7 ( 1 3 ) = 6.26 a n d . 4 8 1 7 ( 1 3 H 7 5 ) = 4 6 9 . 7 d e g r e e s o f f r e e d o m . U s i n g Tab Ie 6 R e s p o n s e s o f s u b j e c t s on t h e a n x i o u s a r p u s a l m e a s u r e s a t t i m e 3 G r o u p Va r i ab 1 e C e n t r o 1 Ar ousa1 SD M SD 1 A n x i e t y s u b s c a 1 e 2 9 . 5 2 3 . 3 41 .7 2 3 . 6 S T A I 1 3 7 . 4 9 . 7 4 9 . 5 1 3 . 2 H e a r t r a t e ^ 7 2 - 3 7 . 4 7 8 . 7 9 . 5 H e a r t t " 3 ' t e a c j j 7 2 . 4 7 6 . 6 G r e a t e r v a l u e s i n d i c a t e g r e a t e r s e l f - r e p o r t e d a n x i e t y . M e a s u r e d i n b e a t s p e r m i n u t e . 8 7 t h i s a d j u s t m e n t ? i t wa s f o u n d t h a t t h e r e w a s a s i g n i f i c a n t e f f e c t o f t i m e ( F (6.26, 4 6 9 . 7 ) = 3 . 6 8 ? £ < . 0 1 ) . A s t h i s e f f e c t i s n o t p e r t i n e n t ? s i m p l e m a i n e f f e c t s w e r e n o t c a l c u l a t e d . T h e i n t e r a c t i o n o f g r o u p a n d t i m e w a s n o t s i g n i f i c a n t <F ( 6 . 2 6 ? 4 6 9 . 7 ) = 1 . 9 6 ? £ > . 0 5 ) . 4 . A n x i o u s a r o u s a l l e v e l f o l l o w i n g a n x i o u s a r o u s a l e q u a l i z a t i o n ( A n x i o u s a r o u s a l l e v e l a t t i m e 4>= R e f e r t o T a b l e 7 f o r a p r e s e n t a t i o n o f m e a n s f o r t h e t w o g r o u p s on t h e t h r e e v a r i a b l e s a s s e s s i n g a n x i o u s a r o u s a l a t t i m e 4 . T h e s u b j e c t s i n t h e t w o g r o u p s d i d n o t d i f f e r w i t h r e s p e c t t o t h e i r s e l f - r e p o r t e d a n x i o u s a r o u s a l l e v e l o n e i t h e r t h e a n x i e t y s u b s c a l e o f t h e M o o d S c a l e ( t , ( 7 4 ) = 0 . 8 1 ? £ > . 4 0 ) ? t h e S T A I ( t ( 7 4 ) = - 2 . 2 0 ? £ = . 0 3 ) o r w i t h r e s p e c t t o t h e i r r e s t i n g h e a r t r a t e ( F ( 1 ? 7 3 ) = 4 . 7 5 ? £ = . 0 3 ) . S e s s i o n 2= 5 . A n x i o u s a r o u s a l l e v e l p r i o r t o t h e a r o u s a l m a n i p u l a t i o n ( A n x i o u s a r o u s a l l e v e l a t t i m e 5 )= R e f e r t o T a b l e 8 f o r a p r e s e n t a t i o n o f t h e g r o u p m e a n s o n t h e t h r e e v a r i a b l e s a s s e s s i n g a n x i o u s a r o u s a l a t t i m e 5 . S e I f - r e p o r t e d a n x i o u s a r o u s a l a n d h e a r t r a t e w e r e e v a l u a t e d w i t h t h r e e u n i v a r i a t e a n a l y s e s t h a t c o m p a r e d s u b j e c t s who w e r e i n t h e c o n t r o l a n d a n x i o u s a r o u s a l g r o u p s d u r i n g s e s s i o n 2 . T h e s u b j e c t s i n t h e t w o g r o u p s d i d n o t d i f f e r w i t h r e s p e c t t o t h e s e t h r e e v a r i a b l e s ( a n x i e t y s u b s c a l e o f t h e M o o d S c a l e : t ( 7 3 ) = - 0 . 3 3 ? £ > . 7 0 ; S T A I : t ( 7 3 ) = D . 4 9 ? £ > . 6 0 ; h e a r t r a t e t ( 7 3 ) = 1 . 3 3 ? £ > . 1 5 ) . Table 7 Responses Qf subjects on the anxious arousal measures at time 4 Group Variable Control Arousal Anxiety subscale .1 STA I Heart rate Heart rate 2 ad j M sp lh. .6 ^ . & 2D .2 15.3 33 . .6 8.7 38.4 9.8 71 . 9 8.9 75. 2 10.4 72, . 1 75. 1 1 2 Greater values indicate greater Measured in beats per minute. s e If - repor ted anx i ety. 8 ? T a b Ie 8 R e s p o n s e s o f s u b j e c t s o n t h e a n x i o u s a r o u s a l m e a s u r e s a t t i m e 5 G r o u p V a r i a b 1 e C o n t r o 1 A r o u s a 1 SD M SD A n x i e t y s u b s c a l e 3 6 . 3 2 5 . 7 3 8 . 1 2 4 . 1 S T A I 1 4 0 . 5 ID . 8 3 9 . 3 1 0 . 2 H e a r t r a t e " * " 7 5 . 7 1 1 . 1 7 2 . 6 8 . 8 G r e a t e r v a l u e s i n d i c a t e g r e a t e r s e l f - r e p o r t e d a n x i e t y . M e a s u r e d i n b e a t s p e r m i n u t e . 6. A n x i o u s a r o u s a l l e v e l f o l l o w i n g t he a n x i o u s a r o u s a l man i puI a t i on ( A n x i o u s a r o u s a l l e v e l a t t i m e 6)• R e f e r t o T a b l e 9 f o r a p r e s e n t a t i o n o f t h e mean s c o r e s on the t h r e e measu re s o f a n x i o u s a r o u s a l at t i m e 6. E a c h o f t h e two s e l f - r e p o r t measu re s o f a n x i o u s a r o u s a l was e v a l u a t e d u s i n g a u n i v a r i a t e t - t e s t t h a t compared t h e r e s p o n s e s of s u b j e c t s in t h e c o n t r o l and a n x i o u s a r o u s a l g r o u p s . The s u b j e c t s in t h e a n x i o u s a r o u s a l g roup r e p o r t e d s i g n i f i c a n t l y more a n x i o u s a r o u s a l as a s s e s s e d by t h e a n x i e t y s u b s c a l e o f the Mood S c a l e ( t (73) = -5.14.. £ < .0001) and t h e STAI ( t (73) = -5.51.1 £ < .0001) . H e a r t r a t e i m m e d i a t e l y p r i o r t o t h e BAT was a n a l y z e d w i t h a one-way a n a l y s i s o f c o v a r i a n c e * w i t h h e a r t r a t e a t t i m e 5 as t h e c o v a r i a t e . The sub j e c t s in t he two g r o u p s d i d not d i f f e r s i g n i f i c a n t l y w i t h r e s p e c t t o t h e i r h e a r t r a t e p r i o r t o t h e BAT (F (1, 72) = 0.15.- £ > .60). B e c a u s e t h e r e was h e t e r o g e n e i t y o f t he r e g r e s s i o n s l o p e s (F (1> 71) = 7.6.i £ < .01).i t h e a d j u s t e d means a r e no t p r e s e n t e d . H e a r t r a t e was a l s o s a m p l e d on s i x o c c a s i o n s d u r i n g t h e i n t e r v a l p r i o r to t h e l a s t B A T J w h i l e s u b j e c t s in t he a n x i o u s a r o u s a l g r oup were e x p o s e d t o t h e random shock c o n t i n g e n c y . T h e s e d a t a were e v a l u a t e d w i t h a 2 (Group 1 C o n t r o l vs A n x i o u s a r o u s a l ) by 6 ( T ime ) a n a l y s i s o f v a r i a n c e ? w i t h r e p e a t e d measure s on t he s e c o n d f a c t o r . T h e r e was a s i g n i f i c a n t main 3 7 f e e t o f gr cup. !' f, (1 • 7 3 ) = 5 12 ? £. < , 0 5 ) . T h e s u b j e c t s in a n x i o u s a r o u s a l g roup had s i g n i f i c a n t l y g r e a t e r h e a r t r a t e 91 T a b l e 9 Responses of s u b j e c t s on the a n x i o u s a r o u s a l measures at t ime 6 Group V a r i a b l e C o n t r o l A r o u s a l SD sp_ 1 A n x i e t y s u b s c a l e 22, ,9 21 .4 5Q . 1 2 4 . 3 S T A I 1 35, .4 9 . 7 4 8 . 8 11 .3 2 Hear t r a t e 73, , 8 I D . 7 7 2 . 1 7 .1 G r e a t e r v a l u e s i n d i c a t e g r e a t e r se I f - r e p o r t e d a n x i e t y . Measured in b e a t s per m i n u t e . ( M = 7 5 . 9 ) t h a n t h e s u b j e c t s i n t h e c o n t r o l g r o u p ( M = 71.6). e v a l u a t i n g t h e e f f e c t o f t i m e a n d t h e i n t e r a c t i o n o f t i m e a n d g r o u p t h e d e g r e e s o f f r e e d o m w e r e a d j u s t e d u s i n g t h e e p s i l a n a d j u s t m e n t p r o c e d u r e t h a t w a s d e s c r i b e d e a r l i e r ? r e s u l t i n g i n . 7 7 0 0 ( 5 ) = 3 . 8 a n d . 7 7 0 0 ( 5 X 7 4 ) = 2 8 4 . 9 d e g r e e s o f f r e e d o m . N e i t h e r t h e e f f e c t o f t i m e ( F ( 3 . 8 ? 2 8 4 . 9 ) = 1 . 2 3 ? P_ > . 2 5 ) n o r t h e i n t e r a c t i o n oi g r o u p a n d t i m e ( F ( 3 . 8 ? 2 8 4 . 9 ) = 1 . 6 9 ? p_ > . 1 5 ) w e r e s i g n i f i c a n t . I n s u m m a r y ? w i t h s e v e r a l m i n o r i n c o n s i s t e n c i e s ? t h e d a t a i n d i c a t e t h a t t h e a r o u s a l m a n i p u l a t i o n i n c r e a s e d b o t h s u b j e c t i v e a n d p h y s i o l o g i c a l i n d i c e s o f a n x i o u s a r o u s a l . A N A L Y S E S O F T H E E F F E C T S O F A N X I O U S A R O U S A L O N F E A R A n a l y s e s ' c o n c e r n i n g e a c h s e t o f p r e d i c t i o n s r e g a r d i n g f e a r l e v e l s w i l l b e p r e s e n t e d i n t h i s s e c t i o n . I n a l l o f t h e a n a l y s e s ? s e I f - r e p o r t e d l e v e l s o f f e a r ( S U D S s c a r e s ) w e r e e v a l u a t e d u s i n g e i t h e r u n i v a r i a t e t - t e s t s o r u n i v a r i a t e a n a l y s i s o f v a r i a n c e p r o c e d u r e s . H e a r t r a t e r e s p o n s e s w e r e a n a l y z e d u s i n g a n a l y s e s o f c o v a r i a n c e . H e a r t r a t e i m m e d i a t e l y p r i o r t o e a c h B A T ( i . e . ? r e s t i n g h e a r t r a t e ) w a s c o v a r i e d o u t i n t h e s e a n a l y s e s . I n o r d e r t o c o n t r o l f o r T y p e I e r r o r r a t e ? t h e c r i t i c a l l e v e l o f s i g n i f i c a n c e f o r e a c h u n i v a r i a t e t e s t w a s c a l c u l a t e d u s i n g t h e B o n f e r r o n i i n e q u a l i t y ( i . e . ? . 0 5 / 3 = . 0 1 7 ) . 4 2 O n e a c h a s s e s s m e n t o c c a s i o n ? t h r e e d e p e n d e n t v a r i a b l e s p e r t i n e n t t o f e a r ( S U D S s c o r e ? h e a r t r a t e r e s p o n s e ? s e l f -e f f i c a c y ) w e r e e v a l u a t e d . T h e r e s u l t s f o r t h e t h i r d d e p e n d e n t v a r i a b l e ? s e l f - e f f i c a c y ? w i l l b e p r e s e n t e d i n t h e n e x t s e c t i o n . 9 3 1 . F e a r l e v e l s p r i o r t o t h e a n x i o u s a r o u s a l m a n i p u l a t i o n ( F e a r a t t i me 1> . The l e v e l o f s e I f - r e p o r t e d f e a r o f s u b j e c t s i n t h e c o n t r o l and a n x i o u s a r o u s a l g r o u p s a t t i m e 1 w e r e c o m p a r e d u s i n g a u n i v a r i a t e t - t e s t . The s u b j e c t s i n t h e two g r o u p s w e r e n o t s i g n i f i c a n t l y d i f f e r e n t w i t h r e s p e c t t o t h e i r s e l f -r e p o r t e d l e v e l s o f f e a r ( t ( 7 4 ) = 0 . 6 5 > £ > . 5 0 ) . S u b j e c t s i n t h e c o n t r o l g r o u p r e p o r t e d a mean SUDS s c a r e a f 8 0 . 9 (SD = 8 . 2 ) and s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p r e p o r t e d a mean SUDS s c a r e o f 7 9 . 8 (SD = 8 . 1 ) . H e a r t r a t e r e s p o n s e was a n a l y z e d w i t h a o n e - w a y a n a l y s i s o f c o v a r i a n c e . ' w i t h h e a r t r a t e i m m e d i a t e l y p r i o r t o t h e BAT as t h e c o v a r i a t e . " 1 The two g r o u p s d i d n o t d i f f e r w i t h r e s p e c t t o t h e i r h e a r t r a t e r e s p o n s e a t t i m e 1 (F (1> 7 3 ) = 0 . 7 3 •> £ > . 3 0 ) . G r o u p means f o r h e a r t r a t e i m m e d i a t e l y p r i o r t o t h e BAT> h e a r t r a t e r e s p o n s e and a d j u s t e d h e a r t r a t e r e s p o n s e a t t i m e 2 a r e p r e s e n t e d i n T a b l e 1 0 . 2 . E f f e c t s o f a n x i o u s a r o u s a l on p r e - e x p o s u r e f e a r l e v e l ( F e a r a t t i me 2 ) . The l e v e l s o f s e I f — r e p o r t e d f e a r i n t h e a n x i o u s a r o u s a l and t h e c o n t r o l g r o u p s a t t i m e 2 w e r e c o m p a r e d u s i n g a u n i v a r i a t e t - t e s t . The s u b j e c t s i n t h e two g r o u p s were n o t s i g n i f i c a n t l y d i f f e r e n t w i t h r e s p e c t t o t h i s d e p e n d e n t v a r i a b l e (t . ( 7 4 ) = - 1 . 1 5 . > £ > . 2 5 ) . S u b j e c t s i n t h e c o n t r o l 5 I t may seem t h a t a n a l y s i s o f c o v a r i a n c e p r o c e d u r e s wi I I r emove t h a t e f f e c t o f t h e t r e a t m e n t . T h i s i s n o t t h e c a s e > h o w e v e r . i a s t h e i n d e p e n d e n t v a r i a b l e o f i n t e r e s t i s n o t t h e a n x i o u s a r o u s a l m a n i p u l a t i o n . R a t h e r ? t h e a n a l y s i s o f i - n t e r e s t e x a m i n e s t h e e f f e c t s o f e x p o s u r e t o t h e f e a r e d s t i m u l u s g i v e n t h e d i f f e r e n t l e v e l s o f t h e i n d e p e n d e n t v a r i a b l e . Table ID Mean i n i t i a l heart rate? heart rate response? and heart rate response adjusted for i n i t i a l heart rate at time 1 Group Variable Control Arousal SD SD 1 I n i t i a l heart rate 76. .5 11.5 77.0 12.3 1 Heart rate response 100 , .6 13.2 98.7 12.7 Adjusted.heart rate 1DD . 1 98.6 response Measured in beats per minute. g r o u p r e p o r t e d a mean SUDS s c o r e o f 5 7 . 0 ( S Q = 1 8 . 7 ) a n d s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p r e p o r t e d a mean SUDS s c o r e o f 6 1 . 7 ( SD = 1 8 . 4 ) . H e a r t r a t e r e s p o n s e wa s a n a l y z e d w i t h a o n e - w a y a n a l y s i s o f c o v a r i a n c e ? w i t h h e a r t r a t e i m m e d i a t e l y p r i o r t o t h e BAT a s t h e c o v a r i a t e . T h e t w o g r o u p s d i d n o t d i f f e r w i t h r e s p e c t t o t h e i r h e a r t r a t e r e s p o n s e a t t i m e 2 ( F (1i 7 3 ) = 3 . 0 7 ? £ > . 0 5 ) . G r o u p m e a n s f o r h e a r t r a t e i m m e d i a t e l y p r i o r t o t h e BAT ? h e a r t r a t e r e s p o n s e a n d a d j u s t e d h e a r t r a t e r e s p o n s e a t t i m e 2 a r e p r e s e n t e d i n T a b l e 1 1 . 2 . E f f e c t s o f a n x i o u s a r o u s a l d u r i n g f e a r r e d u c t i o n o n f e a r l e v e l i m m e d i a t e l y f o l l o w i n g f e a r r e d u c t i o n ( F e a r a t t i me 3 ) T h e SUDS s c o r e s r e p o r t e d b y s u b j e c t s i n t h e t w o g r o u p s a t t i m e 3 w e r e c o m p a r e d u s i n g a u n i v a r i a t e t - t e s t . T h e s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p r e p o r t e d s i g n i f i c a n t l y g r e a t e r f e a r (M = 4 1 . 3 ? SD = 2 2 . 0 ) t h a n d i d t h e s u b j e c t s i n t h e c o n t r o l g r o u p (M = 2 8 . 0 ? SD = 2 0 . 4 ) ( t ( 7 4 ) = - 2 . 7 3 ? £ < . 0 1 ) . H e a r t r a t e r e s p o n s e w a s e v a l u a t e d w i t h a o n e - w a y a n a l y s i s o f c o v a r i a n c e ? w i t h h e a r t r a t e i m m e d i a t e l y p r i o r t o t h e B A T a s t h e c o v a r i a t e . T h e r e w a s a s i g n i f i c a n t g r o u p d i f f e r e n c e ( F ( 1 ? 7 3 ) = 6 . 0 3 ? £ < . 0 1 7 ) . T h e s u b j e c t s i n t h e c o n t r o l g r o u p e x p e r i e n c e d s i g n i f i c a n t l y g r e a t e r h e a r t r a t e r e s p o n s e u p o n e x p o s u r e t o t h e s n a k e t h a n d i d t h e s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p . R e f e r t o T a b l e 1 2 f a r a p r e s e n t a t i o n o f mean s c o r e s f o r e a c h g r o u p . T a b l e 11' Mean i n i t i a l h e a r t rate., h e a r t r a t e response.' and h e a r t r a t e  r e s p o n s e a d j u s t e d f o r i n i t i a l h e a r t r a t e at t i m e 2 Group var i ab1e C o n t r o l Arousa1 M. SD M SD 1 I n i t i a l h e a r t r a t e 72.0 8.8 77.5 12. 1 1 H e a r t r a t e r e s p o n s e 71.3 13.4 91 .8 13.2 Ad justed., hear t r a t e r e s p o n s e 93.6 89.5 i M e asured in b e a t s per m i n u t e . Tab le 12 Mje_an i n i t i a l h e a r t ra te . ' h e a r t r a t e response.! and h e a r t r a t e re sponse a d j u s t e d f o r i n i t i a l h e a r t r a t e at t ime 3 Group V a r i a b l e C o n t r o l A r o u s a l d SD M SD 1 I n i t i a l h e a r t r a t e " 72 .3 7.4 78.7 9.5 1 Hear t r a t e re sponse 84 . 1 12.8 85.8 13.8 A d j u s t e d . h e a r t r a t e response 87 .8 82.2 Measured in bea t s per m inu te . 3 . E f f e c t s o f t h e r e m o v a l o f h e i g h t e n e d a n x i o u s a r o u s a l on f e a r I e ve I (Change i n f e a r b e t w e e n t i m e 3 and t i m e 4)= A two ( G r o u p : C o n t r o l v e r s u s A n x i o u s a r o u s a l ) by two ( T i m e : F o l l o w i n g f e a r r e d u c t i o n {T ime 33 v e r s u s F o l l o w i n g a n x i o u s a r o u s a l e q u a l i z a t i o n ( T i m e 4 ) ) u n i v a r i a t e a n a l y s i s o f v a r i a n c e w i t h r e p e a t e d m e a s u r e s on t h e s e c o n d f a c t o r was c o n d u c t e d w i t h t h e SUDS s c o r e d a t a . T h e r e was a s i g n i f i c a n t ma in e f f e c t o f g r o u p (F (1> 74 ) = 9 . 16 ? p < . 0 0 5 ) . The s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p (M = 35.0.< SD = 2 3 . 7 ) r e p o r t e d s i g n i f i c a n t l y g r e a t e r f e a r t h a n d i d s u b j e c t s i n t h e c o n t r o l g r o u p (M = 21.3. . SD = 1 9 . 2 ) . T h e r e was a l s o a s i g n i f i c a n t ma i n e f f e c t f o r t i m e (F (1> 74 ) = 9 6 . 4 5 J P < . • 0 0 1 ) . The s u b j e c t s r e p o r t e d s i g n i f i c a n t l y l e s s f e a r f o l l o w i n g a n x i o u s a r o u s a l e q u a l i z a t i o n (T ime 4) (M = 21.7> SD = 2 1 . 3 ) t h a n t h e y d i d f a l l o w i n g f e a r r e d u c t i o n ( T ime 3 ) (M = 34.7.1 SD = 2 2 . 1 ) . The i n t e r a c t i o n e f f e c t was n o t s i g n i f i c a n t (F < 1 .. 74 ) = 0 . 13.. P > . 70 ) . H e a r t r a t e r e s p o n s e was a n a l y z e d w i t h a two ( G r o u p : C o n t r o l v e r s u s A n x i o u s a r o u s a l ) by two ( T i m e : F a l l o w i n g f e a r r e d u c t i o n ( T i m e 33 v e r s u s F o l l o w i n g a n x i o u s a r o u s a l e q u a l i z a t i o n {T ime 43 ) a n a l y s i s o f c o v a r i a n c e w i t h r e p e a t e d m e a s u r e s on t h e s e c o n d f a c t o r . H e a r t r a t e i m m e d i a t e l y p r i o r t o e a c h BAT f u n c t i o n e d as t h e c o v a r i a t e i n t h e a n a l y s i s . T h e r e was a s i g n i f i c a n t ma in e f f e c t f o r t i m e (F (1.. 73 ) = 1 2 . 3 9 * £ < . 0 0 1 ) . The s u b j e c t s ' mean a d j u s t e d h e a r t r a t e r e p o n s e was s i g n i f i c a n t l y l e s s d u r i n g t h e f o u r t h BAT c o m p a r e d w i t h t h e t h i r d BAT. N e i t h e r t h e ma in e f f e c t o f g r o u p (F ( 1 , 7 3 ) = 4.41.1 £ > . 0 1 7 ) n o r t h e i n t e r a c t i o n o f g r o u p a n d t i m e (F„ ( 1 J 7 3 ) = 0 . 1 4 ? £ > . 7 0 ) we're' s i g n i f i c a n t . T h e m e a n s f o r h e a r t r a t e i m m e d i a t e l y p r i o r t o e a c h BAT ? h e a r t r a t e r e s p o n s e d u r i n g e a c h B A T ? a n d a d j u s t e d h e a r t r a t e r e s p o n s e a r e p r e s e n t e d i n T a b l e 1 3 . 5 . E f f e c t s o f a n x i o u s a r o u s a l d u r i n g f e a r r e d u c t i o n a n d a t f o l l o w - U P o n t h e r e t u r n o f f e a r . ( C h a n g e i n f e a r b e t w e e n t i m e 4 a n d t i m e 6)• T h e f o l l o w i n g p r e d i c t i o n s w e r e e v a l u a t e d w i t h t h r e e t w o -way u n i v a r i a t e a n a l y s e s o f v a r i a n c e a n d t w o t w o - w a y u n i v a r i a t e a n a l y s e s o f c o v a r i a n c e . I n o r d e r t o c o n t r o l t h e p r o b l e m o f e s c a l a t i n g T y p e I e r r o r r a t e a m o n g t h e u n i v a r i a t e a n a l y s e s ? t h e o v e r a l I e r r o r r a t e w a s s e t a t . 1 5 ( t h e sum o f t h e . 0 5 -e r r o r r a t e s f o r t h e t w o m a i n e f f e c t s a n d t h e i n t e r a c t i o n o f t h e m a i n e f f e c t s ) ( K i r k ? 1 7 8 2 ) . U s i n g t h e B o n f e r r o n i i n e q u a l i t y ? e a c h o f t h e 15 e f f e c t s ( t w o m a i n e f f e c t s a n d a n i n t e r a c t i o n e f f e c t i n e a c h o f t h r e e a n a l y s e s o f v a r i a n c e a n d t w o a n a l y s e s o f c o v a r i a n c e ) a s w e l l a s a n y s u b s e q u e n t s i m p l e e f f e c t s ( W i n e r ? 1 9 7 1 ) w e r e e v a l u a t e d a t t h e . 1 5 / 1 5 = .01 s i g n i f i c a n c e l e v e l . I n o r d e r t o e v a l u a t e t h e p r e d i c t i o n made b y d u a l p r o c e s s t h e o r y ( i . e . ? t h a t s u b j e c t s who a r e a r o u s e d a t f o l l o w - u p w i l l s h o w a s i g n i f i c a n t l y g r e a t e r i n c r e a s e i n f e a r b e t w e e n e x p o s u r e a n d f o l l o w - u p r e l a t i v e t.D s u b j e c t s who a r e n o t a r o u s e d a t f o l l o w - u p ) ? a t w o ( A n x i o u s a r o u s a l l e v e l d u r i n g t h e f o l l o w - u p a s s e s s m e n t : C o n t r o l v e r s u s A n x i o u s a r o u s a l ) b y t w o ( T i m e : T i m e 4 v e r s u s T i m e 6 ) u n i v a r i a t e a n a l y s i s o f v a r i a n c e w i t h r e p e a t e d T a b l e 13 Mean i n i t i a l h e a r t r a t e ? h e a r t r a t e r e s p o n s e and H e a r t r a t e r e s p o n s e a d j u s t e d t o r i n i t i a l h e a r t r a t e at t i m e 3 and t i m e 4 Group Time V a r i a b l e C o n t r o l A r o u s a l M SD ' SQ. I n i t i a l h e a r t r a t e 72. 3 7.4 78. 7 7.5 T i me 3 1 H e a r t r a t e r e s p o n s e 64. 1 12.8 85. 8 13.8 A d j u s t e d h e a r t r a t e r e s p o n s e 66. 1 82. 1 I I n i t i a l h e a r t r a t e 71 . 7 8.7 75. 2 10.3 T i me 4 H e a r t r a t e r e s p o n s e 8D . 6 12.3 82. 3 13.4 I A d j u s t e d h e a r t r a t e r e s p o n s e 83. 0 81 . 7 Measured in b e a t s per m i n u t e . 101 m e a s u r e s on t h e s e c o n d f a c t o r was c o n d u c t e d u s i n g t h e SUDS s c o r e s . A g r a p h i c r e p r e s e n t a t i o n o f t h e g r o u p means a t t i m e 4 and t i m e 6 i s p r e s e n t e d i n F i g u r e 2 . T h i s a n a l y s i s i n d i c a t e d t h a t t h e r e was n o t a s i g n i f i c a n t ma in e f f e c t o f g r o u p (F (1> 73) = 0 .22? £ > . 60 ) ? b u t t h e r e was a s i g n i f i c a n t ma in e f f e c t of t i m e (F (1? 73 ) = 17 .16 ? £ < . 0 D 0 1 ) . The s u b j e c t s r e p o r t e d s i g n i f i c a n t l y g r e a t e r f e a r a t f o l l o w - u p (M = 3 1 . 1 ? SO = 2 6 . 5 ) t h a n t h e y d i d a t t h e end o f t h e f i r s t s e s s i o n (M = 2 1 . 7 ? SD = 2 1 . 3 ) . The i n t e r a c t i o n o f g r o u p and t i m e was no t s t a t i s t i c a l l y s i g n i f i c a n t a t t h e .01 l e v e l (F (1? 73 ) = 6 .15 ? £ = . 0 1 5 ) . The e f f e c t o f a n x i o u s a r o u s a l l e v e l a t f o l l o w - u p on h e a r t r a t e r e s p o n s e was e v a l u a t e d u s i n g a two ( A n x i o u s a r o u s a l l e v e l d u r i n g t h e f o l l o w - u p a s s e s s m e n t : C o n t r o l v e r s u s A n x i o u s a r o u s a l ) by two ( T i m e : T ime 4 v e r s u s T ime 6) a n a l y s i s o f c o v a r i a n c e w i t h r e p e a t e d m e a s u r e s on t h e s e c o n d f a c t o r . H e a r t r a t e p r i o r t o e a c h BAT was u s e d as a c o v a r i a t e i n t h i s a n a l y s i s . The ma in e f f e c t o f g r o u p (F (1? 72 ) = 4 .15 ? £ > . 01 ) ? t i m e (F (1? 72 ) = 2.0D? £ > . 15 ) ? and t h e i n t e r a c t i o n o f g r o u p and t i m e (F (1? 72 ) = 0 .57 ? £ > .40 ) we re a l I n o n s i g n i f i c a n t . R e f e r t o T a b l e 14 f o r a p r e s e n t a t i o n o f t h e mean s c o r e s . In o r d e r t o e v a l u a t e t h e p r e d i c t i o n made by c o r t i c a l t h e o r y ? n a m e l y t h a t s u b j e c t s who a r e i n c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l d u r i n g f e a r r e d u c t i o n and a t f o l l o w - u p w i l l e v i d e n c e s i g n i f i c a n t l y l e s s r e t u r n o f f e a r t h a n wi I I s u b j e c t s who e x p e r i e n c e i n c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l on t h e two o c c a s i o n s ? a two ( G r o u p : C o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l v e r s u s I n c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l ) by two 102 Figure 2 Mean SUDQ scores at time 4 and time 6 for subjects in the control group and  anxious arousal group at follow-up s u D S S C 0 R E 50 45 40 35 30 25. 20 15_ 10 5_ 0 + Tin* 4 • Control • Arouse) f— Time 6 TIME 1D3 Table 14 Me.an init i a l heart rate? heart rate r esponse and heart rate response adjusted for in i t i a l heart rate at time 4 and t i me for subjects who were in the control and anx i ous arousa1 groups at f o i l O W - U P T i me Group Var i ab1e C :ont r o 1 Arousal M SD M S_Q 1 Initial heart rate' 73. 8 10.5 73.6 9.0 Time 4 1 Heart rate response 80 . 5 13.• 8Z. 6 12.9 1 Adjusted heart rate 80 . 1 82.3 response 1 Initial heart rate 73. 8 ID .7 72. 1 7.1 Time 6 1 Heart rate response 81 . 3 11.7 83.7 12.9 1 Adjusted heart rate 80 . 8 85. 1 response Measured in beats per minute. 104 ( T i m e : T ime 4. v e r s u s T i m e b) a n a l y s i s a f v a r i a n c e w i t h r e p e a t e d m e a s u r e s an t h e s e c o n d f a c t o r was c o n d u c t e d on t h e SUDS s c o r e s . The m a i n e f f e c t o f g r o u p was n o t s i g n i f i c a n t ( £ ( I J 7 3 ) = b.48J £ = . 0 1 3 ) J h o w e v e r j t h e r e was a s i g n i f i c a n t m a i n e f f e c t o f t i m e (F ( I J 7 3 ) = 1 9 . 9 6 ? £ < . • • • 1 ) . T h i s e f f e c t was q u a l i f i e d by a s i g n i f i c a n t i n t e r a c t i o n a f g r o u p and t i m e (F ( I J 7 3 ) = 7 . 2 Q J £ < . 0 1 ) . S u b s e q u e n t s i m p l e m a i n e f f e c t s a n a l y s e s i n d i c a t e d t h a t s u b j e c t s who e x p e r i e n c e d c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l d u r i n g t h e f i r s t s e s s i o n and a t f o l l o w - u p d i d n o t d i f f e r f r o m s u b j e c t s who e x p e r i e n c e d i n c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l w i t h r e s p e c t t o t h e i r r e p o r t e d f e a r a t t i m e 4 (F ( I J 9 8 . 9 ) = 1 . 0 7 ? £ > . 2 5 ) ; h o w e v e r j s u b j e c t s who e x p e r i e n c e d c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l r e p o r t e d s i g n i f i c a n t l y g r e a t e r f e a r a t t i m e b t h a n s u b j e c t s who e x p e r i e n c e d i n c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l on t h e two o c c a s i o n s (F ( I J 9 8 . 9 ) = 1 1 . 4 2 J £ < . 0 0 5 ) . A l t h o u g h s u b j e c t s wha e x p e r i e n c e d i n c o n g r u e n t s t a t e s of a n x i o u s a r o u s a l on t h e two o c c a s i o n s d i d n o t d i f f e r w i t h r e s p e c t t o t h e i r r e p o r t e d f e a r a t t i m e 4 c o m p a r e d w i t h t i m e 6 (F ( I J 74 ) = 1 . 0 4 ? £ > . 2 5 ) s u b j e c t s who e x p e r i e n c e d c o n g r u e n t s t a t e s o f a n x i o u s a r o u s a l d i d r e p o r t s i g n i f i c a n t l y g r e a t e r f e a r a t t i m e b c o m p a r e d w i t h t i m e 4 (F ( I J 72) = 27.79} £ < . 0 0 1 ) . R e f e r t o F i g u r e 3 f a r a g r a p h i c r e p r e s e n t a t i o n o f t h e g r o u p means a t t i m e 4 a n d t i m e b. In o r d e r t o e x a m i n e t h e s e f i n d i n g s f u r t h e r ? t h e s e d a t a w e r e s u b s e q u e n t l y a n a l y s e d w i t h an a n a l y s i s o f v a r i a n c e on t h e r e s i d u a l g a i n SUDS s c o r e s a t t i m e b w h i c h c o m p a r e d t h e r e s p o n s e s o f s u b j e c t s i n e a c h o f t h e f o u r g r o u p s ' 105 Figure 3 Mean SUDS scores at time 4 and time 6 for subjects i n congruent and incongruent  states of anxious arousalduring session 1 and session 2 106 c o n t r o l g roup - se s s i on 1> c o n t r o l g roup - se s s i on 2 (CC); c o n t r o l g roup - se s s i on 1> anxious arousa l g roup - se s s i on 2 (CA)> anxious arousa l g roup - se s s i on 1> c o n t r o l g roup - se s s i on 2 (AC); anxious arousa l g roup - se s s i on 1J anxious arousa l g r oup - se s s i on 2 (AA). Refer to Appendix E for a d e s c r i p t i o n of t h i s a n a l y s i s . The r e s u l t s i n d i c a t e d that the groups d i f f e r e d with respect, to t h e i r r e s i d u a l ga in scores (F (3; 71) = 6.65J £ < .001). The data were f u r t h e r ana lysed us ing Newman-KeuIs m u l t i p l e comparison p rocedures . The r e s u l t s of t h i s a n a l y s i s i n d i c a t e d that s u b j e c t s in group AC e x h i b i t e d s i g n i f i c a n t l y less r e t u r n of fear than p r e d i c t e d compared with s u b j e c t s in group AA ( £ < .001) or group CC ( £ < .01). Sub jec t s in group AC e x h i b i t e d less r e t u r n of fear than p r e d i c t e d compared with sub jec t s in group CA? however.! t h i s d i f f e r e n c e was not s i g n i f i c a n t ( £ = .015). None of the other d i f f e r e n c e s were s i g n i f i c a n t ( a l l £5 > .10). Refer to Tab le 15 for a p r e s e n t a t i o n of SUDS scores at time 4J time 6? and the r e s i d u a l ga in SUDS scores for sub jec t s in the four groups. T h e four groups were a l s o compared with re spec t to the p r o p o r t i o n of s u b j e c t s i n e a c h group who e x h i b i t e d r e t u r n o f f e a r ( d e f i n e d as an increase in s e l f - r e p o r t e d fear of at leas t 10 SUDS u n i t s between time 4 and time 6 ) . The r e s u l t s of a chi square t e s t i n d i c a t e d that the four groups d i f f e r e d s i g n i f i c a n t l y with respect to the p r o p o r t i o n of sub jec t s who exper ienced r e t u r n of fear ( (3> N = 75) = 14.72* £ < .01). Refer to Table 16 for a t abu la r p r e s e n t a t i o n of the percentage of s u b j e c t s in each of the four groups who exper ienced re tu rn of f e a r . Fo l l ow-up m u l t i p l e comparison 1 0 7 T a b l e 1 5 S U D S s c o r e s a t t i m e 4 •' t i m e 6 .> a n d r e s i d u a l g a i n S U D S s c a r e s  t o r s u b j e c t s i n t h e f o u r g r o u p s . G r o u p AC AA CC CA £1 S D M S D M S D f l S D S U D S s c a r e - 2 7 . 5 2 0 . 2 3 1 . 1 2 8 . 0 1 8 . 9 1 5 . 6 1 D . 0 1 4 . 1 T i m e 4 S U D S s c a r e - 2 1 . 9 1 6 . 5 4 9 . 2 2 9 . 6 3 2 . 6 2 4 . 8 2 1 . 6 2 5 . 8 T i me 6 R e s i d u a l - 1 4 . 1 1 0 . • 4 . 0 D . 7 g a i n s c o r e T a b l e 16 P r o p o r t i o n of s u b j e c t s i n each of t h e f o u r g r o u p s who showed r e t u r n of f e a r R e t u r n of f e a r No r e t u r n of f e a r AC & lui 11 (2) 8? (17> AA °k inl 67 (12) 33 (6) Group CC It i a ! 63 (12) 37 (7) CA 'A inl 47 (9) 53 (10) 1Q9 t e s t s o n t h e p r o p o r t i o n s i n d i c a t e d t h a t t h e p e r c e n t a g e o f s u b j e c t s who e x h i b i t e d r e t u r n o f f e a r wa s s i g n i f i c a n t l y s m a l l e r i n g r o u p AC c o m p a r e d w i t h g r o u p AA (P_ < . 0 0 1 ) o r g r o u p CC (p_ < . D 0 1 ) T h e p r o p o r t i o n o f s u b j e c t s i n g r o u p AC who e x h i b i t e d r e t u r n o f f e a r w a s s m a l l e r t h a n t h e p r o p o r t i o n o f s u b j e c t s i n g r o u p CA who e x h i b i t e d r e t u r n o f f e a r ? h o w e v e r ? t h i s d i f f e r e n c e w a s n o t s i g n i f i c a n t ( £ = . 0 3 ) . A l l o t h e r c o m p a r i s o n s w e r e n o n s i g n i f i c a n t ( a l l £ 5 > . 3 0 ) . T h e e f f e c t s o f c o n g r u e n c e o f a n x i o u s a r o u s a l b e t w e e n s e s s i o n s o n h e a r t r a t e r e s p o n s e w a s e v a l u a t e d u s i n g a t w o ( G r o u p : C o n g r u e n t v e r s u s I n c o n g r u e n t ) b y t w o ( T i m e 1 T i m e 4 v e r s u s T i m e 6 ) a n a l y s i s o f c o v a r i a n c e w i t h r e p e a t e d m e a s u r e s o n t h e s e c o n d f a c t o r . H e a r t r a t e p r i o r t o e a c h B A T w a s u s e d -as a c D v a r i a t e i n t h i s a n a l y s i s . N e i t h e r t h e m a i n e f f e c t o f t i m e ( F ( 1 ? 7 2 ) = 2 . 2 3 ? £ > . 1 0 ) ? t h e m a i n e f f e c t o f g r o u p ? ( F ( 1 ? 7 2 ) ~ 5 . 6 1 ? £ = . 0 2 ) ? n o r t h e i n t e r a c t i o n o f g r o u p b y t i m e ( F ( 1 ? 7 2 ) = 4 . 4 1 ? £ = . 0 4 ) w e r e s i g n i f i c a n t u s i n g t h e c o r r e c t e d a l p h a l e v e l . R e f e r t o F i g u r e 4 f o r a g r a p h i c r e p r e s e n t a t i o n o f t h e g r o u p m e a n s a t t i m e 4 a n d t i m e 6 . I n o r d e r t o e x a m i n e t h e s e f i n d i n g s f u r t h e r ? t h e s e d a t a w e r e s u b s e q u e n t l y a n a l y s e d w i t h a n a n a l y s i s o f v a r i a n c e o n t h e r e s i d u a l g a i n h e a r t r a t e r e s p o n s e s a t t i m e 6 . T h i s a n a l y s i s c o m p a r e d t h e r e s p o n s e s o f s u b j e c t s i n t h e f o u r g r o u p s ( C C v s . CA v s . AC v s . A A ) . H e a r t r a t e r e s p o n s e a t t i m e 6 ( a d j u s t e d f o r h e a r t r a t e i m m e d i a t e l y p r i o r tD t h e B A T ) was r e g r e s s e d on t h e a d j u s t e d h e a r t r a t e r e s p o n s e a t t i m e 4 . T h e s c o r e t h a t w o u l d b e p r e d i c t e d a t t i m e 6 f r o m t h e a d j u s t e d h e a r t r a t e r e s p o n s e a t t i m e 4 was t h e n c o m p u t e d . T h e r e s i d u a l a d j u s t e d h e a r t r a t e 110 Figure 4 Mean adjusted heart rate responses at time 4 and time 6 for subjects in congruent and incongruent states of anxious arousal during session 1 and session 2 I l l r e s p o n s e a t t i m e 6 w a s c o m p u t e d a s t h e d i f f e r e n c e b e t w e e n t h e a d j u s t e d h e a r t r a t e r e s p o n s e a t t i m e 6 a n d t h e p r e d i c t e d a d j u s t e d h e a r t r a t e r e s p o n s e a t t i m e b. T h e r e s u l t s i n d i c a t e d t h a t t h e r e s i d u a l h e a r t r a t e r e s p o n s e s o f s u b j e c t s i n t h e f o u r g r o u p s w e r e n o t s i g n i f i c a n t l y d i f f e r e n t ( F ( 3 > 7 1 ) = 2 . 7 5 > P_ = . 0 5 ) . T h e r e s i d u a l g a i n s c o r e s w e r e a s f o l l o w s : A C : M r e s = - 5 . 4 0 ; C A : M r e e = .74; C C » M r g s = 2 . 4 1 ; A A : - M r e s = 3 " 4 1 ' A N A L Y S I S O F T H E E F F E C T S O F A N X I O U S A R O U S A L O N S E L F - E F F I C A C Y 1 . E f f e c t o f a n x i o u s a r o u s a l o n s e l f - e f f i c a c y p r i o r t o f e a r r e d u c t i o n ( S e I f - e f f i c a c y a t t i m e 2)• T h e l e v e l s o f r e p o r t e d s e I f - e f f i c a c y a t t i m e 2 o f s u b j e c t s i n t h e c o n t r o l a n d a n x i o u s a r o u s a l g r o u p s w e r e c o m p a r e d u s i n g a t - t e s t . T h e s u b j e c t s i n t h e t w o g r o u p s d i d n o t d i f f e r <t ( 6 4 . 4 ) = 0 . 5 1 > £ > . 6 0 ) . S u b j e c t s i n t h e c o n t r o l g r o u p r e p o r t e d a m e a n l e v e l o f s e l f - e f f i c a c y o f 6 6 . 2 ( S D = 2 0 . 3 ) c o m p a r e d w i t h s u b j e c t s i n t h e a n x i o u s a r o u s a l g r o u p w h o r e p o r t e d a m e a n l e v e l o f s e l f - e f f i c a c y o f 6 3 . 2 ( S D = 3 0 . 4 ) . 2 . E f f e c t o f a n x i o u s a r o u s a l d u r i n g f e a r r e d u c t i o n o n s e l f -e f f i c a c y f o l l o w i n g f e a r r e d u c t i o n ( S e I f - e f f i c a c y a t t i m e 3 ) : T h e l e v e l s o f r e p o r t e d s e I f - e f f i c a c y a t t i m e 3 o f s u b j e c t s i n t h e t w o g r o u p s w e r e c o m p a r e d w i t h a t - t e s t . T h e s u b j e c t s i n t h e t w o g r o u p s d i d n o t d i f f e r ( t . ( 7 4 ) = 0 . 2 2 . ' £ > . 8 0 ) . S u b j e c t s i n t h e c o n t r o l g r o u p r e p o r t e d a m e a n l e v e l o f s e l f - e f f i c a c y o f 7 9 . 8 ( S D = 2 2 . 3 ) c o m p a r e d w i t h s u b j e c t s i n t h e a n x i o u s a r o u s a l group who r e p o r t e d a mean l e v e l of s e l f -e f f i c a c y of 78.7 (SD = 2 0 . 5 ) . 3. E f f e c t of the removal of h e i g h t e n e d a n x i o u s a r o u s a l on seI f - e f f i c a c y (Change in s e I f - e f f i c a c y between tim e 3 and t i m e 4 ) : S e l f - e f f i c a c y s c o r e s were a n a l y s e d u s i n g a two (Group: C o n t r o l v s . A n x i o u s a r o u s a l ) by two (Time: F a l l o w i n g f e a r r e d u c t i o n {Time 3} v s . Fa. I I aw i ng a n x i o u s a r o u s a l e q u a l i z a t i o n {Time 4}) u n i v a r i a t e a n a l y s i s of v a r i a n c e w i t h r e p e a t e d measures on t h e s e c o n d f a c t o r . T h e r e was a s i g n i f i c a n t main e f f e c t of t i m e (F (1? 74) = 13.57? p < .00D5). S u b j e c t s r e p o r t e d s i g n i f i c a n t l y g r e a t e r s e I f - e f f i c a c y at t i m e 4 (M = 88.0? SD = 18.3) compared w i t h t i m e 3 (M = 77.2? SD = 2 1 . 3 ) . N e i t h e r t h e u n i v a r i a t e main e f f e c t af group (F (1? 74) = 0.87? P > .35) nor t h e i n t e r a c t i o n of group and t i m e (F (1? 74) = 1.11? p > .25) were s i g n i f i c a n t . 4. E f f e c t of a n x i o u s a r o u s a l at f o l l o w - u p on s e I f - e f f i c a c y (Change in se I f - e f f i c a c y between tim e 4 and t i m e 6) •• The r e s u l t s of a two ( A n x i o u s a r o u s a l l e v e l d u r i n g t h e f o l l o w - u p a s s e s s m e n t : C o n t r o l v s . A n x i o u s a r o u s a l ) by two (Time: Time 4 vs Time 6) u n i v a r i a t e a n a l y s i s of v a r i a n c e w i t h r e p e a t e d measures on t h e s e c o n d f a c t o r i n d i c a t e d t h a t t h e r e was not a s i g n i f i c a n t main e f f e c t of group (F (1? 73) = 4.27? £ > .01). T h e r e was a s i g n i f i c a n t main e f f e c t af time <F (1? 73) = 7.87? £ < .01). S u b j e c t s r e p o r t e d s i g n i f i c a n t l y l e s s s e I f - e f f i c a c y at f o l l o w - u p (M = 80.8? SD = 18.2) compared w i t h the end of t h e f i r s t s e s s i o n (M = 87.9? SD = 1 8 . 4 ) . The i n t e r a c t i o n of group and time was not s i g n i f i c a n t (F ( 1? 73) 113 = D.9QJ £• > - 3 0 ) . R e f e r t o T a b l e 17 f o r a p r e s e n t a t i o n of mean s e i f - e f f i c a c y s c o r e s of s u b j e c t s in t h e two g r o u p s a t t h e end of t h e f i r s t s e s s i o n and at f o l l o w - u p . T a b l e 17 Mean s e I f - e f f i c a c y s c a r e s a t t i m e 4 and t i m e 6 of s u b j e c t s in  tKe c o n t r o l and a n x i o u s a r o u s a l g r o u p s at f o l l o w - u p Group Time C o n t r o l A r o u s a l at f o l l o w - u p at f o l l o w - u p .a 1 BD M1 SD T i me 4 1 90.0 11 . • 85.3 23.7 T i me 61 85.3 13.7 76.1 21 .0 G r e a t e r v a l u e s i n d i c a t e g r e a t e r r e p o r t e d s e l f - e f f i c a c y . 115 DISCUSSION The effectiveness of the experimental manipulation on measures of anxious arousal i s discussed f i r s t i n t h i s chapter. This i s followed by discussions regarding the e f f e c t of anxious arousal on fear, fear reduction, and the return of fear. The impact of anxious arousal on s e l f -e f f i c a c y expectations i s considered next. This i s followed by a discussion of the t h e o r e t i c a l and c l i n i c a l implications of the findings. The chapter concludes with a summary of the findings and suggested directions for future research. EVALUATION OF THE EXPERIMENTAL MANIPULATION Several predictions were made regarding the e f f e c t s of the experimental manipulation on the subjects' l e v e l of anxious arousal. As predicted, the subjects i n the two groups did not d i f f e r on any of the three measures of anxious arousal p r i o r to the anxious arousal manipulation during the f i r s t session. Also as predicted, the anxious arousal manipulation e f f e c t i v e l y increased self-reported l e v e l s of anxious arousal and heart rate p r i o r to the fear reduction procedure and immediately following the procedure. Subjects who were i n the anxious arousal group also experienced increased heart rate during the fear reduction procedure r e l a t i v e to the subjects i n the control group. The one exception to these findings was with respect to a nonsignificant difference between the two groups on the anxiety subscale of the Mood Scale following fear reduction. However, although the subjects i n the two groups did not 116 d i f f e r on t h i s measure, the difference was i n the expected d i r e c t i o n and approached si g n i f i c a n c e (p = .03). The anxious arousal manipulation was more robust than expected i n the sense that residual anxious arousal e f f e c t s were s t i l l apparent following the anxious arousal equalization period. Although the subjects i n the two groups were not s i g n i f i c a n t l y d i f f e r e n t on the three measures of anxious arousal at t h i s time, t h e i r responses on the STAI and t h e i r resting heart rate indicated a tendency for the subjects who were previously anxiously aroused to continue to be anxiously aroused r e l a t i v e to the subjects i n the control group. This reduces the l i k e l i h o o d of i d e n t i f y i n g differences that are dependent on changes i n anxious arousal l e v e l . As predicted, subjects who were i n the control and anxious arousal groups during session 2 did not d i f f e r on the three measures of anxious arousal p r i o r to the anxious arousal manipulation. As i n session 1, implementation of the anxious arousal manipulation during the second session resulted i n subjective reports of increased anxious arousal for the subjects i n the anxious arousal group compared with the subjects i n the control group. The subjects i n the anxious arousal group also experienced greater heart rate during the six minute i n t e r v a l p r i o r to the BAT, while they were exposed to the random shock contingency, than did the subjects i n the control group; however, the two groups did not d i f f e r with respect to heart rate immediately p r i o r to 117 the BAT. I t i s not e n t i r e l y clear why there i s t h i s inconsistency, however, two possible explanations are apparent. F i r s t l y , heart rate was sampled on s i x occasions during the six minute i n t e r v a l compared with one sample of heart rate which was taken immediately p r i o r to the BAT, r e s u l t i n g i n the p r i o r data set being more r e l i a b l e . Secondly, during the six minute i n t e r v a l , subjects were ac t u a l l y exposed to the random shocks; the subjects were not t o l d that the random shock contingency was no longer i n e f f e c t immediately p r i o r to the BAT but i t may be that t h e i r previously elevated heart rate had decreased as a r e s u l t of not receiving any shocks during the previous several minutes. In summary, although there are several minor inconsistencies, the data indicate that the anxious arousal manipulation successfully increased both subjective and phy s i o l o g i c a l indices of anxious arousal. This i s consistent with p r i o r research that has found threat of shock to be an e f f i c a c i o u s method of increasing anxious arousal (e.g., Bohlin, 1976; Briush & Schwartz, 1980; Carrol & Pokora, 1976; Watts, 1975). EFFECTS OF ANXIOUS AROUSAL ON FEAR Results pertinent to the e f f e c t s of anxious arousal on fear, fear reduction, and the return of fear w i l l be discussed i n the following three subsections. 118 E f f e c t s of anxious arousal on within-session changes i n fear I t was predicted based on dual process theory (e.g., Groves & Thompson, 1970; Thompson et a l . , 1979; Thompson et a l . , 1973; Thompson & Spencer, 1966) that changes i n anxious arousal l e v e l would influence fear l e v e l s . S p e c i f i c a l l y , i t was predicted that fear l e v e l s would increase given increases i n anxious arousal, and decrease given decreases i n anxious arousal. I t was found that neither increases i n anxious arousal p r i o r to fear reduction nor decreases i n anxious arousal following fear reduction s i g n i f i c a n t l y influenced either self-reported l e v e l s of fear or heart rate response upon exposure to the feared stimulus. Thus, i t can be concluded that there i s no support for the prediction based on dual process theory that l e v e l of anxious arousal influences fear within-session. This r e s u l t i s problematic for dual process theory as the prediction that increased s e n s i t i z a t i o n (or, to use the terminology adopted i n the present study "anxious arousal") w i l l r e s u l t i n increased general responsiveness i s a fundamental aspect of t h i s theory. However, the relationship between anxious arousal l e v e l and responsiveness has been documented i n several 5 Because the two groups were not completely equivalent with respect to t h e i r arousal l e v e l s following the anxious arousal equalization period, the evaluation of the e f f e c t of reductions i n anxious arousal i s not as cogent a t e s t of t h i s prediction as would be desired. However, given that there i s not any evidence of a trend to support t h i s p r e d i c t i o n (both p_s for s e l f reported fear and heart rate response are greater than .70) i t i s u n l i k e l y that t h i s r e s u l t would d i f f e r s u b s t a n t i a l l y given greater equivalence between the two groups following arousal equalization. 119 studies (e.g., Edwards & Siddle, 1976; Groves & Thompson, 1970; McKubbin & Katkin, 1971; Rust, 1976; Thompson & Siddle, 1966) and i t appears that the e f f e c t i s a r e l a t i v e l y robust one. Consequently, the theory i s not seriou s l y disputed by t h i s finding. There are two possible explanations to account for the i n a b i l i t y to r e p l i c a t e t h i s f i nding i n the current study. F i r s t l y , i t may be that the experimental manipulation was i n e f f e c t i v e i n changing anxious arousal l e v e l . This p o s s i b i l i t y i s unl i k e l y , however, as the present study used a manipulation that seems more potent than other manipulations (e.g., low i n t e n s i t y tone, l i g h t stimulus) that have found an e f f e c t . Furthermore, the manipulation had the intended e f f e c t with respect to both self-reported anxious arousal l e v e l and heart rate. The second p o s s i b i l i t y concerns the type of stimulus and responses studied. Prio r researchers have used habituating s t i m u l i (e.g., auditory tones, single shock pulses) and responses (e.g., skin conductance response, hind limb f l e x i o n r e f l e x , s t a r t l e reflex) that have d i f f e r e d r a d i c a l l y from those used i n the current study, and the clearest r e s u l t s have been obtained from nonhuman subjects. The s t i m u l i t y p i c a l l y used i n habituation studies d i f f e r from the stimulus used i n the current study i n at lea s t two fundamental respects. F i r s t of a l l , the snake stimulus i s a more complex stimulus than the sti m u l i used i n other studies and secondly, i t has, i n i t i a l l y at least, a negative 120 a f f e c t i v e valence ( i . e . , subjects are f e a r f u l of the stimulus). As well as the differences i n s t i m u l i , there are differences i n the responses that were assessed. S e l f -reported fear i s a more complex response than that t y p i c a l l y assessed. An individual's self-reported fear l e v e l and the magnitude of his or her heart rate response depends on a number of attentional and cognitive operations and evaluations. Although there was a high degree of experimental control for a study of t h i s type, the current study does not allow the degree of experimental precision that has been achieved i n previous habituation studies. I t would be impossible to achieve the degree of control that can be achieved i n other studies that have used d i f f e r e n t s t i m u l i , responses, and experimental preparations. Although the r e s u l t s of the current study do not invali d a t e dual process theory, they do question i t s g e n e r a l i z a b i l i t y to human fear responses to exposure to a feared stimulus. C o r t i c a l theory (e.g., Wagner, 1976; Whitlow, 1975; Whitlow & Wagner, 1984) does not accord a s i g n i f i c a n t role to the e f f e c t s of anxious arousal per se on fear. However, i t was predicted based on t h i s theory that increases i n anxious arousal p r i o r to fear reduction would r e s u l t i n the feared stimulus being less l i k e l y to be cued i n memory p r i o r to the BAT, which would r e s u l t i n an increase i n fear r e l a t i v e to subjects i n the control group who were not exposed to the feared stimulus under conditions of anxious arousal. It should be noted that although the rationale for 121 t h i s prediction d i f f e r s from that of dual process theory, the prediction i s the same. I t was found that exposure to the anxious arousal inducing stimulus p r i o r to fear reduction did not a f f e c t the le v e l s of fear as assessed either through s e l f - r e p o r t or heart rate response. I t was also predicted based on c o r t i c a l theory that the removal of anxious arousal which was present during fear reduction would r e s u l t i n an increase i n fear r e l a t i v e to subjects who experienced fear reduction under conditions of normal arousal. The reason for t h i s prediction was that anxious arousal functions as a memory cue to prime the feared stimulus into short term memory. The subjects who were previously anxiously aroused experienced a greater degree of incongruence i n anxious arousal l e v e l between fear reduction and l a t e r assessment than did subjects i n the control group and thus the feared stimulus w i l l be less primed i n memory upon exposure to the actual stimulus. This prediction d i f f e r s from that based on dual process theory. I t was found that the degree of congruence i n anxious arousal l e v e l did not have any e f f e c t on either measure of fear. Thus, t h i s prediction i s not supported. This f a i l u r e to f i n d an e f f e c t of anxious arousal i s problematic for c o r t i c a l theory but does not necessarily invalidate the theory. It i s possible that other contextual cues were used to prime the stimulus into short term memory. A l l aspects of the experimental s i t u a t i o n , other than anxious arousal l e v e l state, were held constant. I f these other contextual factors were the s a l i e n t 122 ones for the i n d i v i d u a l , then, as was found i n the current study, differences i n fear response would not be expected as a r e s u l t of changes i n anxious arousal l e v e l . Thus, although . i t can be concluded from these r e s u l t s that anxious arousal state was not an important cue used to prime the feared stimulus into short term memory, i t cannot be concluded that the priming process per se i s not important i n determining l e v e l of fear response upon exposure to feared s t i m u l i . As well, the current discussion concerns short term within-session (rather than long term) influences of anxious arousal on fear. E f f e c t s of anxious arousal on fear reduction Both dual process theory and c o r t i c a l theory predict that subjects who experienced anxious arousal during fear reduction would experience s i g n i f i c a n t l y greater fear following fear reduction ( i . e . , s i g n i f i c a n t l y less fear reduction) than would subjects who did not experience anxious arousal during fear reduction. Both theories make t h i s prediction based on the fact that anxious arousal r e s u l t s i n a d i s t r a c t i o n of attention away from the feared stimulus, r e s u l t i n g i n less functional exposure (Borkovec & Grayson, 1980) and emotional processing (e.g., Foa & Kozak, 1985, 1986; Lang, 1977; Rachman, 1980) than would occur given lower l e v e l s of anxious arousal. Dual process theory, i n addition, explains t h i s e f f e c t as due to an increase i n general responsiveness at the time of assessment as a r e s u l t of the anxious arousal. However, as discussed previously, 123 neither decreases nor increases i n anxious arousal had any impact on fear l e v e l s within-session and, consequently, any differences that resulted from anxious arousal during fear reduction are not l i k e l y due simply to increased anxious arousal causing an increase i n fear. A very i n t e r e s t i n g pattern of re s u l t s emerged. The pred i c t i o n made by these two theories was supported with respect to self-reported fear. Fear reduction treatment that occurred while the ind i v i d u a l was i n a state of anxious arousal resulted i n less fear reduction ( i . e . , greater fear following exposure treatment) than did occur under conditions i n which less anxious arousal was present. This finding i s congruent with previous research that has found that anxious arousal during habituation t r a i n i n g impedes habituation (e.g., Bohlin, 1976; Carrol & Pokora, 1976; Goldwater & Lewis, 1978; Lader & Wing, 1964). The opposite pattern was found with respect to heart rate response. The subjects who experienced anxious arousal during fear reduction exhibited less heart rate response upon exposure to the feared stimulus following fear reduction. This finding i s contrary to the prediction made by the dual process and c o r t i c a l theories. I t seems peculiar that treatment conditions that f a c i l i t a t e d the reduction of self-reported l e v e l s of fear would i n h i b i t the reduction of heart rate response. The subjects i n both groups experienced heart rate responses that were of approximately the same magnitude (M = 84.1 for the subjects i n the control group 124 versus 85.8 for the subjects i n the anxious arousal group). The difference i n response i s accounted for by the s i g n i f i c a n t difference i n t h e i r r esting heart rates: the subjects i n the control group had a resting heart rate of 72.3 compared with a resting heart rate of 78.7 for subjects i n the anxious arousal group. Although the responses of the subjects i n the two groups were of the same magnitude, the amount of change upon exposure to the feared stimulus was greater for subjects who were i n the control group. This finding i s a clear example of discordance (Hodgson & Rachman, 1974; Rachman & Hodgson, 1974) between the s e l f -report and physiological (as indexed by heart rate response) components of fear. If heart rate response i s seen s o l e l y as a measure of fear, t h i s finding seems unusual. I f , instead, i t i s viewed as an index of attention to the stimulus and of emotional processing (Foa & Kozak, 1985, 1986; Lang, 1977, 1985; Rachman, 1980) the r e s u l t seems reasonable. The subjects i n the control group were in a r e l a t i v e l y calm, nonanxious state p r i o r to exposure to the feared stimulus. Upon exposure to the stimulus, they were able to f u l l y attend to the stimulus and, consequently, responded with a moderate heart rate response. In contrast, the subjects i n the anxious arousal group were more anxiously aroused p r i o r to exposure to the feared stimulus (as evidenced by t h e i r greater resting heart rate and higher self-reported anxious arousal level) than were the subjects i n the control group. Consequently, i t i s conjectured that they were l i k e l y 125 v i g i l a n t regarding the anxious arousal inducing stimulus, focussing on int e r n a l sensations of anxious arousal, and experiencing in t r u s i v e cognitions of a worrisome nature. As a r e s u l t of these processes they did not l i k e l y attend to the feared stimulus during the BAT as f u l l y as did the subjects i n the control group. Consequently, the magnitude of t h e i r heart rate responses was not as great. I t should be noted that t h i s explanation i s speculative and needs empirical investigation. This finding i s remarkably s i m i l a r to that which was recently reported by Borkovec and Hu (1990). They examined the e f f e c t s of worry on fear induced by imaginally presented phobic scenes. They found that although worry p r i o r to v i s u a l i z a t i o n resulted i n greater self-reported fear i n response to v i s u a l i z a t i o n , less heart rate response occurred compared with subjects who were not worried p r i o r to v i s u a l i z a t i o n . The authors concluded that, to the degree that cardiovascular reaction r e f l e c t s emotional processing, the present outcome suggests that worry may i n h i b i t the processing of phobic material and thus r e s u l t i n a maintenance of the c o g n i t i v e / a f f e c t i v e fear structure despite repeated exposures. It does so without a f f e c t i n g the strong subjective fears that the person reports i n response to the phobic presentations. (P- 72) The present study d i f f e r s from Borkovec and Hu's i n several respects. They used imaginal s t i m u l i as opposed to in vivo s t i m u l i , and they induced task relevant worry rather than anxious arousal. The r e l a t i o n s h i p between anxious arousal and worry i s an i n t e r e s t i n g one that w i l l be 126 discussed i n a l a t e r section. In spite of these differences, the above conclusion seems applicable to the current study. The above r e s u l t s suggest two important fact s . F i r s t of a l l , high l e v e l s of anxious arousal impede the emotional processing of feared s t i m u l i and fear reduction. Secondly, the amount of heart rate response upon exposure to the feared stimulus ( i . e . , the magnitude of change) may be an index of emotional processing and fear reduction. As w i l l be discussed l a t e r , these r e s u l t s have important t h e o r e t i c a l and c l i n i c a l implications. E f f e c t s of anxious arousal on the return of fear The r e s u l t s regarding the e f f e c t s of anxious arousal during fear reduction and at follow-up on the return of fear w i l l now be discussed. It was predicted based on dual process theory that the subjects who were anxiously aroused at follow-up would show a s i g n i f i c a n t l y greater increase i n fear between the two sessions ( i . e . , s i g n i f i c a n t l y more return of fear) than would the subjects who were not anxiously aroused at follow-up. This prediction was made based on the t h e o r e t i c a l premise that experiencing anxious arousal r e s u l t s i n an increase i n general responsiveness as indexed by the two measures of fear. The o v e r a l l i n t e r a c t i o n did not support t h i s prediction (p_ = .015). The r e s u l t s of a subsequent data analysis, which w i l l be discussed shortly, allow a more complex interpretation of these r e s u l t s . Anxious arousal at follow-up did not have a s i g n i f i c a n t e f f e c t on heart rate response. These r e s u l t s do not support 127 the p r e d i c t i o n of dual process theory. The finding of s i g n i f i c a n t differences with respect to self-reported fear (as w i l l be discussed l a t e r ) , but not with heart rate response r e f l e c t s the fact of d i f f e r e n t i a l response system s e n s i t i v i t y (Agras & Jacob, 1971) and i s congruent with other studies that have found a s i m i l a r discrepancy between self-reported fear and heart rate (e.g., Craske & Rachman, 1987). I t was predicted, based on c o r t i c a l theory, that the subjects who experienced congruent states of anxious arousal during the two sessions would evidence s i g n i f i c a n t l y less return of fear than would the subjects who experienced incongruent states of arousal. This prediction i s based on the t h e o r e t i c a l premise that anxious arousal functions as a memory cue that primes the representation of the feared stimulus into short term memory. Contrary to t h i s prediction, the subjects who experienced congruent, rather than incongruent, states of anxious arousal on the two occasions showed a s i g n i f i c a n t increase i n self-reported fear across the follow-up i n t e r v a l . The r e s u l t s regarding the heart rate response data were not s i g n i f i c a n t but suggested a s i m i l a r pattern of r e s u l t s : subjects who experienced congruent states of anxious arousal on the two occasions showed an increase i n the magnitude of t h e i r heart rate response across the follow-up i n t e r v a l compared with subjects who experienced incongruent states of anxious 128 arousal, who did not exhibit any change across the follow-up i n t e r v a l . These puzzling findings were the impetus of a further set of analyses that examined the pattern of change for a l l four groups of subjects: those who were i n the control group during both sessions (CC), those who were i n the control group during one session and i n the anxious arousal group during the other session (CA or AC), and those who were i n the anxious arousal group during both sessions (AA). The subjects i n three of the groups (AA, CC, CA) showed an increase i n self-reported fear across the follow-up i n t e r v a l , e xhibiting return of fear, as would be expected. These three groups did not d i f f e r s i g n i f i c a n t l y with respect to the mean amount of return of fear that they exhibited. In contrast, the subjects who were anxiously aroused during exposure treatment, but not at follow-up (AC), showed a decrease i n subjective fear across the follow-up i n t e r v a l . Refer back to Table 15 for a presentation of these mean scores. An analysis of the proportion of subjects i n each of the four groups was congruent with t h i s finding. Only 11 percent of subjects who were aroused during exposure treatment but not at follow-up experienced a return of fear, compared with 47 to 67 percent of the subjects i n the other three groups. A si m i l a r analysis using the residual heart rate response data was not s i g n i f i c a n t (p_ = .05) but showed a s i m i l a r configuration as was found with the self-reported fear data ( i . e . , the subjects i n group AC exhibited a lesser 129 heart rate response than expected, while the subjects i n the other three groups exhibited a greater heart rate response than expected). Thus, the two e a r l i e r conclusions, namely that anxious arousal at follow-up does not influence the return of fear, and that there i s greater return of fear given congruent, as compared to incongruent, states of anxious arousal, are not e n t i r e l y correct and must be q u a l i f i e d . Increased anxious arousal at the time of follow-up does not r e s u l t i n increased return of fear. Rather, the f l i p s i d e of t h i s proposition seems more appropriate: follow-up assessment i n a calm state following exposure while i n a state of anxious arousal impedes the return of subjective fear and, i n fact, r e s u l t s i n a substantial decrement i n the fear response. This finding cannot be explained simply on the basis of anxious arousal l e v e l at the time of follow-up assessment as would be predicted on the basis of dual process theory. I f t h i s were the case, i n the subsequent analysis of the four groups, the two groups experiencing anxious arousal at follow-up would show greater return of fear than the subjects who were i n a r e l a t i v e l y calm state on both occasions. Yet, these three groups did not d i f f e r . On the other hand, i f the amount of return of fear was p a r t i a l l y accounted for by anxious arousal l e v e l at the time of follow-up, as would be predicted on the basis of dual process theory, and given that there was s t i l l r esidual anxious arousal present during the f i n a l assessment during session one, i t would be predicted that group AC would show 130 the least amount of return of fear. This i s what was found. Thus, t h i s pattern of r e s u l t s o f f e r s p a r t i a l support for dual process theory. The r e s u l t s cannot be explained i n terms of c o r t i c a l theory. Congruence i n anxious arousal state does not impact on the return of fear. Although the i n i t i a l evaluation of congruence e f f e c t s suggested an e f f e c t that was opposite to that predicted on the basis of the theory, the subsequent analysis indicated that i t was a state of incongruence of a s p e c i f i c type, anxious arousal during fear reduction and nonanxious arousal at follow-up, that promoted further habituation of fear. C o r t i c a l theory does not make any allowances for t h i s type of asymmetry. Thus, t h i s theory cannot, except perhaps through some t h e o r e t i c a l gymnastics, explain t h i s finding. Craske and Rachman (1987) found that elevated heart rate p r i o r to treatment did not influence fear reduction but i t did r e s u l t i n increased return of subjective fear. The present study found, i n contrast to Craske and Rachman, that anxious arousal impeded the reduction of fear. I t i s unclear why the current study found an e f f e c t , but a number of methodological differences may account for t h i s discrepancy. For example, the nature of the fear, the source of the anxious arousal, and the treatment a l l d i f f e r e d . Craske and Rachman concluded that heightened heart rate p r i o r to treatment resulted i n increased return of fear, however, the pattern of r e s u l t s i n these two studies do not exclude the 131 p o s s i b i l i t y that anxious arousal l e v e l during treatment and at follow-up may i n t e r a c t i v e l y influence the return of fear. Rachman and Whittal (1989a) were unable to f i n d evidence of increased return of fear as a r e s u l t of anxious arousal at follow-up. As mentioned previously, t h e i r t e s t was not a cogent one as t h e i r manipulation did not increase heart rate. However, i t may also be due i n part to the fact that a l l of the subjects experienced fear reduction i n an equivalent state of anxious arousal. EFFECTS OF ANXIOUS AROUSAL ON SELF-EFFICACY EXPECTATIONS Several predictions regarding the e f f e c t of anxious arousal on s e l f - e f f i c a c y expectations were made on the basis of Bandura's (1977, 1978, 1982, 1986) s e l f - e f f i c a c y theory. There was an absence of support for these predictions. Each prediction w i l l be discussed i n turn. I t was predicted that the subjects who were anxiously aroused during the f i r s t session would report s i g n i f i c a n t l y less s e l f - e f f i c a c y r e l a t i v e to the subjects i n the control group p r i o r to fear reduction. This prediction was based on the t h e o r e t i c a l premise of s e l f - e f f i c a c y theory that increased anxious arousal i s a source of information i n d i c a t i n g to the individual that he or she i s currently vulnerable to stress which may impede coping a b i l i t i e s . The subjects i n the two groups did not d i f f e r with respect to the magnitude of t h e i r reported s e l f - e f f i c a c y expectations. I t was also predicted that the subjects who were anxiously aroused during fear reduction, and who continued 132 to be anxiously aroused during the subsequent assessment, would report decreased s e l f - e f f i c a c y r e l a t i v e to the subjects i n the control group. The reason for t h i s p r e d i c t i o n was two-fold. F i r s t l y , the experience of anxious arousal throughout fear reduction would r e s u l t i n decreased functional exposure and would disrupt the development of s e l f - e f f i c a c y expectations. Secondly, to the extent that anxious arousal at the time of assessment i s a source of information to the individual that he or she i s vulnerable / to stress, there should be a further decrease i n s e l f -e f f i c a c y . The subjects i n the two groups did not d i f f e r with respect to t h e i r reported s e l f - e f f i c a c y expectations following exposure treatment. I t was predicted that the subjects who experienced an a l l e v i a t i o n of anxious arousal would show an increase i n s e l f - e f f i c a c y r e l a t i v e to the subjects i n the control group. It was found that although the subjects i n both groups reported an increase i n s e l f - e f f i c a c y expectations across the time i n t e r v a l , there was not any evidence of a d i f f e r e n t i a l increase. The f i n a l prediction concerned the e f f e c t of anxious arousal at follow-up on s e l f - e f f i c a c y . It was predicted that the subjects who were anxiously aroused at follow-up would evidence a larger decrease i n s e l f - e f f i c a c y across the follow-up i n t e r v a l than would the subjects i n the control group. The subjects i n both groups experienced a decline i n the magnitude of t h e i r s e l f - e f f i c a c y expectations across the, 133 follow-up i n t e r v a l , however, the magnitude of t h i s decline did not d i f f e r between the two groups. In summary, the re s u l t s suggest that a state of anxious arousal, which Bandura (1977, 1978, 1982, 1986) states i s one of the four types of information on which s e l f - e f f i c a c y judgements are made, did not have any influence on s e l f -e f f i c a c y expectations. This study i s the f i r s t empirical attempt to examine the role of changes i n anxious arousal on s e l f - e f f i c a c y and i s consistent with previous research that did not f i n d a relationship between pre-existing l e v e l s of anxious arousal and s e l f - e f f i c a c y (Craske & Rachman, 1987; F e l t z , 1982; Williams & Watson, 1985) but inconsistent with the two studies that did report such a r e l a t i o n s h i p (Williams et a l . , 1984; Williams et a l . , 1985). Several methodological arguments may be made regarding why there was an absence of an e f f e c t . F i r s t , perhaps anxious arousal did not have an e f f e c t on s e l f - e f f i c a c y because the measure was not s e n s i t i v e . This argument does not seem v a l i d as there were highly s i g n i f i c a n t changes i n s e l f - e f f i c a c y across assessment occasions that were i n the expected d i r e c t i o n ( i . e . , s e l f - e f f i c a c y expectations increased during the f i r s t session with repeated exposures to the feared stimulus and decreased s i g n i f i c a n t l y across the follow-up i n t e r v a l ) . Further, as has been found i n other studies (e.g., Bandura & Adams, 1977; Williams et a l . , 1984; Williams et a l . , 1985), a s i g n i f i c a n t inverse r e l a t i o n s h i p between self-reported fear and l e v e l of s e l f - e f f i c a c y was 134 noted. The subjects' s e l f - e f f i c a c y expectations showed highly s i g n i f i c a n t change as a r e s u l t of experience with the feared stimulus and showed an inverse r e l a t i o n s h i p with l e v e l of self-reported fear. In spite of t h i s , t h e i r s e l f -e f f i c a c y expectations were not influenced by generalized changes i n anxious arousal l e v e l . I t i s i n t e r e s t i n g to note that i n s p i t e of the fact that experiencing anxious arousal during fear reduction disrupted fear reduction, i t did not have any impact on s e l f - e f f i c a c y expectations. Given the close r e l a t i o n s h i p between fear and s e l f - e f f i c a c y that has been claimed (e.g., Bandura & Adams, Bandura et a l . , 1977; Bandura et a l . , 1985; Craske & Craig, 1984; Craske & Rachman, 1987; Kendrick et a l . , 1982) i t i s s u r p r i s i n g that t h i s discrepancy occurred. I t suggests that fear response can be influenced without a corresponding change i n s e l f -e f f i c a c y expectations. I t can be argued that the lack of r e l a t i o n s h i p between anxious arousal l e v e l and s e l f - e f f i c a c y i n the present study i s the r e s u l t of the nature of the anxious arousal manipulation. There are several ways in which the s p e c i f i c nature of the anxious arousal mechanism may have prevented the detection of differences that may have been i d e n t i f i e d using alternate methods of increasing anxious arousal. 6 These r e s u l t s were not reported i n the r e s u l t s section. I t was found that the c o r r e l a t i o n between l e v e l of s e l f -reported fear and s e l f - e f f i c a c y on each assessment occasion ranged from -.26 to -.43 with a mean c o r r e l a t i o n of -.34 (df = 74 for 3 of the comparisons and df =73 for 1 of the comparisons, p_ < .01). 135 F i r s t , i t may be that the amount of anxious arousal was not s u f f i c i e n t to cause a disruption of s e l f - e f f i c a c y . The manipulation did successfully increase anxious arousal but perhaps a greater increase, above some minimum c r i t e r i o n l e v e l of anxious arousal, i s necessary. Although t h i s i s an in t e r e s t i n g p o s s i b i l i t y , i t i s a post hoc argument that i s not a part of s e l f - e f f i c a c y theory i n i t s present form. Bandura (1986) states that, " a c t i v i t i e s are often performed i n situations containing varied evocative s t i m u l i . This creates ambiguity about what caused the physiological reactions. The e f f i c a c y import of the resultant arousal on s e l f - e f f i c a c y w i l l , therefore, vary depending on the factors singled out and the meaning given to them" (p. 4 06) . Perhaps anxious arousal only has an e f f e c t on s e l f - e f f i c a c y expectations i f the source of the anxious arousal can not be s p e c i f i c a l l y i d e n t i f i e d , or i s i d e n t i f i e d by the i n d i v i d u a l (whether c o r r e c t l y or incorrectly) as being caused by the feared stimulus. If the in d i v i d u a l cannot i d e n t i f y the source of anxious arousal, e x c i t a t i o n transfer (Zillman, 1983) may occur and the individual may misattribute the source of anxious arousal as being due to the feared stimulus. Individuals tend to a t t r i b u t e t h e i r anxious arousal to st i m u l i that they are focussing on and that s t r i k e them as obvious sources of anxious arousal (Zillman, 1983). In the current study, i t may be that the cause of the anxious arousal was s p e c i f i c a l l y i d e n t i f i e d , and i d e n t i f i e d as being external to, and independent of, the feared 136 stimulus. I t i s not possible to determine the extent to which the anxious arousal that was generated i n the current study was attributed by the subjects to the feared stimulus versus the experimental manipulation. However, the attention of subjects was focussed on the feared stimulus which was, by d e f i n i t i o n , a source of anxious arousal for the subjects. A f i n a l issue concerns the r e l a t i v e influence of anxious arousal compared with the other three possible sources of s e l f - e f f i c a c y information ( i . e . , performance attainments, vicarious experience, and verbal persuasion). Performance attainments and vicarious experience are i d e n t i f i e d as the most potent sources of e f f i c a c y information (Bandura, 1986) and the robust e f f e c t of exposure treatments and vicarious experience i n reducing fear and increasing s e l f - e f f i c a c y are well documented (e.g., Barlow & Beck, 1984; Emmelkamp, 1982a 1982b; Linden, 1981; Rachman & Wilson, 1980). In the current study, both of these sources of e f f i c a c y information were present. I t may be that they are much more s a l i e n t and powerful influences on s e l f -e f f i c a c y compared with anxious arousal state and, consequently, they override any e f f e c t that i t may have on s e l f - e f f i c a c y i f t h i s information i s not a v a i l a b l e . Bandura states that the cognitive processing of s e l f - e f f i c a c y information involves two factors: the type of information that individuals attend to and endorse i n making s e l f -e f f i c a c y judgements; and the rules and h e u r i s t i c s that they use i n integrating a l l of the s e l f - e f f i c a c y information that 1 3 7 i s a v a i l a b l e . Furthermore, "people are much more l i k e l y to act on t h e i r self-perceptions of e f f i c a c y i n f e r r e d from many sources of information rather than r e l y i n g p r i marily on v i s c e r a l cues" (Bandura, 1986, p. 444) . I f t h i s other information had not been available, anxious arousal may have had an e f f e c t on s e l f - e f f i c a c y . In summary, the current study was unable to document an e f f e c t of anxious arousal on s e l f - e f f i c a c y expectations. Several possible reasons for t h i s f a i l u r e were discussed. In l i g h t of the d i f f i c u l t y i n establishing a r e l a t i o n s h i p between anxious arousal and s e l f - e f f i c a c y , i t i s concluded that the r e l a t i o n s h i p may not be a robust one and/or that i t i s tempered by l i m i t i n g or q u a l i f y i n g conditions. Several boundary conditions were hypothesized. Further c l a r i f i c a t i o n s of the theory, as well as accompanying research, w i l l be necessary i n order to further delimit these boundaries. THEORETICAL IMPLICATIONS A number of t h e o r e t i c a l implications derive from the findings of the current study. The f i r s t issue to consider concerns the a b i l i t y of the two theories of habituation, dual process theory and c o r t i c a l theory, to explain these r e s u l t s . A second issue concerns the a b i l i t y of emotional processing theories to explain these r e s u l t s . F i n a l l y , the implications of the findings with respect to s e l f - e f f i c a c y w i l l be considered. 138 Neither dual process theory nor c o r t i c a l theory i s a clear winner i n t h i s comparison. With respect to dual process theory, the following conclusions can be made. When considering short term within-session e f f e c t s of anxious arousal, neither increases nor decreases i n anxious arousal had an e f f e c t on either measure of fear. The ro l e of " s e n s i t i z a t i o n " on response magnitude i s a hallmark of t h i s theory, and the i n a b i l i t y to document an e f f e c t within-session i s problematic. Given that s e n s i t i z a t i o n e f f e c t s have been documented i n other studies, the current findings do not invali d a t e the theory. Rather, they suggest a lack of g e n e r a l i z a b i l i t y of the theory. The second finding concerns the e f f e c t of anxious arousal on fear reduction. Experiencing anxious arousal s u b s t a n t i a l l y impedes reduction of subjective fear. I t should be noted that t h i s prediction was made on the basis of the "revised version" of dual process theory that was developed e a r l i e r and that the e a r l i e r versions of dual process theory do not consider the impact of anxious arousal on the process of fear reduction. This finding o f f e r s further support for t h i s r e v i s i o n of dual process theory and i s congruent with p r i o r studies that have noted the i n h i b i t i v e e f f e c t s of anxious arousal on the habituation process. Unexpectedly, anxious arousal had contrary e f f e c t s on heart rate response ( i . e . , subjects who were anxiously aroused showed less heart rate response) following fear 139 reduction. This e f f e c t was not predicted by dual process theory. This e f f e c t , as well as the accompanying discordance between the two measures of fear, i s better understood within the context of emotional processing. This was discussed i n a previous section and w i l l be considered again l a t e r . An examination of the e f f e c t s of anxious arousal at follow-up found that i t did not have an e f f e c t on fear as assessed by either measure. A subsequent analysis, however, c l a r i f i e d these r e s u l t s . Anxious arousal at follow-up does not r e s u l t i n increased return of fear, as would be predicted by dual process theory. Rather, exposure to the stimulus at follow-up while i n a calm state given fear reduction while anxiously aroused s u b s t a n t i a l l y impedes the return of fear. This finding i s congruent with dual process theory, however, i t would also be predicted on the basis of dual process theory that subjects who experienced fear reduction i n a calm state and follow-up assessment i n an anxious state would experience the most return of fear. This was not found, however. The finding that fear reduction that occurs while i n a state of anxious arousal followed by long-term assessment that occurs while i n a calm state impedes the return of fear i s s i m i l a r to the phenomenon that was termed 'greater than 100 percent habituation' by Thompson et a l . , (1973). They predicted, and had supporting evidence, that i f an animal i s habituated to a high i n t e n s i t y stimulus and l a t e r assessed with a low int e n s i t y stimulus, greater 140 habituation would occur than would occur i f the animal was habituated to and tested with the same low i n t e n s i t y stimulus. In the current context, although the s p e c i f i c feared stimulus ( i . e . , the snake) remained the same on each assessment occasion, i t could be argued that anxious arousal during the f i r s t session became associated with the fear network defining the feared stimulus. At follow-up, experiencing the snake while i n a calm state resulted i n a lesser a c t i v a t i o n of the network that was developed during the f i r s t session (and which now consists of elements of anxious arousal as well as the snake). This could explain the further decrement i n fear at follow-up i n subjects who were anxiously aroused during fear reduction but not at follow-up. The problem with t h i s explanation i s that anxious arousal state did not i n f l a t e fear of the snake during the f i r s t session. This suggests that the anxious arousal state generated by the experimental manipulation was not part of the network defining the feared stimulus. However, i t may be that a time i n t e r v a l i s necessary i n order to allow t h i s consolidation to occur. The issue remains why the reverse does not hold. In other words, i f fear reduction i s conducted while the individual i s i n a calm state and follow-up occurs in a state of anxious arousal why i s n ' t there increased return of fear? As well as being a f f e c t i v e l y congruent with fear, the experience of anxious arousal i s much more s a l i e n t than the experience of a calm 141 state, and, consequently, more l i k e l y associated with the network defining the feared stimulus. The predictions made on the basis of c o r t i c a l theory regarding the e f f e c t s of within-session changes i n anxious arousal were not supported by the data. Neither decreases nor increases i n anxious arousal state influenced either measure of fear. As predicted by c o r t i c a l theory, anxious arousal during fear reduction impeded fear reduction with respect to subjective fear. However, the reverse was found with respect to heart rate response ( i . e . , there was less heart rate response following fear reduction i n the subjects who were anxiously aroused during fear reduction). Regarding the e f f e c t s of anxious arousal on the return of fear, there i s no support for t h i s theory. An asymmetrical e f f e c t of congruence of arousal states was found ( i . e . , experiencing anxious arousal during fear reduction and a calm state at follow-up impedes the return of f e a r ) . This finding was not predicted by the theory and cannot e a s i l y be explained by i t . In summary, both theories of habituation received support from the finding that anxious arousal impedes the process of fear reduction with respect to subjective reports of fear, but the finding that anxious arousal during fear 7 Although the r e s u l t s of the multiple comparison tests were not s i g n i f i c a n t , the subjects who experienced anxious arousal during both occasions did show the greatest return of fear (see Table 15). This would be expected i f the network defining the feared stimulus was modified during the f i r s t session so as to include the anxious arousal that was present during the session. 142 reduction was accompanied by decreased heart rate response following fear reduction was not predicted by either theory. There i s further p a r t i a l support for dual process theory regarding the e f f e c t s of anxious arousal on the return of fear. Both theories have rather l i m i t e d success i n predicting the e f f e c t s of anxious arousal per se on fear. The r e s u l t s of the current study o f f e r support for several predictions made on the basis of emotional processing theories of fear. Rachman (1980, 1990) predicted that relaxation and calm rehearsals f a c i l i t a t e emotional processing and fear reduction r e l a t i v e to high arousal which impedes them. The current study o f f e r s c l e a r support for t h i s prediction. He also predicted that autonomic r e a c t i v i t y enhances emotional processing and that unresponsive autonomic reactions impede emotional processing. Although t h i s study does not o f f e r d i r e c t support for t h i s prediction, the finding that subjects who were anxiously aroused experienced greater subjective fear following fear reduction but less heart rate response i s consistent with t h i s . I f heart rate response i s thought of as an index of emotional processing as compared to a measure of fear, i t would be predicted that individuals who show greater reduction of subjective fear, but who s t i l l report a minimum l e v e l of subjective fear, would continue to show moderate heart rate responses to the feared s t i m u l i . In contrast, indiv i d u a l s who experience minimal heart rate response to moderately f e a r f u l s t i m u l i w i l l show lesser habituation of 143 subjective fear. However, as subjective fear l e v e l s approach zero, individuals who previously exhibited heart rate responses w i l l cease to do so. In other words, a lack of autonomic r e a c t i v i t y can indicate either that the feared stimulus i s not being emotionally processed or that i t has been successfully emotionally processed. Rachman and Whittal (1989a) predicted that anxious arousal at follow-up increases the return of fear. The findings of the current study suggest a more complex re l a t i o n s h i p between anxious arousal state and fear. Assessment i n a calm state which follows fear reduction i n an anxiously aroused state r e s u l t s i n less return of fear than occurs otherwise. Lang (e.g., 1985) and Barlow (1988) argue that arousal,, even i f unrelated to the feared stimulus, can serve to i n t e n s i f y the fear response. In a s i m i l a r fashion, Rachman (1990) predicted that through a process of emotional s p i l l -over, i n which one emotional state influences another, increases i n arousal, e s p e c i a l l y anxious arousal, may r e s u l t i n a k i n d l i n g of the fear network r e s u l t i n g i n an i n f l a t i o n of fear. The findings of the current study did not f i n d evidence of t h i s process within-session. Over the long term, however, the r e s u l t s are congruent with the idea that i f fear reduction occurs while i n an anxious state t h i s anxious arousal becomes associated with the network defining the feared stimulus and that l a t e r assessment i n a nonanxious state w i l l r e s u l t in an i n h i b i t e d a c t i v a t i o n of the network, 144 re s u l t i n g i n a lesser fear response than would otherwise occur. Rachman (1990) d i f f e r s from Lang (e.g., 1985) and Barlow (1988) i n that he states that the type of arousal influences the extent to which emotional s p i l l - o v e r occurs. This d i f f e r e n t i a t i o n of types of arousal seems to be a useful one. As argued by Neiss (1988, 1990), the concept of arousal i s not meaningful without reference to i t s psychological context. It seems that anxious arousal has co-e f f e c t s that do not r e s u l t from forms of arousal (e.g., as induced by physical exertion) that are not negatively valenced with respect to emotion. Exercise, for example, would activate response propositions that are shared with the fear network (e.g., "heart pounds"); however, i t would not l i k e l y activate meaning propositions that elaborate the rel a t i o n s h i p between the stimulus and the response elements of the network (e.g., "This i s a dangerous and threatening situation.") Anxious arousal, i n contrast, would be more l i k e l y to share common meaning propositions that are associated with the feared stimulus. Thus, i t may be that anxious arousal may more e f f e c t i v e l y r e s u l t i n emotional s p i l l - o v e r to the network defining the feared stimulus than w i l l other forms of arousal. Although t h i s s p e c i f i c proposition remains to be evaluated, the finding that the "worry" component of anxiety has a more detrimental impact on task performance i n those with performance anxiety than the physiological component of anxiety (Sarason, 1984, 1985) 145 s u g g e s t s t h a t meaning i n f o r m a t i o n may be more l i k e l y t o i g n i t e f e a r t h a n w i l l p h y s i o l o g i c a l a r o u s a l . The f i n d i n g s o f t h e c u r r e n t s t u d y do n o t a c c o r d any s i g n i f i c a n t e f f e c t o f a n x i o u s a r o u s a l on s e l f - e f f i c a c y . I n t h e p r e v i o u s s e c t i o n , p o s s i b l e r e a s o n s f o r t h i s l a c k o f r e l a t i o n s h i p were d i s c u s s e d . I t does n o t seem t h a t t h e f a i l u r e t o f i n d a s i g n i f i c a n t e f f e c t was due t o i n s e n s i t i v i t y o f t h e s e l f - e f f i c a c y measure. A l t h o u g h t h e a n x i o u s a r o u s a l m a n i p u l a t i o n was r o b u s t , i t i s p o s s i b l e t h a t a g r e a t e r i n c r e a s e i n a n x i o u s a r o u s a l , above some minimum c r i t e r i o n l e v e l , was n e c e s s a r y i n o r d e r t o f i n d an e f f e c t . A l t e r n a t i v e l y , i t may be t h a t t h e n a t u r e o f t h e a n x i o u s a r o u s a l t h a t was g e n e r a t e d , s p e c i f i c a l l y t h e d i s c r e t e n a t u r e o f i t s s o u r c e , p r e v e n t e d a n x i o u s a r o u s a l e f f e c t s t h a t would have o t h e r w i s e o c c u r r e d . These two p o s s i b i l i t i e s can not be e v a l u a t e d i n t h e c u r r e n t s t u d y and a r e not a d d r e s s e d by s e l f - e f f i c a c y t h e o r y i n i t s c u r r e n t form. A f i n a l i s s u e t h a t was d i s c u s s e d c o n c e r n s t h e impact o f a n x i o u s a r o u s a l i n f o r m a t i o n r e l a t i v e t o o t h e r s o u r c e s o f i n f o r m a t i o n such as performance accomplishments o r v i c a r i o u s e x p e r i e n c e . I t may be t h a t t h e s e s o u r c e s o f i n f o r m a t i o n o v e r r o d e any e f f e c t s o f a n x i o u s a r o u s a l . I n summary, t h e r e s u l t s o f t h e c u r r e n t s t u d y s u g g e s t t h a t t h e r o l e o f a n x i o u s a r o u s a l on s e l f - e f f i c a c y needs t o be r e c o n s i d e r e d . A n x i o u s a r o u s a l may not have a r o b u s t e f f e c t on s e l f - e f f i c a c y , and t h e e f f e c t , i f any, i s tempered by s e v e r a l q u a l i f y i n g c o n d i t i o n s . 146 CLINICAL IMPLICATIONS The r e s u l t s of the current study suggest several important c l i n i c a l implications. Before commenting further, however, i t i s important to r e a l i z e that the present study was conducted with the main purpose of further understanding processes underlying fear, fear reduction, and the return of fear. Although the findings suggest several important ramifications regarding processes underlying fear, further research w i l l be necessary i n order to c l a r i f y these findings and to extrapolate them to other populations, settings, treatments, and fears. Given these caveats, several comments can be made. F i r s t l y , the r e s u l t s of the present study suggest that the process of fear reduction i s f a c i l i t a t e d by exposure to the feared stimulus while the i n d i v i d u a l i s i n a calm state. Anxious arousal impedes the habituation of fear. There has been discussion i n the past regarding the importance of t r a i n i n g i n relaxation as a component of fear reduction treatment. Inconsistent e f f e c t s of relaxation have been noted (Borkovec & 0'Brian, 1976; Borkovec & Krogh-Sides, 1979; Levin & Gross, 1985; Mathews, 1971). I t has been suggested that although t r a i n i n g i n progressive muscle relaxation was not a necessary component of fear reduction procedures, i t may f a c i l i t a t e the process of fear reduction i n highly f e a r f u l individuals (McGLynn, Mealiea, & Landau, 1981). The findings of the current study are congruent with t h i s conclusion. However, i t i s not simply that relaxation 147 i s important only during exposure. Rather, the second major finding, that calm exposures at follow-up given fear reduction i n an anxiously aroused state r e s u l t s i n further fear reduction, as opposed to the return of fear which i s more t y p i c a l l y found, suggests a p o t e n t i a l l y more important ro l e for relaxation. I t stresses the usefulness and importance of a s s i s t i n g c l i e n t s i n developing strategies that a s s i s t them i n gaining a degree of personal control over t h e i r anxious arousal state. These strategies include t r a i n i n g i n relaxation, but also l i k e l y extend to other procedures, such as interpersonal problem solving t r a i n i n g , that are useful i n managing the sources of anxious arousal. These r e s u l t s suggest that through a process of emotional s p i l l - o v e r (Rachman, 1990) fear l e v e l s may v a c i l l a t e following treatment, given changes i n the i n d i v i d u a l ' s state of anxious arousal. Arming indivi d u a l s with t h i s knowledge may prove to be a powerful strategy to a s s i s t i n relapse prevention (Cameron, 1978; Marlatt & Gordon, 1980). The purposes of advising i n d i v i d u a l s of the r e l a t i o n s h i p between anxious arousal and fear response are twofold. F i r s t l y , they can respond to increases i n anxious arousal by implementing procedures that e f f e c t i v e l y control anxious arousal. Secondly, i f the i n d i v i d u a l i s forewarned that increases i n fear following increases i n anxious arousal are to be expected and that the fear should decrease as the anxious arousal dissipates he or she w i l l be less 148 l i k e l y to catastrophize the s i g n i f i c a n c e of the increased fear. The r e s u l t s suggest that exposure i s best conducted under calm conditions but that long term maintenance of fear i s best accomplished when exposure i s conducted i n an anxiously aroused state and follow-up occurs i n a calm state. These two findings, although seemingly incongruent, can l i k e l y be combined. I t i s suggested that exposure should optimally occur under calm conditions so as to f a c i l i t a t e the habituation of fear. Once the fear has reduced s i g n i f i c a n t l y , i t may be b e n e f i c i a l to expose the i n d i v i d u a l to the feared stimulus under conditions of increasing anxious arousal. This procedure w i l l allow the i n d i v i d u a l , i n a controlled manner, to confront the feared stimulus while i n an anxiously aroused state, and f a c i l i t a t e the innoculation of the i n d i v i d u a l against increases i n fear given the experience of anxious arousal i n the future. Although the r e s u l t s do not address the issue of whether s e l f - e f f i c a c y i s the primary mediator of behavior, they indicate that the relationship between anxious arousal and s e l f - e f f i c a c y may not be robust. In any event, they do not detract from the fact that there i s a r e l a t i o n s h i p between s e l f - e f f i c a c y and fear behavior. C l i n i c a l l y , s e l f -e f f i c a c y ratings continue to be a useful source of information for the c l i n i c i a n regarding the c l i e n t ' s perception of his behavioral c a p a b i l i t i e s . 149 CONCLUSIONS The r e s u l t s of the current study w i l l be summarized and several avenues of research that merit further exploration w i l l be suggested. The f i r s t set of conclusions concerns the e f f e c t s of anxious arousal on fear, fear reduction, and the return of fear, and the a b i l i t y of the two theories of habituation (dual process theory: e.g., Groves & Thompson, 1970; c o r t i c a l theory: e.g., Whitlow & Wagner, 1984) to explain these r e s u l t s . F i r s t l y , within-session changes i n anxious arousal l e v e l did not influence either measure of fear ( i . e . , s e l f - r e p o r t or heart rate response). This i n a b i l i t y of anxious arousal to a f f e c t fear l e v e l s i s e s p e c i a l l y problematic for dual process theory as the r o l e of ' s e n s i t i z a t i o n ' ( i . e . , anxious arousal) i n determining response i s a defining feature of the theory. Experiencing anxious arousal during fear reduction r e s u l t s i n less reduction of subjective fear ( i . e . , greater fear following fear reduction) than occurs given exposure under r e l a t i v e l y calm conditions. Although t h i s finding was predicted on the basis of both the revised version of dual process theory that was developed e a r l i e r and by c o r t i c a l theory, the finding regarding heart rate response i s problematic for the two theories. S p e c i f i c a l l y , heart rate response upon exposure to the feared stimulus was less, not greater as was predicted, given conditions of anxious arousal compared with r e l a t i v e l y calm conditions. This 150 e f f e c t , and the discordance between the two measures of fear, i s not explainable by either of these two theories. Return of subjective fear was experienced by a l l of the subjects except for those who experienced fear reduction while i n an anxious state and assessment i n a calm state. These subjects experienced a substantial decrement i n s e l f -reported fear at follow-up. This pattern of r e s u l t s can be only p a r t i a l l y explained on the basis of dual process theory, and seems inconsistent with predictions made on the basis of c o r t i c a l theory. The re s u l t s were considered i n reference to the emotional processing model of fear (e.g., Rachman, 1980). The current findings are congruent with reasoning derived from t h i s model, give empirical support to several of the predictions derived from i t , and suggest several refinements to the model. S p e c i f i c a l l y , the disruptive e f f e c t of anxious arousal during fear reduction i s predicted by t h i s model. Although the p a r t i c u l a r pattern of re s u l t s regarding the return of fear were not predicted, they are e a s i l y explained based on t h i s theory. The discordance between heart rate response and self-reported fear, which i s problematic for the two habituation models, i s congruent with the emotional processing model of fear. Neither dual process theory nor c o r t i c a l theory were able to account for these re s u l t s to a s a t i s f a c t o r y extent. Although the theories are not invalidated by the r e s u l t s of the current study, they have a li m i t e d a b i l i t y to predict 151 and explain fear responses i n human subjects. Given how far removed the s t i m u l i and responses of the present study are from those on which the two theories of habituation were derived, i t i s not surprising that they had d i f f i c u l t y i n accounting for these findings. As was suggested e a r l i e r , the complex nature of fear l i k e l y precludes a single explanatory mechanism of fear reduction. Although fear reduction may resemble habituation processes that have been observed i n other contexts, the processes underlying the phenomena may d i f f e r . Consequently, the t h e o r e t i c a l explanations w i l l necessarily d i f f e r as well. Emotional processing models of fear seem very promising i n t h e i r a b i l i t y to predict and explain fear behavior. Although less parsimonious than single explanatory models of fear, t h i s class of models are empirically based and t h e o r e t i c a l predictions based on them can be empirically evaluated. The predicted relationship between anxious arousal l e v e l and s e l f - e f f i c a c y l e v e l (e.g., Bandura, 1986) was not found. Although these results do not preclude such a rel a t i o n s h i p , further t h e o r e t i c a l refinement regarding the e f f e c t of anxious arousal on s e l f - e f f i c a c y are necessary. The impact of anxious arousal on s e l f - e f f i c a c y may not be a robust one. This study i s the f i r s t empirical documentation of the disruptive e f f e c t s of anxious arousal on the reduction of subjective fear. This new finding has t h e o r e t i c a l and 152 c l i n i c a l implications. Further examination of t h i s finding w i l l l i k e l y prove f r u i t f u l . The finding that assessment i n a calm state following fear reduction while i n an anxiously aroused state blocks the return of fear i s also novel. Return of fear i s the t y p i c a l finding i n research of t h i s type. Further research should attempt to i d e n t i f y other methods to prevent the return of fear. In the current study, the amount of return of fear was assessed through an analysis of residual gain scores. This analysis allowed an evaluation of the magnitude of change across the follow-up i n t e r v a l while avoiding the d i f f i c u l t i e s inherent with the use of raw change scores. I t i s expected that analyses of t h i s type w i l l be used i n subsequent evaluations of the return of fear. I t i s proposed that s i m i l a r analyses be undertaken i n evaluations of relapse i n areas other than fear; t y p i c a l l y , the assessment of c l i n i c a l relapse i s studied and reported i n categorical terms. The extension of the residual gain analysis to the assessment of c l i n i c a l relapse w i l l introduce welcome prec i s i o n . There are several l i m i t a t i o n s to t h i s study. The f i r s t l i m i t a t i o n concerns the anxious arousal manipulation. Although the manipulation was shown to be e f f e c t i v e i n increasing subjective and physiological indices of anxious arousal, other forms of experimentally induced anxious arousal such as threat of negative evaluation or watching s t r e s s f u l movies may not have the same e f f e c t s . Further 153 research i s necessary i n order to determine the generality of these findings. A related issue concerns the rel a t i o n s h i p between the anxious arousal produced i n the current study and the experience of chronic l e v e l s of anxious arousal experienced by c l i n i c a l l y anxious in d i v i d u a l s . As noted by Barlow (1988), although the two share common features, experimentally produced forms of anxious arousal should not be confused with c l i n i c a l presentations of anxious arousal. I t i s tempting to extrapolate these findings to the c l i n i c a l s e tting, however, t h i s must await further research that examines t h i s question. A second l i m i t a t i o n concerns the feared stimulus that was used i n the current study. Snake fear i s an appropriate model i n examining fear. However, i t would be useful to re p l i c a t e these r e s u l t s using other feared s t i m u l i . The study would have been improved by the addition of a second follow-up session i n which a l l of the subjects were exposed to the feared stimulus while experiencing equivalent l e v e l s of non-anxious arousal. This would allow statements to be made regarding the d u r a b i l i t y of the e f f e c t s that were noted during the f i r s t follow-up session. Several directions for future research are indicated by the current study. F i r s t l y , i t i s necessary to r e p l i c a t e these r e s u l t s using alternate forms of anxious arousal. I t may be that a d i f f e r e n t pattern of res u l t s would emerge given other sources of anxious arousal such as threat of negative evaluation. Although more robust e f f e c t s may be 154 found with higher l e v e l s of anxious arousal, researchers are l i m i t e d by e t h i c a l constraints regarding the magnitude of anxious arousal that can be induced. One very p r o f i t a b l e avenue may be to compare the r e l a t i v e impact of the two major components of anxious arousal (worry vs. physiological arousal) on fear. Research i n the area of the return of fear has focussed on the important r o l e of autonomic arousal as indexed by heart rate. However, other theory and research (e.g., Barlow, 1988; Sarason, 1984, 1985) suggests that the worry component of anxious arousal may have a detrimental impact on fear. As well, the c l o s e l y related finding that experiencing worry r e s u l t s i n an i n f l a t i o n of subjective fear but reduced heart rate response, without causing a corresponding increase i n baseline heart rate (Borkovec & Hu, 1990), also indicates that worry may play an important role i n fear processes. Research examining the e f f e c t of anxious arousal on predictions of fear would l i k e l y increase our understanding of fear. Predictions of fear and the r e l a t i o n s h i p between predic t i o n and the actual experience of fear have an impact on l a t e r predictions of f e a r f u l behavior (Rachman & Lopatka, 1986a, 1986b). The current study has several important c l i n i c a l implications that were discussed i n the previous section. It would be very useful to examine the extent to which these findings generalize to c l i n i c a l settings, populations, and problems. If these results do generalize, several important implications regarding the management of anxiety-based problems follow. A great deal of research has been generated based on s e l f - e f f i c a c y theory, however, there has been a lack of attention to the construct of anxious arousal and i t s r e l a t i o n s h i p to s e l f - e f f i c a c y . The r e s u l t s of research that has been conducted are inconsistent. Several boundary conditions regarding anxious arousal were suggested. I t would be useful to evaluate these hypotheses i n subsequent research. In summary, several important questions regarding the e f f e c t s of anxious arousal on fear, fear reduction, the return of fear, and s e l f - e f f i c a c y were addressed. Several additional questions were posed and issues were raised. Further examination of these questions and issues w i l l l i k e l y prove f r u i t f u l i n increasing knowledge of fear and fear related processes. 156 References Agras, W. 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I am not I am f am J am i am at a l l s l i g h t l y m o d e r a t e l y e x t r e m e l y t e r r i f i e d f e a r f u l o f : f e a r f u l o f : f e a r f u l o f ; f e a r f u l o f ; o f :  Snakes Cats B i r d s S p i d e r s  Worms Pops  I n s e c t s Horses H e i g h t s  E n c l o s e d Spaces  Name: Phone Number and Be s t Time t o C a l l : I f you a r e i n t e r e s t e d i n p a r t i c i p a t i n g i n a F e a r S t u d y s u p e r v i s e d by Or. S. Rachman p l e a s e f i l l i n your name and phone number. You w i l l r e c e i v e c o u r s e c r e d i t f o r p a r t i c i p a t i n g ( i n s t r u c t o r p e r m i t t i n g ) . APPENDIX B MOOD SCALE Mood Scale 178 Instructions: Please place a slash (/) anywhere along the continuum you feel is appropriate. Please indicate how you are feeling right now. How anxious do you feel? 0 I am not at all anxious 100 I am extremely anxious How sad do you feel? 0 I am not at all sad 100 I am extremely sad How agitated do you feel? 0 I am not at all agitated 100 I am extremely agitated How happy do you feel? 0 I am not at all happy 100 I am extremely happy How relaxed do you feel? 0 I am not at all relaxed 100 I am extremely relaxed How apprehensive do you feel? 0 100 I am not at all apprehensive I am extremely apprehensive APPENDIX C SELF EFFICACY SCALE 180 Questionnaire Instructions: Please place a slash (/) anywhere along the continuum you feel is appropriate. Please indicate how you are feeling right now. How confident are you that you will be able to ? 100 Not at all confident Totally confident APPENDIX D CONSENT FORM 182-' Consent Form Fear Study We are conducting a research project on factors affecting fear levels and would welcome your participation. The experiment will consist of two sessions, four weeks apart. The first session will be about one hour in length and the second will be about 20 minutes in length. In the first session you will be asked to spend some time focusing on bodily sensations of muscle tension or relaxation. In addition, some people who participate in the experiment may experience a series of completely harmless, but painful, electric shocks. Shocks will be given at current intensities that cannot be detected and will increase each time in small increments. At any time during the sequence of shocks, simply saying "Stop" will end the series of shocks and no further increases will be delivered. Following the series of increasing shocks, a further series of shocks may be received. These will be within the tolerable range and will be delivered in a random order of intensities and at random intervals. All subjects will also be asked to slowly approach a live, harmless garter snake. You will be asked at various points throughout each session to report your level of fear. mood, and confidence. Throughout all of this, your heart rate will be recorded using a small monitor that clips onto your ear. The second session is similar in structure to the first session, however, it is only about 20 minutes in length. If for any reason you wish to withdraw from the experiment you are free to do so at any time without jeopardizing your class standing. However, we hope that you will be willing to participate. After completion of the study all participants will be given the opportunity to learn the outcome of the research as well as receive course credit for participation. In addition, please note that all information collected during the course of this study is kept strictly confidential and access to it will be restricted to Dr. S. J. Rachman or Gene Flessati. M. A. For further information, you may contact Gene Flessati, Department of Psychology, UBC (telephone: ). If you have any questions about the procedures outlined above, please feel free to ask. I have read the attached information, consent to participate in this research, and have received a copy of this consent form. Signature: Name: Student «: Date: 183 APPENDIX E RESIDUAL GAIN SCORE ANALYSIS A residual gain score analysis was conducted to assess the amount of change i n self-reported fear between time 4 and time 6. Analysis of raw change scores formed by subtracting the SUDS score at time 4 from the SUDS score at time 6 i s inappropriate as these scores are related to any random measurement error. Unlike raw change scores, res i d u a l i z e d gain scores have no c o r r e l a t i o n between pre-t e s t ( i . e . , SUDS score at time 4) and post-test ( i . e . , SUDS score at time 6) scores. Residualizing the change score removes the portion of the change across the follow-up i n t e r v a l that could have been predicted based on l i n e a r regression of the SUDS scores at time 4. Refer to Cronbach and Furby (1970) for a discussion of the use of change scores. In t h i s analysis, SUDS score at time 6 was regressed on SUDS score at time 4. The score that would be predicted at time 6 (from the SUDS score at time 4) was then computed. The residual SUDS score at time 6 was computed as the difference between the SUDS score at time 6 and the predicted SUDS score at time 6. Thus, a p o s i t i v e residual score indicates that subjects reported greater fear at time 6 than would be predicted from the subjects' reported fear at time 4. Conversely, a negative residual score indicates that less fear was reported at time 6 than would be predicted from the subjects' reported fear at time 4. This analysis i s equivalent to analysis of covariance using the 184 SUDS scores at time 6 with SUDS score at time 4 as the covariate. The mean residual gain score for each group i s equivalent to the adjusted mean obtained from the ANCOVA for that group minus the mean SUDS score at time 6 for the entire sample. I t was decided to present the data i n t h i s fashion because residual gain scores are more e a s i l y interpreted than mean adjusted heart rate response scores. 

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