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UBC Theses and Dissertations

Effects of verbal learning adjuncts on E.E.G. relative power and tympanic temperature as related to recall… Carsley, Norman 1984

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EFFECTS OF VERBAL LEARNING ADJUNCTS ON E.E.G. RELATIVE POWER AND TYMPANIC TEMPERATURE AS RELATED TO RECALL AND COMPREHENSION OF PROSE NORMAN CARSLEY B.A. Honors University of Winnipeg, 1973 M.A. University of Victoria, 1975 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY (Department of Educational Psychology) We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA March 1984 )Norman Carsley, 1984 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the requ i rements f o r an advanced degree a t the U n i v e r s i t y o f B r i t i s h Co lumb ia , I agree t ha t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s tudy . I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e copy ing o f t h i s t h e s i s f o r s c h o l a r l y purposes may be g ran ted by the head o f my department o r by h i s o r her r e p r e s e n t a t i v e s . I t i s unders tood t h a t copy ing o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l ga i n s h a l l no t be a l l owed w i thou t my w r i t t e n p e r m i s s i o n . Department o f The U n i v e r s i t y o f B r i t i s h Columbia 1956 Main Mall Vancouver , Canada V6T 1Y3 DE-6 (.3/81) B r a i n a n d L e a r n i n g i i Abstract A s t u d y w a s c o n d u c t e d t o e x a m i n e t h e r o l e o f i m a g e r y ( i n d u c e d a n d i m p o s e d ) d u r i n g l e a t n i i i g on Ja ra j.n k e u t i s p h e r i o p r o c e s s e s a n d o n r e c a V l a n d c o m p r e h e n s i o n p e r f o r m a n c e . S i x t y u n d e r g r a d u a t e s u b j e c t s w e r e r a n d o m l y d i v i d e d i n t o t h r e e g r o u p s a n d g i v e n a n a d a p t e d c h a p t e r o n p s y c h o p a t h o l o g y f r o m I n t r o d u c t o r y P s y c h o l o g y t e x t b o o k s . B e f o r e s t u d y i n g t h e t e x t u a l m a t e r i a l , o n e g r o u p w a s g i v e n a p a s t e u p o f p i c t u r e s , s e l e c t e d f r o m I n t r o d u c t o r y P s y c h o l o g y t e x t b o o k s d e p i c t i n g t h e v a r i o u s m e n t a l d i s o r d e r s . T h e s e c o n d g r o u p w a s g i v e n i n s t r u c t i o n s t o g e n e r a t e s e l f c r e a t e d i m a g e r y a b o u t t h e m e n t a l d i s o r d e r s . T h e c o n t r o l g r o u p w a s g i v e n some i r r e l e v a n t m a t e r i a l ( f r o m a t e x t o n g e n e t i c s ) t o o c c u p y t h e m f o r t h e same d u r a t i o n a s t h e o t h e r t w o g r o u p s . B r a i n w a v e s a n d t y m p a n i c t e m p e r a t u r e s w e r e m o n i t o r e d d u r i n g t h e l e a r n i n g p h a s e . R e c a l l a n d c o m p r e h e n s i o n t e s t s c o r e s w e r e s u b s e q u e n t l y t a k e n . T h e r e s u l t s s h o w t h e f a c i l i t a t i o n o f r e c a l l p e r f o r m a n c e b y p i c t u r e s ( i m p o s e d i m a g e r y ) b u t n o t f o r t h e s e l f c r e a t e d i m a g e r y ( i n d u c e d i m a g e r y ) . A n a l y s i s o f t h e E . E . G . p o w e r s p e c t r u m s h o w s a l i k e l y e n g a g e m e n t o f t h e r i g h t c e r e b r a l h e m i s p h e r e c o m m e n s u r a t e w i t h l e a r n i n g w i t h p i c t u r e s b u t n o t f o r t h e i n d u c e d i m a g e r y . A n a l y s i s o f t h e t y m p a n i c t h e r m a l r e s p o n s e s s h o w s n o i n d i c a t i o n o f h e m i s p h e r i c d i f f e r e n c e s b e t w e e n c o n d i t i o n s a l t h o u g h a d i r e c t i o n a l t r e n d w a s o b s e r v e d . Q u e s t i o n s c o n c e r n i n g t h e r e l i a b i l i t y o f t h e t h e r m a l i n d i c a t o r , t h e v a r i o u s f o r m s o f p i c t u r e s a n d f o r m s o f i n d u c e d i m a g e r y p o s s i b l e t o a m e l i o r a t e l e a r n i n g a n d t h e v a r i o u s m e a n s o f a s s e s s i n g p e r f o r m a n c e w e r e r a i s e d . T h e g e n e r a l c o n c l u s i o n w a s t h a t p i c t u r e s may a s s i s t v e r b a l l e a r n i n g b y p o s s i b l e e n g a g e m e n t o f t h e r i g h t c e r e b r a l h e m i s p h e r e . D i s c u s s i o n o f f u t u r e r e l a t e d r e s e a r c h p o s s i b i l i t i e s i s g i v e n . i i i T A B L E O F CONTENTS P a g e A c k n o w l e d g e m e n t . 1 A b s t r a c t 2 C h a p t e r I . A n a l y s i s o f R e s e a r c h P r o b l e m s a n d H y p o t h e s e s I n t r o d u c t i o n 3 P s y c h o l o g i c a l R e p r e s e n t a t i o n P r o c e s s e s 7 I n d u c e d I m a g e r y 7 P i c t u r e s a n d D i a g r a m I l l u s t r a t i o n 9 M e a s u r e s o f L e a r n i n g P e r f o r m a n c e . . 1 4 O t h e r R e l a t e d V a r i a b l e s 1 6 B r a i n N e u r o p h y s i o l o g i c a l C o r r e l a t e s o f L e a r n i n g 1 9 G e n e r a l C e r e b r a l F u n c t i o n 1 9 B r a i n H e m i s p h e r i c S p e c i a l i z a t i o n 22 B r a i n E l e c t r o e n c e p h a l o g r a p h ^ R e s p o n s e s 2 8 B r a i n B l o o d C i r c u l a t i o n a n d T h e r m o d e t e c t i o n 36 T y m p a n i c T e m p e r a t u r e s 4 2 T h e C e n t r a l H y p o t h e s i s 4 5 E x p e r i m e n t a l E x p e c t a t i o n s 4 6 C h a p t e r I I . M e t h o d o l o g y S u b j e c t s a n d D e s i g n 4 7 I n d u c e d I m a g e r y I n s t r u c t i o n 4 8 P i c t o r i a l D i a g r a m s 4 9 C o n t r o l G r o u p 4 9 C r i t e r i o n T e s t s M a t e r i a l s o f R e c a l l & C o m p r e h e n s i o n . . . 5 0 A p p a r a t u s 5 0 E . E . G . , S i g n a l A n a l y z e r , a n d I n s t r u m e n t a t i o n F . M . R e c o r d e r 5 0 i v Thermodetector 51 Filtering Units and Others 51 Computers 52 Software 52 Experiment Room 52 Procedure 52 Post Experimental Debriefing 54 Methods of Observations and Measurements 54 E.E.G. Artifact Rejection 54 E.E.G. Data Signal Processing 60 Digital Filtering and Average Power Computation . . . . 65 Calibration . . . . . . . . 65 The Meaning of Average E.E.G. Power Changes and Tympanic Temperature Changes 70 Chapter III. Results 75 Neurophysiological Measures 77 Verbal Recall and Comprehension Test Scores . 79 Relationship Between Two Neurophysiological and Two Verbal Performance Measures 80 Chapter IV. Discussion and Conclusion Neurophysiological Measures E.E.G. Indicators of Brain Hemisphere Activity . . . . 83 Thermal Indicators of Brain Hemisphere Activity . . . . 87 Neurophysiological Variables Combined 88 Verbal Performance Measures Recall . 89 Comprehension 91 Verbal Learning Test Score Variables Combined 92 Correlations of Verbal Response Variables with the Neurophysiological Responses 94 Conclusions 102 Contribution of th'is study 1 0 5 References 106 Figures 122 Tables 125 Appendix A - Materials Used in the Study Student Objectives 129 Irrelevant Material 130 Induced Imagery . 134 Imposed Imagery 138 Textual Material 139 Recall Test 152 Comprehension Test -153 I B r a i n a n d L e a r n i n g • f l ACKNOWIZLXSF l f f iNTS I w o u l d l i k e t o t h a n k my a d v i s o r D r . S t e p h e n F o s t e r f o r t h e s u p p o r t a n d g u i d a n c e r e c e i v e d d u r i n g a l l p h a s e s o f t h i s r e s e a r c h . I a l s o t h a n k t h e m e m b e r s o f my c o m m i t t e e , D r . S e o n g - S o o L e e , D r . G o r d o n N e l s o n , D r . L e o n K r a i n t z a n d D r . M i c h a e l B e d d o e s f o r t h e i r e n c o u r a g e m e n t , h e l p f u l s u g g e s t i o n s a n d c o m m e n t s . I am v e r y g r a t e f u l t o D r . M. B e d d o e s f o r a r r a n g i n g t h e a v a i l a b i l i t y o f e l e c t r o p h y s i o l o g i c a l u n i t s e m p l o y e d a n d u s e o f t h e f a c i l i t i e s i n E l e c t r i c a l E n g i n e e r i n g , t o D r . L e o n K r a i n t z f o r e q u i p m e n t f r o m H e a l t h S c i e n c e s , a n d t o B o b S t e e l e f o r e q u i p m e n t f r o m G r a p h i c A r t s . I am " g r a t e f u l f o r t h e c o o p e r a t i o n r e c e i v e d f r o m t h e u n d e r g r a d u a t e s t u d e n t s who p a r t i c i p a t e d i n t h i s s t u d y . F i n a l l y , I w o u l d l i k e t o t h a n k D r . F l e e t P e r r y , C h r i s S h e f f i e l d , A n t h o n y L e u b n e r , D a v i d H o l m e s a n d t h e n u m e r o u s o t h e r p e r s o n s w h o h e l p e d me i n v a r i o u s s t a g e s i n t h e c o m p l e t i o n o f t h i s p r o j e c t . Leaves 1 and 2 omitted in page numbering B r a i n a n d L e a r n i n g 3 E f f e c t s o f V e r b a l L e a r n i n g A d j u n c t s o n E . E . G . R e l a t i v e P o w e r a n d ' l y m p a n i c T e m p e r a t u r e a s R e l a t e d t o R e c a l l a n d C o m p r e h e n s i o n o f P r o s e C h a p t e r I . A n a l y s i s o f R e s e a r c h P r o b l e m s a n d H y p o t h e s e s I n t r o d u c t i o n T h e g e n e r a l p r o b l e m i n v e s t i g a t e d i n t h i s p r o j e c t c o n c e r n s t h e b r a i n n e u r o p h y s i o l o g i c a l r e s p o n s e s t o u s i n g p u r p o r t e d e n h a n c e r s a s . a d j u n c t s t o v e r b a l l e a r n i n g a n d w h e t h e r t h e s e b r a i n r e s p o n s e s c a n b e e l i c i t e d b y s u c h a d j u n c t s ( a d j u n c t s a r e p r e s e n t a t i o n s w h i c h a r e p u r p o r t e d t o i n f l u e n c e t h e l e a r n a b i l i t y o f g i v e n m a t e r i a l ) . T h e o t h e r i s s u e o f c o n c e r n wa s w h i c h t y p e o f a d j u n c t p r o d u c e s m o s t e f f e c t o n b r a i n r e s p o n s e s a n d w h e t h e r t h i s / t h e s e c o r r e s p o n d ( s ) t o t h e o n e ( s ) w h i c h i n d u c e s u p e r i o r l e a r n i n g . T h i s p r o j e c t t h u s h a s p r a c t i c a l s i g n i f i c a n c e - t h e s t u d y o f t h e d y n a m i c s o f c o g n i t i v e p r o c e s s e s u n d e r l y i n g v e r b a l l e a r n i n g m e c h a n i s m s a n d t h e o r e t i c a l s i g n i f i c a n c e -t h e e l u c i d a t i o n o f u n d e r l y i n g n e u r o p h y s i o l o g i c a l p r o c e s s e s . A c c o r d i n g t o W i t t r o c k ' s ( 1 9 7 7 , 1 9 8 0 ) t h e o r y o f g e n e r a t i v e p r o c e s s i n g i n v e r b a l l e a r n i n g ( i n t e r h e m i s p h e r i c e n h a n c e m e n t a n d c o m p l e m e n t a r i t y o f f u n c t i o n i n g ) t h e b r a i n f u n c t i o n s o p t i m a l l y a n d l e a r n s b e s t i f t h e m a t e r i a l b e i n g l e a r n e d i s p r e s e n t e d i n s u c h a w a y a s t o i n v o k e a c t i v i t y i n b o t h o f t h e c e r e b r a l h e m i s p h e r e s ( B o g e i i , 1 9 7 7 ; M y k e l & D a v e s , 1 9 7 9 ; C a t e r i n o , 1 9 7 9 ; T o m l i n s o n - K e a s y & K e l l y , 1 9 7 9 ; B r a i n a n d L e a r n i n g 4 B a i r d , 1 9 7 9 ) . W i t t r o c k s u g g e s t s t h a t l e a r n i n g b y r e a d i n g v e r b a l m a t e r i a l i n v o k e s l e f t h e m i s p h e r e a c t i v i t y b u t n o t n e c e s s a r i l y t h e r i q h t h e m i s p h e r e t o a n y s i g n i f i c a n t d e g r e e . O t h e r r e s e a r c h e r s a r g u e t h a t l e a r n i n g v e r b a l m a t e r i a l e n g a g e s p r i m a r i l y t h e l e f t h e m i s p h e r e . I n o r d e r t o e n g a g e a d d i t i o n a l l y , t h e r i g h t h e m i s p h e r e a c o n c o m i t a n t h o l i s t i c , s i m u l t a n e o u s , o r p i c t o r i a l p r e s e n t a t i o n o f t h e s u b j e c t m a t t e r i s r e q u i r e d . W i t t r o c k f u r t h e r s t a t e s t h a t t h i s d u a l r e p r e s e n t a t i o n o f m a t e r i a l b e i n g l e a r n e d f a c i l i t a t e s t h e a c q u i s i t i o n p r o c e s s e s a n d e l i c i t s s u p e r i o r r e c a l l a n d c o m p r e h e n s i o n . T h e i d e a o f i n t e r h e m i s p h e r i c e n h a n c e m e n t i s c o m p a t i b l e w i t h s ome p s y c h o l o g i c a l r e p r e s e n t a t i o n a l p r o c e s s e s a s s u m e d t o b e i n v o l v e d i n t h e l e a r n i n g o f v e r b a l m a t e r i a l s . F o r i n s t a n c e , P a i v i o ' s ( 1 9 7 7 , 1 9 8 0 ) t h e o r y o f i m a g e r y p r o p o s e s a " d u a l c o d i n g h y p o t h e s i s " ( C f . B u g e l s k i , 1 9 7 4 ; B o w e r , C l a r k , L e s g o l d , & W i n z e n z , 1 9 7 0 ; K i n t s e h , 1 9 7 5 ; D e l i n , 1 9 6 9 , e t c . ) . T h i s t h e o r y s u g g e s t s t h a t v e r b a l a n d i m a g e r y i n f o r m a t i o n a r e r e p r e s e n t e d a n d p r o c e s s e d i n s e p a r a t e c o g n i t i v e s y s t e m s . T h e i m a g e r y s y s t e m i s a c t i v a t e d b y p i c t u r e s w h i l e t h e v e r b a l s y s t e m i s a c t i v a t e d b y l i n g u i s t i c s t i m u l i . A c c o r d i n g t o P a i v i o , i n t e r c o n n e c t e d n e s s r e f e r s t o t h e f a c t t h a t v e r b a l i n f o r m a t i o n c a n b e t r a n s f o r m e d i n t o n o n v e r b a l i n f o r m a t i o n a n d v i c e v e r s a a n d t h e a c t i v a t i o n o f b o t h s y s t e m s e l i c i t s s u p e r i o r r e c a l l . P a i v i o ( 1 9 7 5 ) h a s r e c e n t l y e l a b o r a t e d . h i s t h e o r y t o i n c l u d e n e u r o l o g i c a l ( i n t e r h e m i s p h e r i c ) c o n s i d e r a t i o n s . A l t h o u g h m u c h o f P a i v i o ' s w o r k d e a l t w i t h w o r d p a i r s a n d Brain and Learning 5 pictures there is considerable suggestion that this enhancement in performance via dual coding may also apply to the learning of textual material (Kintsch, 1975; Buzan, & Dixon, 1974; Lorayne & Lucas, 1974). Paivio (1980) suggests that mental images serve as visual aids representing knowledge in memory and cites experimental evidence that these images can be used as learning and memory enhancers in numerous tasks and thus be used as an informational base for cognitive operations as aids to new learning (Denburg, 1977). Some researchers have shown that pictures and other illustrations may have helpful effects oh' memory (Kosslyn, Holyoak, & Huffman, 1976; Nelson & McEvoy, 1979; Weaver & Stanny, 1978; Paivio, 1978; Srivastava, 1978, etc.) and there have been various suggestions that pictures can operate as advance organizers to summarize the studied verbal material. Other studies have not shown such positive findings perhaps due to the nature of the pictures used as adjuncts. The extent to which they capture comprehensively the fu l l complexity of information provided in the textual material, variations in their salience, etc, has not been shown. Buzan (1976, 1980) provides evidence that diagrammatic illustrations (patterned notes) sometimes in conjunction with pictures, can be very helpful in improving recall and comprehension of textual material. He proposes that such devices enable the learner to use both sides of his brain (Buzan, 1974, p.4) and has even developed programs to teach individuals to create their own picture-diagrams to represent various bodies of knowledge. Brain and Learning 6 Wittrcck (1967, 1974, 1975); Wittrock, Marks & Doctorow (1975) and Wittrcck and Lumsdaine (1977) do not exclusively specify that the coding necessarily be pictorial to activate the right hemisphere, but that other forms of holistic encoding could also accomplish this, and adjuncts such as induced imagery, advance organizer and taxonomic organization provide vehicles to the integration of information. Hence, there might be a possibility that such holistic (right hemisphere) encodings could be activated via such verbal learning adjuncts as imagery instructions (induced imagery), picture diagrams, (imposed imagery) or taxonomic organization. Related variables from the educational psychology literature such as advance organizers (Ausubel, 1960, 1962, 1977) or adjunct questions (Rothkopf, 1970) might also accomplish this. This is especially plausible in light of the fact that induced imagery, picture diagrams and taxonomic organization have frequently been reported in the research literature as enhancers for verbal learning, and that Wittrock's (1978) theory of generative learning specifies these methods as enhancers of recall and comprehension. In pilot studies I have replicated some of the above findings (i.e. see Carsley, 1981, 1982 for the enhancing effects of imagery and taxonomic organization cn learning). But there remains the question as to whether this enhancement occurs by virtue of invoking the right brain hemisphere as would be suggested by Wittrock, or by some other means. According to Ornstein (1973) there may be a number of kinds of stimulation that could invoke the right brain hemisphere during verbal B r a i n a n d L e a r n i n g 7 l e a r n i n g a l t h o u g h e a c h m e t h o d c o u l d d o s o i n a s l i g h t l y d i f f e r e n t m a n n e r . O r n s t e i n a l s o p r o v i d e s e m p i r i c a l e v i d e n c e s h o w i n g d i f f e r e n t i a l ' h e m i s p h e r i c a c t i v i t y d e p e n d e n t u p o n t h e n a t u r e o f t h e p r e s e n t a t i o n o f t h e m a t e r i a l b e i n g s t u d i e d ( e . g . d i s c r e t e v s . c o n t i n u o u s o r v e r b a l v s p i c t o r i a l ) . T h e o b j e c t i v e o f t h i s s t u d y w a s t h u s t o i n v e s t i g a t e w h i c h , o f s ome o f t h e m o s t c o m m o n l y c o n s i d e r e d i n t h e l i t e r a t u r e , e n h a n c i n g t e c h n i q u e s m a x i m i z e s u c h e n g a g i n g o f t h e w h o l e b r a i n ( b o t h h e m i s p h e r e s ) a n d w h e t h e r s u c h e n h a n c i n g t e c h n i q u e ( s ) c o r r e s p o n d t o t h a t w h i c h i n d u c e ( s ) s u p e r i o r r e c a l l a n d c o m p r e h e n s i o n o f t h e v e r b a l m a t e r i a l l e a r n e d . P s y c h o l o g i c a l R e p r e s e n t a t i o n P r o c e s s e s I n d u c e d i m a g e r y . T h e b o d y o f l i t e r a t u r e o n v i s u a l i n d u c e d i m a g e r y s e e m s t o d e a l w i t h g i v i n g s u b j e c t s i n s t r u c t i o n s t o v i s u a l i z e , i n t h e m i n d ' s e y e , v i v i d ( M o n t a g u e & C a r t e r , 1 9 7 3 ) a n d a c t i v e i m a g e s d e p i c t i n g t h e c o n t e n t o f w h a t i s b e i n g l e a r n e d ( L e v i n & D e v i n e - H a w k i n s , 1 9 7 4 ) . T h e r e i s , h o w e v e r , c o n t r o v e r s y i n t h e l i t e r a t u r e c o n c e r n i n g w h e t h e r a d u l t s t u d e n t s b e n e f i t f r o m b e i n g g i v e n a m n e m o n i c s t r a t e g y s u c h a s " i m a g e r y i n s t r u c t i o n s " , a n d r e s e a r c h e r s s u c h a s R o h w e r ( 1 9 6 8 , 1 9 7 3 ) s u g g e s t d e v e l o p m e n t a l c h a n g e s d u r i n g m i d c h i l d h o o d a n d a d o l e s c e n c e . G i v e n a l e a r n i n g t a s k s ome d a t a i n d i c a t e t h a t t h e l a t e m i d d l e c h i l d h o o d s u b j e c t may n o t l i k e l y b e a b l e t o m e d i a t e a s s o c i a t i o n s ( b y e l a b o r a t i o n ) b e t w e e n w o r d s t o b e r e m e m b e r e d . R o h w e r ( 1 9 7 3 ) c l a i m s t h a t i t w o u l d p r o b a b l y n o t o c c u r t o s u c h a c h i l d t o p i c t u r e m e m o r a b l e i n t e r a c t i o n s b e t w e e n w o r d r e f e r e n t s a n d t o c r e a t e a s t o r y . I n o t h e r B r a i n a n d L e a r n i n g 8 w o r d s t h i s i n d i v i d u a l w o u l d n o t s p o n t a n e o u s l y e l a b o r a t e d e s p i t e t h e f a c t t h a t h e may p r o f i t f r o m s u c h e l a b o r a t i o n a n d i n d e e d s e e m s t o w h e n e x p l i c i t l y i n s t r u c t e d t o d o s o . O n t h e o t h e r h a n d , R o h w e r ( 1 9 7 3 ) m a i n t a i n s t h a t t h e t e n d e n c y t o d o e x a c t l y t h a t ( p i c t o r i a l e l a b o r a t i o n ) d o e s d e v e l o p d u r i n g a d o l e s c e n t y e a r s , a t l e a s t a m o n g h i g h e r a b i l i t y s u b j e c t s ( R o h w e r & L e v i n , 1 9 7 1 ) , t h u s s u g g e s t i n g t h a t i n s t r u c t i o n s t o e l a b o r a t e m a y n o t b e n e c e s s a r y f o r a d o l e s c e n t s u b j e c t s o r a t l e a s t o n l y b e n e e d e d a s m i n i m a l p r o m p t s . H e n c e , a d o l e s c e n t s m a y n o t i m p r o v e w i t h s u c h i n s t r u c t i o n s s i n c e t h e i n s t r u c t i o n s w o u l d o n l y b e t e l l i n g t h e m t o d o s o m e t h i n g w h i c h t h e y a l r e a d y d o . D a t a r e p o r t e d b y o t h e r r e s e a r c h e r s ( B o w e r & W i n z e n z , 1 9 7 0 ; B u l l & W i t t r o c k , 1 9 7 3 ; D e l i n , 1 9 6 9 ; M u e l l e r & J a b l o n s k i , 1 9 7 0 ; W o o d , 1 9 6 7 , B u g e l s k i , 1 9 7 4 ) d e m o n s t r a t e t h e s i g n i f i c a n t b e n e f i c i a l e f f e c t s o f i n s t r u c t i n g a d o l e s c e n t s t o u s e p i c t o r i a l e l a b o r a t i o n . T h e s e r e s e a r c h e r s i n s t r u c t e d g r o u p s o f c o l l e g e s t u d e n t s t o l e a r n l i s t s o f w o r d s ( s e r i a l l y ) b y l i n k i n g t h e i t e m s t o g e t h e r i n t o a s t o r y w i t h v i v i d i m a g e r y . T h i s m e t h o d i s r e p o r t e d t o h a v e h e l p e d p e o p l e l e a r n t h e l i s t s f a s t e r a n d m a k e f e w e r e r r o r s i n r e c a l l . I n B u g e l s k i ' s ( 1 9 7 4 ) e x p e r i m e n t , f o r i n s t a n c e , c o l l e g e s t u d e n t s who u s e d t h e p i c t o r i a l e l a b o r a t i o n t e c h n i q u e r e c a l l e d a n a v e r a g e o f t h r e e t i m e s a s m a n y w o r d s i n o r d e r a s d i d t h e s t u d e n t s w h o d i d n o t r e c e i v e i n s t r u c t i o n s t o d o s o . L e v i n ( 1 9 7 3 ) , w o r k i n g w i t h f o u r t h a n d f i f t h g r a d e r s f o u n d t h e e f f e c t o f n a r r a t i v e p r o m p t s v a r i e s w i t h t h e n u m b e r o f s e n t e n c e s c o m p r i s i n g t h e n a r r a t i v e g e n e r a t e d a n d t h e p a r t i c u l a r o r d e r . Brain and Learning 9 Lorayne and Lucas (1974) describe a method of applying imagery to enhance learning and recall of prose material. It consists of forming, in the mind's eye, vivid personally memorable pictures representative of the content of what one is reading. Abstract words or ideas are pictorally represented by concrete images that can stand for them and the series of personal images should be made as vivid and interactive as possible. Since Kintsch (1975) has shown that the learning dynamics for prose are essentially the same as for word list s , this technique was expected to improve recall of prose material. It was also expected to improve comprehension (Levin, 1972, 1973). The learning of prose material such as that in an Introductory Psychology text would thus be expected to be amenable to enhancement via these kinds of adjuncts (induced imagery). Pictures and diagram illustrations. These refer to the presentation to the learner of concomitant pictorial stimuli or combined pictorial, diagrammatic and synthetic verbal stimuli. There is ample evidence demonstrating the beneficial effects of such pictorial presentations as adjuncts to learning textual material (Levin & Lesgold, 1978). Some findings, however, have not always demonstrated such positive effects. Some reported that self generated imagery may surpass picture presentation (imposed imagery) as a verbal learning adjunct, and that, in some cases, pictures might distract from the reading task. This may well be tempered, however, by the fact that, generally, recall of pictures has been found to surpass recall of words at a l l age levels (Parker, 1981; Rohwer, 1973; Peloquin, 1979). Brain and Learning 10 It was found by Chmielewska (1975) that lecture plans incorporating a pictorial mode were most effective, even more than questions or other statements in increasing the "scope, durability and conciseness" of content understanding and recall by students. Stone and Glock (1981) studied the effect of illustrations as adjuncts to text on procedural information in 90 university undergraduates and reported positive findings and suggested that certain types of information are more effectively presented in combination with pictorial illustrations (Schallert, 1980). Others, however, such as Duchastel (1980) reported a lack of enhancement of retention of verbal material presented in conjunction with illustrations, and suggest that refinements to the theory need be specified. However, an important issue they seem to have ovelooked is the nature of the illustrations and the extent and manner in which they // capture the content of the verbal material. Using 12 and 13 year olds, Haring (1978), however, obtained pictorial facilitation of immediate and delayed recall with story-like verbal material and, also using undergraduates, Stopher and Kirsner (1981) suggested that depending upon whether unique or shared concept combinations are involved, the study of pictorial items positively influenced retention of sentences with which they shared a concept. The work and teachings of Buzan (1976, 1980) suggested that combined diagrammatic and pictorial presentation before a "to be learned" body of information can significantly enhance comprehension and recall. In The Human Brain, Wittrock, Beatty, Bogen, Gazzaniga, Jerison, Krashen, Nebes & Teler, Brain and Learning 11 (1977), described similar methods of pictorial representation which purport to enhance learning and memory. In a review of the literature, Levin (1981) proposed that methods combining pictures with key words are the "up and coming" mnemonic of the 80's for improving learning and memory. He refered to their "proven effectiveness", "versatility", "adaptability to student differences", and "potential to foster creativity and logical thinking". Levin (1973) found positive outcomes of pictorial mnemonics using children. Others too have obtained similar results using pictures. Purkel and Bornstein (1980) found that pictures (or imagery) enhanced recall of sentences in children. Rusted and Coltheart (1979) investigated the effects of pictures on memory of new words and prose passages in 9 to 12 year olds, good and poor readers. They found that the pictures signficantly improved recall and that there was no interaction with reading ability. The pictures, however, were found to have no effect on recognition or pronunciation. Also using children Murphy and Wood (1981) found that pictorial information significantly improved task performance. Borys (1978) found that experimenter supplied pictures helped recall of prose in retarded adolescents. Bender and Levin (1978) obtained similar results with retarded 10-16 year old children. Using undergraduates, Snodgrass asnd Asiaghi (1977) found that learning with pictures could help concept comprehension in a recognition test. Dragone, Brown, Krane and Krane (1980) found evidence of hypermnesia (increment in recall over multiple recall attempts) when word lists were presented with pictures. Similarly, Brain and Learning 12 Parker (1981) found beneficial effects of pictures but mostly for "recency items". Pictures have been found to also facilitate paired associate learning in children and adolescents especially i f the pictures were such as to elaborate the pairs of stimuli. Some critics have argued that pictures may have only marginal effects, and others who have not obtained positive outcomes, argue that pictures do not help and in some cases can distract (e.g. Samuels, 1977; Willows, 1978; and Thomas, 1979). However, i t seems that the pictures used in these various studies may not be equivalent or even comparable insofar as their nature and the effects they can be expected to produce. There have been many studies comparing the effects of pictures (imposed imagery) to those of subject generated imagery (induced imagery) and the findings have been contradictory. There seems to be lack of agreement about how these effects change with age and about the different focus of the studies. For example some studies present the picture as targets of study and use words as labels, others focus on the verbal learning and use the picture as adjuncts. So, different outcomes might be attributable to the nature of the task required and how it relates to the adjunct or learning enhancer provided. An integration of findings obtained in the research, however, seems to suggest that pictures are generally better remembered than words over a l l ages. Concerning the controversy about whether imposed imagery is better than induced self generated imagery in verbal learning, a synthesis of the research reveals complex interactions. In general, Brain and Learning 13 self generated (induced) imagery may be more advantageous. Various authors have explained this as being due to the more personal nature of self generated imagery and the attendant greater likelihood of producing better associative links. Others have found only slight overall differences or none (Purkel, & Bornstein, 1980) between these two forms of imagery (Snodgrass & Asiaghi, 1977) and ascribe the superiority of a l l forms of imagery to superior sensory and meaning codes. It would, however, seem that the nature of the verbal material to be learned might also be an important determining factor often overlooked. If one were concerned with developmental differences the age variable might also interact in a complex way. Since hemispheric specialization has been shown not to be complete until adolescence (Tomlinson - Keasey, Kelly, & Burton, 1976) and there may be fairly wide individual differences insofar as the nature of and order of lateralization for various tasks (Turner & Miller, 1975) i t is not surprising that inconsistent findings were found concerning the age changes in response to pictures and induced self generated imagery. There is, however, agreement that lateralization is complete in most individuals by adolescence (Wittrcck, 1980; Springer & Deutsch, 1981). Hence work carried out to study these problems with adults might yield more stable findings due to considerable and differing developmental variability. In using presented pictorial stimuli to enhance the verbal textual material, the nature of these stimuli is thus an important, perhaps cri t i c a l , consideration in determining whether the stimuli can Brain and Learning 14 have the desired enhancing effect. If the pictorial stimuli provide sufficient conceptual details to capture the equivalent to the text and induce further elaboration of this material, i t seems likely that they might have an enhancing effect on comprehension and memory. Not any kind of picture, however, can be expected to have an impact on the learner, and the kinds of pictures used need to be tailored to the subject matter. Picture-diagram stimuli which allow rehearsal (Irvin, 1976) and provide additional facilitation and content clarification (Levin, et al, 1977), perhaps by making an elaboration of the material, would be expected to enhance learning perhaps by activating significant areas from both brain hemispheres (Tomlinson - Keasy, Kelly & Burton 1979). Measures of learning performance. Mayer1s work and other experiments that endeavor to test the effects of various learning conditions, or strategies, upon verbal learning performance often concern themselves with different measures of performance. Some examine the effects of various manipulations upon verbatim memory, others consider thematic recall, others consider reading improvement and others comprehension. Sets of conditions which maximize a given measure of verbal performance may not necessarily be the same ones that would maximize another aspect of performance. In other words, depending upon desired outcomes specific learning conditions may e l i c i t different results. Yet, Kintsch (1975) maintains that there is "a striking continuity between memory for word lists and memory for text" (p. 169). He further suggests that the parallels between l i s t learning Brain and Learning 15 and the results of research with texts may be indicators of a "common process" and that the study of textual material can be built upon the solid base of facts and the relatively advanced theoretical understanding which exists in l i s t learning research. Thus, Kintsch's (1974) theory of episodic memory for l i s t learning is said to be extendable to text memory. Kintsch (1975) assumes that the "encoding and storage operations in memory are basically the same whether the material to be learned consists of word li s t s or prose paragraphs" (Kintsch 1975, p. 269). With word list s , Kintsch asserts, processing is necessarily restricted to lower levels of analysis. Syntactic and semantic processing is possible only in a very limited way. Text comprehension on the other hand, involves complex processes at the syntactic and semantic levels, and a need for multiple memory representation arises. Kintsch's (1974) broad theory brings together specific submodels and a wide variety of empirical results by means of a few key concepts and processing assumptions. His theory seems logical and may have overemphasized the similarity between word lists and prose, and does not specify the degree of divergence of word lists from various kinds of prose (i.e. story vs. technical prose, etc.). Since, assuming Kintsch's (1977) theory to be tenable, the presentation of material by way of definitions has approximately equal effect upon comprehension and memory (Anderson & Kulhavy, 1972), comprehension and recall seem like the most educationally relevant variables to study. Comprehension and recall would, however, not be orthogonal. If the theory that superior students already use organizing Brain and Learning 16 and mediating strategies is tenable as well as Ausubel and Fizgerald's (1962), one would expect that those who do not use these strategies already (on the basis of the above rationale with low grade-point-average) would be maximally helped by instructions to do so. A test of the effectiveness of induced imagery and picture diagrams for the learning of material already reasonably organized such as a chapter on "Psychopathology" from a first year college Psychology text was expected to shed light on the processes (Pirozzoio & Wittrock, 1981) involved as well as provide some clarification concerning when each of these techniques might most beneficially be used in teaching. Other related variables Although there are other structural and/or process variables, such as note taking, taxonomic organization, advance organization, symbolic cues around words, questions and other mathemagenics which have been proposed as enhancers of learning, only fragmented knowledge about their function exists. The suggestion that these might invoke possible increase in involvement of the right cerebral hemisphere is interesting. Taxonomic organization of textual material is analogous to l i s t blocking in the learning of word l i s t s . It is a hierarchially arranged organizational summary of the material. Wittrock and Carter (1975) and Ornstein (1970) reported positive effects of taxonomic organization providing a proper hierarchy is used. Material can be provided with organization in a number of other ways, for instance, according to Ausubel (1960, 1977), an early proponent of assimilation theory and developer of the concept "advance organizer", an advance Brain and Learning 17 organizer consists of an adjunct presented before the learned material which links the new material to known knowledge. Many other researchers such as Wittrcck (1980) have also concluded that advance organizers may improve comprehension of prose passages. Richards (1959) used specialized symbols placed around text words to cue analytic behaviors during reading and reported positive effects. Smith and Kulhary (1974) examined the influence of adjunct rules and objectives upon recall without consistent findings. Whereas Rothkopf (1972) reports increases in performance by the use of objectives, others have failed to find such effect. Adjunct rules are also ambiguous with respect to whether they enhance learning or not. Rothkopf (1970) describes any activity that determines and influences the nature of the learning process a "mathemagenic". He also (1966, 1969) provides evidence that questions, before or after a prose text may predictably influence direct and indirect retention which was also supported by Frase (1968). The suggestion is that such adjuncts shape inspection behaviors during reading. Questions, however, can be provided in various ways. For instance, they can be asked during instruction about every important point students should master or they can be more general. They can be spaced in different ways (e.g. after a passage, before a passage, interspersed between paragraphs) but generally, the closer they are to the target information, the better. Response modes (i.e. mulitple choice vs short answer items) also e l i c i t different outcomes. The most accepted theory seems to be that post generations reinforce learning responses by B r a i n a n d L e a r n i n g 1 8 i n v o k i n g a p p r o p r i a t e r e a d i n g s k i l l s i n t h e w a y o f i n s p e c t i o n b e h a v i o r s c o n s i s t e n t w i t h o b j e c t i v e s i m p l i c i t i n t h e q u e s t i o n s . P r e - q u e s t i o n s a r e r e p o r t e d t o i n f l u e n c e r e t e n t i o n o f s p e c i f i c v e r b a t i o n r e c a l l w h e r e a s p o s t q u e s t i o n s f a c i l i t a t e m o r e g e n e r a l c o n c e p t u a l l e a r n i n g a s r e l a t e d t o a " t r a n s f e r t y p e " l e a r n i n g . A l t h o u g h t h e t y p e o f m a t e r i a l s u s e d w e r e r e p o r t e d t o h a v e n e g l i g i b l e e f f e c t u p o n t h e i n f l u e n c e o f q u e s t i o n s g i v e n t h e s u g g e s t i o n o f D o n a l d ( 1 9 8 0 ) , i t s e e m s c l e a r t h a t i n s u f f i c i e n t a t t e n t i o n m a y h a v e b e e n g i v e n t o t h i s p o i n t . Q u e s t i o n s m a y t h u s b e m o t i v a t i o n a l . T h e y m a y a l s o h a v e a r o u s a l a n d a s s o c i a t i v e o u t c o m e s a n d c o n s e q u e n c e s o f t h e q u e s t i o n s f o r l e a r n i n g a n d r e m e m b e r i n g a n d k n o w l e d g e a b o u t q u e s t i o n i n g m a y h a v e i m p o r t a n t i m p l i c a t i o n s f o r e d u c a t i o n . F i n d i n g s f r o m e m p i r i c a l r e s e a r c h s t u d i e s w i t h o u t t h o u g h t f u l c o n c e p t u a l i z a t i o n s , w i t h o u t e x p l i c i t r e s p o n s i b i l i t y f o r d e v e l o p i n g t h e o r y o f i n s t r u c t i o n a n d w i t h o u t c o n t r i b u t i o n t o k n o w l e d g e a b o u t i n s t r u c t i o n ( W i t t r o c k 1 9 6 7 , p . 1 ) s e e m t o c h a r a c t e r i z e m u c h o f t h e r e s e a r c h , s o f a r , i n e d u c a t i o n a l p s y c h o l o g y . T h e p r e s e n t s t u d y c o u n t e r a c t s t h e s e d e f i c i e n c i e s b y f o c u s i n g u p o n t h e r e p o r t e d l y m o s t p o t e n t l e a r n i n g a d j u n c t s a n d r e l a t i n g t h e i r e f f e c t t o W i t t r o c k ' s e m e r g i n g t h e o r y o f i n t e r h e m i s p h e r i c b r a i n e n g a g e m e n t . A l t h o u g h W i t t r o c k ' s t h e o r y s u g g e s t s o t h e r p o s s i b l e e n h a n c e r s t h e p r e s e n t s t u d y d i d n o t i n v e s t i g a t e t h e s e b u t f o c u s e d o n i m a g e r y i n s t r u c t i o n s a n d p i c t o r i a l d i a g r a m s o n l y . Brain and Learning 19 Brain Neurophysiological Correlates of Learning M a n y studies on neurophysiological correlates of learning have involved examining patterns of electrical brain activity during training. Some have involved electroencephalographs (e.g. Barratt, 1956), some brain blood flow (e.g. Franzen & Ingvar, 1975), and others brain blood temperatures (Minard & Coponan, 1963) which are a reflection of blood flow and metabolic activity. The present study is primarily concerned with neurophysiological correlates of learning only in terms of electroencephalographic responses and temperature change in the brain. Therefore, reported studies involving these and related aspects of the brain activity only are examined in the following sections. General cerebral function. The Cerebral Cortex can broadly be divided into two sections: one for reception and the other for execution. The parietal, occipital and temporal lobes seem mainly concerned with reception, perception and interpretation whereas the frontal lobes generally seem concerned with execution or action. The post central gyrus in the parietal lobe and its adjacent-areas of the superior and inferior parietal lobules are responsible for the reception of somatosensory data and its interpretation, respectively. Heschl's transverse gyri in the superior temporal gyrus (temporal lobe) and the adjacent planum temporale and middle temporal gyri seem responsible for auditory reception and interpretation respectively. In the lips of the calcarine sulcus and adjacent regions of the occipital lobe l i e visual reception and its interpretive areas, respectively. These visual interpreting areas also have a region that B r a i n a n d L e a r n i n g 20 g o v e r n s , v i a c o r t i c o t e c t a l f i b e r s , i n v o l u n t a r y c o n j u g a t e e y e m o v e m e n t s , s u c h a s t r a c k i n g a n o b j e c t . Some p l a y a r o l e i n t h e a c c o m o d a t i o n a n d c o n v e r g e n c e r e f l e x v i a E d i n g e r W e s p h a l n u c l e i a n d o c u l a r n u c l e i . T h e l a r g e r e g i o n o f c o n f l u e n c e o f t h e p a r i e t a l , o c c i p i t a l a n d t e m p o r a l l o b e s ( a r o u n d t h e a n g u l a r g y r u s a n d i n f e r i o r p a r i e t a l l o b u l e a n d p o s t e r i o r a n d i n f e r i o r t e m p o r a l g y r i ) a r e a b s t r a c t i n t e r p r e t i v e a r e a s s o m e t i m e s r e f e r r e d t o a s g e n e r a l a s s o c i a t i v e a r e a s b e c a u s e a b s t r a c t i n t e r a c t i o n a n d s y n t h e s i s o f s e n s o r y m o d a l i t y d a t a s e e m s t o o c c u r h e r e . H e r e , d a t a s e e m s t o b e c a r r i e d i n c o d e s t h a t a r e r e m o v e d f r o m a n d t r a n s c e n d t h e s e n s o r y i m p r e s s i o n s a n d t h e s e c o d e s r e a d i l y i n t e r a c t w i t h d a t a f r o m o t h e r m o d a l i t i e s . T h e p r e c e n t r a l g y r u s a n d a d j a c e n t r e g i o n s o f t h e s u p e r i o r , m i d d l e a n d i n f e r i o r f r o n t a l g y r i ( p r e m o t o r ) s e e m i n v o l v e d w i t h s p e c i f i c v o l u n t a r y m o t o r a c t i o n a n d h i g h e r l e v e l m o t o r s e q u e n c e s , r e s p e c t i v e l y . A r e g i o n i n t h e p o s t e r i o r m i d d l e f r o n t a l g y r u s c o n t r o l s v o l u n t a r y c o n j u g a t e g a z e a n d may b e i m p o r t a n t i n r e a d i n g b e h a v i o r . O c u l o m o t o r a n d a b d u c e n s c r a n i a l n e r v e n u c l e i a r e c o o r d i n a t e d v i a t h e m e d i a l l o n g i t u d i n a l f a s c i c u l u s b y t h e p a r a b d u c e n s n u c l e u s w i t h i n f o r m a t i o n f r o m t h e o p t i c n e r v e , t h e p r e t e c t a l n u c l e u s , t h e s u p e r i o r c o l l i c u l u s a n d o c c i p i t a l l o b e a s s o c i a t i o n a r e a s . T h e m o r e a n t e r i o r r e g i o n s o f t h e s u p e r i o r , m i d d l e a n d i n f e r i o r f r o n t a l g y r i ( p r e f r o n t a l c o r t e x ) t o t h e f r o n t a l p o l e s e e m i n v o l v e d w i t h h i g h e r l e v e l e x e c u t i o n s u c h a s I n s e r t F i g u r e 1 a b o u t h e r e Brain and Learning 21 planning, foresight and judgement. A recent study by Bogen (1983) implicates the prefrontal lobes particularly the right one in creativity, and the study by Milner (1983) implicates them in delayed free recall. P.E.T. scan findings by Ingvar (1976) suggest that the prefrontal lobes may be involved in many activities, perhaps involved in response to the limbic system. In the opercular and triangular regions of the inferior frontal gyrus in the left hemisphere lies Broca's area, an important center in expressive language production. Covering the left hemisphere auditory association areas of the planum temporale and extending, according to some authors, to the angular gyrus, lies Wernicke's area. This region is essential for language comprehension. The arcuate fasciculus joining these two language zones also plays an essential role in language related activities. .// Homologous sites of the right cerebral hemisphere function in a way generally similar to those on the left and govern functions of the opposite side of the body. Some systems, though, have bilateral innervation and uncrossed systems function ipsilaterally. Areas of the right hemisphere corresponding to the language areas of the left, however, seem to possess specialized functions and their manner of processing information may be different. Such areas of the right hemisphere appear to play a role in visuospatial and configurational functions as well as in music appreciation. Spatial orientation, color and form perception may be organized in the areas of the right cortex corresponding to Wernicke's and Broca's areas in the left. Such an Brain and Learning 22 area has been discovered in the superior and inferior parietal lobules and right cortical regions of the superior and middle temporal gyri and the planum temporale are also involved with music. Of interest in the present study, however, are the general interpretive areas of the angular gyrus, inferior parietal lobule (areas involved in abstractive association sometimes referred to as "ideational language areas", "general interpretive areas", or sometimes considered part of Wernicke's area) and posterior and inferior regions of the temporal lobes which are claimed to be involved in memory (Milner, 1983). Brain hemispheric specialization. Al though each hemisphere has the potential for many functions and both sides of the brain participate in most activities (theory of mass action), in the normal person the two hemispheres tend to specialize. The left hemisphere is predominantly involved with analytic logical thinking as in verbal and mathematical functions. Its mode of operation appears primarily linear. It processes information sequentially so, implies logical thought and linear time. Sequence, order, language and mathematics, seem to be primarily left hemisphere activities. The right hemisphere seems specialized for holistic (synchronic) functions. Its language abilities appear limited, but i t seems to function in spatial tasks, imagery, facial recognition and comprehending pictures. It is believed to process information more diffusely than the left, and its responsibilities seem to demand a ready integration of many inputs at once. The right hemisphere is thus Brain and Learning 23 more holistic and simultaneous in its mode of operation (Ornstein, 1972). Neurological evidence on the main functions of the two cerebral hemispheres comes mainly from people whose brains have been damaged by accident or illness, or surgery had been performed on them. The work of Penfield (1951, 1952, 1975) and Penfield and Roberts (1959) on brain stimulation has also been very enlightening. Overall findings show that subjects with lesions to the right hemisphere display deficits related to imagery, spatial comprehension and manipulation although their language function usually remains intact, whereas patients with lesions to the left hemisphere display linguistically related impairments (various forms of aphasias) or computational deficits, although their spatial or pictorial abilities tend to remain intact. Milner, Branch, and Rasmussen, (1964) have studied the specific disorders resulting from such brain lesions. They found that lesions to the right hemisphere severely impair performance in visual and spatial mazes, produce spatial agnosia and facial agnosia, whereas lesions in contralateral homologous zones of the same extent produce no deficits for these tasks. Volpe-, Ledoux and Gazzaniga (1979) found the "neglect" syndrome in many patients with right hemisphere damage and various degrees of homonymous hemianopsia depending on the caudal extent of the damage. Milner, et al. (1964) also found that lesions in specific areas of the left hemisphere produce specific language disorders. Lesions (Milner, 1954, 1970) in the anterior left temporal lobe produce verbal memory deficits; lesions in the posterior left Brain and Learning 24 temporal lobe produce speech impairment; damage to the arcuate fasciculus produces conduction aphasia (lack of access to content of language); damage to Broca's area produces an inability to utter normal speech (expressive aphasia) though the semantic content and grammatical structure may be normal; damage to Wernicke's area produces an inability to understand both spoken or written language (receptive aphasia) (Geschwind, 1970); damage to the fibers which connect the occipital cortex to the left hemisphere results in alexia without necessarily agraphia (Geschwind, 1965) but a motor alexia can "5. be produced by lesions in Broca's area. Split brain studies (Sperry, 1966, 1974; Bogen, & Vogel, 1962; Gazzaniga & Sperry, 1967) collectively substantiate the findings from studies of brain lesions concerning the functional purpose of various regions of the human brain. Subtle tests of commissurotomized individuals have supported the findings concerning specialization of each hemisphere. The left hemisphere is specialized for language related functions (speaking, writing, reading, hearing and comprehending language, etc.), whereas the right hemisphere is specialized for spatially or holistically, (gestalt) related functions (form and shape recognition and comprehension, imagery and pictorial representation, figures etc.). Such tests have shown that, whereas the left hemisphere operates largely in a sequential manner, the right hemisphere operates predominantly in a simultaneous manner - i t integrates diverse inputs quickly. Careful tests of these split brain patients also demonstrate the effects of isolation of the capabilities B r a i n a n d L e a r n i n g 2 5 i n h e r e n t i n e a c h h e m i s p h e r e . F o r i n s t a n c e , l i n g u i s t i c a l l y r e l a t e d t a s k s s e n s o r i l y s e n t t o t h e r i g h t h e m i s p h e r e c o u l d n o t b e c a r r i e d o u t . S p a t i a l o r p i c t o r i a l t a s k s s e n s o r i l y d i r e c t e d t o t h e l e f t h e m i s p h e r e c o u l d n o t b e c a r r i e d o u t . G e s c h w i n d (1970, 1979) h a s c a l l e d a t t e n t i o n t o t h e f a c t t h a t u n d e r s t a n d i n g o f w r i t t e n l a n g u a g e r e q u i r e s t h a t s e n s o r y i n f o r m a t i o n i n t h e v i s u a l c o r t e x r e a c h W e r n e c k i ' s a r e a b y m e a n s o f t h e a n g u l a r g y r u s a n d h a s f o u n d i n t e r e s t i n g v a r i e t i e s o f d y s l e x i a f o l l o w i n g l e s i o n s i n t h e s e p a r t s o f t h e b r a i n . G e s c h w i n d c i t e s a p a t i e n t w h o s u d d e n l y l o s t t h e a b i l i t y t o r e a d ( a l e x i a ) , a n d a l o n g w i t h i t s ome a b i l i t y t o s e e i n t h e r i g h t v i s u a l f i e l d . P o s t m o r t e n e x a m i n a t i o n r e v e a l e d s ome d a m a g e t o t h e l e f t v i s u a l c o r t e x ( w h i c h a c c o u n t s f o r t h e p a r t i a l l o s s o f v i s i o n i n t h e r i g h t v i s u a l f i e l d ) , a n d t h e p o s t e r i o r p a r t ( s p l e n i u m ) o f t h e c o r p u s c a l o s s u m w h i c h n o r m a l l y c o n v e y s m e s s a g e s f r o m t h e r i g h t v i s u a l c o r t e x t o t h e l e f t h e m i s p h e r e ( w h e r e r e a d i n g f u n c t i o n s a r e p r o c e s s e d ) . V i s u a l m e s s a g e s w h i c h w e r e r e c e i v e d b y t h e r e m a i n i n g v i s u a l c o r t e x i n t h e r i g h t h e m i s p h e r e c o u l d n o t b e c o n v e y e d t o W e r n i c k e ' s a r e a i n t h e l e f t b r a i n h e m i s p h e r e . I t h a s a l s o b e e n f o u n d t h a t w i d e s p r e a d d a m a g e t o t h e s e a n d n e i g h b o r i n g a r e a s c a n p r o d u c e g l o b a l a p h a s i a . S t u d i e s i n v o l v i n g t h e W a d a t e s t a l s o s u p p o r t s u c h f i n d i n g s c o n c e r n i n g t h e p r i m a r y l o c a l i z a t i o n o f f u n c t i o n s i n t h e h u m a n . - Wada a n d R a s m u s s e n ( 1 9 6 0 ) d e m o n s t r a t e d t h a t , i f t h e l e f t h e m i s p h e r e i s t e m p o r a r i l y a n e s t h e t i z e d , l o s s o f l a n g u a g e f u n c t i o n s r e s u l t . T h i s d o e s n o t h a p p e n i f c o r r e s p o n d i n g p a r t s i n t h e r i g h t h e m i s p h e r e a r e a n e s t h e t i z e d . O t h e r s t u d i e s u s i n g n o r m a l a d u l t s u b j e c t s h a v e s h o w n B r a i n a n d L e a r n i n g 2 6 t h a t w h e n l a n g u a g e t a s k s a r e d i r e c t e d t o t h e l e f t h e m i s p h e r e , a c c u r a c y a n d r e a c t i o n t i m e s a r e b e t t e r t h a n w h e n d i r e c t e d t o t h e r i g h t o n e , W h e n s p a t i a l t a s k s a r e d i r e c t e d ( i n t h e n o r m a l p e r s o n ) t o t h e r i g h t h e m i s p h e r e a c c u r a c y a n d r e a c t i o n t i m e a r e b e t t e r t h a n w h e n d i r e c t e d t o t h e l e f t ( M c K e e v e r , & H u l i n g 1 9 7 0 ) . I n a d d i t i o n , D u r n f o r d a n d K i m u r a ( 1 9 7 1 ) i n a c a r e f u l l y c o n t r o l l e d e x p e r i m e n t w i t h n o r m a l s u b j e c t s f o u n d t h e r i g h t h e m i s p h e r e t o b e s u p e r i o r i n d e p t h p e r c e p t i o n . D e p t h p e r c e p t i o n o b v i o u s l y r e q u i r e s f a i r l y c o m p l e x i n t e g r a t i o n a n d c o m p r e h e n s i o n o f p o s i t i o n , s i z e , s h a d i n g , o v e r l a p , k n o w n s t a n d a r d s , r e t i n a l d i s p a r i t y , p e r s p e c t i v e e t c . I t h a s a l s o b e e n d i s c o v e r e d t h a t t h e y t e n d t o b e q u i c k e r t o s i g n a l " s a m e " t o l e t t e r s w h i c h a r e p h y s i c a l l y ( p i c t o r i a l l y ) s i m i l a r ( E E ) i f t h e v i s u a l s t i m u l i a r e d i r e c t e d t o t h e r i g h t h e m i s p h e r e . I n c o n t r a s t , t h e s e s u b j e c t s a r e q u i c k e r t o d e t e c t t w o l e t t e r s , o f d i f f e r e n t s h a p e b u t t h e s ame s e m a n t i c a l l y ( E e ) i f t h e s t i m u l i a r e d i r e c t e d t o t h e l e f t b r a i n h e m i s p h e r e ( C o h e n 1 9 7 3 ) . E y e m o v e m e n t s t u d i e s ( K i m u r a , 1 9 6 6 ) h a v e a l s o s u p p o r t e d t h e s e f i n d i n g s o n h e m i s p h e r i c s p e c i a l i z a t i o n ( B o g e n , D e z u r e , T e n h o u t e n & M a r s h , 1 9 7 2 ; a n d B a k a n , 1 9 6 9 ) . H u m p h r e y a n d Z a n g w i l l ( 1 9 5 1 ) h a v e f o u n d t h a t d a m a g e t o t h e r i g h t p a r i e t a l l o b e s e e m s t o i n t e r f e r e w i t h d r e a m i n g . A l s o B o g e n ( 1 9 7 7 ) n o t e d t h a t s p l i t b r a i n p a t i e n t s t e n d t o r e p o r t a n a b s e n c e o f d r e a m s a n d c o n c l u d e t h a t t h i s may b e b e c a u s e o f t h e i s o l a t i o n o f t h e p i c t o r i a l ( r i g h t ) h e m i s p h e r e f r o m t h e v e r b a l a n d t h u s n o a c c e s s o f d r e a m p i c t u r e i n f o r m a t i o n t o t h e v e r b a l h e m i s p h e r e . I n a d d i t i o n , d r a w i n g c a p a b i l i t i e s a n d m u s i c a l t a s k s s e e m l o c a l i z e d i n t h e r i g h t h e m i s p h e r e Brain and Learning 27 (Nebes, 1977). The findings of Murray & Carsley (1979) substantiate this and further suggest that the totality of interpersonal and environmental experiences created by the more successful music teachers is such as to invoke this right (minor) hemisphere of the brain. The findings of a l l these studies are not to say that the left hemisphere has no spatial ability at a l l and the right no language at a l l (Zaidel, 1973). It has been found that they possess a l i t t l e of each but that those respective functions (Milner, 1971) reside predominantly in their specialized hemisphere. The localization of functions in the brain appear analogous to overlapping contours of a geographical map or different intensities of waves originating from different focal points. Some functional parts of the brain or a given region of one of the hemispheres may be essential for a given function e.g. Broca's or Wernicke's area for language functions, the somatosensory strip for sensation or the borders of the calcarine fissure for vision. But there seems to be progressive overlap in function between zones in areas such as the prefrontal lobes, the middle and inferior temporal gyri and especially in areas of the angular gyrus and inferior parietal lobule. In those areas, information appears processed in codes that are not modality specific but seem to incorporate the elements of the main modalities of vision, auditory and somesthesis. The two hemispheric functions thus seem to exist as semiindependent information processing units with some overlap of function but with different specialties. The educator Jerome Bruner Brain and Learning 28 (1962) has made many references to this fact (derived from his observations and rinding in educational settings). His admonitions concerning learning through experiencing and discovery suggests that the brain nay be more receptive to comprehending and remembering knowledge obtained in ways that provide a more pictorial appreciation than merely reading about i t . Upon considering these findings Bogen (1977) suggests that instructional materials ought to stimulate not only the analytic and sequential functions (Mondani, 1977) of the left hemisphere but also the imaginal and holistic functions of the right, in view of the fact that i t is in the latter that creativity resides (Gowan, 1979). Bogen (1983) has found the 'right hemisphere plays an important role in creativity. It is believed that the use and development of both hemispheres is essential to complete mental functioning and that almost any idea can be learned more thoroughly i f methods involving both hemispheres are used (Milner, 1983; Bogen, 1983). Judging by the brain functioning of so-called gifted or creative geniusses of our time, i t would seem that these admonitions may be correct. For instance, Einstein reported using imagery for his greatest discoveries, Darwin's theory of evolution and Mendelleiv's discovery of the atomic chart were said to have been arrived at visually and Kekule reportedly discovered the Benzene ring in dream imagery. Brain electroencephalography (E.E.G.). E.E.G. studies of learning have examined changes in patterns of E.E.G. activity produced during learning. E.E.G. waves are summations of excitatory and Brain and Learning 29 inhibitory synaptic potentials of neurons. The E.E.G. represents oscillations in voltage potentials generated by cell neurons within the range of a recording electrode (Cotman & McGaugh, 1980). Evoked electroencephalographic potentials are E.E.G. waves time locked (i.e. recorded in conjunction with the presentation of) to specific stimuli. The question asked in such a study of E.E.G. correlates of learning is whether there are changes in the E.E.G. patterns that are associated specifically with the specific learning process. (i.e. evoked in the presence of learning stimuli and learned responses) In the 1950's many studies investigated E.E.G. activity in animals during learning and reliable outcomes were found in a variety of species. Other findings in a series of studies involving humans (John, 1967, 1972) indicate that learning produces highly specific changes in the wave shapes of evoked potentials recorded from several cortical brain regions. Wave shapes appropriate to the learned behavior consistently occurred in the later learning trails. It was found that responses could be predicted by the shape of the evoked potential elicited by the specific stimuli, which would not be elicited by other different stimuli that did not yield the responses. On the basis of such findings, John (1972) suggests that information about an experience is represented by coherent activity in assemblies of cells and that "the information is read out when the appropriate stimulus activates the representation system in such a way as to cause release of a common mode of activity like that stored during the learning experience" (John, 1972). Brain and Learning 30 A variety of other neurophysiological changes in brain response were found to occur during learning. For instance, during conditioning studies a large number of brain areas were found to show increased firing patterns (Thompson, 1976; Berger, Alger, & Thompson, 1976). Case studies and conditioning experiments involving humans have indicated activity in the hippocampus directly related to the learning process whether i t be classical conditioning, operant learning, or long term memory formation for verbal material. New techniques have been developed which can trace neural events which occur during different kinds of thinking (Geschwind, 1972) even though the person may not be performing any overt behavior. Associated with higher processes are changes in the cortex which can be examined by a variety of means such as E.E.G., brain blood flow, temperature, and (most recent) perhaps P.E.T. (positron emission tomography) scans. In higher level processing of information, the association areas (silent cortex) of the brain (which make up about three-fourths of the human cortex) are the ones mainly involved (Thatcher, 1977). They have been shown to subserve higher processes such as knowing, thinking, understanding and remembering. Much of the information about the functions of these association areas for various types of higher processes comes from the combined results of learning and lesion studies in higher mammals (such as the monkey), electrophysiological record studies of humans, and studies of brain damaged humans. E.E.G. studies of various forms of learning in humans have revealed patterns of brain response . in the association cortex of the Brain and Learning 31 frontal, temporal and parietal lobes as well as the hippocampus (John, 1972). Other more recent approaches to the study of brain states involved in higher processes use averaged evoked E.E.G. potentials (Lehmann & Callaway, 1978), Fourrier transforms of E.E.G. responses (Yeudall, 1977, Flor^lenry, Yeudall, Koles & Howarth, 1979), spectral intensities (Walter, 1968), cross correlation functions (Brazier & Casby, 1952), average alpha and whole band integrated power (Galin & Ornstein, 1972), frequency coherence functions (Davis & Wada, 1974), and average frequency (Giannitrapani, 1969). Averaged evoked potentials can be obtained from the E.E.G. records of a subject engaged in verbal learning. Small changes which seem to be time dependent upon the stimulus material clearly emerge and seem to occur distinctively with each type of stimulus. Studies such as these appear to have quite clearly shown, that the shapes of the averaged evoked potentials depend partly upon the characteristics of the modality of the presented physical stimulus and also upon the meaning of that stimulus to the individual. According to Thatcher (1979) the averaged evoked potential can supply the neurophysiological correlates of higher learning because the shape is different when different kinds of higher processes are going on in the subject's brain. This approach has been used to study the process of attention (Hillyard, Hinkey, Schwent & Picton, 1973), behavioral set and decision making (Begleiter, Porjesz, Yerre & Kissin, 1973), localization of memories (Bartlett, John, Shimokoski, & Kleinman, 1973) and hemispheric Brain and Learning 32 lateralization in various language and pictorial functions (Pedio, 1970; Thatcher, 1977; Ornstein, 1978). Thatcher (1977) has used the average evoked potentials with humans in a number of studies of higher processes. In one study, he presented subjects with a series of stimuli, some of which were simple random pictorial dot displays (controls) and others which were words which yielded the same amount of retinal stimulation as the data displays (experimentals). The subjects did not know how many displays they would see and could not predict when words would be shown. Subsequent words were presented which were either synonym, antonym or neutral with reference to the first one. During a l l of these presentations, E.E.G. recordings from several cortical locations cn both hemispheres were obtained. Because the learning of a word releases a unique pattern of neuron firings compared to that of the random dot display, the evoked potentials to the words were significantly different from those to the random dot displays. Words carry meanings and associations which the random dot displays are not likely to carry (Brown & Wallace, 1980). It was also found that the evoked potentials to the first word were smaller and less widely distributed across the brain than those to the second and subsequent words. Thatcher (1977) explained this by arguing that higher processes going on during presentation of the second and subsequent words are more involved. The reason is that it' would be not only necessary to extract the meaning, but also for the subjects to compare them to the memory of the first word to determine whether they are synomym, antonym Brain and Learning 33 or neutral (Brown & Wallace, 1980). The evoked potentials from the left hemisphere and from the right hemisphere were different for the words compared to the dot displays. During the first word a difference emerged with the left hemisphere shewing the larger evoked potential amplitude. The evoked potentials for the second and subsequent words showed even larger left hemispheric specific E.E.G. components compared to those for the first word, thus clarifying and confirming the engagement of the left hemisphere needed in processing linguistic materials. Cerebral hemispheric differences in evoked potentials as a function of verbal vs. pictorial stimuli have also been discovered by Buchsbaum & Fedio (1969) and Buchsbaum & Fedio (1970). Even more light has been shed on the lateralization of functions during different brain processes by other researchers. Galin and Ornstein (1972) and Ehrlichman & Wiener (1980) for instance, found that if the E.E.G. is recorded from both hemispheres during the performance of verbal or spatial information processing tasks, different "brain-wave" patterns result. During verbal tasks the integrated whole band E.E.G. power in the left hemisphere was less than in the right. During spatial tasks i t was less in the right than in the left. Using frequency analysis Doyle, Ornstein and Galin (1974) found that in a verbal task alpha rhythm in the right hemisphere was greater than in the left, the left showing more beta rhythm (Galin. Ornstein, Kocel & Merrin, 1970). In a spatial task alpha rhythms in the left hemisphere came out greater than in the right, the right now shewing more beta rhythm. Doyle, Ornstein and Galin interpret the appearance of the Brain and Learning 34 greater amounts of alpha rhythm as a "turning off" of information processing in the brain area involved. "As i f to reduce the interference between the two modes of operation of its two cerebral hemispheres the brain tends to turn off its unused side" (Ornstein, 1972) in a given situation calling for activity in a given side. In most ordinary activities of daily l i f e , according to Galin and Ornstein (1972), we alternate between these two modes selecting the appropriate one. Also, they believe that the two modes of operation complement each other without readily substituting for one another. Everyday examples of this complementary function would be in simple acts such as describing a spiral staircase. For instance most people would begin using words and soon begin to gesture in the air (Ornstein, 1972). So, within most persons the two modalities appear to exist simultaneously as two semi independent information processing units with different specialities. There is also some evidence suggesting that the modes of physiological organization may be different in each hemisphere (Shaw, O'Connor & Ongley, 1977). Semmes, Porter, and Randolph, (1974) tested the effects of various brain injuries in 124 war veterans for motor reactions, sensory thresholds and object discrimination. Their evidence suggested that the left hemisphere may be more anatomically specialized for discrete formal information processing such as that underlying logic and that the right hemisphere may be more diffusely organized as would be advantageous for orientation in space or other Brain and Learning 35 simultaneous (synchronous) processing of many inputs (as in pictorial processing). Also using E.E.G. analysis, Morgan, McDonald and McDonald, (1971), Slater, (1960) and Wood (1971) have found various manifestations of greater amounts of E.E.G. electrical activity in the left hemisphere during verbal tasks and relatively greater right hemisphere activity during spatial tasks. According to Ornstein (1972) and Ornstein, Johnstone, Herron and Swencionis, (1980) some persons habitually prefer one mode over the other. He alludes to the fact that our culture, with its emphasis on training the left hemisphere (e.g. the strong emphasis on reading, writing and arithmetic in our schools and the great emphasis on serial logic in our society) may be unwittingly limiting the brain capacity of people by not providing sufficient schooling in the use of the right hemisphere. Kirsner & Brown (1981) have investigated interesting laterality relationships to memory of learned materials. To infer the regions of the brain which partake in various higher processes the cross correlation function is often analyzed. This reveals the phase and amplitude similarities in electrical activity emanating from various E.E.G. electrodes. Workers in the area have suggested that coherence function analysis may be superior to the cross correlation for determining the functional organization of brain states (coupling between the parts).' Davis and Wada (1974) have applied this coherence analysis to study brain states involved in processing simple verbal vs. spatial stimuli. Their findings emerged B r a i n a n d L e a r n i n g 3 6 c o n s i s t e n t w i t h o t h e r s . T h e l e f t h e m i s p h e r e w a s f o u n d r e l a t i v e l y m o r e a c t i v e i n v e r b a l t a s k s b u t t h e r i g h t o n e w a s m o r e a c t i v e i n s p a t i a l t a s k s . B r a i n B l o o d C i r c u l a t i o n a n d T h e r m o d e t e c t i o n T h e b l o o d s u p p l y o f t h e h u m a n c e r e b r a l c o r t e x i s p r o v i d e d b y 3 m a j o r a r t e r i e s , t h e t w o i n t e r n a l c a r o t i d a r t e r i e s a n d a s i n g l e b a s i l a r a r t e r y f o r m e d f r o m t h e v e r t e b r a l a r t e r i e s . M i n o r c o m m u n i c a t i n g a r t e r i e s j o i n t h e s e t o f o r m t h e c i r c l e o f W i l l i s . T h e a n t e r i o r a n d m i d d l e c e r e b r a l a r t e r i e s ( w h i c h e m e r g e f r o m t h e c a r o t i d s ) s u p p l y t h e m a j o r i t y o f t h e m i d d l e , f r o n t a l a n d l a t e r a l z o n e s o f t h e b r a i n w h i l e t h e p o s t e r i o r c e r e b r a l a r t e r i e s ( w h i c h e m e r g e f r o m t h e b a s i l a r ) s u p p l y t h e m o r e m e d i a l p o s t e r i o r z o n e s . T h e l a t e r a l s u r f a c e s o f t h e b r a i n , ( p r e a n d p o s t c e n t r a l g y r i , B r o c a ' s a n d W e r n i c k e ' s a r e a , e t c . ) a r e s u p p l i e d p r i m a r i l y , b y b r a n c h e s o f t h e m i d d l e c e r e b r a l a r t e r i e s f a n n i n g o u t a f t e r t h e y e m e r g e f r o m t h e s y l v i a n f i s s u r e a n d p r o j e c t o n t o t h e f r o n t a l , p a r i e t a l , o c c i p i t a l a n d t e m p o r a l l o b e s . H e n c e t h e y s u p p l y t h e l a t e r a l p r e f r o n t a l , p r e m o t o r , m o t o r , s o m a t o s e n s o r y , g e n e r a l a s s o c i a t i v e , a u d i t o r y a n d p a r t o f t h e v i s u a l a s s o c i a t i v e a r e a s . T h e a n t e r i o r c e r e b r a l a r t e r i e s a n d t h e i r b r a n c h e s s u p p l y t h e a n t e r i o r a r e a s ( f r o n t a l l o b e s ) o n t h e m e d i a l a s p e c t s o f e a c h c o r t e x b u t a l s o s u p p l y a b i t o f t h e l a t e r a l b r a i n s u r f a c e s b e c a u s e t h e y o v e r l a p s u p e r i o r l y a n d p r o j e c t l a t e r a l l y . T h e p o s t e r i o r c e r e b r a l a r t e r i e s a n d t h e i r b r a n c h e s s u p p l y m e d i a l a s p e c t s ( p o s t e r i o r l y ) o f t h e o c c i p i t a l l o b e s , p r i m a r i l y r e g i o n s o f t h e c a l c a r i n e s u l c u s w i t h s ome c o v e r a g e o v e r t h e i n f e r i o r p o r t i o n s o f t h e B r a i n a n d L e a r n i n g 37 t e m p o r a l l o b e s . T h e y w r a p a r o u n d a n d a l s o p r o j e c t o n t o t h e l a t e r a l b r a ^ i i s o r f s o s . T h e r e g i o n c n ' t h e i a t a r a l c o r t i c a l s u r f a c e s e n c o m p a s s i n g t h e f a r t h e s t d i s t r i b u t i o n p o i n t s r e f e r r e d t o a s t h e " w a t e r s h e d a r e a " w h e r e t h e m i d d l e c e r e b r a l a r t e r i e s r e a c h c u t t o w a r d t h e a n t e r i o r c e r e b r a l a r t e r i e s a n d t h e p o s t e r i o r c e r e b r a l a r t e r i e s c o n s t i t u t e s t h e f a r t h e s t a r t e r i a l s u p p l y z o n e o f t h e c o r t e x . H e r e t h e a r t e r i e s g i v e o f f e n d a r t e r i e s w h i c h a n a s t o m o s e a m o n g t h e m s e l v e s a n d s u p p l y d e e p e r s t r u c t u r e s . E x c e p t i n i n s t a n c e s o f u n i l a t e r a l o c c l u s i o n s o r o t h e r a n o m a l i e s , t h e r e i s n o t v e r y m u c h s h a r i n g o f b l o o d b e t w e e n t h e t w o c e r e b r a l h e m i s p h e r e s d u e t o t h e d i r e c t i o n o f f l o w , t h e e q u a l i t y o f p r e s s u r e o n e a c h s i d e a n d t h e s m a l l r a d i u s o f t h e a n t e r i o r c o m m u n i c a t i n g a r t e r y . V e i n s c o r r e s p o n d i n g t o e a c h o f t h e s e a r t e r i e s r e t u r n b l o o d t o d u r a l s i n u s e s s u c h a s t h e s u p e r i o r s a g i t t a l s i n u s , i n f e r i o r s a g i t t a l s i n u s , c a v e r n o u s s i n u s , s t r a i g h t , t r a n s v e r s e s i g m o i d s i n u s e s a n d t h e g r e a t v e i n o f G a l e n . Some o f t h e s e a l s o r e c e i v e c e r e b r o s p i n a l f l u i d d r a i n a g e v i a t h e a r a c h n o i d m i c r o v i l l i f r o m t h e v a r i o u s s u b a r a c h n o i d c i s t e r n s i n t h e b r a i n a n d i t a l l d r a i n s i n t o t h e i n t e r n a l j u g u l a r v e i n s t o e n d i n t h e s u p e r i o r v e n a c a v a . /As w i t h o t h e r o r g a n s a n d t i s s u e s t h r o u g h o u t t h e b o d y , b l o o d f l o w t h r o u g h t h e b r a i n i s a f u n c t i o n o f c a r d i a c o u t p u t a n d v a s c u l a r r e s i s t a n c e . B l o o d v e s s e l r a d i u s c o n s t i t u t e s t h e m a i n d e t e r m i n a n t o f r e s i s t a n c e t o b l o o d f l o w . . S i n c e t h e a r t e r i o l e s a n d m e t a r t e r i o l e s a r e t h e v e s s e l s t h a t h a v e t h e s m a l l e s t r a d i u s b e f o r e b l o o d e n t e r s t h e c a p i l l a r i e s , t h e y s e e m t o c o n s t i t u t e t h e m a j o r s i t e o f c e r e b r a l B r a i n a n d L e a r n i n g 3 8 v a s c u l a r r e s i s t a n c e . T h i s i s p a r t i c u l a r l y i m p o r t a n t s i n c e t h e i r r a d i i a r e u n d e r t h e m o s t p r e c i s e p h y s i o l o g i c a l c o n t r o l b y t h e s m o o t h m u s c l e i n t h e i r w a l l s a n d t h e p r e c a p i l l a r y s p h i n c t e r s i n m e t a r t e r i o l e s . M e c h a n i s m s r e s p o n s i b l e f o r c a r d i o v a s c u l a r c o n t r o l t h u s a r e t h e m a i n d e t e r m i n a n t s o f c e r e b r a l b l o o d f l o w d i s t r i b u t i o n . V e n o u s r e t u r n ( c o n s t r i c t i o n / d i s t e n t i o n ) , b l o o d v o l u m e , i n t e r a c t i o n w i t h c e r e b r o s p i n a l f l u i d , a n d t h e s t a t u s o f b l o o d d e m a n d o f t h e t i s s u e s a n d o r g a n s o f t h e b o d y a r e a l s o i n f l u e n t i a l i n c e r e b r a l c i r c u l a t i o n b u t i n a s e c o n d a r y w a y . W h e n p a r t s o f t h e b r a i n i n c r e a s e t h e i r a c t i v i t y t h e m e t a b o l i c d e m a n d s f o r o x y g e n , g l u c o s e a n d o t h e r m o l e c u l e s e l i c i t i n c r e a s e d a m o u n t s o f b l o o d f l o w t o t h e a r e a s i n v o l v e d ( L a s s e n , 1 9 5 9 , 1 9 7 8 ) . F l o w o f b l o o d t h r o u g h t i s s u e s l e a d i n g t o t h e b r a i n t h u s c h a n g e s w i t h m e t a b o l i c a c t i v i t y i n t h e b r a i n ( I n g v a r & S c h w a r t z , 1 9 7 4 ) . B e c a u s e o f t h e c o n s t a n t r e l a t i o n b e t w e e n t h e n u m b e r o f A T P m o l e c u l e s r e g e n e r a t e d a n d t h e n u m b e r o f o x y g e n m o l e c u l e s u s e d , t h e f u n c t i o n a l a c t i v i t y i n p a r t i c u l a r b r a i n t i s s u e s i s d i r e c t l y r e l a t e d t o t h e f l o w o f o x y g e n a t e d b l o o d i n t h e s e t i s s u e s . H e n c e , l o c a l c h a n g e s i n b l o o d f l o w r e f l e c t l o c a l v a r i a t i o n s i n t h e i n t e n s i t y o f n e r v e c e l l m e t a b o l i s m ( I n g v a r & S o d e r b e r g , 1 9 5 6 ) . T h e r e i s e v i d e n c e t h a t s u b s t a n c e s s u c h a s c a r b o n d i o x i d e , h y d r o g e n i o n s , o t h e r s u b s t a n c e s a n d e l e c t r o l y t e s s u c h a s c a l c i u m i o n s , p o t a s s i u m i o n s , s o d i u m i o n s a n d m a g n e s i u m i o n s a s w e l l a s a d e n o s i n e a s a p h a r m a c o l o g i c a l a g e n t , l a c t i c a c i d , a d e n o s i n e p h o s p h a t e c o m p o u n d s t h e m s e l v e s ( i n b i o l o g i c a l t i s s u e s A D P a n d A T P ) , h i s t a m i n e , k i n i n s , B r a i n a n d L e a r n i n g 39 p r o s t a g l a n d i n s , n o r e p i n e p h r i n e , e p i n e p h r i n e , a n g i o t e n s i n a n d v a s o p r e s s i n n a y a l l e x e r t i n f l u e n c e i n d e t e r m i n i n g a r t e r i o l a r r a a i u s a n d h e n c e , d i s t r i b u t i o n o f c e r e b r a l c i r c u l a t i o n . I n a d d i t i o n t h e r e s e e m s t o b e s ome n e u r o g e n i c a u t o n o m i c a n d o t h e r c o n t r o l a s w e l l a s o t h e r i n f l u e n c e s ( e . g . t e m p e r a t u r e ) u p o n r a d i u s a n d d i s t e n s i b i l i t y o f t h e c e r e b r a l b l o o d v e s s e l s . T h e m e d u l l a r y c a r d i o v a s o m o t o r c o n t r o l c e n t e r , u n d e r t h e i n f l u e n c e f r o m t h e h y p o t h a l a m u s , r e t i c u l a r a c t i v a t i n g s u b s t a n c e o f t h e d i e n c e p h a l o n , m i d b r a i n a n d p o n s a n d t h e c e r e b r a l c o r t e x f u n c t i o n s a s a m o n i t o r i n g s y s t e m t o m a i n t a i n a r e l a t i v e s t e a d y s t a t e i n a c c o r d a n c e w i t h t h e m e t a b o l i c d e m a n d s o f t h e m o m e n t . C a r d i a c o u t p u t i s t h e r e b y c o o r d i n a t e d w i t h a r t e r i o l a r , m e t a r t e r i o l a r a n d p r e c a p i l l a r y s p h i n c t e r r a d i u s t o m a i n t a i n t h i s . T h e l a t t e r a p p e a r i n n e r v a t e d b y v a s o m o t o r f i b e r s o f t h e l o c u s c o e r u l e u s . R e f l e x c o n t r o l o f t h e s e f u n c t i o n s i n v o l v e s s y m p a t h e t i c t r u n k n e r v e s t o t h e h e a r t , a r t e r i o l e s a n d v e i n s a n d p a r a s y m p a t h e t i c n e r v e s t o t h e h e a r t f r o m t h e d o r s a l m o t o r n u c l e u s o f t h e v a g u s n e r v e . R e s e a r c h s u g g e s t s t h a t p i a l v e s s e l s may h a v e s ome s y m p a t h e t i c c h o l i n e r g i c v a s o d i l a t o r f i b e r s . T h e r e a r e , h o w e v e r , m o r e a d r e n e r g i c v a s o c o n s t r i c t i v e f i b e r s t h a t i n n e r v a t e t h e l a r g e r p i a l a n d i n t r a c e r e b r a l v e s s e l s . H o w e v e r , o v e r a l l , s u c h n e u r o g e n i c c o n t r o l s e e m s w e a k b e c a u s e o f t h e l o w r e s p o n s i v e n e s s o f t h e a l p h a - a d r e n e r g i c r e c e p t o r s t o n o r e p i n e p h r i n e . A n i m p o r t a n t c h a r a c t e r i s t i c o f n e u r o g e n i c c o n t r o l o f c e r e b r a l c i r c u l a t i o n i s t h a t a d r e n e r g i c n e r v e s a r e m o r e e f f e c t i v e i n a r t e r i a l h y p e r t e n s i o n , p e r h a p s t o l i m i t c a p i l l a r y B r a i n a n d L e a r n i n g 4 0 i n t r a v a s c u l a r p r e s s u r e a n d p r e v e n t d i s r u p t i o n o f t h e b l o o d b r a i n b a r r i e r * I n a d d i t i o n , b a r o r e c e p t o r s s u c h a s t h e c a r o t i d s i n u s f u n c t i o n a s b l o o d p r e s s u r e s e n s o r s . A n y d e v i a t i o n s f r o m t h e a p p r o p r i a t e s t a t e f o r t h e c o n d i t i o n s a r e r e l a y e d t o t h e h y p o t h a l a m u s a n d m e c h a n i s m s a r e i n i t i a t e d t o r e i n s t a t e t h e b a l a n c e d c o n d i t i o n . C h e m o r e c e p t o r s s u c h a s t h e c a r o t i d b o d y s i g n a l a n y h y p e r c a p n i c o r h y p o x i c c o n d i t i o n a n d i n d u c e v a s o d i l a t a t i o n t o b r i n g a d d i t i o n a l q u a n t i t i e s o f b l o o d t o t h e r e g i o n . T h e r e s e e m s t o b e a p r o n o u n c e d d i r e c t a c t i o n o f c a r b o n d i o x i d e o n c e r e b r o v a s c u l a r s m o o t h m u s c l e d e p e n d e n t o n h y d r o g e n i o n c o n c e n t r a t i o n a n d b i c a r b o n a t e i o n . N o r e p i n e p h r i n e a n d e p i n e p h r i n e ( f r o m t h e a d r e n a l m e d u l l a ) a r e u s u a l l y v a s o c o n s t r i c t i v e a l t h o u g h e p i n e p h r i n e c a n p r o d u c e v a s o d i l a t i o n i n s ome v e s s e l s . A u t o c o i d s a n d h o r m o n e s s u c h a s v a s o p r e s s i n a n d a n g i o t e n s i n a l s o p r o d u c e v a s o c o n s t r i c t i o n w h e r e a s k i n i n s , h i s t a m i n e a n d p r o s t a g l a n d i n s a p p e a r t o b e v a s o d i l a t a t i v e . C a l c i u m i o n s p r o d u c e v a s o c o n s t r i c t i o n w h i l e s o d i u m , p o t a s s i u m a n d m a g n e s i u m i o n s p r o d u c e v a s o d i l a t a t i o n . M e t a b o l i t e s s u c h a s a d e n o s i n e o r h y d r o g e n , i o n w h i c h i n c r e a s e w i t h b r a i n m e t a b o l i c a c t i v i t y , i s c h e m i a o r h y p o x i a h a v e b e e n s h o w n t o i n d u c e s t r o n g d i l a t i o n a t l e a s t i n p i a l v e s s e l s ( K o n t o s , 1 9 8 1 ) . M o r e o v e r , a l k a l o s i s t e n d s t o i n c r e a s e n e u r o n a l e x c i t a b i l i t y a n d a r t e r i a l h y p e r c a p n i a may h a v e a l o c a l h y p e r e m i c e f f e c t . A l t h o u g h t h e c e r e b r a l v e i n s g e n e r a l l y f u n c t i o n a s l o w r e s i s t a n c e c o n d u i t s f o r c o l l e c t i o n a n d r e t u r n o f b l o o d t o t h e h e a r t -and t h e y d o n o t a p p e a r t o h a v e s i g n i f i c a n t v a l v e s s ome w e a k s y m p a t h e t i c c e r e b r a l v e n c c o n s t r i c t i o n may o c c u r u n d e r some c o n d i t i o n s . B r a i n a n d L e a r n i n g 4 1 T h e b r a i n c i r c u l a t i o n t h u s s e e m s t o b e n e u r o g e n i c a l l y a s w e l l a s c h e m i c a l l y r e g u l a t e d b u t b e c a u s e o f t h e n e c e s s i t y f o r u n i n t e r r u p t i v e s u p p l y a t i g h t c o u p l i n g s e e m s t o p r e v a i l b e t w e e n m e t a b o l i s m a n d b l o o d f l o w . I n g v a r ( 1 9 7 6 ) h a s d e m o n s t r a t e d a c t i v a t i o n o f s p e c i f i c c o r t i c a l a r e a s b y s e n s o r y o r m o t o r a c t i v i t y e l i c i t i n g i n c r e a s e s i n b l o o d v o l u m e t o t h e a c t i v a t e d a r e a s . A l s o , e n g a g i n g i n m o r e c o m p l e x m e n t a l a c t i v i t y p r o d u c e d m o r e w i d e s p r e a d i n c r e a s e s i n c e r e b r a l b l o o d v o l u m e d u e t o i n c r e a s e d m e t a b o l i s m ( S o k o l o f f , 1 9 7 7 ) . T h i s r e l a t i o n s h i p o c c u r s v i a v a s o d i l a t o r m e t a b o l i t e s , a d e n o s i n e c o m p o u n d s b e i n g t h e m o s t l i k e l y c a n d i d a t e s p r e s e n t l y c o n s i d e r e d . T h u s t h e m o s t i m p o r t a n t c e r e b r a l b l o o d v o l u m e r e g u l a t i o n f r o m t h e p o i n t o f v i e w o f t h e s t u d y o f c e r e b r a l f u n c t i o n a p p e a r s . t o b e l o c a l m e t a b o l i c a l l y d i r e c t e d r e g u l a t o r y m e c h a n i s m s ( I n g v a r & L a s s e n , 1 9 7 5 ) . S o k o l o f f ( 1 9 7 6 ) a n d L u r i a ( 1 9 7 3 ) h a v e d e m o n s t r a t e d ( i n a n i m a l s ) t h a t t h e m e t a b o l i c r a t e w i t h i n v e r y s m a l l r e g i o n s o f t h e b r a i n c h a n g e s i n c o n s i s t e n t p a t t e r n s d u r i n g v a r i o u s s p e c i f i c a c t i v i t i e s a l o n g w i t h m o r e d i f f u s e d c h a n g e s o c c u r i n g a s t h e g e n e r a l a c t i v i t y o f t h e o r g a n i s m c h a n g e s ( e . g . - d i f f e r e n t a r o u s a l l e v e l s ) . M c G e e r a n d M c G e e r ( 1 9 8 0 ) h a v e s u m m a r i z e d h o w l o c a l b l o o d f l o w c h a n g e s r e l a t e t o h u m a n b e h a v i o r s l i k e l i s t e n i n g , s p e e c h a n d h a n d m o v e m e n t s . L a s s e n , I n g v a r a n d S k i n h o j ( 1 9 7 8 ) h a v e d e m o n s t r a t e d t h a t v a r i o u s f o r m s o f s t i m u l a t i o n a l t e r t h e b l o o d v o l u m e t o d i f f e r e n t r e g i o n s o f t h e b r a i n . F o r i n s t a n c e ; v a r i o u s f o r m s o f l i n g u i s t i c s t i m u l a t i o n c a n c a u s e i n c r e a s e s i n b l o o d v o l u m e t h r o u g h B r o c a ' s o r W e r n i c k e ' s a r e a s ; o t h e r f o r m s o f s t i m u l a t i o n w e r e f o u n d t o p r o d u c e i n c r e a s e s i n f l e w t h r o u g h Brain and Learning 42 the known primary regions for each function (e.g. - visual, auditory, tactile, motor etc.) Stimuli evoking more complex cognitive responses or evoking memory were found to e l i c i t increases of flow through the association areas in the parietal and frontal lobes. Analyses of brain activation during normal reading was found to involve several cortical regions in specific patterns (Risberg & Ingvar, 1973) with more activity recorded in the left hemisphere. Not only do increases in blood volume to specific regions occur but Risberg and Ingvar (1973) found that routines such as recall and reasoning cause, in addition to localized changes, a significant overall increase of cerebral blood flow of sometimes more than 10%. This general increase appears to be distinctly "related to the subject's effort in performing the task" (Risberg & Ingvar, 1973). Others such as Ectors (1969) and Basar (1980) have found a striking "parallism" between cerebral circulation and EES rhythms. Comparatively, high levels of blood flow through the brain because its metabolic rates are very high, particularly during cognitive activity (since the blood flow through the brain is proportioned according to the metabolic needs). Tympanic Temperature Change Changes in blood volume to certain brain regions have been shown to produce temperature changes (Serota & Gerard, 1938) related to the energy release of active nerve cells and to the vasomotor responses associated with such activity. When certain zones of the brain increase their activity, local vasodilation seems to occur, as in the Brain and Learning 43 carotid sinus reflex (Mikhailov, 1962), to allow for the increased siQOCi c i S i i i a u i d . iiiis n«Ci-<3Sis«Ci vcluias of blood to incre active -jjjL*€Sas also helps cool these zones. The results of studies by Hayward and Baker (1969) and Serota and Gerard (1938) show slight net reductions in the temperature of blood in vessels and surrounding tissues which supply the relatively more active brain regions. Using the method of tympanic membrane temperature monitoring of Dickey, Ahlgren and Stephen (1970), Meiners and Dabbs (1977) have demonstrated that tympanic temperature is a measure of core temperature. Also, unilateral decreases in ear tympanic temperature have been found to be associated with brain hemispheric increases in blood volume. Temperature decreases were found to be greater in the left ear during verbal tasks and in the right ear during spatial tasks. They conclude that tympanic temperature provides . a simple indirect indicator of relative hemispheric functioning in a variety of tasks and can be used in studies that relate tasks to relative brain hemispheric activity. They also provide data showing that a thermistor worn as an earplug in the auditory meatus not necessarily in contact with the tympanic membrane can detect these temperature indices of hemispheric activation. The overall review of the literature had led to the expectation that the left brain cerebral hemisphere is primarily active during the "learning of written verbal material, and that methods which incorporate pictorial representations would most likely e l i c i t changes in relative activity in the right and left brain hemispheres. Also, the weight of evidence show the right hemisphere to be responsible for processing B r a i n a n d L e a r n i n g 44 f o r m v i s u a l i z a t i o n , s h a p e s , p i c t u r e s a n d s p a t i a l o r i e n t a t i o n s . T h e m e t h o d s w h i c h h e l p o r g a n i z i n g t h e l e a r n e d v e r b a l m a t e r i a l , b u t n o t u s i n g p i c t o r i a l r e p r e s e n t a t i o n , may e l i c i t s ome c o n c o m i t a n t c h a n g e s i n r e l a t i v e a c t i v i t y i n t h e r i g h t a n d l e f t b r a i n h e m i s p h e r e s . T h e y may f u r t h e r e l i c i t c h a n g e s i n l e v e l s o f a c t i v i t y i n a g r e a t e r n u m b e r o f r e g i o n s o f b o t h t h e h e m i s p h e r e s s i n c e t h e i r c o n t e n t a l b e i t o r g a n i z a t i o n a l i s s t i l l p r e d o m i n a n t l y s y m b o l i c . T h e r e may b e m o r e w a y s t o e n h a n c e r e c a l l a n d c o m p r e h e n s i o n t h a n b y s i m p l y i n v o k i n g c o n c o m i t a n t c h a n g e s i n r e l a t i v e l e v e l s o f r i g h t b r a i n a c t i v i t y , f o r e x a m p l e s y m b o l i c o r g a n i z a t i o n , q u e s t i o n s , o b j e c t i v e s , e t c . a s d i s c u s s e d e a r l i e r . T h e l i t e r a t u r e o n i n d u c e d i m a g e r y a n d i m p o s e d i m a g e r y s u g g e s t s t h i s . S o , a g e n e r a l h y p o t h e s i s w o u l d b e t h a t e n h a n c e d r e t e n t i o n a n d c o m p r e h e n s i o n c a n b e b r o u g h t a b o u t i n d i f f e r e n t w a y s b y s e v e r a l m e t h o d s b e c a u s e t h e u n d e r l y i n g d i m e n s i o n s o f o p e r a t i o n may b e d i f f e r e n t ; s ome may b e p i c t o r i a l b u t o t h e r s m a i n l y s e m a n t i c a l l y a s s o c i a t i v e . F i n a l l y , e n h a n c e r s may b e s p e c i f i c a s t o w h a t t h e y a c c o m p l i s h . I t may w e l l b e t h a t c e r t a i n p i c t o r i a l m e t h o d s s u c h a s i n d u c e d i m a g e r y may e n h a n c e p r i m a r i l y r e c a l l w i t h o u t n e c e s s a r i l y i n d u c i n g a p p r e c i a b l e g a i n s i n c o m p r e h e n s i o n . O n t h e o t h e r h a n d s y m b o l i c s t r a t e g i e s e m p h a s i z i n g t h e o r g a n i z a t i o n o f k n o w l e d g e o r t h e d i s c r i m i n a t i v e l i n k i n g o f k n o w l e d g e t o e x i s t e n t c o g n i t i v e s t r u c t u r e s may i n d u c e o b s e r v a b l e g a i n s i n c o m p r e h e n s i o n w i t h o u t n e c e s s a r i l y p r o v i d i n g m u c h e n h a n c e m e n t i n v e r b a t i m r e c a l l , a s c o m p a r e d t o o t h e r t e c h n i q u e s i n v o l v i n g i m a g e r y o r p i c t u r e s . P i c t o r i a l d i a g r a m s , h o w e v e r , d u e t o t h e i r s i m u l t a n e o u s u s e o f o r g a n i z a t i o n a l f r a m e w o r k s a l o n g w i t h v i v i d d e s c r i p t i v e i m a g e s B r a i n a n d L e a r n i n g 4 5 r e p r e s e n t i n g t h e v e r b a l m a t e r i a l t o b e s t u d i e d , may w e l l p r o d u c e a r e s p e c t a b l e sihancsamant in retention (ever a cositroi group xiot e x p o s e d t o t h e m ) a n d p e r h a p s a l s o a s i g n i f i c a n t e n h a n c e m e n t i n c o m p r e h e n s i o n o f t h e m a t e r i a l . T h i s s t u d y wa s a i m e d a t s h o w i n g w h e t h e r o r t o w h a t e x t e n t t h e s e e x p e c t a t i o n s , d e r i v e d f r o m r e s e a r c h f i n d i n g s , a r e b o r n e o u t . T h e c e n t r a l h y p o t h e s i s . T h e a n a l y s i s o f a v a i l a b l e f i n d i n g s s h o w s n o a p p a r e n t c o r r e l a t i o n o f t h e f i n d i n g s f r o m r e s e a r c h o n v e r b a l l e a r n i n g w i t h t h o s e c o n c e r n e d w i t h t h e s t u d y o f t h e b r a i n f u n c t i o n s . C l e a r l y , t h e r e i s a n e e d f o r s t u d i e s t o r e l a t e t h e f i n d i n g s c o n c e r n i n g i n d u c e d i m a g e r y a n d p i c t o r i a l d i a g r a m s t o t h e f i n d i n g s c o n c e r n i n g b r a i n c o n c o m i t a n t s o f l e a r n i n g a s d e t e c t e d b y b r a i n e l e c t r o p h y s i o l o g y , b l o o d f l o w a n d t e m p e r a t u r e ( P a i v i o , 1 9 7 3 ) . W i t t r o c k ( 1 9 7 7 ) i n h i s p r o p o s e d t h e o r y o f g e n e r a t i v e l e a r n i n g , s u g g e s t e d t o d e t e r m i n e w h e t h e r o r n o t ( c f . B u z a n ' s ) " m e t h o d s w h i c h i n d u c e g e n e r a t i v e l e a r n i n g e n h a n c e t h e l e a r n i n g p r o c e s s b y e n g a g i n g m o r e c e n t e r s i n t h e n o n d o m i n a n t h e m i s p h e r e " , w h i c h t e n d t o r e m a i n r e l a t i v e l y d o r m a n t d u r i n g v e r b a l t a s k s . T h i s i s t h e g e n e r a l r e s e a r c h i s s u e t h e p r e s e n t s t u d y a d d r e s s e d . T h e c e n t r a l h y p o t h e s i s o f t h e p r e s e n t e x p e r i m e n t i s t h a t t h e l e a r n e r s ' p e r f o r m a n c e p r o f i c i e n c y o w i n g t o i m p o s e d a n d i n d u c e d i m a g e r y l e a r n i n g a d j u n c t s w o u l d b e a c c o m p a n i e d b y c o r r e s p o n d i n g h i g h e r l e v e l o f r i g h t h e m i s p h e r i c b r a i n a c t i v i t i e s r e l a t i v e t o l e f t h e m i s p h e r i c a c t i v i t i e s b e c a u s e t h e r i g h t h e m i s p h e r e i s B r a i n a n d L e a r n i n g 4 6 p u r p o r t e d t o p l a y a n i n c r e a s i n g r o l e i n t h e p r o c e s s i n g o f p i c t o r i a l I n o r d e r t o d e t e r m i n e i f t h e m e t h o d s t h a t e n g a g e r e l a t i v e l y g r e a t e r r i g h t h e m i s p h e r e a c t i v i t y c o r r e s p o n d t o t h o s e w h i c h e l i c i t i m p r o v e m e n t s i n l e a r n i n g a s m e a s u r e d b y r e c a l l a n d c o m p r e h e n s i o n , o b v i o u s l y we n e e d t o d e f i n e t h e m e t h o d s e x p e r i m e n t a l l y . A n y s e t o f d a t a t h u s c o l l e c t e d w i l l b e c a p a b l e o f a d d r e s s i n g s ome i n t e r e s t i n g p s y c h o l o g i c a l q u e s t i o n o n t h e e f f i c i e n c y o f l e a r n i n g a d j u n c t s i n t e r m s o f r e c a l l a n d c o m p r e h e n s i o n o f l e a r n i n g m a t e r i a l s i n a d d i t i o n t o t h e f i n d i n g s c o n c e r n e d w i t h t h e l o c a l i z a t i o n s o f c o n c o m i t a n t c o g n i t i v e f u n c t i o n s i n t h e b r a i n ( p a r t i c u l a r l y h e m i s p h e r i c l a t e r a l i z a t i o n ) . E x p e r i m e n t a l e x p e c t a t i o n s . B a s e d o n t h e e a r l i e r a n a l y s i s o f p r e v i o u s s t u d i e s , i t c a n b e e x p e c t e d t h a t i m a g e r y i n s t r u c t i o n a n d p i c t o r i a l d i a g r a m s w i l l f a c i l i t a t e r e c a l l a n d c o m p r e h e n s i o n , t h a t p i c t o r i a l d i a g r a m s w i l l e l i c i t s u p e r i o r r e c a l l a n d c o m p r e h e n s i o n a s c o m p a r e d t o t h e i m a g e r y i n s t r u c t i o n c o n d i t i o n , a n d f i n a l l y t h a t t h e p i c t o r i a l d i a g r a m s a n d i m a g e r y i n s t r u c t i o n w o u l d b e a c c o m p a n i e d b y e n h a n c e d l e v e l s o f c o n c o m i t a n t r e l a t i v e r i g h t h e m i s p h e r e a c t i v i t y . B r a i n a n d L e a r n i n g 47 C h a p t e r I I . M e t h o d o l o g y S u b j e c t s a n d D e s i g n T h e m e t h o d o l o g y u t i l i z e d i n t h i s s t u d y i s i n t i m a t e l y l i n k e d t o t h e r e s e a r c h p r a c t i c e c o n c e n t u a l l y v a l i d a t e d t h r o u g h o u t t h e l i t e r a t u r e . T h e l i t e r a t u r e g e n e r a l l y u s e s i n d u c e d i m a g e r y a s a n i n d e p e n d e n t v a r i a b l e b y p r o v i d i n g t h e e x p e r i m e n t a l s u b j e c t s w i t h i n s t r u c t i o n s t o f o r m i n t e r a c t i v e v i v i d i m a g i n a l i m a g e s r e p r e s e n t a t i v e o f t h e v e r b a l m a t e r i a l b e i n g l e a r n e d . I t u s e s a v a i l a b i l i t y o f p i c t u r e s a s a n i n d e p e n d e n t v a r i a b l e b y p r o v i d i n g t h e e x p e r i m e n t a l s u b j e c t s w i t h a c t u a l p i c t u r e s r e p r e s e n t a t i v e o f t h e v e r b a l m a t e r i a l s t u d i e d . I t c o u l d b e a r g u e d t h a t t h e s e c o n d i t i o n s , w h i l e q u a l i t a t i v e l y d i f f e r e n t , may a l s o n o t b e e q u i v a l e n t i n t e r m s o f p r o v i d i n g d i f f e r e n t " d o s a g e s " o f c o n t e n t t o e a c h e x p e r i m e n t a l g r o u p a n d t h u s n o t b e c o m p a r a b l e e x p e r i m e n t a l l y . I n o r d e r t o r e n d e r t h e s e e x p e r i m e n t a l c o n d i t i o n s p a r a l l e l i t w o u l d b e n e c e s s a r y t o e n s u r e t h a t t h e c o n t e n t i n h e r e n t i n e a c h f o r m o f a d j u n c t b e t h e s a m e . E v e n i f s u c h a n e n o r m o u s l y d i f f i c u l t t a s k w e r e p o s s i b l e t h e m a n i p u l a t i o n s w o u l d n o l o n g e r b e g e n e r a l i z a b l e o r c o m p a r a b l e t o t h e v a s t b o d y o f r e s e a r c h a l r e a d y e x i s t e n t o n t h e s e a d j u n c t s . T h e i r q u a l i t a t i v e n a t u r e w o u l d t h u s b e d i s t o r t e d i n a t t e m p t s t o r e n d e r t h e m q u a n t i t a t i v e l y e q u i v a l e n t f o r c o n t e n t . S o , t h e p r e s e n t s t u d y m e t h o d s r e m a i n e d c o n s i s t e n t w i t h t h e l i t e r a t u r e ( w h i l e p e r h a p s s a c r i f i c i n g p a r a l l e l i s m ) a n d u s e d t h e s e a d j u n c t s i n t h e w a y s t h e y a r e c o m m o n l y e m p l o y e d i n E d u c a t i o n a l P s y c h o l o g y r e s e a r c h . Brain and Learning 48 Sixty right-handed subjects randomly drawn from a pool of volunteers of low GPA (to reduce the likelihood tnat they habitually use these elaborative techniques, Rohwer, 1973) from a Vancouver community college and the University of British Columbia were obtained. Right handers were chosen to ensure most probable left brain hemisphere dominance (normal lateralization of function). If a subject reported writing and doing most daily tasks with the right hand the subject was deemed to be right handed and inferred to most likely be left brain hemisphere dominant. Low GPA subjects (less than 3.5) were chosen to overcome the phenomenon Rohwer (1973) observed. He and others had found that high ability subjects (i.e. subjects who have demonstrated high grade point average) would elaborate using imagery or other organizing strategies spontaneously and did not substantially profit from experimenter induced imagery (instructions) or other mnemonic aids (since they were already performing near their maximum). The sixty subjects thus selected were randomly assigned to three experimental conditions, 20 subjects each. The three included (a) induced imagery instruction, (b) pictorial diagrams, and (c) control conditions. Induced imagery instruction. Based on the method of Lorayne & Lucas (1974) and Rohwer (1968, 1973), instructions to create mentally vivid images concerning the material to be learned were composed. These instructions replicated the usual instructions, for this manipulation, used in the literature but included some words from the text to be read in order that i t be, to some degree, "equivalent" to Brain and Learning 49 the other conditions which by their nature, necessitated such 'material. The instructions were concentrated mainly on "how to" information. These instructions f i l l e d four 8 1/2" x 11" pages and were assembled as a poster. (See Appendix A for the actual text material in this adjunct) Pictorial Diagrams. Based on an adaptation of the methods of Levin & Lesgold (1978); Buzan (1976, 1980) and Vernon (1980), the intrinsic logic of the material and using pictures commonly presented in popular textbooks on the topic of Psychopathology, a "picture diagram" illustration of the to be learned textual material was constructed. This picture-diagram was composed to create a 17" x 22" poster. (See Appendix A for a print of the poster used) Control Group. A poster 17" x 22" containing irrelevant material of an instructional nature (from Genetics) was constructed so each condition is equivalent. (See Appendix A for the actual text material used). *To enhance the salience and importance of these posters, before their exposure, each subject read some student objectives pertaining to knowledge and comprehension (Bloom, Englehart, Furst, H i l l & Krathwohl, 1956) based on the ideas behind Bloom's taxonomy. Based on the main concepts in a typical chapter on "Psychopathology" from a typical "Introductory Psychology" textbook, a chapter was created in such a manner as to cover adequate balance and give appropriate weighting to each of the mental disorders. This constituted the text material the subjects were required to leam. B r a i n a n d L e a r n i n g 50 C r i t e r i o n T e s t M a t e r i a l s o f R e c a l l a n d C o m p r e h e n s i o n T h e r e c a l l t e s t c o n s i s t e d o f a s k i n g t h e s u b j e c t s t o r e c a l l f r e e l y ( W o o d , 1971) a s m a n y o f t h e m e n t a l d i s o r d e r s t h e y h a v e s t u d i e d . I t t h u s m e a s u r e d v e r b a t i m r e c a l l o f i n f o r m a t i o n i n t h e t e x t . A f t e r t h e r e c a l l t a s k t h e s u b j e c t s w e r e g i v e n t h e c o m p r e h e n s i o n t e s t . T h e c o m p r e h e n s i o n t e s t c o n s i s t e d o f 15 m u l t i p l e c h o i c e q u e s t i o n s w h i c h m e a s u r e d u n d e r s t a n d i n g o f t h e c o n c e p t s i n t h e t e x t a s d e f i n e d i n B l o o m ' s T a x o n o m y b y B l o o m , M a d a u s & H a s t i n g s (1981). T h e s e i t e m s w e r e c h o s e n f r o m a p o o l o f i t e m s , c o n s e n s u a l l y j u d g e d v a l i d b y t e a c h e r s o f t h i s i s u b j e c t a n d r e g u l a r l y u s e d a s a c h i e v e m e n t q u e s t i o n s f o r I n t r o d u c t o r y P s y c h o l o g y . I n t e r n a l c o n s i s t e n c y r e l i a b i l i t y c o e f f i c i e n t s ( H o y t ' s A n a l y s i s o f V a r i a n c e ) w e r e c a l c u l a t e d f r o m p r e v i o u s u s e o f t h e s e i t e m s . R e l i a b i l i t i e s r a n g e d f r o m 0.73 t o 0.88 i n 100 i t e m t e s t s . E l e c t r o e n c e p h a l o g r a p h , s i g n a l a n a l y z e r a n d i n s t r u m e n t a t i o n F . M . r e c o r d e r . A G r a s s I n s t r u m e n t C o . 8 c h a n n e l ( o n l y 4 o f w h i c h w e r e u s e d ) e l e c t r o e n c e p h o l o g r a p h i n c o n j u n c t i o n w i t h a P h y s i o g r a p h " M o d e l S i x " p o l y g r a p h ( E . & M . I n s t r u m e n t C o . ) w e r e u s e d t o m o n i t o r t h e E . E . G . b i l a t e r a l l y . F o u r s t a n d a r d E . E . G . e l e c t r o d e s w e r e u s e d a t s i t e s T^ , P „ , T . , P „ r e f e r e n c e d t o C f r o m t h e I n t e r n a t i o n a l 10-20 3 4 4 z s y s t e m . ( S e e F i g u r e 2 f o r e l e c t r o d e l o c a t i o n s ) A " D a t a 6000 -U n i v e r s a l W a v e f o r m A n a l y z e r " ( A n a l o g i c C o r p o r a t i o n ) w a s u s e d t o c h e c k I n s e r t F i g u r e 2 a b o u t h e r e B r a i n a n d L e a r n i n g 5 1 t h e o n g o i n g p o w e r s p e c t r u m i n r e a l t i m e t o e n s u r e c o r r e c t s i g n a l r e c e p t i o n a s n o i s e f r e e a n d a s a r t i f a c t f r e e a s p o s s i b l e . A M o d e l 3 9 6 0 4 - c h a n n e l H e w l e t t P a c k a r d F M I n s t r u m e n t a t i o n T a p e R e c o r d e r w a s u s e d t o r e c o r d t h e E . E . G . d u r i n g e a c h o f t h e p e r i o d s . T h e r m o d e t e c t o r . Two Y e l l o w S p r i n g s I n s t r u m e n t C o . M o d e l 4 9 T A D i g i t a l T e m p e r a t u r e m o n i t o r i n g u n i t s w e r e u s e d a s t y m p a n i c t e m p e r a t u r e s e n s o r s t o m o n i t o r t h e t h e r m a l r e s p o n s e s b i l a t e r a l l y . T w o t h e r m i s t o r t h e r m a l t r a n s d u c e r s , a t t a c h e d t o a n a u d i t o r y c a n a l e a r p h o n e s e t , o n e i n e a c h e a r , w e r e u s e d t o d e t e c t t h e s e r e s p o n s e s . S p e c i f i c a l l y c o n s t r u c t e d f e l t p a d d i n g s w e r e u s e d t o p r e v e n t , a s m u c h a s p o s s i b l e , t h e c o n d u c t i o n o f h e a t a w a y f r o m t h e t r a n s d u c e r s t h r o u g h a m b i e n t a i r . " D u a l A n a l o g F i l t e r U n i t s " w e r e u s e d t o p r o v i d e f o r f i r s t o r d e r N y q u i s t f i l t e r i n g o f t h e E . E . G . s i g n a l s . Two l a r g e d a r k r o o m t i m e r s ( D i m c o G r a y C o . , M o d e l 1 6 5 & 1 7 1 " G r a l a b U n i v e r s a l T i m e r s " ) w e r e u s e d . O n e , i n t h e s h i e l d e d i s o l a t e d c h a m b e r , t o h e l p s u b j e c t s p a c e t h e m s e l v e s a n d o n e f o r t h e o p e r a t o r t o k e e p t r a c k o f t i m e a n d e v e n t s . A c h i n r e s t w a s u s e d t o p r e v e n t e x c e s s i v e m o v e m e n t s t h a t c o u l d d i s r u p t t h e e l e c t r o p h y s i o l o g i c a l s i g n a l s . A n A r c h e r M o d e l 4 3 - 2 2 1 A T r a n s i s t o r i z e d I n t e r c o m S y s t e m w a s u s e d t o p r o v i d e r e m o t e c o m m u n i c a t i o n b e t w e e n t h e o p e r a t o r a n d e a c h o f ^ t h e s u b j e c t s . I n s e r t F i g u r e 3 a b o u t h e r e F i l t e r i n g u n i t s a n d o t h e r s . Two K r o h n - H i t e C o M o d e l 3 3 4 2 R Brain and Learning 52 Computers. A PDP-11/23 MINC DECLAB computer with the RSX-11 Fortran Enhancement Package and A/D, D/A, Digital-In and Clock laboratory modules were used to carry out the E.E.G. analysis. A dedicated hard disk in addition to the "Systems" disk were used for data storage and processing manipulations. A Model 7220C Hewlett Packard plotter was used to display graphs of raw E.E.G. data, Fast Fourier Transform Magnitudes and Power Spectra. The remaining analyses were carried out using the main U.B.C. computing center (Amdahl XXY). Software. Five computer programs were created in Fortran-77 to carry out the E.E.G. analyses. Program "ADTEST" carried out Analog to Digital sampling at the desired frequency and for the desired time intervals. Program "READREC" was used to write the values sampled in a record. Program "DISPLAY" which graphs the raw data, the Fourier Coefficients or Power Coefficients was used as ongoing check and to obtain figures. Program "DMUX" demultiplexed the signals when 4 simultaneous channels of data were processed at once. Program "POWER" calculated the Fast Fourier Transform and the power spectrum and took average powers for designated numbers of records. Experiment Room. An electrically shielded and soundproofed laboratory-designed isolation chamber (Electrical Engineering, McLeod Building, room 257) was used to ensure proper attention to stimuli and eliminate incidence of electrical noise and other artifacts from the neurophysiological measures. Procedure Subjects were randomly assigned to one of the three conditions Brain and Learning 53 by drawing their number from a table of random numbers as they presented themselves for the experiment. Each subject first signed the disclaimer and was given general information and practice on the sequence. He/She had the electrodes from the electroencephalograph appropriately attached (at positions T_, P., T. and P. and C J J 4 4 z based on the international 10 - 20 System) and the ear probes placed in position. Electrode impedance was measured less than 5000 ohms at each electrode location. Since reading constitutes a low artifact E.E.G. task (Ornstein et al., 1979) a verbal learning paradigm was used. Each subject was then given five minutes to study the student objectives during which time I calibrated the settings with an input signal of 10 Hz at 50 V, verified proper operation of the systems, and ensured stabilization of temperature. The poster presenting the adjunct format appropriate to his/her condition was presented by instructing the subject, over the intercom, to remove the cover and thereby expose the paste up in front of him/her and set the timer to 5 minutes. (Pre-training on these movements had been given during the provision of general information cn the sequence). Each subject was thus given five minutes to study the Adjunct material in front of him/her. When this five minute period was over, each subject was instructed to set the timer for 15 minutes and studied the text material during this time. Throughout this whole period (of 20 minutes) each subject's neurophysiological responses were monitored. The 4-channel E.E.G. signals were recorded on the FM recorder and a permanent record of them kept while the temperature samples were written down every minute as Brain and Learning 54 per Meiners & Dabbs (1977). After this 15 minute interval I signalled, on the intercom, that this was the end of the study period. I entered the chamber, turned over the adjunct poster and took the text material. I set the timer so each subject was thus given 10 minutes to do the paper and pencil recall task and the comprehension test. When this 10 minute period was over I entered the chamber and took the tests signalling that this was the end of their time. I then scored their recall and comprehension tests to provide feedback and I explained the study to them. Post Experimental Debriefing I asked the subjects i f they had any questions or comments, whether they had experienced any discomfort wearing the electrophysiological unit during the procedure or due to the arrangement of things or whether they had felt the room comfortable for temperature, ventilation, etc. or i f they had any other complaints. I did a manipulation check to ensure that the subjects in each condition were influenced in the manner needed for the experiment and encouraged comments, criticisms and questions during every part of this debriefing period. Methods of Observations and Measurements E.E.G. artifact rejection. The raw data were examined using the program DISPLAY to determine obvious artifacts, signal loss or blatant extraneous electrical noise. These were edited out of the analysis by manual procedures such as recommended (or used) by Gevins and Yeager (1975). More subtle sources of noise and artifacts were fairly well Brain and Learning 55 c o n t r o l l e d f or by the f i l t e r i n g processes. The main sources of E.E.G. a r t i f a c t s and extraneous noise include extracerebral sources such as eye movement a r t i f a c t s (BOG), eye b l i n k s , eye and f a c i a l muscle EMG a r t i f i c a t s , EMG from other muscle p o t e n t i a l s of the body neck and head, pulses and EKG (contamination of E.E.G. by car d i a c a c t i v i t y p o t e n t i a l s ) , sweating and GSR contamination, s t a t i c e l e c t r i c i t y on the subject or around him/her, subject movement or object movement a r t i f a c t s , cross t a l k between E.E.G. channels, varying electrode r e s i s t a n c e a r t i f a c t s , and other sources such as p o l a r i z a t i o n of electrodes s t r a y capacitance, r e s p i r a t i o n a r t i f a c t s , a r t i f a c t s a s sociated with tremor of head or limbs and c o n t r a c t i o n or d i l a t i o n o f s c a l p s k i n c a p i l l a r i e s which give r i s e to s k i n p o t e n t i a l s as w e l l as c o n d u c t i v i t y changes. Other sources of E.E.G. a r t i f a c t s can be summarized as a r i s i n g from various sources of external e l e c t r i c a l •i i i n t e r f e r e n c e . E l e c t r o s t a t i c and electromagnetic i n t e r f e r e n c e from external sources i n i n t e r a c t i o n with the subject or i n and of themselves c o n s t i t u t e another group of a r t i f a c t s . Radio frequency i n t e r f e r e n c e , i n t e r f e r e n c e due to machine f a u l t s , power surges, switch f a u l t s , a m p l i f i e r r a d i a t i o n or a m p l i f i e r f a u l t s , p o l a r i z a t i o n e f f e c t s , and contact f a u l t s . According to a study by Chen, Drangsholt, Dworkin & Clark (1983) the alpha band showed no s i g n i f i c a n t a r t i f a c t u a l change i n power with various behaviors. The alpha band i s not a f f e c t e d by e x p l i c i t b e h a v i o r a l movements since these a r t i f a c t e f f e c t s are centered predominantly i n the low frequency d e l t a band and the high frequency Brain and Learning 56 30-50 Hz band. Since the analog low pass Nyquist filters had a cut off at 25 Hz and the digital filters had high pass and low pass cut offs at 8 Hz and 14 Hz, these artifacts would be expected to have been excluded prior to the analyses. O'Donnell, Berkhout & TAdey (1974) observed l i t t l e i f any EMG infiltration of the E.E.G. signals below 14 Hz except when the E.E.G. electrode was very close to a contracting muscle. /According to Gevins, Yeager, Zeitlin, Ancoli & Dedon (1977) there could be high frequency artifacts associated with EMG of over 34-44 Hz and low frequency Electro-Oculo-Gram (EOG) artifacts (Girton & Kamiya, 1973) both which would have also been rejected by the processing system. Movement artifacts would also have been minimized by the requirement that the subjects use the chin rest and that the task did not require any significant motor responses. Smiling and laughing are said to e l i c i t increments in power artifacts whereas moving the eyes or squinting tends toward power reduction artifacts but the nature of the material was not such that would e l i c i t these responses. Chen et al. (1983) also reported that major muscle artifacts f a l l in the high frequency range and that the alpha band (the one analyzed in this study) is least affected by movement of frontalis, masseter or biceps muscles. Frontalis activity is reported to affect power in the delta and theta bands only (O'Donnell et al., 1974). Chen et a l . (1983) also reported that, in their studies of E.E.G. artifacts, no laterality differences were observed, however, variations were often apparent between different subjects performing the same movements. B r a i n a n d L e a r n i n g 5 7 "EMG i n f i l t r a t i o n i s a b s e n t i n t h e E . E . G . b e l o w 1 4 H z e v e n w h e n m u s c l e s a r e c o n t r a c t e d f o r l o n g p e r i o d s o f t i m e " ( O ' D o n n e l l e t a l . , 1 9 7 4 ) . H o w e v e r , w h e n a m u s c l e d i r e c t l y u n d e r a n e l e c t r o d e c o n t r a c t s t h e r e c a n b e s u d d e n m a s s i v e i n c r e a s e i n s p e c t r a l p o w e r o v e r t h e e n t i r e f r e q u e n c y r a n g e ( J o h n s o n , W r i g h t & S e g a l l , 1 9 7 7 ) . C l o s e o b s e r v a t i o n o f t h e p o w e r s p e c t r u m d u r i n g t h e a n a l y s e s d i d n o t r e v e a l a n y e v i d e n c e o f s u c h m a s s i v e g e n e r a l i n c r e a s e i n s p e c t r a l p o w e r . E y e m o v e m e n t p o t e n t i a l s ( EGG ) a r e d u e t o t h e a c t i o n o f t h e e y e a s a v a r i a b l e e l e c t r i c d i p o l e ( t h e c o r n e a b e i n g p o s i t i v e w i t h r e s p e c t t o t h e r e t i n a ) . W i t h e y e m o v e m e n t t h i s c o r n e o - r e t i n a l p o t e n t i a l p r o d u c e s a n i n t e r f e r e n c e w i t h t h e E . E . G . a t t h e s a m e t i m e a s c h a n g e s i n p o t e n t i a l a t s i t e s n e a r t h e e y e . T h e s e p o t e n t i a l s a r e t r a n s m i t t e d t h r o u g h o u t t h e w h o l e h e a d b u t b e c o m e s i g n i f i c a n t l y a t t e n u a t e d w i t h i n c r e a s i n g d i s t a n c e f r o m t h e e y e . T h e s e h a v e p r e s e n t e d a p r o b l e m w i t h s t u d i e s r e c o r d i n g t h e E . E . G . p a r t i c u l a r l y i n c o n t i n g e n t n e g a t i v e v a r i a t i o n m e a s u r e m e n t s a n d i n c r o s s c o r r e l a t i o n s t u d i e s ( H i l l y a r d & G a l a m b o s , 1 9 7 0 ) . S i n c e t h e s e a r e v e r y s l o w l y c h a n g i n g p o t e n t i a l s , a s i m p l e m e t h o d i s t o e x c l u d e s e g m e n t s w h i c h s h o w e y e m o v e m e n t a r t i f a c t . V a r i o u s e l e c t r o d e p l a c e m e n t s a r e d i f f e r e n t i a l l y a f f e c t e d b y v e r t i c a l o r h o r i z o n t a l c o m p o n e n t s o f e y e m o v e m e n t a r t i f a c t . G e r t o n a n d K a m i y a ( 1 9 7 3 ) h a v e d e v i s e d a n c n l i n e t e c h n i q u e f o r s u b t r a c t i n g e y e m o v e m e n t a r t i f a c t s f r o m t h e E . E . G . w h i c h r e q u i r e s t h a t v e r t i c a l a n d h o r i z o n t a l BOG e l e c t r o d e s b e a t t a c h e d a n d i n t e g r a t e d w i t h a V e r t e x t o M a s t o i d E . E . G . r e c o r d e r . E y e m o v e m e n t a r t i f a c t s a r e h o w e v e r m u c h m o r e p r o n o u n c e d f o r t h e m o r e f r o n t a l e l e c t r o d e p l a c e m e n t s . T e m p o r a l a n d B r a i n a n d L e a r n i n g 5 8 p a r i e t a l p l a c e m e n t s a r e s a i d t o n o t b e t o o i n f l u e n c e d b y t h e s e a r t i f a c t s { C o o p e r , O r n s t e i n & S h a w , I 9 6 0 ) . T e m p o r a l p l a c e m e n t s s u c h a s i n t h i s p r e s e n t s t u d y s o m e t i m e s e v o k e a r t i f a c t s a s s o c i a t e d w i t h a c t i v a t i o n o f t h e t e m p o r a l i s o r m a s s e t e r m u s c l e s ( j a w m u s c l e s ) . T h e s e a r e u s u a l l y e l i m i n a t e d b y i n s t r u c t i n g t h e s u b j e c t t o r e l a x h i s / h e r j a w l i g h t l y o n t o t h e c h i n r e s t a n d o n c e e l i m i n a t e d d o n o t t e n d t o r e t u r n . I n f o u r i n s t a n c e s , d u r i n g t h e s e t t i n g u p s t a g e o f t h e p r e s e n t s t u d y s u c h a d m o n i t i o n s w e r e c o n v e y e d t o t h e s u b j e c t s . I n a d d i t i o n , v i s u a l e x a m i n a t i o n s w e r e c a r r i e d o u t o f g r a p h i c a l d i s p l a y s o f t h e F F T ' s a n d p o w e r s p e c t r a ( L e v y , S h a p i r o & M e a c h e , 1 9 8 0 ) t o d e t e c t c o n t a m i n a t i o n o f E . E . G . s p e c t r u m b y c r a n i o f a c i a l m u s c l e c o n t r a c t i o n b u t , a s s t a t e d a b o v e , t h e r e i s a g e n e r a l l a c k o f p r o b l e m u s i n g t h e g i v e n e l e c t r o d e p o s i t i o n s . C o n t r o l f o r p o s s i b l e p u l s e o r E K G c o n t a m i n a t i o n w a s a c c o m p l i s h e d b y h a v i n g t h e e l e c t r o d e b o a r d s u s p e n d e d a b o v e t h e s u b j e c t s , s h o r t l e a d s t o i t a n d n o c o n t a c t w i t h t h e s u b j e c t b y t h e w i r e s g o i n g f r o m t h e e l e c t r o d e s t o t h e a m p l i f i e r s . S w e a t i n g a n d G S R p o t e n t i a l a r t i f a c t s w e r e c o n t r o l l e d f o r b y h a v i n g t h e e x p e r i m e n t a t i o n a r e a w e l l v e n t i l a t e d b y o p e n i n g t h e w i n d o w s a n d b y t h e l a c k o f c o n t a c t a n y w h e r e o n t h e s u b j e c t e x c e p t a t t h e e l e c t r o d e p o s i t i o n . D e b r i e f i n g o f t h e s u b j e c t s c o n f i r m e d t h a t t h e r o o m t e m p e r a t u r e r e m a i n e d c o o l e n o u g h . T h e y h a d n o t e x p e r i e n c e d h i g h e n o u g h l e v e l s o f a m b i e n t t e m p e r a t u r e t o e x p e r i e n c e s w e a t i n g n o r d i s c o m f o r t . P o s s i b l e s t a t i c e l e c t r i c i t y o n t h e s u b j e c t o r a r o u n d h i m / h e r w a s e l i m i n a t e d b y h a v i n g a l l o b j e c t s t o u c h i n g p a r t s o f t h e s h i e l d e d r o o m g o i n g t o g r o u n d a n d a s p e c i a l e a r l o b e g r o u n d i n g e l e c t r o d e t o g r o u n d e a c h s u b j e c t . S i n c e Brain and Learning 59 subject movements were minimal and there were no moving objects within the experimentation chamber, these sources of artitacts should nave been at a minimum. Possible cross talk between channels was eradicated 0 by having each of the leads physically very separate from the others and the use of shielded coaxial cable leads (with the shielded portion connected to its own separate ground). This procedure also eliminated possible stray capacitance effects. Possible artifacts caused by varying electrode resistance were controlled for by ensuring proper electrode impedance (less than 5,000 ohms) prior to the experimental tests and by test runs on various subjects to ensure constant contact pressure by the electrode band. The system was closely monitored throughout to ensure that no radical changes might have occurred due to electrode polarization. Possible respiration artifacts were eliminated by the very direct routing of wires from the scalp electrode positions to the electrode boards and thence to the amplifiers. Each subject had been encouraged to relax during the electrode attachment phase and since as mentioned before, the area was relatively cool, responses are not likely to have been drastic enought to induce radical departures of the E.E.G.'s. Alteration of possible external sources of electrical interference was accomplished by ensuring that the shielded room was a l l arranged as designed. 60 Hz interference from mains a.c. lines was rejected by the extensive shielding of a l l cables and by the low pass filtering at 25 Hz and at 14 Kz by the analog and digital filters respectively. Possible interference from motor generators, magnetic fields, radio frequency sources, microphonics, switches, telephones, Brain and Learning 60 radio and other machines were thus controlled for. Also, the possibility of radiation from noisy tubes or batteries was carefully monitored and excluded by the extensive grounding. E.E.G. data signal processing. (a) Analog filtering and  digitizing. The E.E.G. data collected on the FM Instrumentation Recorder were fed into first order Nyquist low pass analog filters. The low pass cut offs were set at 25Hz to ensure a comfortable margin for anti-aliasing. For the 20 minutes of data for each subject the four channels of E.E.G. were thus lew pass filtered at 25 Hz with the Krohn-Hite 3342 analog filters and then digitized at 64 Hz using the DECLAB MNCAD module and the program ADTEST. This thereby constituted 307000 data points per subject. These filtered signals were thus fed to the Analog to Digital converter which, in conjunction with the Clock module and the program ADTEST sampled the one second signals sweeps at 64Hz. This epoch provides for multiples of 1Hz of the digitized data. (b) Demultiplexing: One channel at a time, these data were demultiplexed using "DEMUX" to create four files each 300 data records long. (c) Windows: The fourier transform and power spectrum algorithms essentially compute the frequency spectrum from the input block of samples (epoch) taken by quantization. The fourier transform and power spectrum assume that this epoch is infinitely repeated. When measuring a continuous signal like the E.E.G. the epoch does not usually contain a number of cycles consistent with the input E.E.G. wave since, depending on where the sampling process happens to "catch" B r a i n a n d L e a r n i n g 6 1 t h e w a v e , i t p r o d u c e s d i f f e r e n t r e p r e s e n t a t i o n s o f f r e q u e n c y c o m p o n e n t s i . e . w n e n t h e w a v e f o r m i s n o t p e r i o d i c i n t h e e p o c h , t h e t o u r i e r t r a n s f o r m a n d p o w e r s p e c t r u m a l g o r i t h m s t h u s g e t c o m p u t e d o n t h e b a s i s o f a d i s t o r t e d w a v e f o r m ( s a m p l i n g i s t h u s s u c h t h a t t h e e p o c h c a u g h t a l o n g t h e w a v e i s n o t p e r i o d i c ) s i n c e s h a r p p h e n o m e n a i n t h e t i m e d o m a i n a r e s p r e a d o u t i n t h e f r e q u e n c y d o m a i n . T h e s p e c t r u m t h u s b e c o m e s d i s t o r t e d . " T h e m i s s i n g e n d p o i n t o f o n e s e q u e n c e s a m p l e d i s t h e b e g i n n i n g o f t h e n e x t p e r i o d " ( H a r r i s , 1 9 7 8 ) . T h e f i n i t e f o u r i e r t r a n s f o r m m u s t b e made t o a p p r o x i m a t e t h e i n f i n i t e ( t h e o r e t i c a l ) o n e . I f t h e w a v e i s n o t p e r i o d i c i n t h e t i m e r e c o r d ( E . E . G . i s n o t p e r i o d i c ) p o w e r g e t s s p r e a d t h r o u g h o u t t h e s p e c t r u m . T h i s e n e r g y l e a k o u t o f o n e r e s o l u t i o n l i n e o f t h e f o u r i e r t r a n s f o r m a n d p o w e r s p e c t r u m i n t o t h e o t h e r l i n e s o f r e s o l u t i o n i s t h e p h e n o m e n o n c a l l e d " l e a k a g e i n t h e f r e q u e n c y d o m a i n " b e c a u s e i t r e s u l t s i n a f o r m o f s m e a r i n g o f e n e r g y t h r o u g h t h e f r e q u e n c y d o m a i n . " F r o m t h e c o n t i n u u m o f p o s s i b l e f r e q u e n c i e s o n l y t h o s e w h i c h c o i n c i d e w i t h t h e b a s i s w i l l p r o j e c t o n t o a s i n g l e b a s i s v e c t o r ; a l l o t h e r f r e q u e n c i e s w i l l e x h i b i t n o n - z e r o p r o j e c t i o n s o n t h e e n t i r e b a s i s s e t " ( H a r r i s , 1 9 7 8 ) a n d " t h e d i s c o n t i n u i t i e s a r e r e s p o n s i b l e f o r s p e c t r a l c o n t r i b u t i o n s ( o r l e a k a g e ) o v e r t h e e n t i r e b a s i s s e t " t h u s " w i n d o w e d d a t a a r e s m o o t h l y b r o u g h t t o z e r o a t t h e b o u n d a r i e s s o t h a t t h e p e r i o d i c e x t e n s i o n o f t h e d a t a i s c o n t i n u o u s . " ( H a r r i s , 1 9 7 8 ) . I f t h e E . E . G . w a v e w e r e p e r i o d i c w i t h i n t h e e p o c h s a m p l e d t h i s w o u l d n o t h a p p e n b u t g i v e n t h e i r r e g u l a r i t y o f t h e E . E . G . w a v e t h i s l e a k a g e i s l i k e l y . A l s o , i f i t w e r e p o s s i b l e t o o b t a i n a n i n f i n i t e B r a i n a n d L e a r n i n g 6 2 t i m e r e c o r d ( e p o c h ) t h i s w o u l d a l s o n o t o c c u r . " P r o c e s s i n g a f i n i t e d u r a t i o n o b s e r v a t i o n i m p o s e s i n t e r e s t i n g a n d i n t e r a c t i n g c o n s i d e r a t i o n s o n t h e h a r m o n i c a n a l y s i s " ( H a r r i s , 1 9 7 8 ) . B u t , s i n c e t h e c o n t i n u o u s i n p u t f r o m t h e E . E . G . i s n o t p e r i o d i c i n t h e e p o c h , l e a k a g e w h i c h may b e s e v e r e e n o u g h t o m a s k s m a l l s i g n a l s , ( d u e t o t h e d i s c o n t i n u i t i e s ) d i s t o r t i o n o f t h e r e p r e s e n t a t i o n i s l i k e l y t o o c c u r . W i n d o w i n g p r o v i d e s a p a r t i a l s o l u t i o n t o t h i s p r o b l e m ( H a r r i s , 1 9 7 8 ) . S i n c e m o s t o f t h e p r o b l e m s e e m s t o b e a t t h e e d g e s o f t h e e p o c h a w i n d o w c a u s e s t h e f o u r i e r t r a n s f o r m a n d p o w e r s p e c t r u m t o i g n o r e t h e e n d s a n d c o n c e n t r a t e o n t h e m i d d l e o f t h e e p o c h . S o , i n w i n d o w i n g , t h e t i m e r e c o r d i s m u l t i p l i e d b y t h e w i n d o w f u n c t i o n w h i c h i s z e r o a t t h e e n d s a n d l a r g e i n t h e m i d d l e . C o r r e c t c h o i c e o f w i n d o w p r o v i d e s v a s t i m p r o v e m e n t o f t h i s l e a k a g e s i n c e i t r e d u c e s w e i g h t i n g o f t h e e n d s w h e r e a s t h e c e n t e r g e t s t h r o u g h f i n e ( H a r r i s , 1 9 7 8 ) . F o r s ome a p p l i c a t i o n s s u c h a s i n t h e c a s e o f t r a n s i e n t w a v e s o n e m i g h t w a n t t o u s e a l l t h e d a t a i n t h e t i m e r e c o r d e q u a l l y a n d u n i f o r m l y . T h e r e c t a n g u l a r w i n d o w , w h i c h w e i g h t s a l l t h e t i m e r e c o r d u n i f o r m l y a n d g i v e s s h a r p c u t o f f f o r c i n g t h e i n p u t t o z e r o a t t h e b e g i n n i n g a n d e n d m i g h t s e r v e b e s t s i n c e i t p r o v i d e s l e a s t e r r o r i n t h e m e a n s s q u a r e d e r r o r s e n s e . I t i s t h u s t h e c l o s e s t o n e c a n g e t f o r t h e i n f i n i t e e x t e n t . T h e m e a n s q u a r e e r r o r m a y b e l e a s t w i t h a r e c t a n g u l a r w i n d o w b u t t h i s i s n o t t h e c r i t e r i o n o f i n t e r e s t i n a p p l i c a t i o n l i k e E . E . G . B r a i n a n d L e a r n i n g 6 3 s p e c t r a l a n a l y s i s . S o we m u l t i p l y , i n t h e t i m e d o m a i n , t h e E . E . G . w a v e f o r m b y a s u i t a b l e w i n d o w a n d g e t t h e p o w e i s p e c t r u m o f t h i s w i n d o w e d f u n c t i o n . C e r t a i n s p e c t r a l c o m p o n e n t s o f f r e q u e n c y i n v i s i b l e w i t h a r e c t a n g u l a r w i n d o w c a n b e s e e n u s i n g o t h e r w i n d o w s . F o r m e a s u r i n g w h i t e n o i s e - l i k e s i g n a l s s u c h a s t h e E . E . G . , a w i n d o w f u n c t i o n w i t h a m o r e g r a d u a l r o l l o f f a t t h e e n d s a n d a m o r e r o u n d e d t o p a t t h e c e n t e r o f t h e r e c o r d m i g h t b e d e s i r a b l e . A t r a d e o f f h o w e v e r i s n e c e s s a r y w i t h r e s p e c t t o c e r t a i n a s p e c t s o f d o i n g t h i s . " W i n d o w s i m p a r t o n m a n y a t t r i b u t e s o f a h a r m o n i c p r o c e s s o r " ( H a r r i s , 1 9 7 8 ) . F o r i n s t a n c e , o n e c a n e n d u p w i t h a s p e c t r u m o f b r o a d e r b a n d w i d t h t h a n o n e s t a r t e d w i t h ( r i p p l e s o n e a c h s i d e o f t h e m a i n l o b e ) . O n e c a n a l s o , w i t h s u c h a w i n d o w , e n d u p w i t h b r o a d e r t h a n o r i g i n a l r e s o l u t i o n o r a d e c r e a s e d o r i n c r e a s e d w i d t h o f t h e m a i n l o b e . T h e e q u i v a l e n t n o i s e b a n d w i d t h ( n o i s e p o w e r o f t h e o u t p u t o f t h e w i n d o w p e r u n i t b a n d w i d t h ) n e e d s t o b e c o n s i d e r e d . T h e r e i s a l s o t h e p r o c e s s i n g c o h e r e n t g a i n . I n c o h e r e n t p o w e r o u t p u t i s t h e p r o d u c t o f t h e p r o p o r t i o n o f v a r i a n c e o f t h e n o i s e a n d t h e sum o f s q u a r e d o f t h e w i n d o w f u n c t i o n . I n a d d i t i o n t h e r e i s s c a l l o p i n g l o s s , w o r s t c a s e p r o c e s s i n g l o s s , o v e r l a p c o r r e l a t i o n , h i g h e s t s i d e l o b e a n d s i d e l o b e f a l l o f f . A l l t h e a d v a n t a g e s a n d d i s a d v a n t a g e s o f t h e s e p a r a m e t e r s h a v e t o b e t a k e n i n t o a c c o u n t i n r e f e r e n c e t o t h e d a t a a n d t h e p u r p o s e o f o n e ' s a n a l y s i s w h e n s e l e c t i n g a w i n d o w f u n c t i o n t o a p p l y t o t h e g i v e n d a t a . M a n y k i n d s o f w i n d o w s b e s i d e s t h e r e c t a g u l a r w i n d o w c a n b e u s e d d e p e n d i n g o n o n e ' s p u r p o s e . B r a i n a n d L e a r n i n g 64 /Among t h e s e a r e t h e t r i a n g u l a r w i n d o w , t h e H a m m i n g ( C o s i n e f a m i l y ) v r i n d o w s , t h e H a m m i n g w i n d o w , t h e B l a c k n a n w i n d o w , t h e R i e s z ( B o c h n e r . P a r z e n ) w i n d o w , t h e R i e m a n n w i n d o w , t h e J a c k s o n , P a r z e n w i n d o w , t h e T u k e y w i n d o w , t h e B o h m a n w i n d o w , t h e H a n n i n g - P o i s s o n w i n d o w , t h e C a u c h y ( A b e l , P o i s s o n ) w i n d o w , t h e G a u s s a n ( W e r e r s t r a s s ) w i n d o w , t h e D o l p h - C h e b y c h e v w i n d o w , t h e B a r c i l o n - T e w e s w i n d o w a n d t h e K a i s e r B e s s e l a n d F o u r P o i n t K a i s e r B e s s e l w i n d o w . a. T h e K a i s e r B e s s e l w i n d o w i s a s m o o t h c u r v e w i t h o r d i n a t e s z e r o a t t h e e n d s b u t a w i n d o w s u c h a s t h e F o u r P o i n t K a i s e r B e s s e l w i n d o w s e e m s o p t i m u m i n g i v i n g i m p r o v e d a c c u r a c y a n d f r e q u e n c y d o m a i n f r e q u e n c y r e s o l u t i o n . I t s e e m s t o p o s s e s s t h e b e s t c o m p r o m i s e i n t e r m s o f p o s i t i v e a n d n e g a t i v e c h a r a c t e r i s t i c s a n d s o g i v e s t h e b e s t r e p r e s e n t a t i o n o f f r e q u e n c y ( w h i c h i s t h e f a c t o r o f i n t e r e s t i n t h e p r e s e n t , s t u d y ) . U s i n g "POWER" t h e d i g i t i z e d s i g n a l s w e r e p r e p r o c e s s e d b y m u l t i p l y i n g b y a K a i s e r B e s s e l f o u r p o i n t w i n d o w t o p r e v e n t t h e d i s c o n t i n u i t i e s d u e t o l e a k a g e i n t h e f r e q u e n c y d o m a i n a s d i s c u s s e d a b o v e . T h e K a i s e r B e s s e l w i n d o w a p p e a r s s u p e r i o r t o t h e C o s i n e o r H a m m i n g w i n d o w s ( s e e F i g u r e 4) b e c a u s e i t o f f e r s t h e b e s t c o m p r o m i s e o f e q u i v a l e n t n o i s e b a n d w i d t h , c o h e r e n t g a i n , s c a l l o p i n g l o s s , h i g h e s t s i d e l o b e , s i d e l o b e f a l l o f f , w o r s t c a s e p r o c e s s i n g l o s s , e t c . C o n s i d e r i n g i t s p r o p e r t i e s , i t w a s f e l t t o I n s e r t F i g u r e 4 a b o u t h e r e Brain and Learning 65 be the best compromise of positive features for a window. After windowing the data was Fourier transformed using a 64 point FFT. Digital filtering and average power computation. Subsequent to digital filtering, second by second power spectra were obtained for the Alpha band (8 to 14 Hz) and averaged for each second. Second by second power spectra were then averaged over 2 minutes 40 seconds and eight of these were collected and averaged over the whole 20 minutes. (See Figure 5 for sketch of signal processing system) Insert Figure 5 about here (7_£ Calibration, (a) Computer software scaling; Power values were calibrated by the computer routines to convert to a representation of the voltages at the input to the A/D converter rather than the digitized quantization values (scaling due to the A/D process) the computer worked with. Values of the order of V^/Hz were thus returned by the program POWER. (b) Applied external calibration (for the system): To these values produced by the program POWER the various system gains had to be 2 applied to arrive at a correct y> v /Hz value (which represents the input at the E.E.G. electrodes). The overall system block diagram starting with the E.E.G. signal at the electrode cap and leading to the PDP-11 is shown in Figure 6. Insert Figure 6 about here Ap^^o (2 7 Brain and Learning 66 The value of the overall averaged power presented by the program POWER took into account the quantization scaling but not the gains of the amplifier tape recorder and analog filters. To obtain the true power (representation at the E.E.G. electrodes) the values returned by the program POWER were divided by the gains G^  through G^ . Thus the true value of power is given by: 2 True Power (^ v /Hz) = Computer Calculated Power (3) G l G2 G3 G4 To process the data from a subject, each 75 4K buffers of 4 channel data collected using ADTEST needed 20 minutes per channel of data or 1200 total raw data records. To demultiplex these 20 minutes of data per channel (1200 raw data records) required 5 minutes per channel and to average the powers using POWER and windowing the data required 5 minutes per channel. The total time involved in calculating the average power for the 4 channels for each subject was plus 65 minutes. Examining displays and plots required additional time. Hemispheric averages were computed by taking the mean for the two left hemisphere electrodes and the mean for the two right hemisphere electrodes. These were used as dependent variables along with the relative right hemispheric average power ratios as per Steadman & Morgan (1974) and Doyle et al., (1974) and Matousek & Petersen (1973) and the log power ratios as per Ornstein et a l . (1979) and Gasser, Bacher and Mocks (1982). Brain and Learning 67 Most experts suggest transforming the absolute power values before performing statistical analyses. According to ornstein, et a l . (1979) statistical analyses ought to be computed cn natural logarithmic transforms of hemispheric ratio because ratios have been found to not meet assumptions required of the analysis of variance. According to Ehrlichman & Wiener (1979) this is accomplished to make the ratios symmetrical about unity and to reduce the impact of extreme scores. According to Cooper Osselton & Shaw (1980) and Matousek and Petersen (1973) the analysis of variance needs to be carried out on square root transformed E.E.G. power values as well as the log power ratios. Matthis, Scheffner & Benninger (1981) examined the mathematical properties of E.E.G. spectral parameters and maintain that relative power parameters are robust, numerically stable etc...but do not meet the theoretical models for statistical tests. Gasser et a l . (1982) however have studied various transformations of E.E.G. spectral parameters for skewness, kurtosis and Wilk's W. and conclude that relative power is not too distorted only in the Delta band. They do, however, recommend using the square root and natural log transformation of absolute power. Statistical techniques which rely on the normal distribution thus cannot be used i f absolute power values are used because their empirical distribution does not follow the normal distribution in samples of healthy individuals (Gasser et al., 1982). These deviations ' are ostensibly quite substantial, resulting from asymmetry and long tails in the empirical distribution. They may arise from different sources such as being inherent in the scale used, Brain and Learning 68 intrinsic in the biological systems generating the E.E.G., sample heterogeneity (such as unrecognized pathology in some subjects), recording techniques, or the parameters themselves (Gasser et al., 1982). Since the ratio of right hemisphere power to left hemisphere power has been shown to give a value concordant with left hemisphere activity to right hemisphere activity and that in the present study, right hemisphere activity was of main interest I used the inverse of this ratio. The ratio can thus be taken to represent a value concordant with activity proportional to the relative right hemisphere. In right handed people the Right to Left ratio of alpha power is typically higher during tasks predicted to primarily engage the left hemisphere (verbal tasks) and the Left to Right ratio of alpha power is typically higher during tasks predicted to primarily engage the right hemisphere (i.e. spatial tasks)(Ornstein et al., 1979). Left hemisphere power is thus divided by right hemisphere power to compute a ratio of relative right hemisphere activation. This ratio of alpha power measure is said to be somewhat more stable than raw E.E.G. alpha power; computing ratios is (Ornstein, et al., 1979) analogous to normalizing the index within subjects and reflects relative hemispheric engagement concisely. There is thus a disagreement in the literature about the method in which E.E.G. average power data ought to be analyzed. Some have done inferential tests on raw E.E.G. power averages but according to many authors, including Ornstein et al, (1979), analysis of variance B r a i n and Le a r n i n g 69 carried out on raw E.E.G. power may be erroneous because of the data i'iot. iieieting the disfci'iDutior* requirements as per the aLove arguments. So, i t is recommended, to obtain the assumptions of inferential s t a t i s t i c a l tests that an analysis of variance be carried out on the root power and the natural logarithmic transform of the hemispheric ratios. In accordance with this, in the present study, the main analysis of E.E.G. was carried out using the natural logarithmic transforms of the ratios. These showed to be more conservative tests of the effects. A probability level of P < .05 was chosen as cr i t e r i o n for rejecting the null hypotheses for a l l the planned comparisons. The two orthogonal planned comparisons were chosen "a p r i o r i " on the basis of the specific hypotheses of the study. The main consideration, in this study was experimental in nature and the logic, relevance and specific groups chosen as well as the methods and / ' procedures were predicated on carrying out the specific contrasts chosen. The planned comparisons were conducted instead of the omnibus F test. Considering the seriousness of Type II errors - (overlooking of potentially important effects either because they are small or because of attentuation by experimental error) and that the replication process ought to provide protection from Type I errors (since independent demonstrations themselves reduce chances of spurious or inaccurate findings), in the present study I adopted a .05 alpha level for the two orthogonal planned comparisons. The two post, .hoc comparisons were carried out using an adjustment to the alpha level as per the Dunnett procedure when the comparisons are referenced to a B r a i n a n d L e a r n i n g 7 0 c o n t r o l g r o u p . S i n c e t h e o b t a i n e d p r o b a b i l i t y l e v e l s s e e m q u i t e c l e a r ( n o e f f e c t s w i t h t h e r a n g e o f m a r g i n a l i t y t h a t w o u l d m a k e a d i f f e r e n c e ) t h i s i s n o t a p r o b l e m w h i c h e v e r w a y i t i s d o n e . T h e m e a n i n g o f a v e r a g e E . E . G . p o w e r c h a n g e s a n d t h e r m a l  c h a n g e s . T h e p o t e n t i a l s r e c o r d e d f r o m t h e s c a l p E . E . G . a p p e a r t o b e p r o d u c e d w i t h i n t h e c o r t e x i t s e l f . T h e p y r a m i d a l c e l l s a p p e a r t o b e t h e p r i n c i p a l c e l l u l a r e l e m e n t s c o n t r i b u t i n g t o t h e E . E . G . a n d i t h a s b e e n f o u n d t h a t v i s u a l s e n s o r y s t i m u l i c a n e v o k e s i m u l t a n e o u s a c t i v a t i o n o f l a r g e c o r t i c a l s u r f a c e s . T h e E . E . G . p o t e n t i a l s e v o k e d b y n a t u r a l o r a r t i f i c i a l s t i m u l a t i o n o f a f f e r e n t s e n s o r y p a t h w a y s a r e u s u a l l y c o m p o s e d o f a p o t e n t i a l w h i c h a t f i r s t h a s a p o s i t i v e w a v e a t t h e s u r f a c e o f t h e c o r t e x w i t h r e s p e c t t o a r e m o t e r e f e r e n c e f o l l o w e d b y a n e g a t i v e w a v e . T h e s e c a n b e f o l l o w e d b y l a t e r p o s i t i v i t y . T h e i n i t i a l p o s i t i v i t y c a n b e s p l i t i n t o s e v e r a l c o n s t i t u e n t s ( D o n d e y & G a c h e s , 1 9 7 4 ) . T h i s w o u l d u n d o u b t e d l y r e s u l t i n e n h a n c e d a v e r a g e p o w e r a t t h e a r e a o f r e c o r d i n g e l e c t r o d e . T h e i n i t i a l p o s i t i v e w a v e o f t h e s e n s o r y e v o k e d p o t e n t i a l s c a n b e s u p p l e m e n t e d b y a l a t e r p o s i t i v i t y , l o n g e r l a s t i n g , w h i c h may b e c a u s e d b y i n h i b i t o r y p o s t s y n a p t i c p o t e n t i a l s . T h e s e s e e m t o b e d u e t o i n h i b i t i o n o f c o r t i c a l n e u r o n s . T h e s e p o t e n t i a l s a r e c l a i m e d t o a f f e c t l a r g e r e g i o n s o f c o r t e x b u t a r e m i x e d w i t h s p o n t a n e o u s r a n d o m a c t i v i t i e s w h i c h o f t e n m a s k t h e m . T h e a v e r a g i n g p r o c e s s a l l o w s m o r e o r l e s s a t t e n u a t i o n o f t h e s p o n t a n e o u s p a r t o f t h i s a c t i v i t y . E l e c t r i c a l a c t i v i t i e s w h i c h a r i s e i n t h e c o r t e x h a v e b e e n r e p o r t e d t o d i f f u s e a w a y f r o m t h e i r o r i g i n . T h e p o t e n t i a l d i f f e r e n c e d u e t o d i f f u s i o n s e e m s t o d e p e n d o n t h e i n t r a c o r t i c a l Brain and Learning 71 generators. Cellular columns at the cortical surface follow a somatotopic pattern. This leads to physiologically homogeneous zones being represented by groups of neighboring and synergistic columns. The glia l covering constitutes a supplementary route for diffusion of currents and moderates or attenuates their intensities. This is why the E.E.G. is normally less than the 1 0 0 V range (Dondey & Caches, 1974). Between the cortex and the E.E.G. electrodes there is a series of electrically inactive media which interfere with the passage of currents. These are the cerebrospinal fluid, the meninges, the skull and the scalp; the cerebrospinal fluid, and meninges providing the most interference. Within the 8 to 14 Hz range there have been established certain varieties of waves reliably related to activities as in reading (Kappa) and to problem solving cognitive function (K - complex), possible Lambda waves, Mu rhythm (7 to 11 Hz), other periodic activity up to 20 Hz, and various other undefined wave patterns associated with certain activities and conditions. The average alpha power spectrum is taken cn a l l these waves within the alpha frequency band and is a reflection of the degree of synergistic activity along a l l these dimensions of brain activity. Given that the E.E.G. is derived from neural electrical activity in the brain in an hitherto misunderstood way, some speculations can be asserted with regards to the possible meaning of the average power spectrum of the E.E.G. Given the E.E.G. as a time series, the average power spectrum can be thought of as a statistical estimate of the B r a i n a n d L e a r n i n g 72 e l e c t r i c a l i n t e n s i t y o r e n e r g y c o m i n g o f f f r o m t h e c o r t e x a t t h e p o i n t o f a g i v e n E i . E . G . e l e c t r o d e . From t h e E . E . G . w a v e f o r m i n t h e t i m e d o m a i n t h e A/D c o n v e r s i o n s a m p l e s p o i n t s a l c n g t h i s wave fo rm a t a r a t e p e r u n i t t i m e ( i n t h i s s t u d y , 64 s a m p l e s p e r s e c o n d ) . I n t h e f a s t f o u r i e r t r a n s f o r m , t h e s e 64 d a t a p o i n t s s a m p l e d a t i n t e r v a l s o f t i m e o f one s e c o n d a r e t r a n s f o r m e d i n t o 64 f o u r i e r c o e f f i c i e n t s i n t h e f r e q u e n c y d o m a i n , one e a c h f o r t h e s i n e and t h e c o s i n e t e r m s . T h i s t r a n s f o r m i s e q u i v a l e n t t o m u l t i p l y i n g b y t h e c o s i n e and s i n e f r e q u e n c i e s . S i n c e f o r random d a t a t h e f o u r i e r c o e f f i c i e n t s h a v e random p h a s e s , t h e power s p e c t r u m i s more u s e f u l . The o r i g i n a l u n i t t i m e d a t a p o i n t s y i e l d h a l f t h e number o f power s p e c t r a l e s t i m a t e s i n f r e q u e n c y s p a c e e a c h w i t h two d e g r e e s o f f r e e d o m (one e a c h f r o m t h e s i n e and c o s i n e t e r m s ) . To i m p r o v e t h e a c c u r a c y o f t h e e s t i m a t e s , one a v e r a g e s t h e power s p e c t r u m o f s e v e r a l s m a l l s u b s e t s o f d a t a p o i n t s and t h e n a v e r a g e s t h e power s p e c t r u m f r o m e a c h g r o u p . Thus a v e r a g i n g s e v e r a l f r e q u e n c y b i n s p r o v i d e s c o n s i d e r a b l y more d e g r e e s o f f r e e d o m and t h u s c o n s i d e r a b l y more a c c u r a c y o f t h e e s t i m a t e d power s p e c t r u m . I n a b o u t 2/3 o f c a s e s t h e t r u e power s p e c t r u m c a n b e e x p e c t e d t o b e b e t w e e n V 2/D (D=df) o f e a c h e s t i m a t e ( C o o p e r , e t a l . , 1 9 8 0 ) . A c o m p l e x w a v e f o r m s u c h as t h e E . E . G . c a n t h u s b e shown t o b e r e p r e s e n t e d b y t h e sum o f a number o f s i n e waves o f d i f f e r i n g f r e q u e n c i e s and a m p l i t u d e s . The f o u r i e r method p r o v i d e s a t r a n s f o r m o f t h e w a v e f o r m w h i c h t e l l s t h e r e l a t i v e s t r e n g t h s o f t h e d i f f e r e n t f r e q u e n c y s i n e waves t h a t , when added t o g e t h e r , w i l l g i v e t h e o r i g i n a l Brain and Learning 73 time domain waveform. This waveform is assumed to be periodic. The i o U i i s c ffiBCfiod i s QiUiS iiks iuulL j .plying LTi<= frequency coaiponeiits by Liie various cosine and sine harmonics and average the values obtained for each. This process determines which of the harmonics are present since when sine waves are multiplied the mean cross product is finite when their frequencies are the same and zero when their frequencies are different (Cooper, et al., 1980). In fourier analysis the complex waveform is thus separated into harmonically related components the fundamental having a period equal to the epoch length. For instance, a sample of 1 second of E.E.G. can be represented by a fundamental waveform of 1 Hz and harmonics of 2, 3, 4 etc. Hz. One can thus represent a component at each frequency as the sum of sine and cosine components of the particular frequency. The power spectrum combines the sine and cosine components while giving up the information about phase (Cooper, et al., 1980). The average power spectrum is, however, not a unique description of the waveform since the same spectrum can result from quite different waveforms. Also, the average power spectrum is a manifestation of not only amplitude but also duration of certain frequencies within the band pass. It thus gives the relative intensities of sine waves that would reconstitute the signal. Thus the average alpha power spectrum gives a representation of the extent of synchronous electrical activity occurring at the particular E.E.G. electrode. This may be a manifestation of correlated activity between groups of neural ensembles indicating synchronic thinking. Holistic cognitive processing may be B r a i n a n d L e a r n i n g 74 t h e m e c h a n i s m u n d e r l y i n g t h i s E . E . G . s p e c t r a l m a n i f e s t a t i o n s i n c e s y n e r g i s t i c c e l l a c t i v i t y m a y b e i n v o l v e d . T h e m e a n i n g o f t h e r m a l c h a n g e s : b a s e d o n p r e v i o u s f i n d i n g s r e l a t i v e u n i l a t e r a l d e c r e a s e s i n e a r c a n a l t e m p e r a t u r e f r o m t h e i n i t i a l b a s e l i n e l e v e l s d u r i n g c o g n i t i v e t a s k s c a n b e e x p e c t e d t o r e f l e c t r e l a t i v e l y i n c r e a s e d b l o o d f l o w t o t h a t s i d e o f t h e b r a i n h e n c e g r e a t e r u n i l a t e r a l h e m i s p h e r i c u t i l i z a t i o n . Brain and Learning 75 Chapter III. Results Initially, the data collection of the present experiment yielded a set of 8 measurements for each subject, defined as follows: (1) Two second by second integrated alpha spectral powers from the left and right brain hemispheres as per Doyle, et al., (1974) and Furst, Gardner and Kamiya (1974) averaged over 2 minutes 40 seconds and then over the 20 minute period. The histogram of the treatment means of the powers are shown in Figure 3. (2) /An E.E.G. index of relative right hemispheric activity (ratio) as per Doyle et al., (1974). The natural logarithmic transform of this ratio was also analyzed as per Ornstein, et al., 1979). (3) Two thermal response indices (maximum decrease temperature) from the left and right tympanum areas as per Meiners and Dabbs (1977). The histogram of the treatment means of the thermal indices are also shown in Figure 7. Insert Figure 7 about here J^0dj&A2uf (4) A temperature index of relative right hemispheric activity as per Doyle et al., (1974). (5) Recall score. (6) Comprehension score. Bickel and Doksum (1981), as well as Carroll and Ruppert (1981), report that one can choose a good transformation of E.E.G. power Brain and Learning 76 spectral data but this is difficult or impossible to reliably do from the data. For power spectrum analysis, Matousek and Petersen (1973) and others have been using the E.E.G. square root power transformation instead of absolute power. According to Gasser et a l . (1982) this transformation is superior to the absolute power values and to other root transformations. For the present purpose,it was decided to use two neurophysiological measures, E.E.G. power ratio and thermal index ratio, and two verbal response measures, recall and comprehension scores. It was found that the experimental conditions were indeed linked to the procedure. The outcome of the manipulation check showed that each condition had been influenced as required. The control group reported having read the irrelevant material and having experienced no help toward the learning. The induced imagery group reported having created their own se^f generated imagery. The picture group reported having examined the poster and having been helped by i t . In order to test the predictions derived from the central general hypothesis i t was necessary to make two orthogonal contrasts. The first contrast (hereinafter referred to as the "Effect of Learning Adjuncts") was to compare the linear combination of mean vectors for Imagery Instruction and Pictorial Diagrams conditions with the mean vector of the control condition. The second contrast (hereinafter referred to as "Imagery vs. Picture Effect") was to compare the mean vector of the Induced Imagery condition with that of the Pictorial Diagram condition. The means and mean squared errors of the E.E.G. power ratios and tympanic temperature ratio index are reported along Brain and Learning 77 with those of verbal r e c a l l and comprehension scores i n Table 1. Insert Table 1 about here Jjp^-_L2-_i Presented also in Table 1 are natural logarithms of the relative right hemisphere a c t i v i t y E.E.G. ratio indices and their mean squared errors. The means for the E.E.G. average power generally indicate a difference due to pictures. The means of the E.E.G. power ratios (also of the E.E.G. power log ratios) indicate a difference due to pictures and a possible slight difference for the Imagery Instruction condition. The means of decreases in temperature for the right and l e f t hemispheres indicate s l i g h t l y greater right hemisphere decreases for the experimental conditions than for the control condition. The means for the temperature indices of right hemisphere a c t i v i t y reveal a possible difference due to pictures. An examination of the means shows that the effect of pictures (imposed imagery) seems to have induced superior r e c a l l and comprehension than the effect of the two other conditions. The Imagery Instruction seems to have e l i c i t e d s l i g h t l y better r e c a l l and comprehension than the control condition but not always significantly so. Neurophysiological Measures - E.E.G. Power Ratio and Thermal Index Ratio" A multivariate analysis was carried out taking the two neurophysiological variables as dependent variables in the logical temporal order of their occurrence. The planned orthogonal comparisons B r a i n a n d L e a r n i n g 7 8 f o r t h i s a n a l y s i s c o n s i s t e d o f t h e j o i n t l e a r n i n g a d j u n c t e f f e c t a n d t h e I m a g e r y v s . P i c t u r e e f f e c t . T h e j o i n t e f f e c t c o n t r a s t e d t h e t w o e x p e r i m e n t a l c o n d i t i o n s i n c o m b i n a t i o n w i t h t h e c o n t r o l c o n d i t i o n . T h e I m a g e r y v s . P i c t u r e e f f e c t c o n t r a s t e d t h e i m a g e r y i n s t r u c t i o n w i t h p i c t u r e d i a g r a m c o n d i t i o n . S t e p d o w n a n a l y s e s o f v a r i a n c e s w e r e a l s o c a r r i e d o u t . T h e r e s u l t s o f s t a t i s t i c a l a n a l y s e s a r e s h o w n i n T a b l e 2 . I n s e r t T a b l e 2 a b o u t h e r e F o r t h e j o i n t l e a r n i n g a d j u n c t e f f e c t t h e o v e r a l l m u l t 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 wa s n o 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 , F ( 2 , 5 6 ) = 2 . 2 1 9 , £ < . 1 1 8 2 . N e i t h e r o f t h e s t e p d o w n F v a l u e s a s s o c i a t e d w i t h t h i s t e s t e d s t a t i s t i c a l l y s i g n i f i c a n t . F o r t h e I m a g e r y I n s t r u c t i o n v s . P i c t u r e D i a g r a m c o n t r a s t e f f e c t t h e m u l t i v a r i a t e v a r i a n c e a n a l y s i s w a s s t a t i s t i c a l l y s i g n i f i c a n t , F ( 2 , 5 6 ) = 6 . 0 7 3 , £ < . 0 0 4 2 . T h i s s h o w s a r e l i a b l e d i f f e r e n c e b e t w e e n t h e t w o f o r m s o f l e a r n i n g a d j u n c t s f o r t h e e f f e c t u p o n t h e p h y s i o l o g i c a l v a r i a b l e s . T h e s t e p d o w n v a r i a n c e a n a l y s i s s h o w s t h a t t h e m o s t o f t h i s e f f e c t c a n b e a c c o u n t e d f o r b y t h e E . E . G . r e s p o n s e v a r i a b l e ( E . E . G . s t e p d o w n F ( 1 , 5 7 ) = 9 . 9 0 3 , p < . 0 0 2 7 ) . T h e t h e r m a l r e s p o n s e v a r i a b l e a c c o u n t s f o r a m a r g i n a l l y n o n s i g n i f i c a n t p o r t i o n o f t h i s c o n t r a s t , s t e p d o w n F = 2 . 0 5 9 ( 1 , 5 7 ) , £ < . 1 5 6 9 ) . A n o t h e r p o s t h o c m u l t i v a r i a t e t e s t c o m p a r e d t h e p i c t u r e d i a g r a m a n d i m a g e r y i n s t r u c t i o n c o n d i t i o n s s e p a r a t e l y w i t h t h e c o n t r o l c o n d i t i o n . I t s h o w e d t h a t E . E . G . p o w e r r a t i o o f t h e p i c t u r e d i a g r a m wa s t h e o n l y o n e Brain and Learning 79 distinctively different from two other treatment means, F(l,57) = 12.356, £ < .0009. This set of findings in conjunction with the neural impact on the left hemispheric activities as shown in Figure 3 suggests that pictures are superior to Imagery Instruction to eliciting a neurophysiological response. Verbal Recall and Comprehension Test Scores The overall multivariate analysis of variance for the combined recall and comprehension scores was statistically significant. F value approximation, Roy's criterion and associated probability are given in The joint effect was significant, F (2,56) = 7.997, £ <.. .0009. These findings corroborate the hypothesis of pictorial superiority. This means that the two forms of learning adjuncts combined influenced learning as reflected on recall and comprehension test scores. The step down F was statistically significant for recall. F (1,57) = 15.813, p< .0002. The fact that the step down F for comprehension score was not statistically significant indicates that the recall effect can account for pretty much of comprehension effect, F(l,57) 1.0, p< .552. For the Imagery vs. Picture effect the F ratio was statistically not significant, F (2,56) = 2.9549, £ < .0603. This-means that there is no overwhelmingly reliable statistical difference between the two forms of learning adjuncts for their influence upon the Table 3. Insert Table 3 about here Brain and Learning 80 combined r e c a l l and comprehension test scores. The step down F, however, was s t a t i s t i c a l l y significant for r e c a l l , F(l,57) = 4,551, £< .037 for r e c a l l score, but the step down F for comprehension was not significant, F(l,57) = 1.332, £ < .253. This means that the effect of this contrast can be accounted for by r e c a l l , or vice versa since the univariate analyses were significant. Another post hoc multivariate test compared the picture diagram with the control. It showed that both verbal r e c a l l and comprehension scores of the picture diagram were significantly greater than the control conditions, while the imagery instruction condition effect f e l l between two extremes, as can be seen in Table 1. Relationship Between Two Neurophysiological and Two Verbal Learning  Measures A multivariate analysis of variance was also carried out taking the four measures in the logical temporal order of their occurrence, in order to determine the correlational structure of two sets of response domains, neurophysiological and verbal responses. The multivariate results for the relative right hemisphere E.E.G. log ratio, the relative right hemisphere temperature index, the r e c a l l and comprehension variables are presented in Table 4. The planned orthogonal comparisons for this analysis also consisted of the learning adjunct effect and the Imagery Instruction vs. Picture Diagram effect. Step down analyses of variance were carried out, the results of which are shown in Table 4. Brain and Learning 81 Insert Table 4 about here For the learning adjunct effect the overall multivariate analysis of variance analysis was statistically significant, multivariate F (4,54) = 5.066, £ < .0012. This shows that taken .together the effect of both forms of learning adjuncts seems to influence reliably the set of four response variables. The step down analysis shows that there is the only one significant effect recall in terms of F(4,54) = 14.515, £ < .0004. This means that recall is the only variable affected by this influence. The neurophysiological variables did not show statistically significant effects as before. When recall score was let to account for the effect, the comprehension variable had very l i t t l e to account for. This means that there is l i t t l e relationship between the neurophysiological variables and the verbal response variables as far as the effects of both learning adjuncts are concerned. The Imagery Instruction vs. Pictorial Diagram contrast shows a reliable difference between the two forms of learning adjuncts for their effect on the set of four response variables, multivariate F(4,54) = 4.346, £ < .0041. When the step down analysis was performed on the four response variables as shown in Table 4, the effect of the picture diagram vs. imagery instruction turned out to be significant f i r s t in terms of the E.E.G. power ratio, and then a l l other three variables did not show up any significance. Brain and Learning 82 It should be noteworthy here that the earlier multivariate tests, particularly that of the learning adjuncts, and univariate F tests of the imagery instruction vs. picture effect were significant in terms of the verbal measures, as shown in Table 3. When we let the E.E.G. power ratio to account for the effect, the previously significant variance analyses for the verbal response variables are no longer shown to be significant, step down Fs (1,57) = 2.48 and 2.13, ps < .12 and .15, recall and comprehension, respectively. This finding shows a relationship between the E.E.G. measure and the verbal measures, particularly recall measure. That is to say, the E.E.G. concomitant to learning for recall may well be a precursor to the subjects' abilities to perform well on a recall task. The picture diagrams facilitated more of left hemisphere processing via the intermediary of the right hemisphere. Synchronous neural activity in the right hemisphere seems to have possibly induced synchronous neural activity in the left hemisphere which gave rise to superior verbal performance. These findings corroborate the central hypothesis of relative hemispheric utilization during learning with the pictorial diagram adjunct. B r a i n a n d L e a r n i n g 8 3 C h a p t e r I V . D i s c u s s i o n s a n d C o n c l u s i o n s T h e f i n d i n g s o b t a i n e d g e n e r a l l y c o r r o b o r a t e t h e p r e d i c t i o n s f r o m W i t t r o c k ' s t h e o r y o f g e n e r a t i v e l e a r n i n g . O u t c o m e s o f t h e d e b r i e f i n g p r o c e d u r e m e a n s t h a t 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 s p e r f o r m e d a s t h e y h a d b e e n d e s i g n e d t o . T h e u s e o f p i c t u r e s s e e m s t o h a v e e n c h a n c e d l e a r n i n g v i a a l t e r a t i o n i n b r a i n s t a t e o f a c t i v i t y b u t t h e e f f e c t o f i m a g e r y i n s t r u c t i o n s r e m a i n s s o m e w h a t u n c l e a r . P a i v i o ' s t h e o r y o f d u a l c o d i n g p r o c e s s e s i s a l s o c o r r o b o r a t e d . H e n c e , t h e p r e s e n t f i n d i n g s s h e d some l i g h t o n t h e r e s e a r c h i s s u e i n e d u c a t i o n a l p s y c h o l o g y , b r a i n e l e c t r o p h y s i o l o g y a n d t h e l i n k b e t w e e n t h e t w o a n d t h e m e a n i n g o f t h i s l i n k . T h e f i n d i n g s n e e d t o b e e x a m i n e d f o r n o t o n l y i n t e r n a l v a l i d i t y b u t a l s o e x t e r n a l v a l i d i t y . N e u r o p h y s i o l o g i c a l M e a s u r e s E l e c t r o e n c e p h a l o g r a p h i c i n d i c a t o r s o f b r a i n h e m i s p h e r e  a c t i v i t y . A l t h o u g h t h e f i n d i n g s o b t a i n e d i n t h i s s t u d y s t a n d u n i q u e b e c a u s e o f i n v o l v i n g a l e a r n i n g c o m p o n e n t , t h e a n a l y s e s f o r t h e E . E . G . a c t i v i t y a s s o c i a t e d w i t h t h e t a s k s s h o w t h a t t h e r a t i o s s h o w i n g r e l a t i v e h e m i s p h e r i c E . E . G . a c t i v i t y a p p e a r g e n e r a l l y i n k e e p i n g w i t h t h e r e s u l t s r e p o r t e d i n t h e g e n e r a l l i t e r a t u r e i n v o l v i n g o t h e r t a s k s b y D o y l e e t a l . ( 1 9 7 4 ) , O r n s t e i n e t a l . ( 1 9 7 9 ) , G a l i n a n d O r n s t e i n ( 1 9 7 2 ) a n d G a l i n e t a l . ( 1 9 7 8 ) . T h e s u g g e s t i o n o f f e r e d b y G e v i n s , Z e i t l i n , D o y c e , Y i h g l i n g , S c h a p p e r , C a l l w a y a n d Y e a l e r ( 1 9 7 9 ) a n d t h e " e v o k e d p o t e n t i a l " l i t e r a t u r e t h a t E . E . G . a l p h a a s y m m e t r y f i n d i n g s c o u l d b e a t t r i b u t a b l e t o t a s k r e l a t e d d i f f e r e n c e s i n e f f e r e n t a c t i v i t y , s t i m u l u s Brain and Learning 84 characteristics and performance rather than cognition ought, however, to be re-examined. There was a general overall increase in power in both hemispheres with pictorial cognitive tasks. This is consistent with the expectations from theoretical knowledge of the relationship between E.E.G. and neural activity and the empirical findings of Simpson, Paivio and Rogers (1967), Short (1953), Short and Walter (1954) and Slatter (1960) and with the reports of some critics of Galin's (1974) and Galin, Johnstone, and Herron (1978) and Doyle's (1974) studies. Doyle's studies did not involve learning processes but compared writing letters to block designs or other perceptual or motor processes. Differential physical activity may be a factor that could have produced some hemispheric alpha blocking since an individual can be expected to exert efferent motor activity in writing with the right hand but would be expected to not necessarily use the preferred hand in doing a block design. In the present study, however, physical activity was constant for a l l conditions so the differences observed are purely attributable to cognitive processing differences. Also some of the literature suggests unilateral changes in the alpha power spectrum with hemispheric utilization without jumping into the beta range. This is what was observed in this study. According to Simpson, et al., (1967), who investigated the relation between E.E.G. activity and imagery, significant results were obtained that contradicted those reported in previous investigations as well as some findings reported primarily from the Langley Porter Brain and Learning 85 Neuropsychiatric Institute. Whereas Dcyle et a l . (1974) and Galin et a l . (1978) as well as others had found decreases in right hemispheric alpha with pictorial processing, Simpson, et al., (1967) found higher alpha amplitude during visual tasks and lower alpha amplitudes during verbal tasks. /Alpha amplitude is a component of average alpha power. Barratt (1956) had also found that suppression of alpha rhythm was not reliably associated with imagery. It seems, according to Paivio (1973), as i f the data could also be interpreted in terms of "general activation or arousal" related to task difficulty. Visual tasks, including the kind of visually assisted learning as carried out in the present study, may be less difficult than analogous purely verbal tasks. Lesser alpha attenuation while working on a visual as compared to a verbal task could be due to the greater cognitive arousal needed to learn by the less facilitative, strictly verbal approach. Kamiya (1969) also reported that alpha amplitude was suppressed during mental effort, and Paivio (1973) reports that this alpha suppression may be related to strictly verbal processes. The literature on proactive and retroactive inhibition and facilitation could serve as an explanation. Interpreting i t in terms of difficulty, something bordering on a form of proactive inhibition may have been at work for the control group. After reading the irrelevant, perhaps, in the overall sense, confusing with respect to the "learning task, information on "Genetics" the control subjects may have had a jumble of quite similar but incoherent facts in their mind. This may have interfered with their capability to recall and comprehend B r a i n a n d L e a r n i n g 8 6 t h e t e x t o n m e n t a l d i s o r d e r s . T h e I n d u c e d I m a g e r y g r o u p , o n t h e o t h e r h a n d , w o u l d h a v e h a d n o p r o a c t i v e i n h i b i t i o n s i n c e t h e i n s t r u c t i o n s t o c r e a t e i m a g e s w e r e c o u c h e d i n n o n c o m p l e x f o r m . On t h e o t h e r h a n d , t h e p i c t u r e g r o u p ( I m p o s e d I m a g e r y g r o u p ) h a d b e e n p r e s e n t e d , i n t h e a d j u n c t , m a t e r i a l s o f a v i s u a l n a t u r e , w h i c h s e e m e d t o h a v e a s s i s t e d e v e n t u a l r e c a l l o f t h e t e x t m a t e r i a l . T h i s e n h a n c e m e n t o f r e c a l l v i a p r e s t u d i e d m a t e r i a l c o u l d b e r e f e r r e d t o a s " p r o a c t i v e f a c i l i t a t i o n " . T h e f a c t t h a t t h e p i c t u r e m a n i p u l a t i o n a s w e l l a s t h e i n d u c e d i m a g e r y c o n d i t i o n p r o d u c e d s i g n i f i c a n t E . E . G . p o w e r o u t c o m e s f o r b o t h t h e l e f t a n d r i g h t h e m i s p h e r e s s u g g e s t s t h a t p i c t o r i a l c o g n i t i v e p r o c e s s i n g , i n g e n e r a l , i n d u c e d c h a n g e s i n n e u r a l a c i t i v i t y i n b o t h h e m i s p h e r e s . C h a n g e s i n h e m i s p h e r i c n e u r a l a c t i v i t y s e e m c o r r e l a t e d w i t h a l t e r a t i o n s i n v e r b a l t e s t s c o r e p e r f o r m a n c e . D u a l c o d i n g o f l e a r n i n g m a t e r i a l s i s t h u s s t r o n g l y s u g g e s t e d i n t h e p r e s e n t l y o b t a i n e d e m p i r i c a l d a t a . T u l v i n g ' s n o t i o n s o f e p i s o d i c v s . s e m a n t i c m e m o r i e s s e e m a l s o s u p p o r t e d . One a l s o n e e d s t o c o n s i d e r o t h e r f i n d i n g s ( o f G r a b r o w , A r o n s o n , G r e e n & O f f o r d , 1 9 7 9 ) t h a t i t i s l e f t h e m i s p h e r e a c t i v a t i o n t h a t i s m o s t a f f e c t e d b y d i f f e r e n t i a l p r o c e s s i n g t a s k s ( v e r b a l v s . s p a t i a l ) . R i g h t h e m i s p h e r e E . E . G . a c t i v i t y s e e m s t o r e m a i n m o r e o r l e s s t h e s a m e w i t h d i f f e r e n t i a l c o g n i t i v e t a s k s w h i c h a p p e a r s t o b e v e r y s i m i l a r t o t h e p r e s e n t f i n d i n g ( c f . F i g u r e 3 ) . S o , f r o m t h e p o i n t o f v i e w o f b r a i n a c t i v a t i o n t h e p r e s e n t s t u d y b r i n g s t o g e t h e r c o n s i d e r a b l e k n o w l e d g e i n t e g r a t i n g i t i n t o c o g n i t i v e p r o c e s s i n g Brain and Learning 87 theories which taken together corroborate Wittrock's generative learning theory. The pictorial diagrams as learning adjuncts appear, however, to have induced differences in the E.E.G. power ratios in the direction predicted from previous results. The treatment effect of the pictorial diagram was manifested only in terms of the E.E.G. power ratio. In the analysis of the E.E.G. log power ratios the picture effect was statistically significant compared to the imagery instruction condition effect, which in turn was not significantly different from the control condition. /Another possible interpretation of the observed differences in average E.E.G. alpha power might be that the pictorial diagram as a subjectively experimental stimulus may have continued to exert its effect during the text learning phase as i t did during the i n i t i a l 5 minutes. This possible differentiation in E.E.G. average alpha power outcome had been anticipated so power spectrum data -for the first 5 minutes were by computer compared to that for the last 15 minutes. Since no differences were observed for these time segments in each of the conditions they were combined and the analysis was carried out on the whole 20 minutes. -Thermal indicator of brain hemispheric activity. The analyses of the temperature indicator showed that task related increases in left brain hemisphere activity , were not statistically significant for a l l comparisons involved. In this study, the subjects started off reading text materials, i.e., the objectives and instructions, and continued Brain and Learning 88 a l l the way through in a l l conditions. Except for small fluctuations, no s t a t i s t i c a l l y significant changes in this variable due to mental a c t i v i t y are not big surprises in view of spurious random fluctuations, due to minute changes in environmental temperature and body temperature. These fluctuations were anticipated and accounted for by focusing mainly on task dependent departures from baseline rather than absolute amounts. The analyses of the temperature indicator showed that task related increases in the right brain hemisphere a c t i v i t y were also not s t a t i s t i c a l l y significant. If such effect had attained s t a t i s t i c a l significance the minute change in temperature difference would have been consistent with the results of Meiners and Dabbs (1977) but much less powerful than reported by these authors. L i t t l e temperature variations attributable to the experimental treatments are most l i k e l y due to the capricious character of such temperature measurements and the d i f f i c u l t y in measuring temperature at such fine levels of accuracy. A future research suggestion would perhaps focus cn this temperature hemisphericity • variable with greater levels of environmental, instrumentation and subject control. Neurophysiological Variables Combined The E.E.G. neurophysiological measures emerged as d i s t i n c t l y more relevant than the tympanic thermal measure in this study. A high discriminability was observed for this E.E.G. ratio in a l l the effects tested. Brain and Learning 89 Verbal Performance Measures Recall. The analyses of recall scores reveals a reliable difference between imagery instruction vs. pictorial diagram. The pictures produced a dramatic enhancement of memory for the material studied whereas the Imagery Instruction did not. This is at variance with the literature (e.g. Willows, 1978) which, despite some findings consistent with this, generally reports either no difference between pictorial and imagery instruction or a superiority of imagery instruction over pictorial diagram, given prose materials. The explanation generally offered (e.g. Samuels, 1977) ("focal attention hypothesis") states that self generated images are more appropriate and more personally relevant than externally imposed fixed, designated pictures. This is not supported in the present study since the opposite was found. A major issue earlier raised from my reviews of the literature pertains to the general lack of studies addressing the point of different varieties of pictures and their effects as well as the point of different varieties of induced imagery and their potential effects and comparisons to the varieties of pictures. The general statistical significance of the joint effect of both types of learning adjuncts can be accounted for primarily by the powerful effect manifested, in this study, by the pictures. Perhaps the substantial amount of information intrinsic to the pictures which was not provided by the instructions to create self generated images, may have contributed significantly to the difference. This effect was also manifested in the imagery instruction vs. pictorial diagram contrast. Brain and Learning 90 Debriefing of the subjects also confirmed this surmise. In the debriefing i t was confirmed that the control, induced imagery and picture conditions had triggered the desired state in the subjects, as previously described. The adjuncts were being used by the subjects in the manner designed. Those who had been exposed to the imposed imagery tended to say that the pictures were very helpful in providing mnemonics and a structure for their r e c a l l of the mental disorders, whereas, despite having constructed their own mental images, this was largely absent or only vaguely stated by those in the induced imagery condition. The hypothesis that induced imagery would equal the effect of imposed imagery is thus not supported. Differential time on task among conditions i s an issue which could be raised as a possible contributor to the d i f f e r e n t i a l performance and neurophysiological outcomes observed between the p i c t o r i a l diagram and the other two conditions. However, i f this were the case, the differences between the performance of the Imagery Instruction group would have been expected to diverge more from that of the control group than i t did since the former had more time cn task by virtue of the organizational statement of the mental disorders provided at the beginning of their adjunct. If time on task had been of substantial relevance one would have expected a s t a t i s t i c a l l y significant difference between these groups. But this was not observed. A future research suggestion would be to tease out the relative dynamics of different kinds of pictures and different kinds of induced imagery for learning of various content subjects with images. B r a i n a n d L e a r n i n g 9 1 C o m p r e h e n s i o n . T h e a n a l y s e s o f c o m p r e h e n s i o n s c o r e s s u g g e s t t h a t b o t h f o r m s o f l e a r n i n g a d j u n c t s e n h a n c e d c o m p r e h e n s i o n w i t h some d i f f e r e n c e b e t w e e n t h e m . T h e p i c t o r i a l d i a g r a m s i g n i f i c a n t l y e n h a n c e d c o m p r e h e n s i o n o f t h e m a t e r i a l s t u d i e d w h i l e t h e i m a g e r y i n s t r u c t i o n d i d n o t . T h i s f i n d i n g i s a l s o s o m e w h a t a t v a r i a n c e w i t h t h e l i t e r a t u r e ( e . g . B o b r o w & B o w e r , 1 9 6 9 ) , b u t c o n s i s t e n t w i t h t h e h y p o t h e s i s o f t h i s s t u d y w h i c h h a d e m e r g e d f r o m e x a m i n a t i o n o f t h e l i t e r a t u r e t a k e n w i t h t h e s p e c i f i c m a t e r i a l s u s e d h e r e . T h e p i c t o r i a l m a t e r i a l s u s e d , w h i c h h a d b e e n e x t r a c t e d f r o m i n t r o d u c t o r y p s y c h o l o g y t e x t b o o k s , a p p e a r t o p r o v i d e c o n c e p t u a l d e s c r i p t i o n o f t h e i d e a s c o n c e r n e d a n d t h e r e b y s e e m t o h a v e c o n t r i b u t e d a d d i t i o n a l s t r u c t u r e b y w h i c h t o o r g a n i z e t h e m e a n i n g s . On t h e o t h e r h a n d , t h e r e s e e m s t o b e a d i s t i n c t i v e l a c k o f t h e i m a g e r y i n s t r u c t i o n e f f e c t . T h e s e l f - g e n e r a t i o n o f i m a g e r y c a n o n l y b e e n c o u r a g e d i f i t i s i n d e e d d e s i r e d t h a t s e l f - c r e a t e d p e r s o n a l i m a g e s b e u s e d . E x c e s s i v e i n s t r u c t i o n s a b o u t w h i c h p i c t u r e s o r w h i c h t y p e o f p i c t u r e s , t o u s e i n t h e c r e a t i o n o f s e l f - g e n e r a t e d i m a g e s c a n r e s t r i c t t h e s u b j e c t ' s f r e e d o m o r d i s p o s i t i o n t o i n d e e d m a k e u p h i s o w n p e r s o n a l i m a g e s . A f o l l o w u p s t u d y t o t h i s w o u l d e x p l o r e t h e d i f f e r e n c e s b e t w e e n t w o d i f f e r e n t k i n d s o f i n d u c e d i m a g e r y i n c o m p a r i s o n t o i m p o s e d i m a g e r y . One k i n d o f i n d u c e d i m a g e r y w o u l d b e a s u s e d i n t h i s s t u d y , n a m e l y " h o w " d i r e c t i o n s o n t h e c r e a t i o n o f s e l f g e n e r a t e d i m a g e s . A n o t h e r k i n d o f i n d u c e d i m a g e r y w o u l d , t h r o u g h d i r e c t i o n , g i v e s p e c i f i c i n s t r u c t i o n s o n w h a t s p e c i f i c i m a g e s t o c r e a t e i n t h e m i n d a s a p p l i c a b l e t o t h e s p e c i f i c m a t e r i a l s b e i n g l e a r n e d . T h i s l a t t e r w o u l d o n l y d i f f e r f r o m t h e i m p o s e d i m a g e r y c o n d i t i o n i n a s Brain and Learning 92 much as words in textual format would be used to describe the mental pictures to be visualized. The mental pictures recommended, however, would themselves correspond to the condition provided with actual pictures. These comparisons to be explored in a subsequent separate study would carry considerable theoretical significance in an understanding of the effects of the various kinds of induced imagery and imposed imagery. This problem as applied to comprehension also seems inadequately treated in the literature to date. The general s t a t i s t i c a l significance of both types of learning adjuncts taken jo i n t l y can be attributed primarily to the powerful effect of the provided pictures. This was confirmed also in informal post-experimental questioning. In post-experimental debriefing of subjects, this effect was however, not generally reported to have been f e l t as strongly subjectively, as the case for recall scores. Nevertheless, their performance on the comprehension test seemed to show that they comprehended more of the textual materials than they might have realized (Nisbett & Wilson, 1977). Verbal Learning Test Score Variables Combined The post hoc tests show that the effect of pictures is s t a t i s t i c a l l y significant upon both re c a l l and comprehension whereas the effect of imagery instruction is not. The step down F's show that this effect is localized more upon the re c a l l variable than on the comprehension variable. The pictures seem to have provided a framework as well as a mnemonic to reconjure during r e c a l l . The conceptual Brain and Learning 93 meanings also conveyed in the pictures assisted in the comprehension tests. Imagery instruction does not seem to provide the conceptual structure needed for comprehension nor apparently the mnemonics needed for r e c a l l . There is the additional problem that despite the elaborate verification carried out to ensure that the manipulations took, there is no way to be absolutely certain, in this type of manipulation, that the subjects did indeed use self generated images nor that i f they did generate images, that these would be adequate or effective for the purposes intended. Post experimental questioning of subjects in this condition generally yielded the reply of having tried to visualize images the best they could and the general feeling that this technique was of help in learning the material. Their performance, however, did not confirm the latter. The multivariate analysis of the verbal learning test variables decomposed into planned contrasts for a general experimental effect over control shows a confirmation of the powerful effect due to pictures thus confirming the previous assertions. The verbal learning tests multivariate planned contrast between the two experimental groups is not s t a t i s t i c a l l y significant. Hence, we can conclude that there is l i k e l y some difference between the experimental groups compared to each other with respect to their effects upon the verbal learning tests variables together. Brain and Learning 94 Correlations of Verbal Response Variables with the Neurophysiological  Responses The multivariate analysis of the verbal response variables in conjunction with the E.E.G. power and temperature index variables for the picture effect contrast is an important one to note. The step down analysis of variance showed the E.E.G. power ratio being associated with the rec a l l variable. These findings incorporate into and supplement well the existing nomological network of information in this area. The clear association between the verbal performance measure of rec a l l and the E.E.G. neurophysiological indication of brain neural a c t i v i t y was established. The interaction between the brain hemispheres during cognitive processing for learning was demonstrated. For the joint effect of the experimental groups the multivariate analysis of the verbal learning test variables with the temperature hemisphere indicator was s t a t i s t i c a l l y not significant. For the verbal learning tests taken with temperature relative right hemisphere index indicator, however, the multivariate test of the picture effect and of the general learning adjuncts used by experimental groups jointly are s t a t i s t i c a l l y significant. The pictures could help only during the phase of picturing. With reading text this effect may have become combined with the text processing mode hence a return back to relatively dominant l e f t hemisphere processing may have occurred but in a different cognitive mode and brain state. The multivariate analysis of the verbal learning test variables in conjunction with the E.E.G. power indicators of l e f t and right Brain and Learning 95 hemisphere a c t i v i t y for the picture effect contrast was s t a t i s t i c a l l y significant. This is somewhat at variance with the temperature indicators of hemispheric a c t i v i t y . Given the tenuous nature of the temperature measure and the different processes probed by i t , however, one cannot place excessive reliance on i t in such a comparison. Also, there nay be some processes underlying the dynamics of temperature regulation in connection with brain blood flow that may d i f f e r from processes underlying E.E.G. manifestations of e l e c t r i c a l a c t i v i t y of the brain. One would also expect a lag in temperature manifestation which would not be expected to occur for the E.E.G. because temperature conduction takes longer than e l e c t r i c a l conduction. For the verbal learning test variables taken with E.E.G. log power ratio indicator of relative right hemisphere a c t i v i t y the multivariate post hoc test of the picture effect was s t a t i s t i c a l l y significant. The step down analysis of variance gives an indication that the variance of this contrast i s mainly located in the ratio index i t s e l f . Pictures thus influenced relative hemispheric a c t i v i t y and verbal performance. For the induced imagery effect the multivariate test taking the power ratio indicator was not s t a t i s t i c a l l y significant but r e c a l l seems emphasized in the step down analysis of variance. This negates the premises of the focal attention hypothesis of Samuels (1977). Pictures did not distract from learning but quite conversely helped substantially. The multivariate general experimental effect of learning adjuncts, however, was s t a t i s t i c a l l y significant when taking the achievement tests with the E.E.G. power ratio. A high contribution Brain and Learning 96 for r e c a l l and a high contribution for the ratio indicator were demonstrated also in the multivariate test for the contrast of imagery instructions vs. pictures. For the verbal learning test variables the relative right hemisphere a c t i v i t y E.E.G. log ratio for the pictures thus seem to have had a profound influence. The step down analysis of variance also, shows the greater emphasis of re c a l l over comprehension going along with the log ratios. These collectively substantiate the internal v a l i d i t y of the findings in this study. This can be interepreted to mean that i t may be due to the picture effect being associated with re c a l l and the log power ratio whereas the imagery instruction having a spurious association with comprehension and the log power ratio. The observation that the multivariate comparison contrasting the imposed to the induced forms of imagery came cut s t a t i s t i c a l l y significant indicates that the difference between these forms of adjuncts is dependable with regard to the effect on relative right brain hemisphere activation. One can estimate from the other analyses that the pictures may have had the bulk of the effect and one can estimate from the step down analyses of the two physiological measures that the relative E.E.G. was the most sensitive in accounting for this discrimination. Upon examination of the same multivariate comparisons taking not only the neurophysiological measures but also the verbal learning test measures we find a confirmation of the above assertions with respect to the neurophysiological measures namely that the relative right hemisphere E.E.G. provides the only s t a t i s t i c a l l y Brain and Learning 97 significant step down F value for the picture diagram vs. imagery instructions effect. The fact that the relative right hemisphere thermal response variable is s t a t i s t i c a l l y not significant in the step down analysis could be due to the considerable random error possibly associated with this measure. The interesting part of the step down analysis, however, concerns the s t a t i s t i c a l l y significant joint experimental effect of learning adjuncts (i.e. effect of Imposed and Induced imageries together) upon the linear combination of the four dependent measures in the planned contrast analysis. The step down variance analyses for the neurophysiological measures are here s t a t i s t i c a l l y nonsignificant (though marginally so) but the step down F values reveal the strong effect of adjuncts in general, for the enhancement of r e c a l l . So, enhancement in r e c a l l , on the basis of these step down analyses, may be associated with concomitant generalized shifts in relative brain hemispheric a c t i v i t y . When looking at both forms of adjuncts together the relative ineffectual effect of the imagery instructions may be masking the effect of the pictures as i t comes out in the pure comparison. What we find, essentially, is that since average alpha power may reflect intensity or energy of brain a c t i v i t y the p i c t o r i a l diagrams e l i c i t e d enhanced amounts of this energy in the right brain hemisphere which, in turn, evoked enhanced a c t i v i t y (hence cognitive processing) in the l e f t brain hemisphere. This enhancement of l e f t brain hemisphere energy via enhanced right brain hemisphere energy can explain the drastic improvement in r e c a l l observed by those in the p i c t o r i a l diagram Brain and Learning 98 condition over those in the control condition. Thus, neural activity in the brain (left hemispheric via the right hemispheric) can be taken as the concomitant to efficient learning and thus the precursor to efficient recall and performance. The imposed imagery (picture-diagram) facilitated more of left hemisphere processing via the intermediary of the right hemisphere. A general mnemonic strategy such as induced imagery as applied in this study does not seem superior to presented pictures in eliciting superior recall or comprehension. Given that subjects with stated G.P.A. of less than 3.5 were used in this study plus the observation by Rohwer (1973) that there may be individual differences in the use of strategies depending upon academic ability i t is possible that, with the kind of imagery instruction provided, the subjects could not use i t or did not know how to use i t . Since the general nomological network of the literature reports a change in the ratio of right to left hemisphere average power with pictorial cognitive processing the results herein obtained f i t in well with bimodal theory. The absolute amounts of average power are not specified as especially relevant but the relative right to left power is what is considered important. Gevins et al, (1979) specify the following as criteria for studies examining task related brain asymmetries in the E.E.G.: Minimal differences between tasks in stimulus properties, no differences in efferent activities, minimal differences in performance related factors, behavioral validation of the tasks, E.E.G. patterns from the left and right hemispheres Brain and Learning 99 presented separately and extracerebral artifacts rejected. The present study rigorously adhered to these criteria. Crowell, (1975) cited in Swartz and Shaw (1975) found increases in power spectral density energy of the E.E.G. in the right hemisphere of children with the presentation of flashes of light patterns. It revealed increases in the region of 3 Hz to 14 Hz. "The right side of the brain may dominate in adult visual acuity because i t develops that capability before the left side does" (Swartz & Shaw, 1975). Moreover, Galin & E l l i s (1975) and others have frequently stated that their findings show a hemispheric enhancement of evoked potentials with lateralized cognitive processing which is somewhat at odds with the results of general activity. "The visual evoked response is enhanced over the right posterior temporal cortex when evoked by a spatially intricate stimulus" (Vella, Butler & Glass, 1972 p. 125). "Effect of imageability on recall is related to the more extensive bilateral processing of such words" (Rugg & Venables, 1980). "When a stimulus is task relevant, the evoked potential amplitude increases as a function of increasing attention or involvement" (Galin & E l l i s , 1975). "It is unclear whether the E.E.G. patterns found to distinguish complex behaviors are related to the cognitive components of the tasks or to the sensory - motor and performance - related factors" (Gevins et al, 1979). In the present study, the tie between verbal learning and neurophysiology is thus established. Judging from the results i t would seem that the recall variable has this profound association with the B r a i n a n d L e a r n i n g 1 0 0 E . E . G . m e a s u r e o f r e l a t i v e h e m i p h e r i c a c t i v a t i o n . S u c h a n o b s e r v a t i o n c l e a r l y d e m o n s t r a t e s t h a t t h e s o u r c e o f e f f i c i e n t r e c a l l may w e l l b e r e l a t i v e b r a i n h e m i s p h e r i c a c t i v i t y b e c a u s e t h e E . E . G . i s l i k e l y a m a n i f e s t a t i o n o f t h i s a c t i v i t y . T h e E . E . G . , h e n c e b r a i n a c t i v i t y , p a t t e r n s a r e t h u s c l e a r l y r e l a t e d t o c o g n i t i v e c o m p o n e n t s o f l e a r n i n g p e r f o r m a n c e . T h e e s s e n c e o f W i t t r o c k ' s t h e o r y i s t h u s d e m o n s t r a t e d i n f o u r w a y s . F i r s t , t h a t t h e r e i s a l i n k b e t w e e n c o g n i t i v e p r o c e s s i n g a n d n e u r a l a c i t i v i t y i n t h e b r a i n . S e c o n d , t h a t a r e l a t i v e h e m i s p h e r i c u t i l i z a t i o n o c c u r s d u r i n g l e a r n i n g . T h i r d , t h a t i n g e n e r a t i v e c o g n i t i v e p r o c e s s i n g t h e r i g h t b r a i n h e m i s p h e r e m a y p l a y a n i n c r e a s i n g r o l e . F o u r t h , t h a t t h e p a t t e r n o f a c t i v a t i o n t h r o u g h o u t t h e w h o l e b r a i n , i n c l u d i n g t h e s e m a n t i c a s s o c i a t i o n a r e a s , may b e d i f f e r e n t w h e n u s i n g a g e n e r a t i v e p r o c e s s i n g s t r a t e g y f o r l e a r n i n g . I t i s s u g g e s t e d t h a t s y n c h r o n o u s a c t i v i t y ( s y n c r a t i c , s i m u l t a n e o u s , p a r a l l e l p r o c e s s i n g , e t c . ) may w e l l b e t h e mode o f n e u r a l n e t w o r k ' a c t i v i t y d u r i n g g e n e r a t i v e p r o c e s s i n g . C o n c e r n i n g t a s k r e l a t e d a l p h a p o w e r r a t i o s i t h a s b e e n f o u n d t h a t " h e m i s p h e r i c p r o c e s s i n g i s a f u n c t i o n o f t h e t a s k p r o c e s s i n g d e m a n d s a n d n o t j u s t r e l a t e d t o p e r c e p t u a l r e q u i r e m e n t s " ( W i l l i s e t a l , 1 9 7 9 ) . " L a r g e b i l a t e r a l a r e a s o f c e r e b r a l c o r t e x ' a r e i n v o l v e d i n c o g n i t i v e h i g h e r f u n c t i o n s " ( G e v i n s , e t a l , 1 9 7 9 ) . " C r o s s c o r r e l a t i o n a n a l y s i s i n d i c a t e s a c o n s t a n t p h a s e r e l a t i o n s h i p b e t w e e n a l p h a w a v e s f r o m t h e t w o h e m i s p h e r e s w i t h o n e o r t h e o t h e r l e a d i n g " ( H o o v e y , H e i n e m a n n & C r e u t z f e l d t , 1 9 7 2 ) . T h a t c h e r ( 1 9 7 7 , 1 9 7 9 ) f i n d s t h a t t h e a v e r a g e e v o k e d p o t e n t i a l i s l a r g e r o v e r t h e r i g h t h e m i s p h e r e t h a n t h e Brain and Learning 101 l e f t in a visuospatial task but the presentation of verbal stimuli often results in enhanced average evoked potential amplitude on the l e f t side. No clear explanations have been offered for these average evoked potential amplitude asymmetries. "With respect to the E.E.G. studies of human short term memory and neurophysiological state," research has produced what seem to be paradoxical results as e f f i c i e n t performance has been associated with low states of activation (Gale, Jones & Smallbone, 1974). Taken together, the above findings in conjunction with this study show that one can expect not only quantitative changes in task related relative hemispheric processing but also concomitant qualitative changes in the waveform that may be specific to the cognitive task performed and to the performance demands in the study. Interest in this study was with the verbal learning  processes associated with pictures or aroused imagery but not simply the effect of examination of pictures. So i t was essential to look at the overall learning experience rather than segments of p i c t o r i a l or instructional perception. This can explain the patterns of outcomes found. Moreover, overall external v a l i d i t y i s hereby confirmed. The general relationship between the use of pictures during verbal learning and concomitant hemispheric brain processes appears to be that the right hemisphere may play a crucial role when learning with pictures which may not necessarily occur i f learning by using induced imagery. It may enable ef f i c i e n t processing of verbal material by the l e f t hemisphere. A shift in the ratio from predominance of the l e f t to predominance of the right is observed which suggests overall general B r a i n a n d L e a r n i n g 1 0 2 q u a l i t a t i v e c h a n g e s i n b r a i n f u n c t i o n i n g o c c u r r i n g d u r i n g l e a r n i n g w i t h p i c t u r e s . A l a c k o f c l e a r t h e o r y c o n c e r n i n g t h e n a t u r e o f b r a i n f u n c t i o n i n g , h o w e v e r , r e m a i n s . G i v e n t h a t a m p l i t u d e a n d d u r a t i o n o f g i v e n f r e q u e n c y c o m p o n e n t s a r e b o t h m a n i f e s t e d b y a n d i n t r i n s i c t o t h e p o w e r s p e c t r u m , a c e r t a i n i n d e t e r m i n a n c y i n i n t e r p r e t a t i o n i s t o b e e x p e c t e d . A l s o , w h e t h e r v a r i o u s t y p e s o f E . E . G . s h i f t s c o u l d b e p o s s i b l e d e p e n d i n g o n t h e n a t u r e o f t h e m a t e r i a l , t a s k s a n d w h e t h e r a s s o c i a t e d e f f e r e n t a c t i v i t y , t a s k d e m a n d s o r s t i m u l u s c h a r a c t e r i s t i c s a r e i n v o l v e d s t i l l r e m a i n s t o b e d i s s e c t e d i n f u t u r e s t u d i e s . M o r e r e s e a r c h i s n e e d e d t o t e a s e o u t t h e f i n e r d e t a i l s o f t h e E . E . G . a n d a s s o c i a t e d c o g n i t i v e a n d e f f e r e n t p r o c e s s e s i n v o l v e d w i t h h e m i s p h e r i c p r o c e s s i n g i n p i c t o r i a l l e a r n i n g v e r s u s t e x t u a l l e a r n i n g . A c o n t r o l l e d s t u d y e x a m i n i n g t a s k d e p e n d e n t E . E . G . c o h e r e n c e c h a n g e s ( a s p e r B e a u m o n t , ^ M a y e s & R u g g , 1 9 7 8 ) d u r i n g l e a r n i n g v a r i o u s m a t e r i a l s b y / m e a n s o f v a r i o u s f o r m s o f p i c t o r i a l p r o c e s s i n g w o u l d b e e x c e l l e n t a s a f u t u r e p r o j e c t t o a t t e m p t t o s o r t o u t t h e s e a d d i t i o n a l p o i n t s . C o n c l u s i o n s T h e p r e s e n t s t u d y f o u n d t h a t p i c t o r i a l d i a g r a m s a s l e a r n i n g a d j u n c t , f a c i l i t a t e r e c a l l e v e n w i t h r e m o v a l o f a n y p o s s i b l e d i f f e r e n t i a l e f f e c t o f t i m e o n t a s k ( s i m i l a r i t y b e t w e e n t h e c o n t r o l a n d t i n d u c e d i m a g e r y c o n d i t i o n s p r e c l u d e s a n y s u c h d i f f e r e n c e ) . T h e n e u r o p h y s i o l o g i c a l p r e c u r s o r t o t h i s f a c i l i t a t i o n may w e l l b e s y n c h r o n o u s a c t i v a t i o n o f t h e r i g h t h e m i s p h e r e w h i c h m i g h t i n d u c e s y n c h r o n o u s a c t i v i t y i n t h e l e f t . T h e l o c u s o f t h e e x p e r i m e n t a l Brain and Learning 103 effect, in particular the pictorial diagrams, was observed to be in the left hemisphere in terms of the E.E.G. perhaps through the intermediary of the right hemipshere. The effect of learning adjuncts localized in the left hemisphere seems due to facilitative effects of the nature of right hemisphere activity. A clear brain neurophysiological correlate of efficient verbal recall was established. Although i t had been hypothesized that imagery instructions would enhance recall by a similar concomitant brain mechanism this was not observed in the present study. A clear link of these conclusions to the procedures employed was shown to be manifested. When college students (of g.p.a. of less than 3.5) learn a passage on mental disorders taken from introductory psychology textbooks the use of imposed imagery (pictures) appears to assist learning so i t elicits better performance. It was found to enhance recall and comprehension. Instructions of how to visualize in the mind's eye, without defining which actual images to conjure up does not appear to augment recall nor comprehension over the presentation of irrelevant material. It appears, however, to induce minute changes in cognitive processing as inferred from the concomitant E.E.G. The relative superiority of pictorial diagrams over imagery instructions can be traced to concomitant activity in the brain. The pictorial diagrams appear to produce statistically observable relative engagement of the right and left brain hemispheres. The synchronous activity induced in the left hemisphere may be produced via the right hemisphere. Qualitative changes in cognitive processing are suggested Brain and Learning 104 during learning. The imagery instruction may also induce concomitant changes in relative hemispheric brain a c t i v i t y . The nature of, and content information i n t r i n s i c to the pictures, various kinds of induced imagery, and varieties of tests were suggested as having a determining effect on the performances concerned. The relationship of the kinds of imposed imagery and induced imagery to the material to be learned is also of utmost importance particularly in regard to the amount of detail provided and the concepts thereby conveyed. Also, findings of the effects of imposed and induced imagery in adults may vary from that discovered with children and adolescents in the literature. This study did not examine the f u l l variety.of adjuncts used in educational settings nor did i t examine the f u l l complex of adjuncts proposed by Wittrock's theory of generative learning. Because this was an investigation into the effects of these adjuncts on brain correlates of learning i t did not examine the interactive effects of combinations of these adjuncts jointly or with effects of other variables. The study also did not examine the f u l l configurations of brain and physiological responses that occur during various kinds of e f f i c i e n t verbal learning but i t focused on hemispheric brain responses only. Future studies of exact zones of the brain involved in various ways of cogitating about verbal material (which would further enlarge the scope of such understanding) might use the P.E.T. (position emission tomograph) - now being installed at U.B.C. This equipment can display a three dimensional view of the brain depicting the relative a c t i v i t y of specific zones in the brain during various kinds of higher level Brain and Learning 105 information processing (Sargent, 1980). Contribution of this study. This study compared some of the major adjuncts used to improve learning (imagery instructions and p i c t o r i a l diagrams) and determined which one(s) might best enhance re c a l l and which one(s) best improve comprehension. Since these techniques are frequently used and have been recommended by various authors as methods of improving the teaching of subject matter, this study may contribute to educators' understanding of pedagogical benefits of alternate instruction techniques and their combinations. It thus provided information of practical value. It showed which of the above techniques are most l i k e l y to be helpful for specific purposes. So one might say, i t had pragmatic value. But i t is also of theoretical value in increasing our depth of understanding. It showed why some adjuncts such as the use of pictures work better (for certain purposes) than others. So far, exact explanations as to why these techniques work have been lacking or at best hypothetical. This study provides psycho-neurophysiological explanations for the dynamics of operation of these enhancing strategies. In addition to having a sort of empirical validity, such explanations have the added advantage of being grounded in the hard sciences (Neurology, Medicine, Engineering, Physiology, Biology, Physics and Chemistry) from which information can be drawn to complement and c l a r i f y the findings. It also provides the opportunity for some rapproachment and consensual validation between educational science and technology and the basic sciences. Brain and Learning 106 References Anderson, R.C. & Kulhavy, R.W. (1972) Learning concepts from definitions. American Educational Research Journal. 9, 385-390. Ausubel, D.P. (1960) The use of advance organizers in the learning and retention of meaningful verbal material. Journal of Educational  Psychology, 51, 267-272. Ausubel, D.P. (1977) The facilitation of meaningful verbal learning in the classroom. Educational Psychologist. 12(2), 162-178. Baird, J.C. (1979) Studies of the cognitive representation of spatial relations. I, Overview. 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Canada's Mental Health, 25(2), 7-15. Zaidel, E. (1973) Linguistic competence and related functions in the right hemisphere of man following cerebral commissurotomy and  hemis pherectcmy. Unpublished doctoral disertation, California Institute of Technology. Figure Caption Figure 1. Language Receptive and Execution Areas ANT.CENTRAL UPPER PART OF PRECENTRAL SULCUS SUP.FRONT.GYRUS SUP .FRONT.SULCUS MID.FRONT.GY M ID . FRONT . SUL . LOWER PART GYRUS CENTRAL SULCUS P E R C E N T . S U L 7 -INF. FR .SUL OPER..TRI . & ORB/' , P ITS OF I N F . " FR.GYRUS ANT .HOR . 4 A N T _ ASCEND.RAMI OF L A T . F ISSURE POST.RAMUS L A T . F I S S U R E SUP.TEMP GYKUS ./ P O S T C E N T R A L GYRUS POSTCENTRAL SULCUS / SUP .PAR IETAL LOBULE ' / SUPRAMARG I NAL ' •' GYRUS ANGULAR GYRUS INTERPARIETAL SULCUS TRANS .OCC IP ITAL SULCUS OCC IP ITAL POLE v l NF.TEMPORAL GYRUS MID.TEMPORAL SULCUS MID.TEMPORAL GYRUS SUP.TEMPORAL SULCUS^ Language Execution (Broca's Area) Language Receptive and General A s s o c i a t i v e Areas (Wernicke's Area) Bra in and Learning 123 B r a i n and l e a r n i n g 124 Figure Caption Figure 3. Tympanic Temperature Sensing Jfonitor Unit Brain and Learning 125 Figure Caption Figure 4 . Four point Kaiser -Besse l window compared to Hamming window Hamming: Wjc(n)= .54 - . 46cos (2Pi (n) ) N 0 < n < N - l 4 Point Kaiser B e s s e l : Wk(n)= .40243 -.49804cos(2Pi(n)) «• .09831cos(4Pi(n)) N N -.00122cos(6Pi(n)) N 0 < n < N - l 1.00 amminq window 40.00 80.00 IFoToO ifeo.00 200.00 240\o0 N 2&0.00 Brain and Learning 126 Figure Caption Figure 5. Signal Processing System Sequence A.M\?ACTS &6LOW oft. A&e>Je. Trtis ( « • » • A/P C 0 A > v 6 f e S t O » * AT l * BIT* CHO^W kftveic) l " * LPkiT «*tH S « C X # • • e r r W H A FiL-TtA, 8 T » \¥- H » . 6 A N O ^ / of 8 i» I T H I . W » (••••) 3 • • • • PUfc VALU£$ P4A *fec. A*lt«.A«« op ( i t c Pu>A- VAU/ts A>»t6.A<< €» • • • » ) , tfHiju'c A»£AAfreS F i g u r e C a p t i o n F i g u r e 6 . B l o c k d iagram o f EEG t o PDP-11 System Ga ins E . E . G , PRE AMP G POWER AMP G2 — v -F .M . RECORDER G 3 —>-L .P . F ILTER Gi P re Amp Ga in G2 Power Amp Ga in G3 Ga in due t o F.M. Recorde r G 4 MNCAD G, PDP-11 G4 F i l t e r G a i n Gq Q u a n t i z a t i o n G a i n fO H' 3 3 5 Brain and Learning .128 F i g u r e 7 F i g u r e C a p t i o n : BAR GRAPHS ELECTROENCEPHALOGRAPH: VOLTAGE EQUIVALENTS MICROVOLTS+ r s D C3 " HCy AVERAGE MAXIMUM THERMAL DECREASES Brain and Learning 129 Table 1 Means and Means Squared E r r o r s of E.E.G. Power Rati o , Log E.E.G. Power Rati o , Thermal Index R a t i o , R e c a l l and Comprehension Scores by Three Experimental Conditions (N=60) vMeasure E.E.G. Verb a l Learning Power Thermal Scores Ratio Ratio R e c a l l Compreh. Exp. \ Cond. \ (Log Ratio) C o n t r o l 0 . 9 4 0 9 ( - 0 . 0 1 7 2 ) a 1 . 0 4 3 0 6 . 7 0 0 0 5 . 7 5 0 0 Imagery I n s t r . 0 . 9 5 4 5 ( - 0 . 0 5 7 9 ) ' 1 . 1 4 5 0 8 . 6 5 0 0 6 . 4 5 0 0 P i c t u r e Diagram 1 . 5 3 0 0 ( + 0 . 5 6 5 2 ) 1 . 3 7 6 5 1 0 . 4 0 0 0 7 . 9 0 0 0 MSe 0 . 0 4 6 0 ( 0 . 3 9 2 0 ) 0 . 4 6 5 0 6 . 7 2 9 2 S . 4 1 2 8 a The f i g u r e s i n the parentheses are the n a t u r a l logarithms Brain and Learning 130 Table 2 / Results of Multivariate Analysis of Variance on Relative Log Power Ratios of E.E.G. and Thermal Indices Source SCP's Roy's Approx. df p Step p Largest Root F Down F  Effect of Learning Adjuncts 6.437 .0734 2.219 2,56 .1182 Univariate M.S. F df p Log (E.E.G. Power Ratio 0.979 2.496 1,57 .1197 2.496 .1197 Thermal Index Ratio 0.632 1.360 1,57 .2484 1.903 .1733 Source SCP's Roy's Approx. df p Step p Largest Root F Down F  Picture vs Imagery Instruction 6.556 .1782 6.073 2,56 .0042 Univariate M.S. F df p Log (E.E.G. Power Ratio) 3.883 9.903 1,57 .0027 9.903 .0027 Thermal Index Ratio 0.536 1.153 1,57 .2875 2.059 .1569 Brain and Learning 131 Table 3 Planned Contrasts: Multivariate Analysis of Variance Table for Two Verbal  Learning Tests Source SCP's Roy's Approx. df p Step p Largest Root F Down F  Effect of Learning Adjuncts 11.700 .2222 7.997 2,56 .0009 Univariate M.S. F df p Verbal Recall 106.408 15.814 T75l .0002 15.813 .0002 Comprehension 27.075 5.003 1,57 .0293 .359 .5516 Source SCP's Roy's Approx. df p Step p Largest Root F Down F  Picture vs Imagery Instruction 11.600 .0955 2.9549 2,56 .0603 Univariate M.S. F df p Verbal Recall 30.625 4.551 1*757 .0373 4.551 .037 Comprehension 21.025 3.885 1,57 .0536 1.332 .253 Brain and Learning 132 Table 4 Planned Contrasts: Multivariate Analysis of Variance Two Physiological and Two Verbal Learning Dependent Variables Source SCP's Roy's Approx. df P Step P Largest Root F Down F Effect of Learning Adjuncts 18.068 .2729 5.066 4,54 .0012 Univariate M.S. F df P Log (E.E.G. Power Ratio 0.979 2.496 1,57 .1197 2.496 .1197 Thermal Index Ratio 0.632 1.360 1,57 .2484 1.903 .1733 Verbal Recall 106.408 15.814 1,57 .0002 14.515 .0004 Cbmprehens ion 27.075 5.003 1,57 .0293 .442 .5090 Source SCP's Roy's Largest Root Approx. F df P Step Down F P Picture vs. Imagery Instruction 18.028 .2435 4.346 4,54 .0041 Univariate M.S. F df P Log (E.E.G. Power Ratio 3.883 9.903 1,57 .0027 9.902 .0027 Thermal Index Ratio Verbal Recall Comprehens ion 0.536 30.625 21.025 1.153 4.551 3.885 1,57 1,57 1,57 .2875 .0373 .0536 2.059 2.478 2.133 .1569 .1212 .1500 B r a i n a n d L e a r n i n g 1 3 3 A P P E N D I X A M a t e r i a l s U s e d i n t h e S t u d y STUDENT O B J E C T I V E S T h e s t u d e n t : K n o w s s p e c i f i c f a c t s . 1 . I d e n t i f i e s n a m e s o f c o n c e p t s . 2 . D e f i n e s t h e c o n c e p t s . 3 . L i s t s m e n t a l d i s o r d e r s . 4. L i s t s c h a r a c t e r i s t i c s o f m e n t a l d i s o r d e r s . C o m p r e h e n d s . x 1 . R e c o g n i z e s i n s t a n c e s o f t h e c o n c e p t s . 2 . P r o v i d e s e x a m p l e s o f t h e c o n c e p t s i n h i s o w n w o r d s . 3 . D i s t i n g u i s h e s t h e v a r i o u s m e n t a l d i s o r d e r s . 4. T r a n s l a t e s a n a b s t r a c t d e f i n i t i o n i n t o a s p e c i f i c e x a m p l e . 5 . E x p l a i n s a b n o r m a l b e h a v i o r i n t e r m s o f m e n t a l d i s o r d e r s . 6 . R e l a t e s m e n t a l d i s o r d e r s t o e a c h o t h e r . Brain and Learning 134 IRRELEVANT MATERIAL (Control Group Condition) Darwin named the agent by which selection operates "survival of the f i t t e s t , " referring by the phrase to the d i f f e r e n t i a l mortality of individuals within a species. His concept has since been broadened to include the selective agent of d i f f e r e n t i a l f e r t i l i t y . Differential mortality operates on individuals prior to reproductive age, and therefore determines that group of individuals who survive and may potentially produce the offspring who w i l l constitute the next generation of a population. Differential f e r t i l i t y operates within this surviving group of individuals who have reached reproductive age. It refers to the differences in the contribution made to the next generation by individuals due to their inequalities in reproductive performance. Although d i f f e r e n t i a l mortality and d i f f e r e n t i a l Brain and Learning 135 f e r t i l i t y operate through separate means and on different age groups, their ultimate genetic consequences for a population are much the same. Unlike Darwin, we now know, that in any population there are genotypes that d i f f e r from one another and that the differences are due to mutation. Briefly stated, mutation provides the raw material of evolution in the form of al l e l e s , and selection then determines the fate of these a l l e l e s in a gene pool. Over time an advantageous mutation may eventually either displace the former allele(s) or achieve a state of equilibrium with i t s allele(s) through the action of opposing, balanced selective forces acting on the locus in question. Selection may therefore operate as both a st a b i l i z i n g and a dynamic force in a population. In either role i t exerts systematic pressure cn the gene pool so that the direction and magnitude of genetic changes Brain and Learning 136 are determinate in principle. As a sta b i l i z i n g agent in both eliminates deleterious mutations each generation (normalizing selection) and maintains a gene pool's existing a l l e l e frequencies through time in equilibrium with the environment (stabilizing selection). Simultaneously, selection is also an important dynamic agent of evolution, changing a population's genetic composition as the environment changes (directional selection). A disadvantageous a l l e l e may be maintained at a very low frequency in a gene pool (generally 1 percent or less) by the balanced opposing forces of normalizing natural selection and recurrent mutation. An advantageous a l l e l e may increase in a gene pool and attain a frequency greater than that which can be maintained by recurrent mutation alone. Genetic polymorphism may be transient or balanced. In the case of transient polymorphism natural selection is operating as a dynamic Brain and Learning 137 agent of evolutionary change. An advantageous mutant gradually displaces the normal allele(s) in the gene pool u n t i l the lat t e r is reduced to a low frequency maintained by recurrent mutation alone. At this point, of course, by definition a polymorphism no longer exists at that particular locus, and selection is of a normalizing type. Until this point is reached, however, a polymorphism does exist. Balanced polymorphism, on the other hand, is the result of natural selection operating as a s t a b i l i z i n g agent. Brain and Learning 138 INDUCED IMAGERY (Imagery Instruction Condition) Personality disorders are the addictions, the sexual perversions, the sociopathies and psychopathies. Neuroses are the phobias, the obsessive-compulsions, the hysterias and the hypochondrias. Psychoses are the manias, the melancholias, the schizophrenias and the paranoias. Learn the next presented passage much as you normally would. However, while you are reading i t , picture in your mind's eye vivid and dynamic images of the ideas presented. Imagine a story with continuity, as a series of pictures like a movie as you read through the material i n terms of characteristics of the figures described and concrete pictures of them in action. Link the scenes you visualize together. Lucid images are very useful to help your mind during learning. Brain and Learning 139 If bizarre, obscene or grotesque images that relate to the material come to mind as you read, do not hold back or worry about being foolish, etc. You w i l l not be asked to disclose these. They w i l l be kept private, to yourself. Use these more bizarre and vivid pictures to help you remember. These bizarre types of mental images strike your fancy and hold your attention. You w i l l find them easy to remember ij afterwards. • The more of an impression the mental image you use makes on your mind, the easier you w i l l find i t to remember the material you have studied afterwards. Outlandish images can also be very useful in making clear and memorable the memory traces of what you-read. If you come across unfamiliar or more abstract words, substitute for them with concrete things you know about. Picture these concrete ideas v i v i d l y while at the same time bearing in mind the term i t is substituted for. Apply this method to names, words, facts and Brain and Learning 140 concepts. Look for key words as you read and build your mental picture around them. Remember the mental disorders, what they are and what they mean this way. Try to understand them by presenting to yourself these unique self generated images. In depicting their conceptual basis by imagery in your mind's eye you w i l l find that understanding them i s easy. Apply this method even i f i t seems to slow down your reading rate. You w i l l not have to go over the material again. As you apply this system, your proficiency w i l l increase because when i t comes time to remember something from this reading, a l l you w i l l need do i s bring back the images you created in your mind and you w i l l know i t . Remember to keep making a continuous p i c t o r i a l story as you read every sentence. Brain and Learning 141 For e.g. for pyromania, you might imagine a person, carbon character or someone you know being compelled to sneak into a house at night and set f i r e without anybody's knowledge. Then this person would watch the f i r e with fascination and revel with excitement at the panic, commotion and sight of f i r e trucks coming and people being awed and shocked by the flames and smoke. This individual would be pleased with himself and tickled for having created this shock effect. Have the feeling that you can keep these private pictures you created in your mind's eye to yourself forever and that they can be re-conjured at w i l l whenever needed. Remember that you should not only know the material you read, but also comprehend what i t means. Brain and Learning 142 BTOSED IMAGERY (Pictorial Diagram Condition) Personality Disorders Neuroses • Psychoses »iV<.K>»»THT IT |.;" iL 1 W a* TEXTUAL MATERIAL  MENTAL DISORDERS Three bread categories of mental disorders each have four sub-types. The categories are personality disorders, neuroses and psychoses. Personality disorders are the addictions, the sexual perversions, the sociopathies, and psychopathies. Neuroses are the phobias, the obsessive-compulsions, the hysterias, and the hypochondrias. Psychoses are the manias, the melancholias, the schizophrenias and the paranoias. Personality disorders are ingrained habitual patterns of character that limit an individual's functioning in a responsible way. Addictions involve dependencies upon the ingestion of particular substances. Sexual perversions are abnormal patterns of sexual desire which conflict with the practices of society. Sociopathies are disorders in which the person entertains a code of ethics which is different from that of the dominant social or legal structure. Psychopathies are disorders in which the individual has no moral values, acts on momentary impulses and does not learn from experience. Neuroses are disorders in which an individual is unable to cope with anxieties and conflicts, hence, exhibits abnormal symptoms. Phobias are persistent irrational fears of objects, places, or situations. Obsessive compulsions involve recurrent thoughts of a disturbing nature accompanied by i r r e s i s t i b l e urges to repeat stereotyped or r i t u a l i s t i c acts. Hysterias involve two or more personalities being entertained by an individual or bodily symptoms due to some psychic c o n f l i c t . Hypochondrias involve morbid concern over Brain and Learning 143 Brain and Learning 144 one's health and exaggerations of bodily symptoms. Psychoses are severe mental diseases involving serious disruption of cognitive and emotional processes along with loss of contact with r e a l i t y . Manias are characterized by excitement and elation. Melancholias involve sadness and despondency accompanied by gloomy thoughts of worthlessness and hopelessness. Schizophrenias involve a s p l i t between expressions and exigencies of r e a l i t y along with withdrawal from r e a l i t y . Paranoias involve bizarre delusions of persecution, grandeur or reference. Personality disorders are characterized by deeply ingrained maladaptive patterns of behavior which frequently show a l i f e - long history. The patient is generally unconcerned with the problem and treatment is usually obtained involuntarily. The maladjustment is usually expressed in overt behavior rather than in thought disturbances, emotional disturbances, or anxiety. The personality disorders manifest themselves in a wide variety of ways, and usually involve some form of social maladjustment. These behaviors may have diverse causes and may occur in persons with different kinds of personalities. ' These patterns frequently show a life-long history. In most cases these persons are unconcerned with their problems. If they obtain treatment, i t is due to the insistence of their families or as a result of clashes with society or law. Addiction i s seen in psychological and/or physical dependence on alcohol, cigarettes, drugs, or gambling. Such a state can have disastrous consequences physically, psychologically, and socially. It is apparently learned and maintained because of short-term reinforcement. Brain and Learning 145 Compulsive gambling is learned and maintained in a similar manner. Addictions imply i l l e g a l a c t i v i t i e s and these a c t i v i t i e s make the addict a criminal. The loss of self regulating capacities can also have disastrous physical consequences on the health of the addicted person. This stems directly from the excessive amount of foreign substance and the indirect effects of inadequate diet and contagious disease conditions. At the psychological level there i s a loss of self control accompanying lowered self-esteem with a loss of interest in usual l i f e a c t i v i t i e s and goals. The dominant moral code of society defines a wide range of sexual  perversions, such as the expression of sexual desire for children (pedophilia), and obtaining sexual enjoyment from observing sex acts and objects (voyeurism) and from the display of parts of the body in public (exhibitionism). Homosexuality is also c l a s s i c a l l y defined as i deviant; the s t a t i s t i c a l surveys of Kinsey indirectly have called into question the oversimplified c l a s s i f i c a t i o n of homosexuals as deviants by pointing to the extensiveness of homosexuality among males. Some deviations from the norm are clearly considered in need of control; other types of deviant sexual behavior create legal or social problems only in certain instances. The sociopath deviates because of a moral code he holds which differs from the one endorsed by 4 general society. It results in deviant behavior because the individual has a strong allegiance with standards which d i f f e r from those of the general social group. The sociopath has personal moral feelings, but does his dyssocial acts Brain and Learning 146 because he feels they are right. For instance, the young gang member or gangster nay be very loyal to their own kinds but have no g u i l t about their violence toward society. The psychopath represents behaviors that violate society's norms or laws. The psychopathic personality violates these codes because of an absence of internalized moral values. This individual is typically impuslive and frequently turns to crime. He is largely incapable of loyalty to other individuals, groups or social values. This individual is selfish, irresponsible and unable to leam from experience or feel g u i l t . This disorder stems from faulty psychosocial development in which social standards have never been introjected. The impulsive thief or murderer would be examples of this type. In general, the various neuroses are assumed to arise when the person's conflicts are not adequately handled by the various defense mechanisms; the core of the neurosis li e s at the point where anxiety has blocked or distorted the learning process so that new learning essential to adjustment cannot take place. The neurotic person's symptoms may shift from time to time, but among his shifting symptoms a dominant pattern can usually be detected. This dominant pattern probably t e l l s us something about the nature of the individual and of his problems, just as the characteristic pattern of defense mechanisms in the individual t e l l s us something about his personality. Some of the generally recognized forms of psychoneurotic reactions are the following. Brain and Learning 147 Phobias are intense fears of objects or situations that in fact present no real danger. We are a l l familiar with the term "claustrophobia" and know that this term i s applied to an intense fear of closed places. There are many other types of phobias, however, such as pathophobia (fear of disease), nyctophobia (fear of darkness) and hematophobia (fear of blood). Many well-adjusted people have strong fears that we would not c a l l phobias. The fear of mice by some people, fear of water by many people, and fear of high places, for example, are not generally phobic in nature. Most of these fears are developed through unfortunate childhood experiences. Patients suffering phobias, however, are not aware of the basis of their fears, react violently to the feared object, and are often greatly inconvenienced by their fears. In many cases, the individual realizes his fear is irrat i o n a l but is helpless to do anything about i t . A l l phobias have certain features in common. Obsessive-compulsions are characterized by obsessive and unavoidable thoughts, often unpleasant and unwelcome to the person(s), and by compulsive irrational acts, which follow from i r r e s i s t i b l e urges. The person's obsessive thoughts may have to do with fear that he is "losing his mind," that his child is "going to have an accident," that he i s "going to strike someone," or they may have to do with insistent thoughts of an erotic nature. The compulsive acts frequently take the form of repetitive r i t u a l i s t i c behavior, such as highly routinized ways of moving, dressing, or eating. The compulsive act often appears to be "magic way" of warding off the unpleasant obsessive Brain and Learning 348 thought. An adolescent boy, for example, was characterized by a neurotic compulsion to wash himself repeatedly during the day, spending a great deal of his time in a series of acts relating to body cleanliness. Investigation indicated that he suffered obsessive g u i l t feelings from acts of masturbation, which he regarded as "unclean." The hysterias may manifest themselves as a conversion reaction, a disorder in which the anxiety is converted into a physical malfunction, with no underlying physical or organic damage. Conversion hysterias typically occur in situations of stress and confl i c t . In such situations, the patient develops an organic symptom, rather than a purely psychological symptom. In other words, we might say that the psychological stress is converted into a bodily disturbance. The hysterical reaction may also involve a problem in the psychological sphere only, as in the dissociative reaction, in which the individual attempts to control anxiety by removing from consciousness those parts of the personality which are producing i t . Examples of this reaction are amnesia, fugue reaction, arid multiple personality. In multiple personality, the person manifests two or more completely different systems of personality, changing from one to the other for periods of a few minutes or' even several years. Usually the personalities involved are quite different from one another. One may be carefree and fun-loving while the other is quiet and serious. Often, while one personality is dominant, the person cannot remember the other or how he behaved when the other was dominant. Brain and Learning 149 The hypochondriac evidences a morbid concern over his health and bodily processes. Commonly found in individuals in late middle age, hypochondrias occur more often in women than in men. These people usually have many physical complaints, and their general overconcern with health keeps them cn the alert for signs of new and different illnesses. Often they are avid readers of popular writings of health topics, and frequently, there is an excessive concern with excretory and digestive functions. Some patients keep charts of bowel movements and detailed information on diet, constipation, and trends in evacuation. Typically, they are always looking for new methods of treatment for their imaginary illnesses, and they provide a large market for every new patent medicine. Psychoses are forms of mental illness that are much more severe and disabling than neuroses. The term "insanity" was formerly used to refer to such disorders, although today insanity is primarily a legal term usually used to refer to those individuals who are unable to manage their a f f a i r s properly because of a severe mental disorder. The psychotic individual's personality is generally disorganized, he is incapable of functioning socially in a normal way, and frequently he must be hospitalized. Some experts in this area believe that there is a continuity from the normal, or well- adjusted, through the psychoneuroses and psychoses. The differences are regarded as largely a matter of severity of symptoms, rather than differences in kind. Not a l l psychologists and psychiatrists, however, hold this position. Some feel that psychoses are fundamentally different from neuroses. Brain and Learning 150 The so-called "manic", or excitable, involves a generalized excitement, elation of mood or euphoria, overactivity such as pacing back and forth, singing, and so on, and a " f l i g h t of ideas," during which the patient's conversation jumps from one topic to another with l i t t l e apparent connection. With excessive elation, he becomes manic, and, i f he goes too far, explodes into violent and unrestrained behavior, sometimes dangerous to others or to himself (thus the common term "manias"). The disorder, known as melancholia, occurs when the individual reacts to problems and conflicts with or spontaneously acquires feelings of hopelessness, dejection, and depression. The depression often but not necessarily results from some specific event, such as the death of a loved one, but i t continues for an excessively long period of time. There is good prognosis that the patient w i l l recover but the most serious danger is the p o s s i b i l i t y of suicide. In the depressive reaction the patient appears sad, discouraged, and inactive. The hallucinations are characteristically those of self-degradation. Schizophrenias are characterized by a wide variety of symptoms, not a l l found in any one person. In general, there appears to be a peculiar distortion of the emotions and feelings; the person may seem completely insensitive to things that would normally be expected to evoke emotional response, for example, news of the death of a member of the family. His standards of conduct, dress, personal hygiene, and social relations may show severe deterioration. He may become excessively withdrawn, out of a l l touch with the external world, even Brain and Learning 151 to the point at which he may s i t completely immobile for hours, during which time the limbs can be moved about by someone else and w i l l remain in the positions in which they are placed. He may often be subject to halluciantions in which he "hears voices" or "sees visions." He may exhibit bizarre behavior, confused thought processes or chaotic speech. The patient may also experience auditory hallucinations - hearing voices talking to him from some unknown source. "Paranoia" i s a condition characterized by delusions of persecution and/or grandeur. These delusions are usually well systematized and tig h t l y knit. The personality of this type of patient is not severely disorganized, and thus the condition is differentiated from paranoid schizophrenia. The paranoid state, second of the paranoid disorders, typically involves transitory or temporary delusions that lack the logic and systematization of paranoia. Delusions and hallucinations of a religious nature, among other symptoms, are often found in both types of paranoid disorders. RECALL TEST Brain and Learning 152 L i s t as many of the mental disorders you have just learned as you can remember. Brain and Learning 153 COMPREHENSION TEST A major consequence of most addictions is the: a. acceleration of self-confidence feelings to unrealistic heights b. unreasonably high sense of self control c. loss of interest in usual l i f e a c t i v i t i e s d. heightened orientation to many social reinforcers e. heightened creativity Sexual perversion is to hysteria as: a. paralysis is to overactivity b. crutch is to fantasy c. simile i s to metaphor d. doing is to forgetting e. feeling i s to apathy Which of the following i s an example of Sociopathy? a. militant behavior on the part of individuals belonging to organized crime b. chronic anxiety about exposure to other people c. unrealistic fear of appearing foolish in public d. hearing voices e. having a bizarre behavioral pattern in one's repertoire Psychopathy is to obsessive compulsion as: a. impulse is to mortality b. frozen is to molten c. reading i s to speaking d. youth is to old age e. random is to repetitive Individuals with personality disorders: a. exhibit problems similar to psychosis b. suffer much anxiety because they feel responsible for the troubles they cause c. typically perceive their problems as being related to luck or to the faults of others d. generally do quite well in l i f e e. have the most severe kind of mental disorders Brain and Learning 154 6. Neurotic disorders have been said to involve: a. hallucinations and delusions b. feelings of anxiety and inadequacy c. unusual sexual preferences d. an antisocial personality e. fixation upon a certain substance 7. Psychosis is to Schizophrenia as: a. metaphor is to simile b. comfort is to discomfort c. sex is to motive d. plant is to flowers e. blaming is to curing 8. Phobia is to Paranoia as: a. emotion is to beast b. laughter is to seriousness c. appropriateness is to uniqueness d. fear is to belief e. thought is to action i . . . / 9. /Addiction is to Mania as: a. symptom is to cause b. need is to energy c. lion i s to beaver d. ego is to mother e. moon is to earth 10. A person who wants to believe he/she is i l l when no physical illness is present is a: a. malingerer b. compulsive patient c. narcissistic person d. substance abuser e. hypochondriac Brain and Learning 155 11. Last night your roommate went out at midnight and h i t the neighbor's sheep. He told the police that the sheep appeared in the t o i l e t bowl and said he was Satan in sheep's clothing. His symptoms reflect a case of: a. mania b. melancholia c. schizophrenia d. hysteria e. obsessive compulsion 12. A writer working at home changes his clothes at least five times a day. Each time he changes clothes he experiences a reduction in anxiety. He would prObably be diagnosed as: a. phobic b. hysterical c. paranoid d. perverted e. compulsive 13. A woman who is orderly, consistent and logical in most situations also believes that she i s Joan of Arc and in danger of being k i l l e d . This woman is displaying symptoms of: a. a hysterical nature / b. an addictive nature c. a phobic nature d. a paranoid nature e. an obsessive compulsive nature 14. Intense feelings of anxiety that become displaced to objects or situations that the individual believes are responsible for his anxiety or fear are referred to as: a. phobias b. chronic anxieties c. acute anxieties d. obsessions e. delusions Brain and Learning 156 Which of the following characterizes melancholia: a. deep sorrow following the loss of a loved spouse b. feelings of depersonalization after viewing an accident c. a strong sense of profound despondency that arises for no apparent reason d. the recurrence of unwanted thoughts which cannot be banished frcm consciousness e. separate identities invading the personality at different times. 

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