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A neurobehavioral investigation of orienting behavior Midgley, Glenda C. 1978

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A Neurobehavioral Investigation  of Orienting  Behavior  by  G l e n d a C. M.A. , C a r l e t o n  Midgley  University,  197^  A THESIS SUBMITTED I N P A R T I A L F U L F I L L M E N T OF THE REQUIREMENTS FOR THE DEGREE,OF •  DOCTOR OF PHILOSOPHY  in  THE FACULTY OF GRADUATE STUDIES (DEPARTMENT OF PSYCHOLOGY)  We a c c e p t t h i s  t h e s i s as- c o n f o r m i n g  to the r e q u i r e d  standard  THE U N I V E R S I T Y OF B R I T I S H COLUMBIA  ©  G l e n d a C. M i d g l e y ,  1978  In  presenting  this  an a d v a n c e d  degree  the  shall  I  Library  further  for  scholarly  by h i s of  agree  this  written  thesis at  the U n i v e r s i t y  make that  it  purposes  for  freely  permission may  representatives. thesis  in p a r t i a l  is  financial  University  of  British  Date  Columbia,  British  by  for  gain  Columbia  shall  the  that  not  requirements I  agree  r e f e r e n c e and copying  t h e Head o f  understood  permission.  2075 Wesbrook P l a c e Vancouver, Canada V 6 T 1W5  of  for extensive  Depa r t m e n t The  of  available  be g r a n t e d  It  fulfilment  of  this  be a l l o w e d  or  that  study. thesis  my D e p a r t m e n t  copying  for  or  publication  without  my  ii  ABSTRACT Models of the suggest that the one  mammalian b r a i n has  involved i n pattern vision,  to v i s u a l stimuli. by  n e u r a l "basis o f v i s u a l l y g u i d e d "behavior  the  independent v i s u a l systems: other  involved i n orienting  measured i n t h i s s e r i e s o f  o f v i s u a l and  displays.  of o r i e n t i n g behavior with repeated presentation  a l s o examined. c a l and  The  The  while  the  of the  v i s u a l s y s t e m and  investigation revealed  appropriate  the  corti-  influence  t h a t l e s i o n s of the  superior  inability  o r i e n t i n g response i s a v a i l a b l e i n the b e h a v i o r a l i t i s not  always emitted  intact"animals  c o l l i c u l u s l e s i o n e d a n i m a l s do  d i s p l a y s which are  more s a l i e n t f o r t h e  d e f i c i t i n o r i e n t i n g to the r e d u c e d o r e l i m i n a t e d by t o t e s t i n g and  and  to  per-  motor responses i n v o l v e d i n o r i e n t i n g ; r a t h e r ,  v i s u a l d i s p l a y s t h a t the  shock.  of a d i s p l a y ,  i n t r i n s i c v a r i a b l e s were a s s e s s e d .  lesioned animal,  superior  Habituation  e f f e c t on t h i s b e h a v i o r o f v a r i o u s l y s i z e d  c o l l i c u l u s dov.not r e s u l t i n v i s u a l a g n o s i a o r t h e form the  the  s u b s e q u e n t i n t r o d u c t i o n o f changes i n i t were  s u b c o r t i c a l l e s i o n s of the  o f e x t r i n s i c and  in  a u d i t o r y d i s p l a y s and  p o s t u r a l responses to the  d i s h a b i t u a t i o n to the  studies  t h i r s t y r a t ' s a b i l i t y to disrupt l i c k i n g  response to the p r e s e n t a t i o n a n i m a l ' s h e a d and  and  O r i e n t i n g was  e x a m i n i n g "both t h e  two  they are  "less"  i n response to  t r e a t as l e s s s a l i e n t .  the The  orient to ancLllocalize v i s u a l i n t a c t animal.  s a l i e n t stimulus  changing the  repertoire  Further,  d i s p l a y s can  the be  degree of water d e p r i v a t i o n p r i o r  capable of u s i n g  t h i s d i s p l a y as a s i g n a l o f  i i i  Lesions  r e s t r i c t e d to a very  small portion of the l a t e r a l  edges o f t h e deep l a y e r s o f t h e s u p e r i o r c o l l i c u l u s and t h e d o r s a l t e g m e n t u m h a d t h e same c o n s e q u e n c e s a s s u p e r i o r c o l l i c u l u s while  l e s i o n s which i n c l u d e d only the s u p e r f i c i a l l a y e r s o f t h e  superior colliculus d i d not.  Lesions  of the s t r i a t e  and e x t r a s t r i a t e  cortex d i d not s i g n i f i c a n t l y affect orienting*behavior.  Rats  l e s i o n s o f t h e s u p e r f i c i a l or- d e e p l a y e r s o f t h e s u p e r i o r and  lesions, •  r a t s with lesions i n c l u d i n g area  striate  and e x t r a s t r i a t e cortex,  colliculus  7 o f c o r t e x as w e l l as t h e  did,however, habituate  than i n t a c t animals t o the repeated  with  more q u i c k l y  presentation of the v i s u a l  dis-  p l a y s , and g e n e r a l l y d i d n o t d i s h a b i t u a t e i n response t o t h e changes i n the visual displays. These f i n d i n g s s u g g e s t a r e l a t i o n s h i p - b e t w e e n the  the;cortex,  s u p e r f i c i a l l a y e r s , and t h e deep l a y e r s o f t h e s u p e r i o r  collicu-  l u s and t h e a b i l i t y o f animals t o s h i f t a t t e n t i o n w i t h i n a  stimulus  modality. important  The d e e p l a y e r s o f t h e s u p e r i o r c o l l i c u l u s may a l s o b e f o r s h i f t s of a t t e n t i o n between stimulus  Levey, & C a r l s o n , regard  1972).  modalities  O v e r a l l , t h e s e r e s u l t s were d i s c u s s e d  to a possible modulating.role-of  cortex i n o r i e n t i n g behavior  (Jane, with  the s u p e r i o r - c o l l i c u l u s and  and i n terms o f t h e parameters o f  o r i e n t i n g w h i c h must be t a k e n i n t o a c c o u n t i n t h e d e v e l o p m e n t o f a n adequate model o f t h e n e u r a l b a s i s o f o r i e n t i n g  behavior.  T A B L E OF CONTENTS  ABSTRACT  i i  T A B L E OF CONTENTS  iv  • L I S T OF -FIGURES  ::•  v-i  L I S T OF .TABLES, '"  viii  L I S T OF APPENDIXES.  viii  INTRODUCTION  1  EXPERIMENT I  19  Introduction  19  Method  22  Results  29'  Discussion  >2  EXPERIMENT I I Introduction Method  m.  Results Discussion EXPERIMENT I I I  51  Introduction  51  Method  52-  Results  53  Discussion  62  EXPERIMENT I V Introduction  G\ 6k  V  Method  65  Results  68  Discussion  75  EXPERIMENT V  77  Introduction  77  Method  78  Results  79  Discussion  83  EXPERIMENT V I  85  Introduction  85  Method  86  Results  89  Discussion  95  GENERAL D I S C U S S I O N  98  REFERENCES  119  APPENDIX A  1-27  APPENDIX B  146  APPENDIX C  152  APPENDIX D  156  APPENDIX E  162  APPENDIX F  167'  vi  L I S T OF Figure  1.  g e n i c u l o - s t r i a t e pathway of the c a t .  3  F i g u r e 2.  V i s u o m o t o r mechanisms i n the S y r i a n hamster.  6  F i g u r e 3«  Schematic f l o w diagram i n d i c a t i n g the major connect i o n a l r e l a t i o n s h i p s o f the t h a l a m i c and c o r t i c a l v i s ual apparatus. 13  Figure  The a p p a r a t u s u s e d t o e x a m i n e d i s r u p t i o n o f l i c k i n g response t o the p r e s e n t a t i o n of the l i g h t d i s p l a y .  Figure 5(  F i g u r e 6.  The  FIGURES  a _ e  in  )Mean number o f l i c k s d u r i n g t h e - b a s e l i n e a n d d u r i n g , 4he". p r e s e n t a t i o n "of t h e a p p a r e n t l y , m o v i n g a n d stationary, light displays. ' The h e a d a n d b o d y movements e l i c i t e d b y of a l i g h t d i s p l a y .  the  2h  3©  presentation 31  F i g u r e 7C.A-D). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o SC a n d s u r r o u n d i n g t i s s u e a n d c o r t i c a l damage. 3^ F i g u r e 8 ( a - c ) . H i s t o l o g i c a l r e c o n s t r u c t i o n s and b e h a v i o r a l r e s u l t s f o r i n d i v i d u a l SG l e s i o n e d a n i m a l s .  35  F i g u r e 9 ( a - c ) . H i s t o l o g i c a l r e c o n s t r u c t i o n s and b e h a v i o r a l r e s u l t s f o r i n d i v i d u a l " SP l e s i o n e d a n i m a l s .  37  F i g u r e 10(a-c). H i s t o l o g i c a l r e c o n s t r u c t i o n s and b e h a v i o r a l r e s u l t s f o r i n d i v i d u a l ST l e s i o n e d a n i m a l s . Figure l l ( a - e ) . Mean n u m b e r o f l i c k s d u r i n g t h e b a s e l i n e d u r i n g the p r e s e n t a t i o n of the a u d i t o r y " tone.  H^O  and k8  F i g u r e 1 2 ( a - e ) . Mean number o f l i c k s d u r i n g t h e b a s e l i n e and' •' during«the .:.presenta£ld.n- .of. t h e , l i g h t .-.displays, w i t h . the r e d p l a s t i c f i l t e r s . r e m o v e d . •  55  F i g u r e 13(A-D). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o SG a n d s u r r o u n d i n g t i s s u e a n d c o r t i c a l damage.  57  F i g u r e . l 4 ( a - b ) . H i s t o l o g i c a l r e c o n s t r u c t i o n s and b e h a v i o r a l r e s u l t s f o r i n d i v i d u a l SP l e s i o n e d a n i m a l s f o r l i g h t d i s p l a y s w i t h the- r e d p l a s t i c f i l t e r s removed.  59  Figure  15(a-e). Mean number o f l i c k s d u r i n g t h e b a s e l i n e a n d d u r i n g the p r e s e n t a t i o n of the "approaching" l i g h t displays.  70  vii  Figure  16(ATD). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o SG a n d s u r r o u n d i n g t i s s u e  71 Figure  Figure  Figure  Figure  i 7 ( A - D ) . Mean number o f l i c k s d u r i n g t h e b a s e l i n e a n d during the presentation of the c i r c l i n g l i g h t display.  73  18(A-D). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o SG a n d s u r r o u n d i n g t i s s u e a n d c o r t i c a l damage.  74  1 9 ( a - d ) . Mean number o f l i c k s d u r i n g t h e b a s e l i n e a n d d u r i n g t h e p r e s e n t a t i o n o f t h e " a p p a r e n t l y " moving light display.  80  20(A-G). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o SC a n d s u r r o u n d i n g t i s s u e .  82 Figure  Figure  Figure  21.  Mean number o f t r i a l s t o c r i t e r i o n s u p p r e s s i o n a n d v a r i a n c e f o r SH, SG, SP, DP a n d ST l e s i o n e d a n i m a l s .  90  2 2 ( a - e ) . Mean number o f l i c k s d u r i n g t h e b a s e l i n e a n d d u r i n g t h e p r e s e n t a t i o n o f t h e " a p p a r e n t l y " moving l i g h t d i s p l a y s w h i c h were f o l l o w e d b y a n u n a v o i d a b l e f o o t shock.  92  23(A-D). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o SG a n d s u r r o u n d i n g t i s s u e a n d c o r t i c a l damage.  93  Figure  24.  Figure  25(a-d). Mean number o f l i c k s d u r i n g t h e b a s e l i n e a n d during the presentation o f the "apparently"'moving light displays.  148  F i g u r e 26(A-C). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o t h e SG a n d s u r r o u n d i n g t i s s u e .  149  Figure  A s c h e m a t i c d i a g r a m o f t h e • r e l a t i o n s h i p s ^ - b e t w e e n " • •;- the- b e h a v i o r a l i m p a i r m e n t o f o r i e n t i n g a n d l e s i o n s o f the v i s u a l system. ••Ill  27(A-G). (A) R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o t h e SG a n d s u r r o u n d i n g t i s s u e . (B) Mean number o f l i c k s d u r i n g t h e b a s e l i n e a n d ' , during the presentation of the s o l i d l i g h t displays. 154  viii  Figure  28.  A h i s t o l o g i c a l r e c o n s t r u c t i o n of the r a t ' s s u p e r i o r c o l l i c u l u s s h o w i n g the 7 l a m i n a e and t h e d i v i s i o n i n t o s u p e r f i c i a l and deep l a m i n a e .  165  ix  LIST OF TABLES  Table 1.  Assignment of Animals, Experiment VI.  87  LIST OF APPENDICES  APPENDIX A.  Analysis of variance F tables.  127  APPENDIX B.  Counterbalanced presentation of stationary and "apparently" moving l i g h t displays.  146  The effect of increased i n t e n s i t y per se on orienting.  152  The effect of v i s u a l cortex and subcortical lesions on open f i e l d a c t i v i t y .  155  The effect of geniculo-striate and tecto-pulvinar inputs to the cortex on o r i e n t i n g .  1.60  Figure 28.  165  APPENDIX C. APPENDIX D. APPENDIX E. APPENDIX F.  X  ACKNOWLEDGEMENTS I w o u l d l i k e t o t h a n k D r . R i c h a r d C. T e e s a n d t h e o t h e r members o f my a d v i s o r y c o m m i t t e e : Phillips in  D r . D . P a p p a g e o r g i s , D r . A. G. r  a n d D r . D. M. W i l k i e f o r t h e i r a s s i s t a n c e a n d d i s c u s s i o n s  the preparation of this thesis.  I am a l s o g r a t e f u l f o r t h e s.  a s s i s t a n c e o f L i n c o l n Chew, J o h n N e s b i t t a n d D r . Di. M. W i l k i e i n t h e development o f t h e b e h a v i o r a l t e s t i n g equipment and t o F r e d Derek Van d e r Kooy and P e t e r Van Oot f o r a s s i s t a n c e w i t h and  surgical  LePaine,  histological  procedures.  A warm t h a n k y o u i s a l s o e x t e n d e d t o a l l t h e g r a d u a t e students  a n d o t h e r members o f t h e B i o p y s c h o l o g y  D e p a r t m e n t who  a s s i s t e d by h e l p f u l d i s c u s s i o n and encouragement.  I would  to thank Ken P r k a c h i n f o r h i s a s s i s t a n c e w i t h t h e graphics  like and f o r  h i s encouragement and comradeship d u r i n g t h e p r e p a r a t i o n o f t h i s thesis. Finally,  a s p e c i a l t h a n k s i s e x t e n d e d t o Rod Midgley,whose  c o n t r i b u t i o n s t o t h i s t h e s i s cannot b e ' l i s t e d . and  support  enjoyable.  made b e i n g a g r a d u a t e s t u d e n t  H i s encouragement  bearable  and often  1. INTRODUCTION I n a l l v e r t e b r a t e s the r e t i n a has a t l e a s t three projections:  the thalamic,  pathways c o u l d r e p r e s e n t  tectal,  three  v i s u a l l y guided  behavior  and p r e t e c t a l pathways. 'These  separate  e i t h e r d i r e c t o r i n d i r e c t access  major  visual  systems' w i t h  t o the musculature i n v o l v e d i n  (Sprague, Levey, Diberardino,  & Berlucchi,  1977).'' I n non-mammalian v e r t e b r a t e s , models o f t h e n e u r a l of v i s u a l l y guided way.  behavior  have emphasized t h e r e t i n o - t e c t a l  The t e c t u m h a s b e e n c o n s i d e r e d  formation  of v i s u a l information into adaptive  ( i n g l e & Sprague,  motor p a t t e r n s and t h e of v i s u a l l y  guided  1975)-  I n mammalian s p e c i e s a t t e m p t s t o model t h e n e u r a l of v i s u a l l y guided  behavior  tion, and  This thalamic  system) has been c o n s i d e r e d  pathway ( t h e g e n i c u l o -  e s s e n t i a l f o rp a t t e r n d i s c r i m i n a -  t h e e v a l u a t i o n o f t h e b e h a v i o r a l s i g n i f i c a n c e .of v i s u a l  the transformation of v i s u a l information into adaptive  behaviors and  basis  have emphasized t h e r e t i n o - t h a l a m i c  pathway t o t h e s t r i a t e c o r t e x . striate  path-  the e s s e n t i a l l i n k i n the trans-  "highest i n t e g r a t i v e center" i n the mediation behavior  basis  (Sprague e t a l . ,  1977).  The r e t i n o - t e c t a l ,  stimuli,  motor  retino-pretectal,  o t h e r r e t i n o f u g a l pathways have g e n e r a l l y been t h o u g h t o n l y t o  mediate "simple  reflexive behaviors",  l a r y adjustments t o l i g h t .  such as o r i e n t a t i o n and p u p i l -  These r e f l e x i v e v i s u a l b e h a v i o r s  t h e i r s u b c o r t i c a l s u b s t r a t e s have been t h o u g h t t o operate d e n t l y and without  influence of the c o r t i c a l pattern  and  indepen-  analysing  2. and  i n t e g r a t i v e system (e.g., The  196?,'1969)•  Schneider,  models which emphasize t h e g e n i c u l o - s t r i a t e pathway  are  p r i m a r i l y based on f i n d i n g s which s u g g e s t e d t h e importance o f  the  striate cortex  (area  17) f o r p a t t e r n v i s i o n .  1935), h a m s t e r ( S c h n e i d e r , Smith,  1969), c a t ( S m i t h ,  I n r a t (Lashley,  1937), d o g ( W i n g &  19^2), a n d monkey ( K l u v e r , 19^1, 19^2, 1951), l e s i o n s o f .  neocortex which included area loss of pattern The  17 h a v e b e e n r e p o r t e d  t o r e s u l t i nthe  vision.  p r o p o s i t i o n t h a t t h e s t r i a t e c o r t e x was n e c e s s a r y f o r  p a t t e r n v i s i o n was a l s o b o l s t e r e d b y t h e e l e c t r o p h y s i o l o g i c a l s t u d i e s of Hubel and Wiesel  (1962, I965, 1968).  t h e i r model i s p r e s e n t e d  i n Figure  1.  i n c r e a s i n g l y complex r e c e p t i v e f i e l d progressed a r e a s 17,  A schematic version o f  Based on t h e i r f i n d i n g s o f p r o p e r t i e s o f n e u r o n s a s one  f r o m r e t i n a t o l a t e r a l g e n i c u l a t e n u c l e u s (LGN), t o c o r t i c a l 18, a n d 19, t h e y p r o p o s e d a n a r r a n g e m e n t i n w h i c h t h e r e c e p %  t i v e field- properties of the c e l l s of area v e r g e n c e o f s i m p l e r LGN p r o c e s s e s . converge on t h e c e l l s o f a r e a in  17 w e r e t h e r e s u l t o f c o n -  A r e a 17 c e l l p r o c e s s e s ,  i n turn,  18 a n d 19 a n d t h i s c o n v e r g e n c e r e s u l t e d  the complex and hypercomplex r e c e p t i v e f i e l d p r o p e r t i e s and t h e  selective responding of c e l l s optimal  i n t h e s e a r e a s t o l i n e s a n d edges o f  s i z e and o r i e n t a t i o n ( i . e . , The  presence of c e l l s  patterns).  i n s t r i a t e cortex which responded  s e l e c t i v e l y t o l i n e s and c o n t r a s t i n g edges s u g g e s t e d t h a t area  was t h e n e u r a l s u b s t r a t e  involved i n pattern vision.  this  of the feature abstraction process While the discovery  of these c e l l s d i d  3 A.  F i g u r e 1. The g e n i c u l o s t r i a t e p a t h w a y o f t h e c a t s h o w i n g , a t each l e v e l , the r e c e p t i v e f i e l d s o f the neurons and t h e i r trigger features or optimal s t i m u l i . + = ON r e s p o n s e ; - - - =. OFF r e s p o n s e . ( F r o m B a r l o w , N a r a s i m h a n , & R o s e n f e l d , 1972).  3 B. Receptive Fields  Object  Trigger Features  Local Brightening  Retina  +- _ + + -~r + + -- +  Local Dimming  Local Brightening  + --_ + +  Local Dimming  ++ +  Complex Moving Edges E t c . A p p e a r t o b e combinations of simple u n i t s o f same o r i e n t a t i o n and/or d i s parity.  Hyper Complex I I L i n e Segments, Corners, E t c . P o s s i b l y formed from p a i r s of Hyper Complex I .  Moving, S l i t s , Bars, o r Edges, £ ~ of S p e c i f i c + O r i e n t a t i o n and Binocular Disparity.  Ends o f L i n e s . E t c . P o s s i b l y e x c i t e d by one.Complex and i n h i b i t e d ' by o t h e r s of same o r i e n t a t i o n .  4.  l e n d credence area  t o the models which  emphasized the importance  17 t o a f e a t u r e a b s t r a c t i n g s y s t e m ,  of  i t has not been demonstra-  t e d t h a t these c e l l s a r e necessary and s u f f i c i e n t f o r p a t t e r n v i s i o n or even t h a t they r e p r e s e n t a necessary f i r s t  stage i n the proposed  system. Attempts  h a v e b e e n made t o e x t e n d H u b e l a n d W i e s e l ' s  (1962,  I965) b a s i c s e r i a l .model, t o i n c l u d e a - s t a g e i n w h i c h t h e . b e h a v i o r a l s i g n i f i c a n c e o f p a t t e r n e d v i s u a l s t i m u l i i s ".evaluated" (Jones & ' Mishkin,  1972).  I t was h y p o t h e s i z e d t h a t t h e c o n t o u r a n d e d g e ( o r  pattern) a n a l y s i s accomplished cortex  by areas  17,  18, 19*and t h e t e m p o r a l  i s f o l l o w e d by a f u r t h e r stage i n which  emotional significance of the s t i m u l i  the motivational or  i s determined.  This  stage  i n t h e sequence g e n e r a l l y has.been i d e n t i f i e d w i t h t h e l i m b i c T h i s e x t e n s i o n o f t h e model.has reeeived-.some (though.equivocal) support.  system.  experimental  B i l a t e r a l d e s t r u c t i o n of the temporal  l o b e s , a d j a c e n t c o r t i c a l a r e a s , hippocampus,and amygdala have been r e p o r t e d t o r e s u l t i n t h e K l u v e r and Bucy  (1939) s y n d r o m e o f " p s y c h i c  b l i n d n e s s " ; ( t h e i n a b i l i t y t o d i f f e r e n t i a t e food from non-food o b j e c t s ) and  excessive and m i s d i r e c t e d e m o t i o n a l i t y w i t h respect t o v i s u a l  stimuli.  T h i s impairment  has been viewed  as r e s u l t i n g from  s o c i a t i o n o f the a n a l y s i s o f v i s u a l s t i m u l i by the s t r i a t e , a t e , =and t e m p o r a l  system  from  the determination of t h e i r  o r emotional s i g n i f i c a n c e by the l i m b i c system Misantone, connections  the d i s extrastri-  associational  (Horel, Keating, &  1975; J o n e s & M i s h k i n , 1972), o r v i a t h e l i m b i c s y s t e m ' s f  t o t h e hypothalamus ( R o l l s , Judge, & Sanghera,  1977).  5.  While these notions about the anatomical basis of v i s u a l l y guided behavior have i n i t i a t e d extensive research, acceptance of the models i s c l e a r l y premature.  The models involve untested  assumptions  with respect to both the underlying anatomical substrates and the nature of sensory-perceptual and associational processes.  Of prime  concern to the present i n v e s t i g a t i o n i s , however, the dependence of these models on the geniculo-striate system and limbic system as the sole integrative mechanism and the f a i l u r e to consider other retinofugal pathways to the limbic system. Schneider (1967, I969) has presented another model of v i s u a l l y guided behavior which extends Hubel and Wiesel's ideas and e x p l i c i t l y treats the transformation of v i s u a l information into adaptive motor behaviors.  A schematic version of Schneider's two  v i s u a l system hypothesis i s presented i n Figure 2.  In keeping with  Hubel and Wiesel's model, he proposed that the geniculo-striate system was responsible f o r pattern v i s i o n .  The appropriate motor  responses to patterned v i s u a l s t i m u l i were-assumed to occur at a l a t e r stage through the geniculo-striate's connections to the motor system.  On the other hand, the t e c t a l system (superior c o l l i c u l u s )  and i t s subcortical motor connections were suggested to function r e f l e x i v e l y i n response to v i s u a l s t i m u l i :  to i n i t i a t e appropriate  head and eye movements required to orient to, and l o c a l i z e s t i m u l i . A l l of these models have been valuable i n generating research.  They have, however, also provoked a number of important  c r i t i c i s m s and the c o l l e c t i o n of data which suggest substantial  Figure 2. Visuomotor mechanisms i n the Syrian hamster. The flow of information from the r e t i n a to two subsystems f o r motor cont r o l i s represented i n accordance with 3 experimental studies of neuroanatomical connections- and behavioral effects of s u r g i c a l l e s i o n s . Top to bottom i n the diagram.corresponds with r o s t r a l to caudal i n the b r a i n . LGd = dorsal nucleus of l a t e r a l geniculate body; LP = nucleus l a t e r a l i s posterior of thalamus. (Schneider, 1975).  6 b.  Striate C o r t e x  Juxtastriate C o r t e x  Subsystem for control of go / no-go responses  L J  I  Subsystem  for  control of head turning a n d associated  I  adjustments  postura  1  I  revisions are needed.  Before-reviewing the research  involved'"with  these questions a "brief description of some - of the connections of the three major retinofugal pathways i s necessary. (1) The..-Thalamic Projection (Geniculo-Striate System) The., .retinal pathway, to the thalamus terminates in-"the dorsal l a t e r a l geniculate nucleus (LGNd) and t h i s nucleus sends a ..substan:  t i a l projection to the s t r i a t e cortex (area 1 7 ) ' cortex  (Kreig, 19.46 a, b).,  in  the posterior  neo-  The s t r i a t e cortex, i n turn, projects  to the b e l t of cortex surrounding area 1? (extrastriate cortex) i n a l l mammals•studied to date. .Extras t r i a t e cortex has numerous projections to temporal and f r o n t a l cortex and the limbic system as described e a r l i e r (see, Chalupa, 1977; Weiskrantz, 1974,  Graybiel, 1974;  Jones, 1974;  and  f o r a complete d e s c r i p t i o n ) .  The s p e c i f i c projections beyond area 18 have not been examined f o r r a t ; however, i t i s generally assumed that comparable connections e x i s t f o r t h i s species as f o r cat and monkey, tree shrew, and hedgehog (Chalupa, 1977;  Diamond, 1976;  Gould & Ebner, 1978).  (2) The Tectal Projection (Tecto-Pulvinar System) The r e t i n a l pathway to the superior c o l l i c u l u s (SC) terminates i n i t s s u p e r f i c i a l s l a y e r s . In addition to projections which descend from the deep layers of the SG to the oculo-motor nucleus and s p i n a l cord, there i s a substantial projection to the thalamus. The  terminal nuclei i n the thalamus vary between species.  In r a t ,  the s u p e r f i c i a l layers are reported to project to the nucleus l a t e r a l i s posterior (NLP), while other thalamic projections  • -  8 are not known at present (Hughes, 1977).  In cats and monkeys, however,  the SC projects to the subdivisions of the,posterior nuclei of the thalamus and to the pulvinar (Chalupa, 1977).  The thalamic nuclei  which receive SC projections (tecto-pulvinar system) i n turn project to the cortex.  In r a t s , the NLP  (areas 18 & 18A),  projects to the extrastriate cortex  to area 7 of the p a r i e t a l cortex,and to area 20 of  temporal cortex (Hughes, 1977).  A h i s t o l o g i c a l reconstruction of the  rat's superior c o l l i c u l u s showing the 7 laminae and the d i v i s i o n into • s u p e r f i c i a l and deep laminae-is presented i n Figure  28,-, of Appendix F.  (3) The P r e t e c t a l Projection The pretectum of a l l species apparently receives a r e t i n a l projection and has descending projections to brainstem nuclei involved i n the p u p i l l a r y l i g h t r e f l e x t  C o r t i c a l projections are not known  f o r rat; however, i n cat and monkey there i s a substantial projection to area 21 of the temporal cortex (Chalupa, 1977). As indicated e a r l i e r , there have been a number of important questions and challenges directed at the s e r i a l processing  model and  i t s extensions and the behavioral significance of each of these 3 projections.  F i r s t , i s the geniculo-striate system, i n exclusion of other  retinofugal pathways, e s s e n t i a l f o r discrimination of v i s u a l stimuli? Second, what i s (are) the r o l e ( s ) of the subcortical pathways i n v i s u a l l y guided behavior?  Third, what i s the role of the above connections  and interactions between the three major retinofugal pathways i n v i s u a l l y guided behavior? a t e l y described  Fourth, are orienting and l o c a l i z a t i o n appropri-  as "simple r e f l e x i v e behaviors'.'?  A b r i e f review of  . research stemming from these concerns i s outlined below.  9.  The to pattern (Hughes,  notion  that  In rat  1977), c a t s , ( D o t y , 1971; S p r a g u e e t a l . , 1977), a n d monkeys 1972)  l e s i o n s which include  of the e x t r a s t r i a t e cortex  projection but  pathway i s c r i t i c a l  v i s i o n h a s b e e n e x a m i n e d i n a number o f s p e c i e s .  (Schilder, Pasik,& Pasik, parts  the geniculo-striate  a r e a 17 a n d  ( t h u s r e m o v i n g t h e e n t i r e LGN  t o t h e c o r t e x ) do n o t d e s t r o y p a t t e r n  only r e s u l t i n extended l e a r n i n g  or relearning  discriminations of pattern  dis-  criminations. Lesion-behavior investigations clearest  i l l u s t r a t i o n of this issue,  m e n t i o n e d a b o v e , t h e LGN p r o j e c t s species. cortex  i n tree  sinceunlike  shrews p r o v i d e t h e the'-mammals  e x c l u s i v e l y t o a r e a 17 i n t h i s  W h i l e t h e models r e v i e w e d e a r l i e r emphasized t h e s t r i a t e ( a r e a 17) o f mammals a s t h e p i v o t a l f i r s t  stage i n pattern  p e r c e p t i o n and e x c l u d e d t h e o t h e r r e t i n o f u g a l pathways t o s u b c o r t i c a l v i s u a l l y responsive areas from involvement i n t h i s process, K i l l a c k y , Snyder, and ablating  Diamond  (1971) a n d S n y d e r a n d D i a m o n d (1968) f o u n d t h a t  a r e a 17 d i d n o t h a v e a n y c o n s p i c u o u s e f f e c t o n t h e a c q u i s -  i t i o n or retention  of pattern  discriminations  Apparently then, the g e n i c u l o - s t r i a t e this  i n tree  shrews.  system i s n o t necessary  for  component o f v i s u a l l y g u i d e d b e h a v i o r and h e n c e a t t e n t i o n must be  f o c u s s e d on-'the. p o t e n t i a l r o l e of-' s u b c o r t i c a l - a r e a s - fL  11  Cooper and h i s c o l l e a g u e s completed a s e r i e s which also provide t i o n with cortex  lesions  a demonstration of residual pattern of the visual cortex.  were removed c o m p l e t e l y ;  pattern  vision.  of studies discrimina-  S t r i a t e and e x t r a s t r i a t e  thus, the entire  geniculo-striate  1  and  most o f t h e t e c t o - p u l v i n a r s y s t e m ' s p r o j e c t i o n s  eliminated. of using  The s t r i a t e  s p a t i a l v i s i o n ( F e r r i e r & Cooper,  i n a t i o n of flux-equated by  and e x t r a s t r i a t e ablated  patterned'visual  to cortex  r a t s were  contour o r pattern  flux differences  (Miller,  were  capable  1976)-.- - M o r e o v e r , d i s c r i m -  s t i m u l i was  less impaired  s t r i a t e and e x t r a s t r i a t e l e s i o n s than by an o c c l u s i o n  which eliminated  o.  cues b u t l e f t  local  -  procedure luminous  1973; M i l l e r & C o o p e r , 1974).  Attempts t o examine t h e c o n t r i b u t i o n o f a l l t h e i n d i v i d u a l subcortical projections not  been undertaken.  o f the r e t i n a and t h e i r c o r t i c a l p r o j e c t i o n s  H o w e v e r , some i n d i c a t i o n s o f t h e c o n t r i b u t i o n  of the major s u b c o r t i c a l r e t i n a l p r o j e c t i o n s Blochert,  F e r r i e r , and Cooper  i n the r a t are a v a i l a b l e .  (1976) h a v e e x a m i n e d t h e c o n t r i b u t i o n  of p r e t e c t a l l e s i o n s t o u t i l i z a t i o n o f t o t a l luminous f l u x cues and found a d r a s t i c impairment by p r e t e c t a l l e s i o n s o f a d i s c r i m i n a t i o n i n w h i c h o n l y f l u x cues c o u l d be u s e d . the  LGNv a r e a l s o r e p o r t e d  black-white  discriminations  L e g g & Cowey,  have  to impair (Blochert  L e s i o n s o f the pretecturn and  a c q u i s i t i o n and r e t e n t i o n of e t a l . , 1976;  Horel,  1968;  1977), b u t n o t s t r i p e o r i e n t a t i o n d i s c r i m i n a t i o n s . - I t  a p p e a r s t h a t t h e s u b c o r t i c a l p r e t e c t u m i s .preeminent', i n i n t e n s i t y d i s c r i m i n a t i o n s when t h i s c u e i s a v a i l a b l e f o r t h e s o l u t i o n o f a discrimination (Blochert  et a l . ,  1976).  Since patterns  involve  l o c a l changes i n l i g h t i n t e n s i t y , these data suggest t h a t t h e p r e t e c t u m may b e i n v o l v e d i n some a s p e c t o f p a t t e r n  discrimination'.  The... r o l e • o f t h e SC i n p a t t e r n v - i s i o h ^ a l s o h a s b e e n -  e x a m i n e d . _A n u m b e r o f s t u d i e s -  i n r a t (Cooper, Bland, G i l l e s p i e ,  &  11  Whitaker, 1970;  Dyer, Marino, Johnson,& Kruggel, 1976;  .  Thompson,  1969), golden hamster (Schneider, 1969). and rhesus monkey (Anderson & Symmes, 1969; mal  Rosvold,. Mishkin,& Scharzhart, 1969)? indicate mini-  ( i f any) d e f i c i t i n postoperative  i n a t i o n a f t e r lesions of the SC. son, 196^;  1971;  retention of a  pattern...discim-  However, i n cats (Anderson & William-  Berlucchi,. Sprague, Levey, & DiBerardino, 1972;  Sprague, Berlucchi, & DiBerardino, 1970)  Myers,  and tree shrews  (Casagrande & Diamond, 197^), d e f i c i t s have been reported i n postoperative a c q u i s i t i o n of a discrimination but not in:'.the retention of a preoperatively  learned  discrimination.  An explanation with postoperative retention  of why  the SC-pretectal  lesions i n t e r f e r e  a c q u i s i t i o n of a pattern discrimination but  not  i s not immediately apparent-from the r e s u l t s of these  s p e c i f i c studies.  A tentative conclusion, however, may  of the retinofugal systems discriminations.  be that none  i s ' c r i t i c a l or p i v o t a l i n these pattern  Rather, each of the retinofugal pathways may  be  d i f f e r e n t i a l l y responsive to d i f f e r e n t parameters or dimensions of a stimulus display, such as the i n t e n s i t y and s p a t i a l c h a r a c t e r i s t i c s of p a r t i c u l a r v i s u a l targets.  Moreover, anatomical studies demonstrate  the presence of connections between the major v i s u a l systems providing a substrate f o r interactions and the r e c i p r o c a l modulation of acitivity,.  In. fact,, i t appears that v i s u a l systems "are so intimately  interconnected not being  neural  that i t i s impossible to conceive of a c t i v i t y i n  .influenced by a c t i v i t y i n the others" (Jones, 197^,  one, p.  225).  12 A.  In a l l mammals studied, the three terminal areas of the r e t i n a l projections have overlapping c o r t i c a l targets. • Jhe.main points of i n t e r a c t i o n of- the v i s u a l areas are described i n the accompanying diagram (Figure 3, from Jones, 197^, p. 226).  In r a t , the  tectofugal and geniculosstriate system have overlapping projections to e x t r a s t r i a t e cortex and perhaps i n areas 20 and ?•  Although the  s t r i a t e projections to these areas have not been examined to date, they have, been demonstrated i n other species as cat and monkey (Jones, 197^). The geniculo-striate and tecto-pulvinar systems also overlap and l i k e l y modulate each other's a c t i v i t y v i a s p e c i f i c connections between them.  There are substantial projections from area 1? to the  s u p e r f i c i a l layers of the superior c o l l i c u l u s in. the r a t (Lund, 1966). These connections are r e c i p r o c a l i n that the s u p e r f i c i a l laminae of SG are l i k e l y the source of the. l a t e r a l posterior nucleus projections to areas 18, 7# and 20.  In cat and monkey, the extrastriate cortex  and temporal cortex have descending projections primarily to the deep layers" of the SC (Sprague, 1975) •  Similar connections'.likely occur  i n the rat', however, these have not. been demonstrated  to date.  In addition to the r e c i p r o c a l c o r t i c o - t e c t a l pathways, a l l the v i s u a l c o r t i c a l areas appear to have r e c i p r o c a l projections to t h e i r thalamic sources.  Reciprocal connections between the  v i s u a l l y responsive c o r t i c a l areas and t h e i r thalamic sources have been demonstrated i n cat and monkey ( c f . Chalupa, 1977).  Only a  p r o j e c t i o n of area 17 to the NLP of thalamus has been demonstrated  12 B.  Figure 3. Schematic flow diagram i n d i c a t i n g the major connect i o n a l relationships of the thalamic and c o r t i c a l v i s u a l apparatus. (From Jones, 1974).  SUPERIOR COLLICULUS AND PRETECTUM  PARIETO-TEMPORAL (20, 21, TG, ? others)  T  PERISTRIATE (areas 18 8 19)  STRIATE, (area  17)  FRONTAL  L P V PULVINAR  J3  in  the r a t to date  (Ribak & Peters,  Very l i t t l e  1975)•  d a t a e x i s t on t h e n a t u r e o f a l l t h e  inter-  a c t i o n s b e t w e e n t h e r e t i n o f u g a l p a t h w a y s w h i c h one m i g h t  expect  the  However,  in  b a s i s o f t h e a n a t o m i c a l c o n n e c t i o n s o u t l i n e d above. cat (Wickelgren & Sterling,  a n d r a t ( G o o d a l e , 1973) striate  I969), monkey ( C y n a d e r & B e r m a n ,  the importance of the p r o j e c t i o n from  c o l l i c u l u s has b e e n d e m o n s t r a t e d .  1972)  the  cortex i n modulating the f u n c t i o n of the c e l l s of the A b l a t i o n or cooling of the  r e s u l t e d i n t h e l o s s o f d i r e c t i o n s e n s i t i v i t y and b i n o c u l a r i t y ties of single c e l l  on  superior cortex proper-  responses i n the s u p e r f i c i a l laminae of the c a t ,  the  loss of responsiveness to v i s u a l s t i m u l i  i n the deep laminae  the  monkey, a n d a d e p r e s s i o n i n t h e a m p l i t u d e o f  visually-evoked  p o t e n t i a l s i n the superior c o l l i c u l u s of the r a t .  These  preliminary  f i n d i n g s of the modulation of the r e s p o n s e c p r o p e r t i e s o f c e l l s the  r e t i n o - t e c t a l pathway by t h e a c t i v i t y  striate  of c e l l s i n the  In  geniculo-  pathway s u g g e s t the t h r e e r e t i n o f u g a l pathways a r e  independent  not  systems.  While the nature o f the i n t e r a c t i o n between  visual  c e n t e r s a s y e t c a n n o t be d e s c r i b e d , a f e w s t u d i e s p o i n t o u t  the  p o t e n t i a l i m p o r t a n c e o f t h e s e dynamic i n t e r a c t i o n s i n a r r i v i n g a t adequate Meyer  model o f v i s u a l l y  guided behavior.  Kirvel,  Greenfield,  an and  (1974), a n d S p r a g u e (1966) f o u n d t h a t u n i l a t e r a l SG o r s t r i a t e  a b l a t i o n s i n r a t s and c a t s r e s u l t e d i n a n absence f o l l o w i n g of v i s u a l s t i m u l i i n the v i s u a l f i e l d the  of  l e s i o n , and i p s i v e r s i v e  of l o c a l i z a t i o n  contralateral  to  c i r c l i n g when s t i m u l i w e r e p r e s e n t e d  and  14.  i n the i p s i l a t e r a l visual f i e l d . behavioral  A dramatic recovery from  these  d e f i c i t s was o b s e r v e d when a l e s i o n was s u b s e q u e n t l y  p l a c e d i n t h e c o n t r a l a t e r a l c o l l i c u l u s o r when t h e t e c t a l c o m m i s s u r e was c u t ( S h e r m a n ,  1974, 1977)-  The r e c o v e r y f r o m c o n t r a l a t e r a l  l e c t o f v i s u a l s t i m u l i c a n be c o n s i d e r e d a n i m p o r t a n t of an i n t e r a c t i o n between t h e g e n i c u l o - s t r i a t e The  i p s i v e r s i v e c i r c l i n g i s , however, l i k e l y  demonstration  s y s t e m a n d SG.  o n l y a n a r t i f a c t due  t o u n i l a t e r a l damage t o t h e m o t o r s y s t e m a s C o o p e r e t a l . have  (1971)  suggested. Hughes  (1977) a l s o p r o v i d e d a n i n t e r e s t i n g i l l u s t r a t i o n  of an i n t e r a c t i o n o f the g e n i c u l o - s t r i a t e system i n . a p a t t e r n  system and  discrimination"in the-rat.  tecto-thalamic  He f o u n d t h a t  o f a r e a 17 a l o n e h a d o n l y a m o d e s t e f f e c t o n p o s t o p e r a t i v e of a s t r i p e o r i e n t a t i o n , d i s c r i m i n a t i o n . (the any  Animals' with  lesions  learning  lesions  o f NLP  t h a l a m i c component o f t h e t e c t o - c o r t i c a l s y s t e m ) d i d n o t e x h i b i t impairment.on t h i s k i n d  controls.  of pattern  discrimination  permanent d e f i c i t o f p a t t e r n  posterior  cortical ablations.  of both the g e n i c u l o - s t r i a t e lesioned'to  relative, to  When, h o w e v e r , b o t h N L P a n d a r e a 17 w e r e a b l a t e d ,  s u b s e q u e n t i m p a i r m e n t was s i m i l a r t o , .'but the  neg-  impair pattern  not quite  discriminations  as dramatic a s ,  following  Thus, perhaps t h e t e r m i n a l and t e c t o - p u l v i n a r  the  radical area  s y s t e m s must be  vision.  While these studies  do n o t p r o v i d e a d e s c r i p t i o n  of the  nature o f i n t e r a c t i o n s between t h e v i s u a l systems o r t h e d i r e c t i o n of modulating influences  b e t w e e n t h e s y s t e m s (i-..e.,'which  system  1 5.  modulates which), they c l e a r l y demonstrate  the importance  e r i n g the r e l a t i o n s h i p between the systems. modeljand  The  of consid-  serial processing  i t s extensions dichotomized v i s u a l l y guided behavior  and  the n e u r a l s u b s t r a t e s and n e g l e c t e d the r o l e of c o n n e c t i o n s between the  systems. A l t h o u g h the models o f v i s u a l l y g u i d e d b e h a v i o r can (and  be  c r i t i c i z e d i n terms of t h e i r treatment of o r i e n t i n g b e h a v i o r  s i m p l e and r e f l e x i v e , t h e r e i s c o n s i d e r a b l e evidence t h a t the has  t o be i n v o l v e d i n o r i e n t i n g .  The  SC  (stratum  1975)•  the deep l a m i n a e  o f t h e SG  to l o w e r s p i n a l and b r a i n s t e m motor areas  are a  c a t a n d r h e s u s monkey, e l i c i t s  o f h e a d , eye,, a n d b o d y t o w a r d s  the r e g i o n o f v i s u a l space  i n g t o t h e a r e a r e t i n o t o p i c a l l y mapped o n t o t h e SC t h e e l e c t r o d e ( i n g l e & S p r a g u e , 1975;  source  ( i n g l e & Sprague,  E l e c t r i c a l s t i m u l a t i o n o f these pathways i n f r e e l y  animals such as the r a b b i t ,  Stryker,  SC  i s a major t e r m i n a l of the t o p o g r a p h i c a l l y  o r g a n i z e d r e t i n a l f i b e r s and of f i b e r s  SG  adaptive  I n mammals, t h e s u p e r f i c i a l lamina.- o f t h e  opticum)  as  i s i d e a l l y l o c a t e d anatom-  i c a l l y f o r the t r a n s f o r m a t i o n of v i s u a l i n f o r m a t i o n i n t o motor b e h a v i o r .  moving turning  correspond-  and s t i m u l a t e d by  S c h a e f e r , 1970;  Schiller.&  1972). E l e c t r o p h y s i o l o g i c a l r e c o r d i n g studies also support  the  p r o p o s i t i o n t h a t t h e SC i s r e s p o n s i b l e f o r t h e i n i t i a t i o n o f  the  o r i e n t i n g response  which  a l l o w an organism another.  will)  and c h a n g e s i n t h e h e a d and eye p o s i t i o n s t o s h i f t f i x a t i o n f r o m one  v i s u a l stimulus to -  C e l l s i n t h e s u p e r f i c i a l l a y e r s o f t h e SC,  whose r e c e p t i v e  16.  f i e l d s are peripheral f i r i n g rate  t o the c e n t e r of gaze, w i l l i n c r e a s e  j u s t p r i o r t o a n e y e movement w h i c h s h i f t s t h e c e n t e r  of gaze i n t o the c e l l s ' In addition,  rats  receptive  field  (Wurtz & Goldberg,  (Barnes, Smith & L a t t s ,  1970;  I965), t r e e  (Denny-Brown,  shrews  1972).  Kirvel et a l . ,  197^)> h a m s t e r s ( S c h n e i d e r , 1969), c a t s ( S p r a g u e , 1966; Meikle,  their  ( C a s a g r a n d e & D i a m o n d , 197^0  Sprague » and  &  monkeys  I962) w i t h b i l a t e r a l a n d u n i l a t e r a l r e m o v a l o f t h e  o p t i c t e c t u m o r SG a p p e a r n o t t o o r i e n t ,  localize, follow,  or  track  visual stimuli. There i s , t h e r e f o r e , supports the p r o p o s i t i o n o r i e n t i n g response: s e n s o r y map  with  motor systems,  that  a s u b s t a n t i a l body o f e v i d e n c e  t h e SC p l a y s a s i g n i f i c a n t r o l e i n t h e  ( l ) the presence o f a topographically  more o r l e s s d i r e c t a c c e s s t o t h e o c u l a r  (2)  the e l e c t r o p h y s i o l o g i c a l  the data  o r i e n t i n g c a n be e l i c i t e d by e l e c t r i c a l s t i m u l a t i o n ,  tant has  the lesion-behavior  findings.  organized and  and  finally,  However, t h e r e a r e s e v e r a l  not been c l e a r l y demonstrated t h a t  no i n v o l v e m e n t o f g e n i c u l o - s t r i a t e Further,  i t i s not  i n t h e models o f v i s u a l l y g u i d e d b e h a v i o r what i s p r e c i s e l y by the terms o r i e n t a t i o n and l o c a l i z a t i o n .  impor-  First, i t  t h e SC i s e x c l u s i v e l y  o t h e r c o r t i c a l and s u b c o r t i c a l pathways.  which  that  a s s u m p t i o n s t h a t have n o t been q u e s t i o n e d o r t e s t e d .  s i b l e f o r orienting with  spinal  evidence of neurons  r e s p o n d p r i o r t o a s h i f t i n v i s u a l f i x a t i o n , (3)  (4)  which  responor clear meant  I 7  Research concerned p r i m a r i l y w i t h the nature of  orienting  and i t s h a b i t u a t i o n has c o n c e i v e d o f t h e o r i e n t i n g r e s p o n s e i n v e s t i g a t o r y reactions to novel s t i m u l i .  These r e a c t i o n s  as include:  p h y s i o l o g i c a l changes which i n c r e a s e the s e n s i t i v i t y o f the organs  sense  and r e s u l t i n l o w e r e d t h r e s h o l d t o a s t i m u l u s , changes i n  the s k e l e t a l musculature r e q u i r e d t o t u r n and d i r e c t t h e s e n s o r y o r g a n towards t h e s o u r c e of t h e s t i m u l u s , changes i n t h e g e n e r a l s k e l e t a l m u s c u l a t u r e which t e m p o r a r i l y a r r e s t ongoing b e h a v i o r and c o n c u r r e n t autonomic  nervous  system changes ( c f . Lynn,  1966).  R e s e a r c h c o n c e r n e d w i t h t h e i n v o l v e m e n t o f t h e SC i n v i s u a l l y g u i d e d b e h a v i o r g e n e r a l l y has . t r e a t e d o r i e n t i n g l o c a l i z a t i o n as synonymous;  and  Animals have been r e q u i r e d t o 7  localize  a n d s p e n d a n e x t e n d e d amount o f t i m e e x p l o r i n g t h e t e s t s t i m u l u s i n o r d e r t o c o n c l u d e t h a t o r i e n t i n g was either explicitly  (two v i s u a l systems  not impaired.  The  models  hypothesis) or i m p l i c i t l y  p r o c e s s i n g model o f Hubel and W i e s e l ) s u g g e s t t h a t o r i e n t i n g l o c a l i z a t i o n of v i s u a l s t i m u l i  (serial  and  are simple, r e f l e x i v e and'unitary  r e s p o n s e s t o n o v e l s t i m u l i t h a t do n o t d e p e n d o n a n y t h i n g o t h e r t h a n t h e presence o f a s t i m u l u s i n t h e v i s u a l f i e l d and an tectum.  The  intact  m o d e l s do n o t i n c l u d e a p r o c e s s w h i c h w o u l d a l l o w  t i v i t y of t h i s behavior i n response to v i s u a l s t i m u l i . the o r i e n t i n g response  selec-  Obviously,  can n o t and does n o t o c c u r t o e v e r y  visual  stimulus. The  s e l e c t i v i t y o f o r i e n t i n g i s l i k e l y t o be  by both i n t r i n s i c  a n d . e x t r i n s i c parameters.  The  determined  e f f e c t of  intrinsic  I  8  (Miner,  197*0 o r a t t e n t i o n a l a n d m o t i v a t i o n a l f a c t o r s ( i n g l e &  Sprague,  197*0 o n t h e o r i e n t i n g r e s p o n s e h a s b e e n s u g g e s t e d b y r e c e n t  s t u d i e s i n amphibians ( i n g l e , include  1973, 1975)' T h e s e p a r a m e t e r s m i g h t  such f a c t o r s as t h e s t a t e o f d e p r i v a t i o n o f t h e organism,  p r i o r experience with"the  stimulus  (e.g.,  i t s novelty  association with aversive  o r rewarding consequences).  o r previous The p r o p o s i %  t i o n that a t t e n t i o n a l , e x p e r i e n t i a l and m o t i v a t i o n a l f a c t o r s ence t h e f e a t u r e  a n a l y s i s i n v o l v e d i n shape p e r c e p t i o n  tion i s well established  (e.g.,  D o d w e l l , 1975)  influ-  and recogni-  and perhaps a l l t h e  same p r o c e s s e s c a n o r may h a v e a s i g n i f i c a n t i m p a c t o n o r i e n t a t i o n behavior.  E x t r i n s i c parameters o r " a t t e n t i o n - g e t t i n g " p r o p e r t i e s  (Miner,  197*+) o f t h e s t i m u l u s may i n c l u d e s u c h c h a r a c t e r i s t i c s a s  size, distance motion r e l a t i v e and be can  from t h e observer, t o the observer.  i n t e n s i t y , s p a t i a l p o s i t i o n , and I n addition, the specific  i n t e n s i t y configuration of a stimulus an important determinant o f o r i e n t i n g .  (i.e.,  i t s pattern)  spatial may  I f stimulus  configuration  i n f l u e n c e t h e degree o f o r i e n t i n g , a r e f o r m u l a t i o n  o f t h e models  w h i c h d i c h o t o m i z e v i s u a l l y g u i d e d b e h a v i o r i n t o two s e p a r a t e  systems,  one  concerned with a n a l y s i n g t h e s p a t i a l c o n f i g u r a t i o n o f t h e stimu-  lus  a n d a n o t h e r i n d e p e n d e n t s y s t e m c o n c e r n e d w i t h t h e i n i t i a t i o n ..of  an  o r i e n t a t i o n response, would be c a l l e d f o r .  19EXPERIMENT I O r i e n t i n g t o "Apparently" Moving and S t a t i o n a r y Visual Stimuli. A c h a r a c t e r i s t i c o f v i s u a l s t i m u l i t h a t may he o f c o n s i d e r a b l e importance i n e l i c i t i n g o r i e n t i n g from an animal motion.  T h i s dimension has a l s o been suggested as an  i s stimulus important  parameter which a f f e c t s the response p r o p e r t i e s of i n d i v i d u a l o f t h e SC d i f f e r e n t l y f r o m t h o s e  c e l l s i n the s t r i a t e  cells  cortex.  W h i l e we do n o t y e t h a v e g o o d e l e c t r o p h y s i o l o g i c a l e v i d e n c e i n t h e r a t , i n o t h e r m a m m a l i a n s p e c i e s s u c h a s t h e c a t a n d monkey, t h e c e l l s i n t h e s t r i a t e c o r t e x show a g r e a t d e a l o f p r e c i s i o n i n r e s ponse t o t h e s t i m u l u s parameters o f shape, o r i e n t a t i o n and c o l o u r and  a r e l e s s p r e c i s e i n r e s p o n s e t o s t i m u l u s movement  1973;  H u b e l -..&  W i e s e l , 1968).  (Dow & : G o u r a s ,  The SG c e l l s a r e n o t a s  responsive  to o r i e n t a t i o n , shape, o r c o l o r , b u t a r e p r e c i s e l y tuned and s e l e c tive  t o t h e p o s i t i o n o f s t i m u l i and a r e responsive  movement.  to stimulus  T h e i r f i r i n g r a t e i n c r e a s e s when e y e movements a r e d i r e c -  t e d towards ther e c e p t i v e f i e l d entially to:  o f t h e c e l l s and they respond  differ-  ( l ) movement o f a t a r g e t a g a i n s t a s t a t i o n a r y b a c k g r o u n d ,  (2) movement o f t h e t a r g e t c a u s e d b y e y e movements ( W u r t z & M o h l e r ,  1976) . The  array of apparently  human o b s e r v e r ) study  allowed  moving ( a p p a r e n t l y moving t o t h e  o r s t a t i o n a r y b u t f l i c k e r i n g l i g h t s employed i n t h i s  an assessment o f t h e importance of t h i s  s i o n i n e l i c i t i n g the o r i e n t i n g response.  stimulus  The u s e o f t h e s e  dimen-  lights  20  also avoided the i n c l u s i o n of other (e.g., auditory, somatic or sensory) cues which generally are confounded with v i s u a l cues when rats are tested i n situations i n which small, hand-held s t i m u l i are used (Schneider, 19&7,  19&9)•  ^  n  addition, the animals i n the present  study were not i n motion when the stimuli were presented , thus avoiding  confusion between stimulus motion per se and stimulus movement  produced by the animal's own movement.  Previous research on orienting  has often confounded these f a c t o r s ; f o r example, by incorporating running i n the discrimination test (Dyer et a l . , Muirison, 1975;  1976;  Goodale &  Goodale, Foreman, & M i n e r , 19-78).  In reviewing the available evidence on the e f f e c t of part i c u l a r lesions on v i s u a l l y guided behavior, one thing i s clear: there i s considerable confusion as to what "orienting" i s and what constitutes evidence of i t s occurrence.  In v i s u a l research the •:  orienting response - generally has been conceived of as a unitary and r e f l e x i v e behavior by which animals l o c a l i z e a v i s u a l stimulus i n space (but, see Lynn, 1966  f o r other conceptions of orienting).  Consequently, i n tests of orienting the animal usually has been required to d i r e c t i t s a c t i v i t y towards a stimulus f o r a considerable amount of time to allow an i n v e s t i g a t o r .to conclude that the animal has noticed, localized, and looked at the stimulus?.  The o r i e n t i n g r e s -  ponse, however, can be viewed as being comprised of a number of separate behavioral elements.  These include: the cessation of ongoing behavior  when a stimulus i s presented, the i n i t i a l saccadic eye and head movements to the generalllocation of the stimulus ( l o c a l i z a t i o n ) ,  2 I  and perhaps f i n e r eye and head position adjustments to accurately f i x a t e the stimulus.  In addition, the term "orienting" has been  used to r e f e r to a l l the reaching, tracking, f o l l o w i n g , and locomotor responses made towards v i s u a l s t i m u l i (ingle & Sprague, 1975)- In the present study disruption of ongoing behavior i n response to the presentation of the l i g h t display was employed as the basic measure. The a b i l i t y to perform t h i s element of o r i e n t i n g i s fundamental to the complete series of behaviors commonly defined as "the" o r i e n t i n g response. The following study attempted to determine i f lesioned animals were capable of the f i r s t and necessary phase of the o r i e n t i n g response to a large f i e l d novel v i s u a l stimulus.  An attempt was made  to produce lesions of the SC which were comparable i n s i z e to those of other investigators whose data have been interpreted as suggesting that the SC i s necessary to v i s u a l orienting (Barnes et a l . 1 9 7 0 ; Dyer et a l .  1 9 7 6 ; Schneider, I 9 6 7 ,  I969).  Smaller SC lesions were  also made to assess the involvement of the s u p e r f i c i a l and deep laminae of the SC i n the o r i e n t i n g response d e f i c i t .  Striate  cortex lesioned animals were employed both as controls f o r the non-specific c o r t i c a l e f f e c t s of the SC l e s i o n procedure as well as to assess the possible involvement of the s t r i a t e and e x t r a s t r i a t e cortex i n o r i e n t i n g behavior.  Method Subjects Forty naive male rats (Rattus Norvegicus) from the LongEvans s t r a i n were obtained at approximately 200 g body weight from the Canadian Breeding Farms and Laboratories, Ltd., or reared i n the Biopsycology vivarium at the University of B r i t i s h Columbia. l e s i o n each animal received was determined randomly.  The type of The animals were  housed i n groups of 4-8 animals i n wire mesh cages (64 X 18 XI18  cm)  and maintained on water and ad-lib food f o r at least 7 days p r i o r to surgery and housed i n d i v i d u a l l y f o r 7 days following surgery (Tees, 1968,  1975).  The colony l i g h t s were on a 12 hr. l i g h t , 12 hr. dark  schedule and animals were tested between 1600  and 2400 h r s .  Surgery A l l the animals were between 250-350 g at the time of surgery.  A l l surgery was performed under sodium pentobarbital anes-  t h e t i c and supplemented Van Oot, 1977)-  with c h l o r a l hydrate when necessary (Pinel &  The following lesions were made.  (a) Superior c o l l i c u l u s (SC) lesions were made stereotaxically i n 8 animals with a radio frequency l e s i o n maker (Radionics model RFG4) using an electrode t i p exposure of 1 mm.  The inter-aural l i n e and  upper edge of the i n c i s o r bar were i n the horizontal plane.  The  electrode placements were made 1.8 mm on each side of the midline, 2.7 mm anterior to the most posterior aspect of the lambdoidal suture, and 3»7 mm below the c o r t i c a l surface. The r f current was applied f o r 90 sec. „Tip temperature f o r these animals was 70°C.  2 3.  (Adapted from Goodale ahd.J-Iuirisor., 1975) •  •  (b) S u p e r f i c i a l c o l l i c u l u s laminar (SP) lesions were made i n 9 a n i mals.  The t i p ' s temperature varied "between 50°G and 60°C (one at  50 C, three at 55°C and four at 60°C). o  The stereotaxic coordinates  were the same as those used f o r the SC group except that the electrode was only lowered to 3-5 mm below the c o r t i c a l surface. (c) Deep superior c o l l i c u l u s laminar (DP) lesions were made i n 4 .animals.  Electrode placement was i d e n t i c a l to that described above  except the electrode was lowered to 5 mm below the c o r t i c a l surface. T i p temperature was 55°G f o r half the subjects and 60°G f o r the remaining h a l f . (d) S t r i a t e cortex (ST) lesions were produced by aspiration i n 9 animals.  The dorsal surface of the s k u l l was removed f o r approxi-  mately 2 mm behind bregma to lambda and from approximately 1 mm l a t e r a l to the s a g i t t a l suture to the zygoma.  Suction was used to  remove the exposed c o r t i c a l tissue under v i s u a l guidance (Tryggvason & Tees, 1 9 7 4 ) .  An attempt was made to vary the .placement of the l e s i o n  to include area 17'only, or area 1 7 , 18, a h d 18A (Kreig,  1946a,,1946b).  (e) Sham operated controls (SH) were treated i d e n t i c a l l y , however, no tissue was removed or current applied f o r these animals. were a t o t a l of 10 sham operated animals.  There  The s t r i a t e cortex l e s i o n  procedure was used f o r 5 SH animals and the SG l e s i o n procedure was used f o r the remaining 5 animals. Histology After completion of behavioral testing, operated animals  24.  were perfused with .9% saline solution followed by 10% Formalinsaline . Brains were removed and placed i n 10% Formalin-saline. The brains of SP and DP lesioned animals were freeze, sectioned at 30 urn.  Every f i f t h section was saved and stained with thionin.  The  SG and ST lesioned brains were either embedded i n g e l a t i n and sectioned at 30 um or at 50 um.  The extent of retrograde degeneration i n the  dorsal l a t e r a l geniculate nucleus was examined f o r s t r i a t e lesioned brains.  These sections were stained with c r e s y l v i o l e t and l u x o l blue  s t a i n i n g procedure.  Every f i f t h section through the l e s i o n and every  second section through the thalamus was saved. Apparatus A diagram of the behavioral t e s t i n g apparatus i s presented i n Figure 4.  The box was housed i n a 66.2 X 66.0 X 50.8 cm outer  l i g h t and sound attenuating box with a v e n t i l a t i o n fan which produced a 60 dB masking noise.  Nine 5-9 cm diameter l i g h t s covered by red  p l a s t i c f i l t e r s were positioned 1?.8 cm from the t i p of the glass water spout, extending from the plexiglass wall. subtended approximately 98° of v i s u a l angle.  The entire display  The i n t e n s i t y of the  l i g h t s measured at the water spout with a Weston l i g h t meter and recorded as approximately .6? cd/m rat  f o r the set of 3 l i g h t s .  The  could be observed during the presentation of the l i g h t display  through a 14.0 X 14.0 cm one-way viewing screen. Presentation of the l i g h t s and counting of the number of l i c k s were automatically c o n t r o l l e d by electro-mechanical counters and s o l i d state (BRS/LVE) l o g i c .  25 A.  F i g u r e 4. The a p p a r a t u s u s e d t o e x a m i n e d i s r u p t i o n o f response t o the p r e s e n t a t i o n of the l i g h t d i s p l a y .  licking  Prodedure One week f o l l o w i n g s u r g e r y t h e r a t s w e r e w a t e r d e p r i v e d for in  48 h o u r s .  E a c h r a t was t h e n a l l o w e d a c c e s s t o t h e w a t e r  the apparatus f o r 3 p r e t e s t days.  for  The  n u m b e r o f l i c k s was  15 m i n u t e s a f t e r t h e i n i t i a t i o n o f d r i n k i n g .  consumed i n t h i s  t i m e was s u f f i c i e n t  t h e d e e p l a m i n a e o f t h e SG  their  counted  The a m o u n t o f w a t e r  to maintain at least  weight i n the majority of animals tested. to  tube  9 0 f o  Animals s u s t a i n i n g  body lesions  (DP l e s i o n e d a n i m a l s ) d i d n o t r e m a i n a t  preoperative weight using t h i s  procedure.  Consequently,  they  w e r e a l l o w e d a n a d d i t i o n a l 15 m i n u t e s a c c e s s t o w a t e r i n t h e i r  home  cage f o l l o w i n g a d a p t a t i o n t o t h e box on p r e t e s t days. was s u f f i c i e n t  This  procedure  t o m a i n t a i n 80^-9Q?S b o d y w e i g h t i n t h e s e a n i m a l s .  On t h e f o u r t h d a y , d i s r u p t i o n o f l i c k i n g i n r e s p o n s e t o t h e presentation of the l i g h t d i s p l a y s , habituation,and d i s h a b i t u a t i o n of this the  r e s p o n s e were measured.  a n i m a l i n i t i a t e d a b a s e l i n e p e r i o d o f 5 s e c d u r i n g w h i c h t h e num-  b e r o f l i c k s were c o u n t e d . ing  On e a c h t r i a l t h e e i g h t h l i c k made b y  The e i g h t h l i c k made b y t h e a n i m a l f o l l o w -  t h e b a s e l i n e p e r i o d i n i t i a t e d t h e l i g h t s , a n d t h e number o f l i c k s  were c o u n t e d f o r  5  s e c  '  (Adapted from F i l e ,  1973)-  A l l the animals  w e r e o b s e r v e d t h r o u g h t h e one-way v i e w i n g s c r e e n o n t h e f i r s t a n d some a n i m a l s w e r e o b s e r v e d o n a l l t h e t r i a l s i n t h e e n t i r e The f o l l o w i n g l i g h t d i s p l a y s w e r e p r e s e n t e d i n t h e t e s t i n g (Si)  trial session.  session.  " A p p a r e n t l y " moving l i g h t d i s p l a y , a t 1 p e r l / l O s e c .  The f i r s t  light  display  ( S i ) was a s e t o f " a p p a r e n t l y " m o v i n g  lights.  The f i r s t  light  on t h e r i g h t o f e a c h o f t h e t h r e e p a n e l s ( s e e F i g u r e 4)  2 7  was illuminated, f o r l / l O sec followed by each of the middle and then l e f t l i g h t s i n each panel with an i n t e r l i g h t latency of l / l O sec.  One  l i g h t from each panel was illuminated to ensure that regardless of the d i r e c t i o n of the animal's head one panel would always be within the visual f i e l d .  The above display was presented f o r 15 t r i a l s .  (52) S t a t i o n a r y - f l i c k e r i n g display, at 1 per 1/10 sec.  The  r i g h t l i g h t of the right panel, the middle l i g h t , and the l e f t l i g h t of the l e f t panel were presented f o r l / l O sec with an i n t e r v a l of l / l O sec ( i . e . , three l i g h t s f l i c k e r i n g every l / l O sec). one l i g h t from each panel was illuminated.  Again,  This display (S2) was  presented on the l6th to 30th t r i a l . (53) "Apparently" moving display, at 1 per l / l O sec.  The  "apparently" moving l i g h t s described above were again presented, however, the i n t e r l i g h t i n t e r v a l and duration of the l i g h t s were changed to l/5 sec.  This display (S3)  was presented on the 31st to 35th t r i a l s .  (54) S t a t i o n a r y - f l i c k e r i n g , at 1 per 1/5 sec.  The stationary  display was presented with an i n t e r l i g h t i n t e r v a l and l i g h t duration of l/5 sec.  This display (S4) was presented on the 36th to 40th t r i a l .  Data Presentation and Analysis Differences between the a b i l i t y of rats i n each of the groups to disrupt l i c k i n g , habituate,.and dishabituate to the various l i g h t displays presented were assessed by analysis of variance.  To  f a c i l i t a t e data analysis and allow the use of available computer programs two separate analyses were conducted.  The f i r s t assessed  only the data from the f i r s t 5 t r i a l s f o r each l i g h t display  2 8.  p r e s e n t e d ( S I , S 2 , S3, & S 4 ) . from the e n t i r e  15  t r i a l s p r e s e n t e d f o r each of S i and  Statistical to ber  The ;second a n a l y s i s a s s e s s e d t h e d a t a  r e l i a b i l i t y of d i s r u p t i o n of l i c k i n g  t h e p r e s e n t a t i o n o f t h e l i g h t s was of l i c k s  licks  S2. i n response  a s s e s s e d b y c o m p a r i n g t h e num-  i n t h e p r e c e d i n g b a s e l i n e p e r i o d w i t h t h e number o f  d u r i n g the p r e s e n t a t i o n of the l i g h t s  t comparisons.  The  on e a c h t r i a l  by a  priori  c o m p a r i s o n s w e r e b a s e d on t h e p a t t e r n X t r i a l  X  s t i m u l u s X g r o u p i n t e r a c t i o n e s t i m a t e of-, . v a r i a n c e a n d t h e d e g r e e s freedom a s s o c i a t e d with-  the Geisser-Greenhouse conservativeeF  s u g g e s t e d f o r r e p e a t e d measures d e s i g n s ( K i r k ,  1968).  The  SG,  of  test SP,  DP, a n d ST l e s i o n e d a n i m a l s w e r e c o m p a r e d t o t h e SH c o n t r o l a n i m a l s b y D u n n e t t ' s m u l t i p l e c o m p a r i s o n p r o c e d u r e b a s e d on t h e groups trial  X stimulus i n t e r a c t i o n estimate of variance.  This  X  analysis  a s s e s s e d d i f f e r e n c e s between the l e s i o n e d a n i m a l s and c o n t r o l s i n amount o f d i s r u p t i o n o f l i c k i n g  during the presentation of stimulus  d i s p l a y s and d i f f e r e n c e s i n amount o f b a s e l i n e The was  a n a l y s i s of the e n t i r e  supplemented by a p r i o r i  above.  15  licking.  t r i a l s f o r each of SI and  t t e s t s and Dunnett's t e s t as  T h i s a n a l y s i s a l l o w e d a separate assessment  of the  S2  described entire  number o f t r i a l s o n w h i c h t h e a n i m a l s r e l i a b l y  disrupted licking  r e s p o n s e t o S i and S2 f o r each o f t h e l e s i o n e d  groups.  i n  Results The r e s u l t s of the analysis of variance which compared the lesioned animals on the f i r s t 5 t r i a l s i n response to the four light, ; 1  displays are presented i n Table 1 of Appendix A•and those of the anals i s - ©f- -variance which included" the-entire-. -1"5" t r i a l s i n which S.I and.S2 were presented are included, as • Table 2-of .Appendix' A. r  The  SG, SP, and DP animals d i f f e r e d markedly from the SH animals and each other i n terms of disruption of l i c k i n g i n response to the l i g h t s , habituation, and dishabituation. for  The r e s u l t s are presented  the SH and each of the lesioned groups i n Figure 5(a-e), and  w i l l be discussed separately below. Sham lesions (SH) Behavioral r e s u l t s .  The presentation of SI, the apparently  moving l i g h t s , r e s u l t e d i n marked disruption of l i c k i n g by the SH animals on the f i r s t t r i a l .  Photographs of a video-taped  of a representative shamllesioned  recording  animal are presented i n Figure 6.  They i l l u s t r a t e the orienting and body movements e l i c i t e d by this l i g h t display which are not compatible with maintaining contact with the water spout.  Repeated presentation of the apparently moving  l i g h t display resulted i n a waning.of t h i s response (habituation) and eventually the animals drank thoughout the entire 5 sec present a t i o n of the l i g h t s .  Disruption of l i c k i n g was r e l i a b l y d i f f e r e n t  from baseline on the f i r s t 5 t r i a l s i n response to SI ( t , << = .05/2 = 6.66, df = 30). The SH animals r e l i a b l y disrupted l i c k i n g on the f i r s t t r i a l when the l i g h t display was changed (dishabituation).  30 A.  F i g u r e 5(a-e). M e a n number o f l i c k s p e r 5 s e c d u r i n g b a s e - l i n e (B) and d u r i n g the p r e s e n t a t i o n o f the stimulus ( S ) , f o r l i g h t d i s p l a y s S I , S2, S3, a n d Sk. ( a ) SH, ( b ) S T , ( c ) SG, ( d ) SP, a n d ( e ) DP l e s i o n e d a n i m a l s . The a s t e r i s k i n d i c a t e s t h e t r i a l s o n w h i c h d i s r u p t i o n o f l i c k i n g was s t a t i s t i c a l l y r e l i a b l e . •-  Mea i GROUP 5  DP  N - 4  o  GROUP 6  3 .  1 1 1 1 1 1 1  SP  Number  N • 9  B  of  . GROUP  S  3  1 1 1 1 1 1 1  •  1  Licks SC  per  5  3  GROUP S  5  :'  7 i  i i  \  i i  i  :.  1  :  :  .1  :  : •  7  :  11  i  i  ^  i  i  i  i i  i  :  \ i  1  i  i  i  i  :  I.I  I I  1 1 1 1  /  :  ...  i  :  /  .  :  /  :  /  :  •  i  i  /  •  • :  ./•  i i i  i  i  i  i  i i i  1  :  \:  /  :  :  /  :  \  :  /  :  .  /  /  :•  I  :  :  /  :  :  / .  :  / .  :  I  : :  .  I I  l •  -  '/•  •  /  :  : • :  /  :  y I  :  / I  :  . i  \  .  \ :  S  *  i  \ :  i  :  / ' i  i  :  \  i i  i  /  :  i  i  /  \ :  i  8  \  • /  /•  :  :  :  '  /  / i  SS  S  /  :  / • '  N - 10  :\  :  i i  S  SH  -**  \  i  :  GROUP  v  I' ./  3  N - 9  •  :• V  ST.  1 1 1 1 1 1 /  :• .  &  S ec.  N - 8  i  1 i  i  i  i  i  I  l l  :•  • I  :.  /  :  :  /  :••  • .1 . :  /•  x  • /  /  31 A.  F i g u r e 6. P h o t o g r a p h s f r o m v i d e o t a p e d r e c o r d i n g s o f the. r e s p o n s e s " of. r e p r e s e n t a t i v e a n i m a l s t o t h e l i g h t d i s p l a y o n t h e f i r s t trials ( a ) a n SH c o n t r o l a n i m a l ' s d r i n k i n g when t h e l i g h t s f i r s t come o n , ( h ) i t s h e a d a n d p o s t u r a l a d j u s t m e n t s a n d ( c ) a n d ( d ) i t s further exploratory behavior, ( e ) , ( f ) , a n d ( g ) , a n SG l e s i o n e d animal d r i n k i n g thoughout the e n t i r e t r i a l .  31 B.  31 C.  31 E.  (g)  T r i a l s on which l i c k i n g was r e l i a b l y d i f f e r e n t from "baseline f o r the entire session are marked by an a s t e r i s k i n Figure 5(a). Superior C o l l i c u l u s Lesions (SC) Behavioral r e s u l t s .  Animals with large lesions of t h e S C  including the s u p e r f i c i a l and deep lamina did not r e l i a b l y disrupt l i c k i n g i n response to the presentation of any of-the l i g h t d i s p l a y s . As can be see i n Figure 5(c), small differences between l i c k i n g during baseline andl during the' presentation' of the light? display f o r these animals were not s t a t i s t i c a l l y r e l i a b l e ( t , ° i = .05/2, = 6.66, df = 30).  On the t h i r d presentation of the l i g h t display S4, ( i . e . , the  38th t r i a l ) , however, some of these animals d i d respond to the present a t i o n of the stimulus.  The number of l i c k s made during baseline was  very s i m i l a r to control animals' and d i d not d i f f e r s t a t i s t i c a l l y (Dunnett's t ,  = .05/2, 5, 30 = 8.96).  Anatomical r e s u l t s .  The extent of the lesions sustained  by t h i s group of animals i s depicted i n Figure ?(a).  The l a r g e s t  and smallest lesions a t each of 5 representative l e v e l s of the SC are presented.  The lesions extended i n t o the p r e t e c t a l nuclei,  overlying white matter of the cortex, hippocampus, c e n t r a l grey, tegmentum,and, i n two cases, the p o s t e r i o r thalamic .•nuclei.  The  dorsal tegmentum and c e n t r a l grey were always included i n this l e s i o n . A l l the animals i n this group sustained a large l e s i o n i n the medial portion of the SC, including a l l 7 laminae, the posterior aspect of branchium of the superior c o l l i c u l u s , the dorsal surface of the tegmentum, and touched on the central grey.  3  Behavioral-anatomical  relationships'.  p r i m a r i l y i n the a n t e r i o r - p o s t e r i o r plane. age  The SG l e s i o n s v a r i e d  The e x t e n t o f t h e dam-  w a s , h o w e v e r , c o n s i s t e n t i n t h e c e n t r a l p o r t i o n o f t h e SC  (represented by the middle s e c t i o n i n Figure. 7(A)). had  Four  and hippocampus w h i l e t h e r e m a i n i n g  lesion  animals  more a n t e r i o r l y p l a c e d l e s i o n s w h i c h i n c l u d e d e x t e n s i v e  of the pretectum  3.  damage  4 lesions  w e r e more p o s t e r i o r a n d r e s u l t e d i n c o n s i d e r a b l e damage t o t h e o v e r l y i n g c o r t i c a l white  matter  and i n f e r i o r c o l l i c u l i .  w i t h p o s t e r i o r l y p l a c e d l e s i o n s a n d 1. a n i m a l w i t h  Two  animals  a more a n t e r i o r  :  l e s i o n d i s r u p t e d l i c k i n g b y a t l e a s t h a l f t h e amount o f t h e p r e c e d i n g b a s e l i n e p e r i o d on the f i r s t  trial.  None o f t h e o t h e r a n i m a l s  ponded t o t h e l i g h t d i s p l a y s t o t h i s e x t e n t on t h e f i r s t other  h i s t o l o g i c a l r e s u l t s and b e h a v i o r a l data f o r 2  w i t h p o s t e r i o r l y p l a c e d l e s i o n s a n d 1 animal'- w i t h ar v e r y  large- and a n t e r i o r l y p l a c e d l e s i o n a r e presented Of  o r any  trial. The  animals  res-"  i n Figure 8(a-c).  i n t e r e s t i n t h i s f i g u r e i s t h e absence o f an obvious  between t h e placement, s i z e , a n d . i n c l u s i o n o f ^ a d j a c e n t l e s i o n and t h e presence o r absence o f responding on t h e f i r s t  relationship structures i n the  to the l i g h t d i s p l a y  trial.  S u p e r f i c i a l Laminar Lesions o f the Superior C o l l i c u l u s (SP) Behavioral results.  Rats w i t h s m a l l l e s i o n s r e s t r i c t e d  p r i m a r i l y t o the s u p e r f i c i a l laminae o f the s u p e r i o r d i f f e r e d from-.the SC l e s i o n e d a n i m a l s  colliculus  d e s c r i b e d -above.  r u p t e d l i c k i n g when l i g h t d i s p l a y S I was p r e s e n t e d  They  dis-  on t h e f i r s t  34 A.  Figure 7(A-D). .Representative-sections depicting the extent of damage to SG and surrounding tissue f o r (A) SG, (B) SP, (G) DP, and (D) a surface view of c o r t i c a l damage and corresponding thalamic degeneration. The smallest l e s i o n a t each representative section i s drawn i n black and the largest i s stippled. :  34 B.  35 A.  Figure 8(a-c). H i s t o l o g i c a l reconstructions and behavioral r e s u l t s f o r i n d i v i d u a l SG lesioned animals: (a) SG"#22 had a more posterior l e s i o n , (h) SG #24 had a more posterior l e s i o n , (c) SG #20 had a large anterior l e s i o n .  t r i a l as can be seen i n Figure 5(d-).  They required fewer t r i a l s to  habituate to the repeated presentation of the l i g h t s than the SH animals, however, and d i d not dishabituate to any of the stimulus changes presented.  Disruption of l i c k i n g i n response to presentation '  of the l i g h t s was s t a t i s t i c a l l y r e l i a b l e ( t , »4 = .05/2, = 6.66, df 30) on only the f i r s t 2 t r i a l s (marked by asterisks i n Figure 5<i) • SP animals d i d not d i f f e r s t a t i s t i c a l l y from SH animals i n amount of l i c k i n g during baseline (Dunnett's t, <* = -5, 30 = 8.96). Anatomical r e s u l t s .  The r e s u l t s of the damage to the  s u p e r f i c i a l laminae of the SC and the surrounding  tissue sustained  by this group of animals i s presented in-Figure 7(B). The.largest and smallest lesions a t each l e v e l of the representative coronal sections are presented.  The lesions sustained by SP animals were r e s t r i c t e d  "primarily" to the s u p e r f i c i a l lamina of SC, with minimal involvement of the p r e t e c t a l n u c l e i and minimal, but some, damage to the deep SC -laminae and occasionally the dorsal tegmentum.  The lesions  were r e s t r i c t e d either to the anterior SC and p r e t e c t a l nuclei or the posterior SC and p o s t e r i o r tegmentum but never both. Behavioral-anatomical  r e l a t i o n s h i p s . .. The- h i s t o l o g i c a l - and  behavioral r e s u l t s f o r representative animals with anterior or' posteri o r SP lesions are presented i n Figure 9(A-B).  As can be seen, the  behavioral r e s u l t s are quite s i m i l a r for. these two animals i n s p i t e of the v a r i a t i o n i n anterior-posterior placement of. the l e s i o n s . The damage to both subjects coincides i n the middle of the SC (represented by the middle section i n Figure 7(B). A l l subjects with  37  F i g u r e 9 ( a - c ) . H i s t o l o g i c a l r e c o n s t r u c t i o n s and b e h a v i o r a l r e s u l t s f o r i n d i v i d u a l SP l e s i o n e d a n i m a l s : ( a ) SP #35 has an a n t e r i o r p l a c e d l e s i o n , ( b ) SP #28 has a p o s t e r i o r p l a c e d l e s i o n a n d ( c ) DP #8.  A.  3 8.  damage to this region of the SC behaved i n a fashion t y p i c a l of the SP l e s i o n group and depicted by the averaged data i n Figure 5(d.) • Deep laminar Lesions of the Superior C o l l i c u l u s Behavioral r e s u l t s .  (DP)  Rats with very small lesions  r e s t r i c t e d primarily to the deep: laminae of the superior "colliculus behaved l i k e - t h e SC lesioned-animals and/did.'not"respond to the presentation of the l i g h t displays. animals are presented i n Figure 5(e)- = '05/2  oe  = 6.66,  The r e s u l t s f o r t h i s group of Statistically reliable (t,  df = 30) disruption of l i c k i n g i n response to the  presentation of the l i g h t displays only occurred on the t h i r d t r i a l to the fourth stimulus display ( i . e . , the 38th t r i a l ) .  Licking  during the baseline measures d i d not d i f f e r s t a t i s t i c a l l y from SH  ;  animals (Dunnett's t, <*. = .05/2, 5» 30 = 8.96) Anatomical r e s u l t s .  on any  trial.  The extent of lesions of the DP lesioned  animals at four representative levels are presented i n Figure 7(C). As can be seen i n this f i g u r e these lesions are much smaller and r e s t r i c t e d to the deep laminae-.of the SC and to the-dorsal surface of the tegmentum.  In none of the rats were the p r e t e c t a l nuclei  or branchium of the SC involved i n the l e s i o n . grey was,  Damage to the c e n t r a l  i n two cases, extensive but much less than i n the SC  lesioned animals. at any l e v e l .  . In one case (DP#8), c e n t r a l grey was not involved  This animal's histology and behavioral data are  presented i n Figure 9(c). Behavioral-anatomical  relationships.  A l l the animals i n  t h i s group had s i m i l a r l y placed lesions and the behavioral data were  markedly s i m i l a r such that DP #8 i s representative of this group. S t r i a t e Cortex lesions (ST) Behavioral r e s u l t s .  S t r i a t e lesioned animals did not  d i f f e r from SH lesioned animals.  They r e l i a b l y disrupted l i c k i n g  i n response to the presentation of the l i g h t display, habituated, and 'dishabituated to each of the l i g h t displays-.  The t r i a l s on which  s t a t i s t i c a l l y r e l i a b l e disruption of l i c k i n g i n response to the l i g h t displays occurred ( t ,  = .05/2 = 6.66, df = 30) are marked  by an a s t e r i s k i n Figure 5(b).  Disruption of l i c k i n g i n response  to the presentation of l i g h t display SI was s t a t i s t i c a l l y r e l i a b l e • on the f i r s t 6 t r i a l s , to S2 on the f i r s t 4 trials,--to S3 on. the f i r s t . 2 t r i a l s , and to S4.on the f i r s t t r i a l .  None of the small  differences between the • SH•and ST animals f o r the baseline l i c k i n g or during the presentation of the l i g h t s  approached s t a t i s t i c a l  significance. Anatomical r e s u l t s .  The extent of the damage to the cor-  tex sustained by this group i s depicted i n Figure 7(D).  The small-  est and the l a r g e s t l e s i o n included i n this, group are presented i n a surface drawing and the extent of associated LGN degeneration a t three representative l e v e l s i s also Behavioral-anatomical  presented.  r e l a t i o n s h i p s . Examples of a large  ST l e s i o n that included areas 17, 18, and 18A and t h e ' S m a l l e s t l e s i o n that was r e s t r i c t e d p r i m a r i l y to area 17 are presented i n Figure 10(a-b). included.  The behavioral r e s u l t s f o r each of these animals are also These examples c l e a r l y i l l u s t r a t e that s t r i a t e cortex-or  40 A.  Figure 10(a-c). H i s t o l o g i c a l and behavioral r e s u l t s f o r i n d i v i d u a l ST lesioned animals: (a) ST #3 has a large c o r t i c a l l e s i o n including areas 17, 18 and 18A, (b) ST #22 has a small cort i c a l l e s i o n confined to area 17, (c) ST #7 has a large c o r t i c a l l e s i o n which included areas 17, 18, 18A and 7-  4  1-  s t r i a t e cortex plus e x t r a s t r i a t e cortex are not e s s e n t i a l f o r the disruption of l i c k i n g i n response to v i s u a l s t i m u l i .  Also included  i n Figure 10 are the anatomical and behavioral r e s u l t s f o r ST #7. This animal's data were included as, i n t e r e s t i n g l y , i t behaved l i k e the SC and DP lesioned animals ( i . e . , i t d i d not disrupt l i c k i n g i n response to any of the l i g h t displays i n the entire testing session) While  the animal's c o r t i c a l histology does not appear markedly  d i f f e r e n t from other animals i n this group who sustained large cort i c a l l e s i o n s , the lesion c l e a r l y included a l l of areas 17, 18, 18A , and area 7«  The other animals, had as large lesions of the cortex,  but the lesions d i d not always remove a l l of area 7 and the p o s t e r i o r cortex.  4 2/  Discussion Overall, S c h n e i d e r ' s two  the r e s u l t s o f t h i s i n i t i a l  system  hypothesis.  The  support  g e n i c u l o - s t r i a t e system  not i n v o l v e d i n the o r i e n t i n g response. i d e n t i f i e d w i t h the t e c t a l system  s t u d y seem t o  Orienting  i n t h a t removal  can,, i n f a c t , o f SG  throughout a large f i e l d .  I n a d d i t i o n , i t appears  from  w i t h o n l y the deep l a m i n a e  o f t h e m e d i a l p o r t i o n o f SC  s u r f a c e o f t h e d o r s a l tegmentum. s u p e r f i c i a l laminae visual stimulus.  o f SG  d i d not i m p a i r o r i e n t i n g to the  A s i m i l a r f i n d i n g has been r e p o r t e d by  and  novel Casagrande  of threatening s t i m u l i i f  o f SC w e r e i n c l u d e d i n t h e l e s i o n .  h a v e b e e n i n t e r p r e t e d a s i n d i c a t i n g t h a t t h e SG  These  ( i n g l e & Sprague,  t h a t a number o f q u a l i f y i n g s t a t e m e n t s a n a l y s i s of the r e s u l t s .  One  did  placement  m u s t be a d d e d t o t h i s  t h e y were n o t p e r f e c t l y s o .  super-  then  e l i m i n a t e the response.  the case i n the present study.  were g e n e r a l l y p r e d i c t i v e  indicates  would expect t h a t i f s p e c i f i c  of t h i s s t r u c t u r e would always  n o t a p p e a r t o be  two  1975).  s t r u c t u r e s were e s s e n t i a l f o r the o c c u r r e n c e o f a r e s p o n s e , removal  results  i s , i n fact,  A c l o s e r examination of the l e s i o n - b e h a v i o r data  ficial  the  i n t r e e shrews o n l y i m p a i r e d  o r i e n t i n g t o v i s u a l s t i m u l i and avoidance  f u n c t i o n a l l y separable structures  associa-  L e s i o n s r e s t r i c t e d t o t h e more  a n d D i a m o n d (197*0. L e s i o n s o f SC  the deep l a m i n a e  presen-  these  r e s u l t s t h a t t h i s b a s i c c o m p o n e n t o f o r i e n t i n g c a n be b e t t e r ted  be  resulted i n  the absence o f o r i e n t i n g t o even moving and s t a t i o n a r y s t i m u l i ted  is  Lesion size  the This and  of the a n i m a l ' s b e h a v i o r ; however,  S i x a n i m a l s i n t h i s s t u d y d i d n o t behave  4 3.. in  a manner t y p i c a l o f t h e l e s i o n g r o u p t o w h i c h  t h e ST g r o u p , 2 i n t h e SP g r o u p , a n d 3. i n t h e SC While ior"  (2 w i t h S P l e s i o n s , 3 w i t h SC  the presence  of the l i g h t s  "misbehav-  t h e s e a n i m a l s do p r o v i d e a d d i -  t i o n a l d a t a t h a t are not r e p r e s e n t e d by averaged  in  ( l in  group).  i t i s important not to o v e r i n t e r p r e t the  o f a f e w members o f t h e g r o u p ,  the animals  they belonged  on the f i r s t  results.  lesions) disrupted licking trials,  t h e i r h i s t o l o g i c a l r e s u l t s would i n d i c a t e t h a t they b e e n i n c a p a b l e o f o r i e n t i n g i f t h e SC  Five of  when i n f a c t would have  were e s s e n t i a l .  I n the  para-  d i g m u s e d i n t h i s s t u d y , i t i s p o s s i b l e t h a t t h e a n i m a l s may  have  d i s r u p t e d l i c k i n g on t h e s e p a r t i c u l a r t r i a l s  related  to  the appearance of the l i g h t s ;  t h e r a t s on t h e f i r s t  f o r reasons  not  however, the e x p e r i m e n t e r d i d  t r i a l of the s e s s i o n .  I n three out of the  c a s e s i n q u e s t i o n s h e o b s e r v e d h e a d a n d b o d y movements w h i c h s i m i l a r t o t h o s e o f SH a n i m a l s , a l t h o u g h n o t a s d r a m a t i c , a n d c l u d e d t h a t these t h r e e animals had  observe  l o o k e d a t the  lights.  five  were con-  EXPERIMENT I I O r i e n t i n g t o an Auditory This  Stimulus.  s t u d y was c o n d u c t e d t o d e t e r m i n e i f SG a n d ST  l e s i o n e d a n i m a l s were c a p a b l e o f d i s r u p t i n g l i c k i n g i n r e s p o n s e t o auditory  stimuli.  I t i s p o s s i b l e t h a t the impairment o f o r i e n t i n g  d e m o n s t r a t e d b y SC l e s i o n e d a n i m a l s i n t h e p r e c e d i n g to a g e n e r a l i z e d motor impairment o r i n a b i l i t y ponse such as l i c k i n g under c o n d i t i o n s  s t u d y was due  to withhold  a res-  o f water deprivation  (Winter-  k o r n , 1976). Some s u p p o r t f o r t h i s p r o p o s i t i o n i s p r o v i d e d  by K i r v e l  (1974) f i n d i n g t h a t SC l e s i o n e d r a t s h a d b e h a v i o r a l  e t al'.s.  c i t s i n o r i e n t i n g t o and l o c a l i z i n g o l f a c t o r y and somesthetic equivalent and  t o that found with respect  Muirison  to visual stimuli.  defistimuli  Goodale  (1975) a l s o r e p o r t t h a t SC l e s i o n e d a n i m a l s w e r e n o t  d i s t r a c t e d by tone c l i c k s and f l a s h i n g l i g h t s p r e s e n t e d i n t h e p e r i pheral f i e l d .  Although comparable d a t a f o r r a t s a r e n o t a v a i l a b l e ,  Drager and Hubel  (1976) a n d W i c k e l g r e n a n d S t e r l i n g (1969) r e p o r t  that i n d i v i d u a l c e l l s  o f t h e d e e p l a m i n a e o f t h e SC r e s p o n d e d t o  combinations of auditory,  somesthetic and v i s u a l s t i m u l i  (i.e.,  were  m u l t i m o d a l ) i n b o t h mice and c a t s . In t h i s study very the  s a l i e n t auditory  a u d i t o r y s t i m u l i were n o t a s s o c i a t e d  somesthetic, and v i s u a l s t i m u l i . required  t o n e s were u s e d a n d  with concurrent olfactory,  I n a d d i t i o n , t h e a n i m a l s were n o t  t o l o c a l i z e and d i r e c t a c t i v i t y towards the a u d i t o r y  I n t h e s e ways t h e p a r a d i g m e m p l o y e d r e p r e s e n t s  stimuli.  a better test of the  45.  SC  a n d ST  lesioned animals' a b i l i t y  t o an a u d i t o r y  stimulus  to d i s r u p t l i c k i n g i n response  than those used  previously.  Method Subjects " The 80 animals previously tested i n Experiment I and I I I were subje'cts..  :  - -  -  •-  •  Apparatus A 38 X 30 X 27 cm plexiglass box was housed i n the outer sound and l i g h t attenuating box used i n the previous study.  A sona-  l e r t on one side of the plexiglass box produced a 4500 Hz, 80 dB tone, while a second on the other side of the box produced a 2800 Hz, 80 dB tone.  Presentation of the tones and counting of the number  of l i c k s were controlled by electromechanical counters and s o l i d state (BRS/LVE) l o g i c . Procedure The procedure was i d e n t i c a l to that of Experiment I, except that tones were presented rather than the l i g h t displays (adapted from F i l e , 1973)-  The rats were allowed access to the  water spout i n the auditory t e s t i n g apparatus on the two days f o l lowing v i s u a l testing, f o r 15 min of drinking.  On the next day,  tests of disruption, habituation, and dishabituation to the .auditory stimuli were conducted.  The procedure was i d e n t i c a l to the  v i s u a l testing, except that a 4500 Hz, 80 dB tone pulsed at a rate of 1 per 1/10 sec was presented on the f i r s t 5 t r i a l s .  On t r i a l s 6-10,  the  The 2800 Hz  4500 Hz tone pulsed a t a rate of 1 per l/5 sec.  tone was then presented on the 11th-15th t r i a l .  Results All in  t h e l e s i o n e d a n d SH a n i m a l s r e l i a b l y d i s r u p t e d  response t o the presentation  repeated  habituated  to their  p r e s e n t a t i o n , a n d d i s h a b i t u a t e d t o t h e c h a n g e s f r o m one t o n e  to another. the  o f the tones,  licking  The r e s u l t s a r e p r e s e n t e d ' *  l e s i o n e d a n d SH g r o u p s o f a n i m a l s .  of variance  are presented  i nFigure  11 f o r e a c h o f  The r e s u l t s o f t h e a n a l y s i s  i n T a b l e 3 o f A p p e n d i x A.  T r i a l s on  w h i c h d i s r u p t i o n o f l i c k i n g i n r e s p o n s e t o t h e t o n e were  reliably  d i f f e r e n t f r o m b a s e l i n e d r i n k i n g a r e marked b y a n a s t e r i s k i n F i g u r e  11 ( t , en = .05/2, = 4.96, d f = 60). The SH, ST, SG, SP, a n d DP l e s i o n e d a n i m a l s r e l i a b l y t e d l i c k i n g on a t l e a s t t h e f i r s t  disrup-  t r i a l when t h e l / l O s e c p u l s e d  4500 Hz t o n e was p r e s e n t e d a n d b e g a n t o h a b i t u a t e o v e r t h e n e x t f o u r trials. in  A l l t h e l e s i o n e d a n d SH a n i m a l s d i s h a b i t u a t e d t o t h e c h a n g e  the pulse  sec;  rate of  4500 Hz t o n e f r o m 1 p e r l / l O s e c t o 1 p e r l / 5  h o w e v e r , t h e a n i m a l s w e r e much more r e s p o n s i v e  f r e q u e n c y f r o m t h e 4500 Hz t o n e t o t h e 2800 Hz t o n e . small differences i nl i c k i n g during  thebaseline  p r e s e n t a t i o n o f t h e t o n e s was r e l i a b l e .  t o t h e change i n None o f t h e  o r during the  48 A.  F i g u r e 11. Mean number o f l i c k s p e r 5 © c d u r i n g t h e b a s e l i n e (B) a n d d u r i n g t h e p r e s e n t a t i o n o f t h e a u d i t o r y t o n e (S) f o r : ( a ) SH, ( b ) ST, ( c ) SC, ( d ) SP a n d ( e ) DP l e s i o n e d a n i m a l s . The a s t e r i s k i n d i c a t e s t h e t r i a l s o n w h i c h d i s r u p t i o n o f l i c k i n g was- s t a t i s t i c a l l y reliable. • * s  Discussion The r e s u l t s of t h i s study c l e a r l y demonstrate that lesions of SC do not r e s u l t i n a general impairment of the a b i l i t y to disrupt ongoing behavior.  In addition, they demonstrate the capacity of the  lesioned animals to habituate to the repeated presentation and dishabituate to even subtle changes within another modality.  Winterkorn,  (1976) has suggested that lesions of SC i n cat r e s u l t i n an i n a b i l i t y to disrupt ongoing behavior i n response to changes i n a stimulus and argued f o r a generalized attentive impairment. the  case f o r the r a t .  This i s c l e a r l y not  (Although differences between SC lesioned and  control animals might be observed i f stimuli closer to threshold were employed.) Direct observation of the animals on the f i r s t t r i a l f o r each of the three tones presented demonstrated that they were capable of the apprpriate head and body movements necessary to l o c a l i z e an auditory stimulus.  A l l the rats i n t h i s experiment l i f t e d  their  heads and turned t h e i r bodies i n the d i r e c t i o n of the sonalert on at l e a s t the f i r s t t r i a l i n response to the 4500 Hz, 1 per 1/10 sec pulsed tone and i n response to the 2800 Hz tone.  Some of the animals  approached the sonalerts and reared and s n i f f e d them,"but no SC lesioned animals were observed to engage i n this a c t i v i t y . These findings are somewhat at odds with studies that report multimodal sensory neglect by SC lesioned animals (Goodale & Muirison, 1975; K i r v e l et a l . ,  1974).  differences i n the paradigms employed.  A possible explanation may be The shoulder hold used by  K i r v e l et a l . animals.  may have induced more struggling i n the SC lesioned  These animals were required to l o c a l i z e and make a head  turn i n the d i r e c t i o n of the stimulus to be judged to have oriented. This i s a response even the normal animal i s u n l i k e l y to make as l a t e r a l head movements are not usually made independent of changes i n body p o s i t i o n f o r t h i s species (Drager & Hubel, 1975)-  Changes  i n body p o s i t i o n would have been restrained by the shoulder hold. The measure used by Goodale and Muirison may also have been less sens i t i v e to the disruption of ongoing behavior by SC lesioned animals i n response to the auditory s t i m u l i , p a r t i c u l a r l y since these animals do not display the intense exploratory a c t i v i t y observed f o r the SH control animals i n the present study. Experiment I demonstrated an impairment i n the a b i l i t y of SC lesioned animals to disrupt l i c k i n g i n response to the presentation of a v i s u a l stimulus. The second study suggests that the impairment i n response to the l i g h t s can not be attributed to a general i n a b i l i t y to disrupt behavior or an i n a b i l i t y to make the appropriate head and postural adjustments necessary to l o c a l i z e a stimulus.  51. EXPERIMENT I I I The E f f e c t of Increasing the Intensity of the Lights on Orienting to "Apparently" Moving and Stationary L i g h t Displays. The r e s u l t s of Experiments I.and I I suggested that the SC i s l i k e l y involved i n some aspect of o r i e n t i n g to v i s u a l s t i m u l i . However, the f a c t that i n Experiment I  some SC lesioned animals did  orient to the l i g h t display on the f i r s t t r i a l implied that the SC lesions may  not e n t i r e l y eliminate the'-orienting. response... Moreover,  the d e f i c i t i n orienting that did occur could not he attributed to a general i n a b i l i t y to make the kind of response required i . e . , to disrupt l i c k i n g behavior or to make appropriate head and postural adjustments necessary to l o c a l i z e a stimulus.  I t i s s t i l l possible,  however,- that a l l " the SC lesioned' animals were s t i l l capable of o r i e n t i n g to the l i g h t s , but were simply less l i k e l y to. Although the l i g h t displays employed i n Experiment I were extremely e f f e c t i v e i n e l i c i t i n g orienting f o r SH operated animals, perhaps the impact of this l i g h t display was o r i e n t i n g from the SC lesioned animals.  i n s u f f i c i e n t to e l i c i t  A number of stimulus dimen-  sions besides motion could influence the magnitude of the' o r i e n t i n g response and the ease with which i t i s e l i c i t e d .  The following study  attempted to examine the influence of increasing the physical intens i t y of the l i g h t display to determine i f this stimulus characterist i c would f a c i l i t a t e o r i e n t i n g by the SH and SC lesioned animals.  5 2. Method Subjects Forty naive  male r a t s were o b t a i n e d , f r o m  the  C a n a d i a n B r e e d i n g Farms and L a b o r a t o r i e s L t d . o r r e a r e d i n t h e B i o psychology v i v a r i u m a t the U n i v e r s i t y of B r i t i s h Columbia. m a i n t e n a n c e and s u r g e r y were i d e n t i c a l ment I . mals were  A t o t a l o f 9 SH, 8 SC,  9 SP,  Animal  to that described i n Experi10  ST,, a n d 4 DP  lesioned  ani-  tested.  Apparatus The  testing  a p p a r a t u s was  Experiment I*  The  s p o u t was  5'25  cd/m  intensity  of the l i g h t s  red  plastic  filters  intensity 2  identical  of the l i g h t s  a s c o m p a r e d t o .6? was  to that described i n  recorded a t the water  cd/m  2  i n Experiment I .  i n c r e a s e d i n t h i s s t u d y by removing  from each of the 9 l i g h t s  i n the l i g h t  The the  display.  Procedure The I.  p r o c e d u r e was  identical  to that described i n Experiment  Results The results  of the analysis of variance which compared  the lesioned animals on the f i r s t 5 t r i a l s f o r each of the four l i g h t displays are presented i n Table 4 of Appendix A.  Results of  the analysis of variance which included the entire 15 t r i a l s i n which SI and S 2 were presented are included as Table 5 of Appendix A. results  The  of this study are presented i n Figure 12(a-e) f o r each of the  l e s i o n "groups' and are discussed separately below. Sham Xeslons  (SH)  Behavioral r e s u l t s .  The sham lesioned animals r e l i a b l y  disrupted l i c k i n g i n response to the presentation of the four l i g h t displays.  T r i a l s on which the animals r e l i a b l y disrupted l i c k i n g i n  response to the presentation of the l i g h t displays are marked by an a s t e r i s k i n Figure 1 2 ( a ) . presentation of SI was  Disruption of l i c k i n g i n response to the  N  marked on t r i a l s 1-3 but began to wane on  the fourth and f i f t h t r i a l s as the animals habituated to the presentation of the l i g h t displays.  repeated  The SH animals i n t h i s study  r e l i a b l y disrupted l i c k i n g on the f i r s t 6- t r i a l s to the .light d i s play SI, and oh the f i r s t 3 t r i a l s to each o f the l i g h t "displays ; S2,  S3,  and S 4 ( t , * = .05/2  = 5.89,  df = 30).  Dishabituation  r e l i a b l y occurred to each change from one l i g h t display to another f o r these animals. Superior C o l l i c u l u s  Lesions  (SC)  Behavioral r e s u l t s .  Rats with large lesions which included  the s u p e r f i c i a l and deep laminae of the SC r e l i a b l y disrupted l i c k i n g  in  response  study.  t o the presentation  of the l i g h t display ( S i ) i n this  Unlike the results f o r this  group i n Experiment  I , i n which  o n l y 3 SC l e s i o n e d a n i m a l s l o o k e d a t t h e l i g h t d i s p l a y on t h e f i r s t trial,  a l l t h e SC l e s i o n e d a n i m a l s a p p e a r e d  display i n this  study.  to look a t the l i g h t  A l l h u t 2 o f t h e SC l e s i o n e d a n i m a l s  disrupted  l i c k i n g b y a t l e a s t h a l f t h e b a s e l i n e number o f l i c k s o n t h e f i r s t trial  i n response  to l i f t lights  their  to light display SI.  A l l t h e a n i m a l s were  heads from t h e water spout and appeared  on t h i s  trial.  Unlike  observed  to look a t the  t h e SH a n i m a l s , h o w e v e r , SC a n i m a l s  i n v a r i a b l y resumed l i c k i n g w i t h i n the 5 sec p e r i o d o f exposure lights  t o the  a n d d i d n o t make a n y o b s e r v a b l e p o s t u r a l c h a n g e s o t h e r  t h e h e a d a n d u p p e r b o d y movements While  than  described.  t h e SC l e s i o n e d a n i m a l s d i s r u p t e d l i c k i n g a n d  t o l o o k a t t h e l i g h t d i s p l a y when p r e s e n t e d o n t h e f i r s t animals habituated  trial,  more q u i c k l y t o t h e r e p e a t e d p r e s e n t a t i o n  lights  t h a n t h e SH a n i m a l s .  tation  o f S I was o n l y r e l i a b l y  trial,  while  trials  i n response  appeared these  of the  Disruption of l i c k i n g during the presend i f f e r e n t from b a s e l i n e on t h e f i r s t  SH a n i m a l s r e l i a b l y d i s r u p t e d l i c k i n g o n t h e f i r s t s i x to the presentation of S I .  A l s o , t h e SC l e s i o n e d  a n i m a l s d i d n o t d i s h a b i t u a t e t o a n y o f t h e c h a n g e s f r o m one  light  display to another. Since  these animals d i d n o t respond t o the l i g h t  o n more t h a n t h e f i r s t animals.  trial  they d i f f e r e d  The n u m b e r o f l i c k s d u r i n g  displays  s t a t i s t i c a l l y from  SH  the baseline period d i d not,  h o w e v e r , d i f f e r b e t w e e n t h e SC a n d SH a n i m a l s ( D u n n e t t ' s  t,oC=  55 A.  F i g u r e 12(a-e). The mean number o f l i c k s p e r 5 s e c d u r i n g t h e b a s e l i n e ( B ) and d u r i n g the p r e s e n t a t i o n o f "stimulus ( S ) , f o r the l i g h t d i s p l a y s w i t h t h e r e d p l a s t i c f i l t e r s removed: ( a ) SH, ( b ) ST, ( c ) SG, (d). SP and ( e ) D P l e s i o n e d a n i m a l s . The a s t e r i s k i n d i c a t e s t h e t r i a l s o n w h i c h t h e d i s r u p t i o n o f l i c k i n g was- s t a t i s t i c a l l y reliablev•• / < ' • -.r • c  Mean  o c ———> i i i •  6  -  >  o  o  — — — r r - r  i  :  r .  :  /  l / / l I  z a  p CO  /  -  to ...  6 z >  p CO  g>  \  i  •  : : : :  •i  :•  i  :'  0  1  1  1  1  1  \  : : : :  .1  "  /• • -  i  •• I ' I / /  V : : \ : : • \. : . : • • /.: :• ' ' • 1 •a  1  : •  „  so »  1 1  :• •  y  CO  GROUP ST S  1  GROUP SH  N= 10  8  o  1 1  6  1  1  ••  1  l  N •9  6  ,o  i  i  i  l  •6  i  i  i  :|:  7.  I'.  '  «•  o  -  CO  n  5 S*»c.  "4*.  *  o  •6  .  —i—i—i—i—i—i—r~  <  > o z >  Licks p e r  GROUP SC N • 8  o  o • < z 0  6"  N u m b e r of  GROUP SP N • 9  GROUP DP N * 4  I.I  i  i  II  :• • i :• . ' / : ' I : ' -' / / :' • /.  : . 1 : •• : •' / : . ; / : . _ \ : /, :  /  /' /'  -/  1 1 1 1 1 1. 1  V"  '  /  : . / : • " / : • /  /. : l :  .. •  I : i  i  i  . l I.  i  i  i  i  i  i  i  i  :  A  : :  '• / • l  A"* /  i  / • /• i  y, A  i  : :  I I  I /  •/•'  •  • 7 : :  ' / • /  i  5 6. .05/2, 5, 35 = 7-30). Anatomical r e s u l t s .  T h e e x t e n t o f t h e damage t o SG i s  presented i n f i v e representative  sections  i nFigure  13(a).  The  h i s t o l o g i c a l resultst-were  quite, s i m i l a r t o those'of Experiment I .  A l l the animals sustained  damage t o t h e s u p e r f i c i a l a n d d e e p l a m i n a e  o f SG a n d t h e d o r s a l  tegmentum.  Behavioral-anatomical  relationships.  The l e s i o n s  for  i n d i v i d u a l a n i m a l s v a r i e d somewhat i n t h e i r a n t e r i o r o r p o s t e r i o r p l a c e m e n t a n d t h e i n c l u s i o n o f t h e w h i t e m a t t e r of• t h e p o s t e r i o r tex,  c e n t r a l g r e y , p r e t e c t a l n u c l e i , hippocampus, a n d p o s t e r i o r  mus .  thala-  As was t h e c a s e i n E x p e r i m e n t I , t h e m e d i a l p o r t i o n o f SC a n d  d o r s a l tegmentum were a l w a y s i n c l u d e d the  cor-  behavioral  i n each animal's l e s i o n and  r e s u l t s d i d not vary as a f u n c t i o n o f a n t e r i o r - p o s t e r -  i o r placement o r as a f u n t i o n o f t h e i n c l u s i o n o f e x t r a c o l l i c u l a r tissue. S u p e r f i c i a l Laminar Lesions of Superior Behavioral  results.  C o l l i c u l u s (SP).  Rats w i t h  lesions restricted primarily  to the s u p e r f i c i a l lamina o f the superior t e d l i c k i n g on t h e f i r s t ( t , cL = .05/2  = 6.16,  colliculus reliably  3 t r i a l s i n response t o l i g h t d i s p l a y S I  d f = 30).  The' S P a n i m a l s h a b i t u a t e d  r a p i d l y t h a n t h e SH a n i m a l s a n d d i d n o t d i s h a b i t u a t e c h a n g e s f r o m one l i g h t d i s p l a y t o a n o t h e r . animals habituated  more r a p i d l y  more  t o any o f t h e  S i n c e t h e SP l e s i o n e d  t h e y w e r e r e l i a b l y d i f f e r e n t f r o m SH  animals i nresponse t o the presentation (Dunnett's t ,  disrup-  of the l i g h t displays ,  = .05/2; 5, 35» = 7-30), b u t n o t o n t h e b a s e l i n e  57 A.  F i g u r e 13(A-D). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g t h e e x t e n t o f damage t o SC a n d s u r r o u n d i n g t i s s u e f o r ( A ) SC, ( B ) S P , ( C ) DP a n d ( D ) a s u r f a c e v i e w o f c o r t i c a l damage a n d c o r r e s p o n d i n g t h a l a m i c d e g e n e r a t i o n f o r ST a n i m a l s . The s m a l l e s t l e s i o n a t e a c h l e v e l i s r e p r e s e n t e d "by t h e b l a c k a r e a a n d t h e l a r g e s t b y t h e s t i p p l e d area.  57 B.  5 8.  measure. Anatomical r e s u l t s .  The extent of the SP lesions are  presented at 5-representative levels i n Figure 13(c)..  The"lesions  were comparable to those described i n Experiment I j however, i n a few cases they were not as large and were more d i s c r e t e l y placed f o r i n d i v i d u a l animals. Behavioral-anatomical relationships.  The behavioral r e s u l t s  and anatomical results were quite variable f o r this group of animals and, consequently,  provided an opportunity to examine the importance  of damage to e x t r a c o l l i c u l a r structures and areas ofthe SC c r i t i c a l to the SP l e s i o n impairment of behavior.  Individual histologies and  behavioral r e s u l t s f o r 2-SP lesioned animals are included i n Figure l4(a-e). Comparing Figure - 14(a) and 14(b)'reveals"that lesions of the s u p e r f i c i a l laminae of SC must include a large portion of the branchium of the SC to produce the SP t y p i c a l behavior  (i.e.,  •rapid habituation and.the absence, of dishabituation to changes in  the l i g h t d i s p l a y ) .  t i o n a l animals;.-...:-  These'findings were replicated, i n 2 addi;  -. - - •  Deep Laminar l e s i o n s of the Superior C o l l i c u l u s (DP). Behavioral r e s u l t s•  Rats with lesions r e s t r i c t e d to the  deep laminae of SC r e l i a b l y disrupted l i c k i n g i n response, to l i g h t display SI on the f i r s t 3 t r i a l s ( t , «C = .05/2, = 6.16, df = 30). The results f o r these animals are presented i n Figure 12(e). DP lesioned animals habituated quite rapidly to the repeated  The  59 A.  Figure l4(a-b). H i s t o l o g i c a l reconstructions and behavioral r e s u l t s f o r i n d i v i d u a l SP lesioned animals f o r the l i g h t displays with the red p l a s t i c f i l t e r s removed, (a) SP #14, (b) SP #13.  59  B-  p r e s e n t a t i o n o f t h e l i g h t d i s p l a y , u n l i k e t h e SH a n i m a l s ,  and d i d  n o t d i s h a b i t u a t e t o a n y o f t h e c h a n g e s f r o m one d i s p l a y t o These animals  another.  d i d n o t d i f f e r s t a t i s t i c a l l y f r o m SH a n i m a l s  b a s e l i n e measure (Dunnett's Anatomical  = .05/2; 5, 35, = 7-30).  t,  results.  on the  The e x t e n t o f damage t o t h e d e e p  l a m i n a e o f SC i s d e p i c t e d i n F i g u r e  13(D)  i n representative sections.  The l e s i o n s w e r e v e r y s i m i l a r t o DP l e s i o n s r e p o r t e d i n E x p e r i m e n t I and  d i d not vary s u s t a n t i a l l y w i t h r e s p e c t t o s i z e and l o c a t i o n .  All  the animals  l a t e r a l borders  i n t h i s group had l e s i o n s which i n c l u d e d the o f t h e d e e p l a m i n a e o f SC a n d t h e d o r s a l t e g m e n t u m  but minimal involvement  of c e n t r a l grey and s u p e r f i c i a l  Behavioral-anatomical anatomical animals  relationships.  laminae.  The b e h a v i o r a l a n d .  r e s u l t s were q u i t e c o n s i s t e n t f o r t h i s l e s i o n g r o u p . A l l  s u s t a i n e d l e s i o n s as d e s c r i b e d . a n d . t h e - i n d i v i d u a l  r e s u l t s w e r e as- d e s c r i b e d i n .the g r o u p a v e r a g e s - o f ' F i g u r e  behavioral 12(e).  S t r i a t e Cortex l e s i o n s (ST). Behavioral results.  Animals w i t h s t r i a t e l e s i o n s r e l i a b l y  d i s r u p t e d l i c k i n g i n response t o the p r e s e n t a t i o n of the l i g h t plays , habituated to the repeated  dis-  p r e s e n t a t i o n o f the l i g h t s , and  d i s h a b i t u a t e d w i t h t h e c h a n g e i n p a t t e r n o f t h e l i g h t s . "The  trials  on w h i c h s t a t i s t i c a l l y r e l i a b l e d i s r u p t i o n o f l i c k i n g o c c u r r e d a r e marked by an a s t e r i s k i n F i g u r e  12(b), ( t , X =  .05/2  = 6.16,  df =  30). The ST a n i m a l s a n d S2  t h a n SH a n i m a l s ;  a p p e a r e d t o h a b i t u a t e more q u i c k l y t o S I however, t h e y were n o t s i g n i f i c a n t l y  6  d i f f e r e n t f r o m SH a n i m a l s when c o m p a r e d "by D u n n e t t ' s (Dunnett's  t , o< =  1.  technique  .05/2; 5, 35 = 7>30), a n d t h e r e w e r e no s t a t i s t i -  c a l l y r e l i a b l e d i f f e r e n c e s b e t w e e n t h e SH a n d ST a n i m a l s o n t h e baseline  measure. Anatomical r e s u l t s .  The e x t e n t o f t h e damage t o c o r t e x  and  c o r r e s p o n d i n g t h a l a m i c d e g e n e r a t i o n i s d e p i c t e d i n F i g u r e 13(e).  The  s m a l l e s t l e s i o n a n d one o f t h e l a r g e s t l e s i o n s a r e p r e s e n t e d . Behavioral-anatomical relationships.  Animals  with  complete  d e g e n e r a t i o n o f LGN were n o t d i f f e r e n t i a t e d b e h a v i o r a l l y f r o m sham lesioned animals.  As was t h e c a s e f o r o n e a n i m a l ( S T #7)  m e n t I, some o f t h e a n i m a l s i n t h i s g r o u p b e h a v e d l i k e a n d DP l e s i o n e d a n i m a l s .  i n Experi-  t h e SG, S P  (They h a b i t u a t e d q u i c k l y and d i d n o t d i s h a -  b i t u a t e t o t h e changes i n t h e l i g h t d i s p l a y ) .  I n these cases t h e  l e s i o n s w e r e n o t r e s t r i c t e d t o a r e a 17 o n l y , b u t i n c l u d e d e x t r a s t r i a t e cortex and area 7 of the cortex.  6 2.  Discussion All presentation lesioned the  the lesioned  animals i n t h i s study oriented  o f t h e l i g h t s on a t l e a s t the f i r s t  The SC  a n i m a l s d i d n o t r e l i a b l y o r i e n t t o t h i s same d i s p l a y  l i g h t s , were ' l e s s bright••(i.-e..,>"Experiment'l)  with  trial.  to the  when  . - The a n i m a l s ' "  SC, S P a n d DP l e s i o n s d i d b e h a v e d i f f e r e n t l y f r o m SH a n i m a l s  (they  habituated  more q u i c k l y t h a n SH a n i m a l s a n d d i d n o t d i s h a b i t u -  ate  t o any o f t h e changes i n t h e p a t t e r n  The  SC l e s i o n s  d i d not,  of the l i g h t s presented).  however, r e s u l t i n the e l i m i n a t i o n  of d i s r u p t i o n o f l i c k i n g i n response t o t h e a p p a r e n t l y moving display,-and responsible  light  h e n c e , t h e SC c a n n o t be. c o n s i d e r e d e x c l u s i v e l y f o r the mediation of the o r i e n t i n g response.  Further examinations of the influence o r i e n t i n g were c o n d u c t e d .  o f i n t e n s i t y on  The o r d e r o f t h e l i g h t d i s p l a y  was r e v e r s e d i n a s t u d y d e s c r i b e d  presentation  i n Appendix B and the e f f e c t o f  t r i p l i n g the i n t e n s i t y of the l i g h t s and e l i m i n a t i n g the motion (pattern)  was e x a m i n e d a n d i s i n c l u d e d  these studies the  suggested that  l i g h t display increased  r e s p o n s e i n SC l e s i o n e d dently  of the pattern  large  i n A p p e n d i x C.  increases  The r e s u l t s o f  i n the i n t e n s i t y of  the l i k e l i h o o d o f observing the o r i e n t i n g  a n i m a l s and f a c i l i t a t e d o r i e n t i n g indepen^.  c h a r a c t e r i s t i c s o f t h e d i s p l a y f o r SC  lesioned  animals. The  pattern  c h a r a c t e r i s t i c s , h o w e v e r , may n o t a l w a y s b e  secondary to the i n t e n s i t y of the display. the  pattern  The r e l a t i o n s h i p b e t w e e n  of the l i g h t d i s p l a y and the i n t e n s i t y of the l i g h t s are  examined f u r t h e r i n the  following  study.  64. EXPERIMENT I V O r i e n t i n g t o " A p p a r e n t l y " A p p r o a c h i n g and C i r c l i n g The  Lights  i m p a i r m e n t d e m o n s t r a t e d b y SC l e s i o n e d a n i m a l s i n t h e  p r e v i o u s s t u d i e s c a n p e r h a p s be d e s c r i b e d as n e g l e c t o r  inattention  to v i s u a l s t i m u l i which c a p t u r e normal animals' a t t e n t i o n and a significant reaction.  The  provoke  e x t e n t of the impairment appeared  to  be r e l a t e d t o t h e p h y s i c a l i n t e n s i t y a n d t h e s p e c i f i c p a t t e r n o f t h e lights  employed. I n a d d i t i o n t o i n t e n s i t y and motion, the p a t t e r n  istics  o f a v i s u a l s t i m u l u s may  character-  a l s o be a n i m p o r t a n t d e t e r m i n a n t  o f the o c c u r r e n c e and magnitude o f the o r i e n t i n g r e s p o n s e .  I n the  f o l l o w i n g s t u d i e s two a t t e m p t s ( A & B ) w e r e made t o e v a l u a t e t h e t r i b u t i o n of the p a t t e r n of the l i g h t d i s p l a y .  The  lights  of the  d i s p l a y s appeared t o "approach" o r "recede" i n I V ( A ) and t o the e n t i r e d i s p l a y i n  IV(B).  The  a c t u a l " change i n the. l i g h t  circle intensity  and amount o f a p p a r e n t m o t i o n o f t h e l i g h t d i s p l a y were, however, reduced r e l a t i v e  t o those of the p r e c e d i n g s t u d i e s .  con-  Method Subjects In  E x p e r i m e n t I V ( A ) , t h e s u b j e c t s were n a i v e Long-Evans  hooded r a t s : 6 SH  lesions.  6 s u s t a i n e d l a r g e b i l a t e r a l SG, I n Experiment  IV(B),  s u s t a i n e d l a r g e b i l a t e r a l SG, S u r g e r y and a n i m a l maintenance  4 SP, 4 DP,  4 ST, a n d  Zk n a i v e r a t s w e r e t e s t e d : ,  4 SP, h DP,  k ST, a n d 8 SH  8  lesions.  were i d e n t i c a l t o t h a t d e s c r i b e d i n  Experiment I . Apparatus The  a p p a r a t u s was  i d e n t i c a l to that described i n Experi-  The  p r o c e d u r e was  i d e n t i c a l to Experiment I .  ment I . Procedure The  light  The  middle  d i s p l a y s f o r each s t u d y were: (A) (51) "Apparently"- a p p r o a c h i n g l i g h t d i s p l a y . l i g h t i n t h e m i d d l e p a n e l was the left etc.  r i g h t and l e f t  i l l u m i n a t e d f o r l / l O sec f o l l o w e d  l i g h t s i n the middle panel f o r l / l O sec? then the  l i g h t of the r i g h t p a n e l and the r i g h t l i g h t of the l e f t p a n e l , The  extremes  lights  appeared  t o move f r o m t h e m i d d l e o f t h e b o x t o t h e  of the panels o r t o approach the animal i n a n a s a l t o  temporal d i r e c t i o n .  The  i n t e r l i g h t i n t e r v a l was  "i/iO  (52) ;"Apparently" r e c e d i n g l i g h t display.. was  by  sec. This  display  i d e n t i c a l t o S I ; h o w e v e r , t h e d i r e c t i o n o f t h e l i g h t s was  such t h a t the l i g h t s appeared  t o recede from the extremes  changed  of the  panels to the middle l i g h t .  That i s , the l i g h t s appeared to move  i n a temporal to nasal d i r e c t i o n by presenting f i r s t  the l e f t l i g h t  of the l e f t panel and the r i g h t l i g h t of the right panel, then the next two adjacent lights.,, e t c . - (S3)-ffApparently"••approaching-'light  .display.  The display  was i d e n t i c a l to SI; however, the l i g h t s were illuminated f o r l / 5 sec. -(S4),"Apparently" receding l i g h t display.  The display was  i d e n t i c a l to S2, however, the l i g h t s were illuminated f o r l / 5 sec and the i n t e r l i g h t i n t e r v a l was l / 5 sec. The l i g h t s were covered by the red p l a s t i c f i l t e r s f o r the above stimulus displays, and l i g h t i n t e n s i t i e s were:!: f o r 1 l i g h t on  2  •  2  ."6l cd/m , • and for'2 l i g h t s on .65 cd/m  SI was presented on t r i a l s  1-15, S2 on t r i a l s 16-30, S3 on t r i a l s 31-35, and S4 on t r i a l s 36-40.  (B) (51) C i r c l i n g l i g h t display.  The l i g h t s appeared to move  across the entire s e t of nine l i g h t s from r i g h t to l e f t ( c i r c l i n g ) . The f i r s t l i g h t on the r i g h t was illuminated f o r l / l O sec followed by the second, then the third, etc., to the ninth with an i n t e r l i g h t i n t e r v a l of l / l O sec. (52) C i r c l i n g l i g h t display.  This display was i d e n t i c a l  to that described above; however, each l i g h t was illuminated f o r l / 5 sec and the i n t e r l i g h t i n t e r v a l was 1/5 sec. (53) 1 Random l i g h t display.  The l i g h t s appeared to "jump"  from one p o s i t i o n to another i n this display.  A single l i g h t was  illuminated f o r l / l O sec and the i n t e r l i g h t i n t e r v a l was. '1/10 sec.  The l i g h t s w e r e i l l u m i n a t e d The r e d p l a s t i c light displays. s p o u t was  .61  i n a random o r d e r .  f i l t e r s were u s e d i n a l l o f t h e above  The i n t e n s i t y  cd/m  .  o f one l i g h t m e a s u r e d a t t h e w a t e r  S I was p r e s e n t e d o n t r i a l s  11-20,and S3 o n t r i a l s 21-30.  1-10,  S2 o n  trials  6 8  '  Results  (A) Approaching-Receding- L i g h t ' D i s p l a y s . The r e s u l t s o f p r e s e n t i n g l i g h t s  which appeared t o  " a p p r o a c h " o r " r e c e d e " a r e p r e s e n t e d i n F i g u r e 15(a-e). of  The  results  t h e a n a l y s i s o f v a r i a n c e c o m p a r i n g t h e SH, ST, SG, SP, a n d DP  l e s i o n e d g r o u p s a r e p r e s e n t e d i n T a b l e 6 o f A p p e n d i x A.  Trials  which d i s r u p t i o n of l i c k i n g i n response to presentation of the was r e l i a b l y  on lights  d i f f e r e n t f r o m l i c k i n g d u r i n g b a s e l i n e a r e marked by an  a s t e r i s k i n F i g u r e 15 ( t , *.=  .05/2  = 7.87,  df =  19).  As c a n be s e e n i n t h e f i r s t p a n e l o f F i g u r e 15(a-e), presentation of lights  which appeared t o approach the animal caused  a marked d i s r u p t i o n i n l i c k i n g on a t l e a s t t h e f i r s t for  a l l the animals tested.  A l l the animals disrupted l i c k i n g  appeared t o l o o k a t the l i g h t s presented.  3" t r i a l s  when t h e a p p r o a c h i n g l i g h t s  and  ( S i ) were  A - f e w o f t h e SH a n i m a l s ..reared, a p p r o a c h e d . t h e  p l e x i g l a s s p a n e l and appeared t o f o l l o w the motion of the l i g h t s ; h o w e v e r , t h e m a j o r i t y o f t h e SH a n i m a l s a n d a l l t h e SC a n i m a l s t u r n e d away f r o m t h e w a t e r s p o u t a n d l i g h t  lesioned  display.  W h i l e a l l t h e SC l e s i o n e d a n i m a l s o r i e n t e d t o t h e l i g h t d i s p l a y ( S i ) , they required fewer t r i a l s display.  S i n c e t h e y h a b i t u a t e d more q u i c k l y , t h e y w e r e  d i f f e r e n t f r o m SH a n i m a l s ( F = 1.50, Dunnett's in  to habituate to this  t , OL=  .05/2, 5,  19,  d f = 36,  = 9.18).  171,  P_ =  light  reliably, .05;  -When-the. e n t i r e 1 5 - t r i a l s  r e s p o n s e t o S I and S2 were i n c l u d e d i n t h e a n a l y s i s  ( T a b l e 7,  Appendix A), the SH animals disrupted l i c k i n g when SI was on t r i a l s 1-8 while the ST,-.lesioned--,animals-disrupted  presented  l i c k i n g .on only  the f i r s t 5-, the SC on 4-, the SP on 3, and the...DP on- 5 t r i a l s . In addition to the differences between the SC lesioned animals and SH animals i n the rate of.habituation, dishabituation to the changes i n the l i g h t display was f o r SC lesioned animals.  not as consistent or pronounced  The DP lesioned animals d i d not dishabitu-  ate to any of the changes i n the pattern of the l i g h t s .  The SC,  SP,  and ST animals c l e a r l y dishabituated to some of the changes i n the pattern of the l i g h t s (marked by an a s t e r i s k i n Figure  15).  The h i s t o l o g i c a l r e s u l t s f o r the lesioned animals are presented i n Figure l"6(a-d).  The lesions f o r a l l the groups are  quite s i m i l a r to those presented i n the previous experiments. the exception of the ST lesioned animals, there was  With  l i t t l e variation  i n the anatomical and behavioral r e s u l t s and i n d i v i d u a l animals are represented  by the group averages.  The ST lesions were more extensive f o r the animals i n t h i s study than 'in previous studies.  Two  animals had asymmetrical lesions  which were r e s t r i c t e d p r i m a r i l y to area 17 on one side and included areas 17, 18, 18A,and 7 on the other. i d e n t i c a l to the SH animals.  These animals' behavior  was  They disrupted l i c k i n g on at l e a s t  the f i r s t 5 t r i a l s and dishabituated to a l l the changes i n the T i g h t s . Two  a d d i t i o n a l animals had extensive c o r t i c a l lesions which included  area 17, 18, l8A,and area 7 b i l a t e r a l l y .  These animals' behavior  was  more l i k e that of the SC animals i n that they only disrupted l i c k i n g  70 A.  F i g u r e 15(a-e). Mean number o f l i c k s p e r 5 during baseline (B) and d u r i n g t h e p r e s e n t a t i o n o f t h e s t i m u l u s (s), f o r t h e " a p p r o a c h i n g " l i g h t d i s p l a y s : S I , S2, S3 a n d S 4 . ( a ) SH, ( b ) ST, ( c ) SG, ( d ) S P a n d ( e ) DP l e s i o n e d a n i m a l s . The a s t e r i s k i n d i c a t e s t h e t r i a l s o n w h i c h d i s r u p t i o n o f l i c k i n g was s t a t i s t i c a l l y r e l i a b l e . s  e  c  ro  a  o  cr  OJ  w  w  w  w  w  Mean  GROUP  DP IN * 4)  GROUP SP  Number of  [N ' 4)  GROUP SC  i  : :• :  / /  / \  : :  / • /  : :  i  y X  : I : \ : •\ :  : :  : :  J /  : :  y  / •a  oL  i i i i i i  • I y : I : l  [N = 6)  GROUP  • - —  i  ST [ N - 4 1  GROUP SH (N • 6)  i i ; i  1 1 1 ! 1 1 1  ~ *  _  * -""*  —-—-~#  ^  #  I: y \ i  i i i i i i i  / i  i  i i i i 1  : :  / / : • \ :  *  : : :.  ' / ./ /  : :. :'• : :.  1  I 1 1111  /  /  / .. l : :  ; y ./  • • 1 •  i  :  1  *  \ " / : : :  ' \  : : :  ^ —  Sec.  i i i i i i  *  :  Licks per 5  y y* . /. ' /• ' :  i i i i i i >  —  I  •  1  71  A .  F i g u r e 16(A-D). Representative s e c t i o n s d e p i c t i n g the extent of damage t o SG a n d s u r r o u n d i n g t i s s u e f o r ( A ) SC, ( B ) SP, (c) DP a n d ( D ) ST l e s i o n e d a n i m a l s . The s m a l l e s t l e s i o n a t e a c h r e p r e s e n t a t i v e s e c t i o n i s drawn i n b l a c k and t h e l a r g e s t i s s t i p p l e d .  71  B .  on the f i r s t 2-3 t r i a l s and dishabituated to no more than one of the changes from one l i g h t display to another. (B)'.'.Circling Light Displays.' The results of presenting l i g h t s which appeared to c i r c l e or move across the set of nine l i g h t s are diagrammed i n Figure 17 (a-e).  The results of the analysis of variance comparing the SH,  SC, SP, DP, and ST lesioned groups are presented i n Table 8 of Appendix  A.  T r i a l s on which disruption of l i c k i n g i n the presence of the  l i g h t s was r e l i a b l y d i f f e r e n t from l i c k i n g during baseline are marked by an a s t e r i s k i n Figure 17(a-e), (t, oC = .05/2, = 6.82; df = 20). A l l of the animals r e l i a b l y disrupted l i c k i n g on .at l e a s t the  f i r s t 3 t r i a l s when l i g h t display SI was presented.  A l l the ani-  mals disrupted l i c k i n g and appeared to look at the l i g h t s . animals followed the motion of the l i g h t s .  The SH  The SC lesioned animals  appeared to look a t the l i g h t s b r i e f l y then turned away from the water spout and l i g h t s .  Dishabituation was hot demonstrated to the  change i n speed of the l i g h t s from l / l O sec to l/5 sec f o r any of the groups. the  The SH animals, however, r e l i a b l y disrupted l i c k i n g when  random l i g h t display (S3) was presented. None of the SC, SP,  DP, or ST animals dishabituated to this l i g h t display. The h i s t o l o g i c a l r e s u l t s f o r each of the l e s i o n groups are summarized i n Figure 18 .  The extent of damage f o r each group i s  quite s i m i l a r to that of the previous studies.  There was l i t t l e  v a r i a t i o n i n l e s i o n size and placement within the groups and the i n d i v i d u a l animals are represented by the average data.  73  A .  Figure l?(a-e). Mean number o f l i c k s p e r 5 s e c d u r i n g t h e b a s e l i n e (B) and d u r i n g the p r e s e n t a t i o n o f t h e s t i m u l u s ( S ) , f o r the circling light displays: S I , S2, a n d S3. The a s t e r i s k i n d i c a t e s t h e t r i a l s o n w h i c h d i s r u p t i o n o f l i c k i n g was s t a t i s t i c a l l y r e l i a b l e .  Mean  GROUP  o  DP N • 4  o  8  GROUP  5  SP  N • 4  a  o  Number of  GROUP  SC  Licks  per  5  Sec.  N • 8  GROUP  5 T N -- 4  GROUP  SH  N •8  cn  s \ I  I  \ ; I  i  / ;  *  i  \ N  \  \  ;  \ '  \  \ I  \ o (A  s  I  i  I.I  i  i  i  r  \  \  I  I I  i  I  \  I •I  /  ;  *  \  \  74  A .  Figure 18(A-D). Representative sections d e p i c t i n g the extent o f damage t o SG a n d s u r r o u n d i n g t i s s u e f o r ( A ) SG, ( B ) S P , ( C ) DP a n d ( D ) a s u r f a c e v i e w o f c o r t i c a l damage a n d c o r r e s p o n d i n g t h a l a m i c d e g e n e r a t i o n f o r ST a n i m a l s . The s m a l l e s t l e s i o n a t e a c h l e v e l i s r e p r e s e n t e d by the b l a c k area and the l a r g e s t by the s t i p p l e d - a r e a .  \  74 B.  Discussion These s t u d i e s  c l e a r l y demonstrated  are capable of d i s r u p t i n g t h e i r ongoing visual stimulus.  lesioned animals oriented  t o the l i g h t  The  l i g h t d i s p l a y s appeared  >;""" "  ""The  the  in.'previous  -to. h a v e a g r e a t e r . • i m p a c t - i n  o f movement o f t h e  lights.  S H i a n i m a l s w e r e more r e s p o n s i v e t o t h e a p p r o a c h i n g  receding displays i n that  t h e y r e q u i r e d , more, t r i a l s  of h a b i t u a t i o n  I n terms of  d i s p l a y s used i n the p r e v i o u s s t u d i e s .  The  SH  t i o n of l o o k i n g a t the l i g h t s , and  measures o f the s a l i e n c e  of h a b i t u a t i o n ,  e l i c i t a t i o n of f u r t h e r  study.  While  to  duraA  exploratory  the l i g h t d i s p l a y are l i k e l y a l l p o s s i b l e of a p a r t i c u l a r v i s u a l stimulus.  t i o n s h i p between t h e s e measures has n o t been examined in this  appeared  display.  magnitude of o r i e n t i n g , the r a t e  d i r e c t e d towards  the  a n i m a l s d i d , however,  t o f o l l o w t h e c i r c l i n g l i g h t s a n d i n t h i s way  be more r e s p o n s i v e t o t h i s  activity  the  t o t h e d i s p l a y , t h e SH a n i m a l s w e r e n o t s i g n i f y  i c a n t l y more r e s p o n s i v e t o t h e c i r c l i n g l i g h t s d i s p l a y t h a n t o  The  and  torhabituate" to»•  t h e m t h a n t h e " ' l i g h t d i s p l a y s -of 'the p r e v i o u s s t u d i e s .  attempt  a  displays  :  •terms-of. t h e p a t t e r n  rate  was  a c t u a l l y i n v o l v e d mueh d i m m e r l i g h t s , than- t h o s e v u s e d  studies..  animals  b e h a v i o r and l o c a l i z i n g  Of p a r t i c u l a r i n t e r e s t i n t h e s e s t u d i e s  f i n d i n g t h a t t h e SC which  t h a t SC l e s i o n e d  The  rela-  systematically  these r e l a t i o n s h i p s warrant' f u r t h e r study,  focus of the present r e p o r t  was  to determine  i f SC  were c a p a b l e o f o r i e n t i n g t o v i s u a l s t i m u l i and o r i e n t to the s t i m u l i used i n t h i s study.  The  lesioned  animals  they c l e a r l y d i d pattern  of  the  motion  i n t h e l i g h t d i s p l a y a p p e a r s t o he a n i m p o r t a n t p a r a m e t e r i n demonstrating  this response.  The p a t t e r n  o f t h e l i g h t d i s p l a y may  ence t h e magnitude o f t h e o r i e n t i n g r e s p o n s e as a f u n c t i o n salience  and i n terms of i t s p o s s i b l e  suggestions are i n d i r e c t l y  of i t s  behavioral significance.  examined i n the f o l l o w i n g  influ-  studies.  These  77. EXPERIMENT V The E f f e c t o f M a n i p u l a t i o n o f a n I n t r i n s i c Parameter on O r i e n t i n g I n t h e I n t r o d u c t i o n , i t was a r g u e d t h a t t h e o r i e n t i n g r e s p o n s e was n o t a s i m p l e  r e f l e x i v e behavior that i n e v i t a b l y occurs  to the presence of a v i s u a l stimulus.  The o r i e n t i n g r e s p o n s e was  s a i d t o be c o n t r o l l e d by a number o f p a r a m e t e r s . categorized  as e i t h e r e x t r i n s i c  ted to the stimulus  egory could  t o t h e animal and s p e c i f i c a l l y  c h a r a c t e r i s t i c s (e.g.,  size of the stimulus)  These m i g h t be  o r as i n t r i n s i c  the pattern, intensity or  t o the animal.  include v a r i a t i o n i n the animalis  The l a t t e r  ing  t h e i r novelty o r previous  cat-  alertness or arousal,  or s t a t e o f d e p r i v a t i o n , as w e l l as p r i o r experience w i t h (e.g.,  rela-  association with aversive  the s t i m u l i o r reward-  consequences). The f o l l o w i n g s t u d y e x a m i n e d one o f t h e s e f a c t o r s ;  of d e p r i v a t i o n .  This  was a c c o m p l i s h e d b y a l l o w i n g t h e a n i m a l s  to a d d i t i o n a l water p r i o r t o t e s t i n g .  state access  7 8  Method Subjects A t o t a l o f 16 n a i v e r a t s w e r e t e s t e d : 4 S P , k DP, a n d 4 SH l e s i o n e d a n i m a l s  were t e s t e d .  4 l a r g e b i l a t e r a l SG, Half the subjects  in  e a c h g r o u p were o b t a i n e d f r o m t h e b r e e d e r s  a n d h a l f were  in  the Biopsychology  In  a l l o t h e r r e s p e c t s t h e s u b j e c t s were t r e a t e d a s i n t h e p r e v i o u s  Vivarium a t the U n i v e r s i t y of B r i t i s h  reared Columbia.  studies. Apparatus The a p p a r a t u s  was i d e n t i c a l t o t h a t d e s c r i b e d i n E x p e r i m e n t  The p r o c e d u r e  was i d e n t i c a l t o t h a t d e s c r i b e d i n E x p e r i m e n t  I. Procedure  I  w i t h the f o l l o w i n g exceptions:-  to  water i n t h e i r  testing.  (-2)  (Si) sec  was p r e s e n t e d (S2)  home c a g e s f o r 30 m i n u t e s ,  The d i m m e r l i g h t s  t h i s experiment.  ( l ) The a n i m a l s  were a l l o w e d  access  two t o t h r e e h o u r s p r i o r t o  (with r e dplastic f i l t e r s )  were u s e d i n  (3) T h e a p p a r e n t l y m o v i n g s t i m u l u s 1 p e r l / l O s e c on t h e f i r s t 5 t r i a l s  was p r e s e n t e d  o n t h e 6th t o 10th t r i a l s .  m o v i n g 1 p e r l / 5 s e c (S3)  The a p p a r e n t l y  a n d t h e s t a t i o n a r y 1 p e r l / 5 s e c (S4)  were a l s o p r e s e n t e d f o r 5 t r i a l s  l6th t o 20th t r i a l s ,  and the s t a t i o n a r y 1 p e r l / l O  stimuli  e a c h o n t h e 11th t o 15th t r i a l s a n d  respectively.  Results The presented  r e s u l t s of manipulating  i n Figure  19 a n d t h e a n a l y s i s o f v a r i a n c e  T a b l e 9 o f A p p e n d i x A.  reliable  an a s t e r i s k i n F i g u r e  i sincluded i n  The d i f f e r e n c e s b e t w e e n l i c k i n g d u r i n g t h e  baseline and the stimulus statistically  hours o f water d e p r i v a t i o n a r e  p r e s e n t a t i o n on each t r i a l w h i c h were  ( t , oL = 19.  .05/2, = 9•53» d f = 12) a r e m a r k e d b y  A l l the animals disrupted l i c k i n g i n res-  ponse t o t h e p r e s e n t a t i o n o f S I on a t l e a s t t h e f i r s t t h r e e habituated the  with repeated  stimulus  trials,  presentations, and dishabituated t o  c h a n g e s o f l i g h t s f r o m one p a t t e r n t o a n o t h e r . The  amount o f d i s r u p t i o n o n t h e s e t r i a l s d i d n o t r e l i a b l y  d i f f e r f o r t h e SH a n d SG l e s i o n e d a n i m a l s . required t o habituate was  t o the repeated  also not reliably different.  The^number o f t r i a l s  presentation  of the l i g h t s  D i s h a b i t u a t i o n t o t h e change i n  t h e p a t t e r n o f t h e l i g h t s was n o t a s c o n s i s t e n t f o r t h e SG, SP, a n d DP l e s i o n e d s u b j e c t s a s i t was f o r t h e SH a n i m a l s . reliable  Statistically  d i s r u p t i o n o f l i c k i n g i n r e s p o n s e t o t h e change i n t h e  l i g h t d i s p l a y often d i d not occur u n t i l a n i m a l s . . .. (The c  the second t r i a l  for  these  a v e r a g e d d a t a f o r t h e DP l e s i o n e d a n i m a l s a r e some-  what m i s l e a d i n g .  According  t o the averaged data,  t h e DP l e s i o n e d  a n i m a l s a p p e a r e d t o d i s h a b i t u a t e a s c o n s i s t e n t l y a s t h e SH  animals.  This  g r o u p t r e n d was p r o d u c e d b y t h e p e r f o r m a n c e o f o n e a n i m a l .  This  a n i m a l ' s l e s i o n o n l y damaged t h e l a t e r a l edge, o f t h e SG, n o t  the SP  m e d i a l h a l f o f t h e d e e p SC l a m i n a e a n d a d j a c e n t a n d SC l e s i o n e d a n i m a l s '  tegmentum).  h i s t o l o g i c a l r e s u l t s were q u i t e  The  similar  80  A.  F i g u r e 19(a-d). Mean number o f l i c k s p e r 5 s e c d u r i n g t h e b a s e l i n e ( B ) and d u r i n g the p r e s e n t a t i o n o f the s t i m u l u s ( S ) f o r l i g h t d i s p l a y s S I , S2, S3 a n d S4. (a) S H , (b) S C , ( c ) S P and (d) D P l e s i o n e d a n i m a l s . - The a s t e r i s k i n d i c a t e s t h e t r i a l s o n w h i c h d i s r u p - ' t i o n o f l i c k i n g was s t a t i s t i c a l l y r . e 11 able". r  8 1.  to those reported'in the previous studies.  The extent of the damage  f o r each l e s i o n group i s depicted i n Figure .20 at representative levels of the SC. More important than the quantitative differences between lesioned groups-mentioned above-is the;comparison-of t h e r e s u l t s :  of this study within the r e s u l t s of . Experiment 1.  The- r e s u l t s of - the  analysis of variance which compared the two experiments are presented i n Table 10 of Appendix A. Access to extra water p r i o r to the t e s t session resulted in:  ( l ) s t a t i s t i c a l l y r e l i a b l e disruption of l i c k i n g i n response to  the l i g h t s by the SC lesioned animals ( t , c{. = .05/2, = 7.45, df = 30), (2) dishabituation to the change i n l i g h t patterns by the lesioned animals ( t , ^ = .05/2, = 7.45, df = 30), and (3) an increase i n the number of t r i a l s on which a l l the animals r e l i a b l y disrupted l i c k i n g i n response to the s t i m u l i (F = 5-91, df = 1, 39, £ = -05).  82 A.  Figure 20(A-G). Representative sections depicting the extent of damage to SC and surrounding tissue f o r (A) SC, (B) SP and (c) DP lesioned animals. The smallest l e s i o n at each representative l e v e l i s drawn i n black and the l a r g e s t i s s t i p p l e d .  82 B.  8 3.  Discussion The  r e s u l t s of t h i s study a g a i n demonstrated  l e s i o n e d animals stimulus. t h a t was  are, i n f a c t ,  F u r t h e r , t h e SC  capable  animals  that  of o r i e n t i n g to a  o r i e n t e d to the l i g h t  SC  visual display  i g n o r e d when p r e s e n t e d f o l l o w i n g a l o n g e r p e r i o d o f  water  deprivation. The  e f f e c t o f v a r y i n g amounts o f w a t e r  d e p r i v a t i o n on  disruption to a visual stimulus, habituation,and dishabituation not been examined p a r a m e t r i c a l l y i n t h i s study.  have  The s t u d y d o e s , how-  e v e r , c l e a r l y p r o v i d e some d a t a i n " s u p p o r t o f - t h e p r o p o s a l - t h a t intrinsic animals  v a r i a b l e s i n f l u e n c e the o r i e n t i n g response.  demonstrated  enhanced responding  d i s h a b i t u a t i o n t o t h e c h a n g e i n s t i m u l i was  for  these animals.  to  SI  also potentiated  More i m p o r t a n t l y , t h e m a n i p u l a t i o n o f amount o f  consumed p r i o r t o t e s t i n g r e s u l t e d i n :  s t i m u l i b y t h e SC  SH  on the f i r s t t r i a l s  and  water  The  ( l ) responding  l e s i o n e d animals,'(2) prolonged responding  slower habituation (relative  t o t h e number o f t r i a l s  h a b i t u a t i o n i n the p r e v i o u s s t u d i e s ) , and l e a s t some o f t h e c h a n g e s i n t h e O b s e r v a t i o n of a few  (3)  to  the  and  required f o r  dishabituation to  at  stimuli.  o f t h e l e s i o n e d a n d SH  animals  during  t h e d i s r u p t i o n o f l i c k i n g on t h e f i r s t t r i a l d i d n o t r e v e a l s y s t e m a tic  d i f f e r e n c e s between the groups.  study, l i f t e d  A l l the animals  t h e i r heads f r o m the w a t e r  observed  i n this  spout, appeared to look  at  t h e l i g h t s f o r v a r y i n g a m o u n t s o f time., a n d t h e n g e n e r a l l y t u r n e d  to  e x p l o r e the box  time  o r groom.  The  SH  animals  a p p e a r e d t o s p e n d more  f a c i n g the l i g h t s  t h a n t h e SC  l e s i o n e d animals, which  generally  a p p e a r e d t o l o o k a t t h e l i g h t s f o r a much s h o r t e r t i m e a n d engaged i n o t h e r  activities.  then  85. EXPERIMENT VI Moving and Stationary Light Displays as Signals of Aversive Reinforcement. The preceding studies demonstrated that SG lesions d i d not r e s u l t i n v i s u a l agnosia or the i n a b i l i t y to perform the appropriate motor responses involved i n o r i e n t i n g .  Rather, the o r i e n t i n g  response was possible but not always emitted i n response to s t i m u l i that normal animals r e a d i l y oriented to.  The behavioral d e f i c i t  manifested by the SG lesioned animals can perhaps be appropriately described as v i s u a l neglect or inattention, i n that  the animals  were less e a s i l y d i s t r a c t e d by v i s u a l s t i m u l i . The SG lesioned animals i n the previous studies oriented to the l i g h t displays which the i n t a c t animals treated as more s a l i e n t and the orienting d e f i c i t to the less s a l i e n t l i g h t display was reduced by manipulating the amount of water consumed p r i o r to t e s t i n g . The following study represents an a d d i t i o n a l attempt to v e r i f y that the SC lesioned animals were not b l i n d to the s p e c i f i c l i g h t d i s p l a y that they had ignored.  86.  MethodSubjects A t o t a l of 40 naive rats were tested. b i l a t e r a l SC, 8 SP, 8 DP, 8 ST,and 8 SH lesions.  Eight sustained Surgery and main-  tenance of the animals was i d e n t i c a l to that described i n Experiment I. Apparatus The apparatus was i d e n t i c a l to the apparatus described i n Experiment l,:'with one exception. A scrambled shock source (BRS model SGS-0C4) produced a 1 milliampere (mA) e l e c t r i c shock to the g r i d f l o o r of the t e s t i n g apparatus. Procedure The procedure involved 2 phases.  Phase 1 was i d e n t i c a l  to Experiment I f o r 4 animals i n each of the l e s i o n groups: DP, and SH, and the 8 ST animals.  SC, SP,  The remaining rats were tested i n  Experiments I, I I I , V, and Appendix B, and proceeded to phase 2 of t h i s study.  The order of presentation of the l i g h t displays i n phase  1 and the l i g h t display followed by shock i n phase 2 are described i n Table 1. Phase 2 of the procedure began on the day immediately following the completion of phase 1.  At this time the 5 sec presen-  t a t i o n of the stimulus display was immediately followed by an unavoidable 1 mA shock to the f e e t through the grid f l o o r of the box f o r 1 sec.  The number of l i c k s during the baseline 5 sec period and  the 5 sec stimulus presentation were recorded as i n Experiment I.  87. Table 1 Assignment o f Animals, Experiment I V -  Phase 1 Lesion  Experiment  Group  SH , "SC ,• • n- = 2: S P & DP ;  ST  VI  .  {  - ' M l / l O , S l / l O , .Hi/5-, s i / 5  :i  l i g h t Display . F o l l o w e d "by Shock :/~:Ml/lOO  h = 2  Exp".; V I  S l / l ' O , Ml/10, S l / 5 , M l / 5  Sl/10  n =' 2  Exp.  Ml/10. S l / 1 0 , M l / 5 , S l / 5  Ml/10  n -  Appendix B  Sl/5,  Ml/10  Sl/10  n =:'.2  Exp.-VI  Ml/10, S l / 1 0 , M l / 5 , S l / 5  Ml/10  n = 2  Exp.  S l / 1 0 , M.i/10, S l / 5 , M l / 5  Sl/10  n = 2  Exp. I l l  Ml/10,. S'i/10, M l / 5 , S l / 5  Ml/10  Exp.  Ml/10, S l / 1 0 , M l / 5 , s i / 5  Sl/10  2  ... n = 2 Note.  Exp.  ... O r d e r o f t h e L i g h t s Display  Phase. 2  V  VI  I  M l / 5 , Sl/10,  Ml/lO = a p p a r e n t l y moving l i g h t d i s p l a y , 1 p e r l / l O s e c . Sl/lO = stationary light display, 1 per l / l O sec. Ml/5 = a p p a r e n t l y m o v i n g l i g h t d i s p l a y , 1 p e r l / 5 s e c . Sl/5 = s t a t i o n a r y l i g h t d i s p l a y , 1 p e r l/5 s e c .  8.8.  However, the number of l i c k s which i n i t i a t e d the presentation of the l i g h t display was This was  varied between 8 and approximately 130  licks.  accomplished by r e s e t t i n g the counting mechanism a variable  number of times a f t e r each baseline 5 seconds had elapsed. way a random number of l i c k s -was and stimulus presentation.  In this  interspersed between the baseline  This was  done to prevent the amount of  drinking serving as a cue to the onset of stimulus and shock.• In all-respects, ./this-phasewasidentical .to.phase i except that the r  presentation of the l i g h t display was onset of the shock.  immediately followed by the  Half the animals were shocked following the  presentation of the apparently moving at 1 per l / l O sec and half following the stationary 1 per l / l O sec l i g h t display.  The  stimulus  assigment was made on the basis of whether the moving or stationary display was presented f i r s t i n phase 1. i n each session.  Ten t r i a l s were presented  Daily sessions of 10 t r i a l s were continued  •  until  the animals suppressed l i c k i n g i n the presence of the l i g h t s to a c r i t e r i o n 6nrl8 t r i a l s f o r two successive sessions.  The  suppression  c r i t e r i o n was a r a t i o of .90 determined by (number-ofclicks-during . baseline - number of l i c k s during stimulus pre'sentation)/(number ofl i c k s during baseline).  :? .9. Results Phase  1: The  r e s u l t s f o r phase 1 o f t h i s  to those of Experiment The  experiment  were  identical  I and s u c c e s s f u l l y r e p l i c a t e d those f i n d i n g s .  SH a n d ST l e s i o n e d a n i m a l s d i s r u p t e d l i c k i n g t o S I , h a b i t u a t e d  to. i t s r e p e a t e d p r e s e n t a t i o n , a n d d i s h a b i t u a t e d t o t h e c h a n g e s i n the l i g h t d i s p l a y s . l i c k i n g i n response SP  The SG a n d DP l e s i o n e d a n i m a l s _ d i d  not disrupt  t o t h e l i g h t d i s p l a y s on any o f t h e t r i a l s .  lesioned animals r e l i a b l y disrupted l i c k i n g t o S i l a n d  The  habituated  t o i t s r e p e a t e d p r e s e n t a t i o n b u t d i d n o t d i s h a b i t u a t e t o any o f the changes i n t h e l i g h t d i s p l a y s . Phase  2: The  r e s u l t s o f the a n a l y s i s of variance  l e s i o n e d a n i m a l s o n t h e number o f t r i a l s i n Table  11 o f A p p e n d i x  presentation  comparing  the  to c r i t e r i o n are presented  A. A l t h o u g h t h e a n i m a l s s h o c k e d  following  o f t h e s t a t i o n a r y l i g h t d i s p l a y r e q u i r e d more  trials  t o reach the s u p p r e s s i o n c r i t e r i o n than the animals shocked ing  p r e s e n t a t i o n o f t h e m o v i n g l i g h t d i s p l a y , t h e d i f f e r e n c e was  not s t a t i s t i c a l l y  reliable  mean n u m b e r o f t r i a l s for  follow-  each  (F =  2.97; d f = 1, 30;_p = .095)-  required t o reach the suppression  criterion  o f the l e s i o n groups o f animals a r e p r e s e n t e d i n F i g u r e  As c a n b e s e e n i n t h e f i g u r e , t h e SG a n d DP l e s i o n e d a n i m a l s fewer  The  trials  21.  required  t o r e a c h t h e s u p p r e s s i o n c r i t e r i o n t h a n SH a n d S P  a n i m a l s a n d t h e ST l e s i o n e d a n i m a l s r e q u i r e d s u b s t a n t i a l l y more t h a n t h e SH a n i m a l s  to reach c r i t e r i o n  ( F = 6.15;  d f = 4,  30;  trials  90 A.  F i g u r e 2 1 . Mean number o f t r i a l s t o c r i t e r i o n s u p p r e s s i o n a n d v a r i a n c e f o r SH, SC, SP, DP a n d ST l e s i o n e d a n i m a l s .  9 1.  £ = .001; D u n n e t t ' s t , <* = .05/2, 5, 30 = 17-56) • An a d d i t i o n a l a n a l y s i s o f v a r i a n c e was c o n d u c t e d t o examine d i f f e r e n c e s between- t h e l e s i o n e d a n i m a l s d u r i n g a c q u i s i t i o n of the c o n d i t i o n e d suppression response.  I n this analysis  the d i f -  f e r e n c e s between l i c k i n g d u r i n g b a s e l i n e and t h e p r e s e n t a t i o n o f the l i g h t s were a s s e s s e d f o r t h e f i r s t 4 s e s s i o n s . number o f t r i a l s  (The u n e q u a l  required to reach the suppression c r i t e r i o n  pre-  cluded analysis of a l l the sessions). The Table  results of the analysis of variance are presented i n  12 o f A p p e n d i x  A.  None o f t h e i n t e r a c t i o n s o r t h e m a i n  contrasting the specific  effect  l i g h t d i s p l a y s employed (motion v e r s u s  t i o n a r y ) were s t a t i s t i c a l l y r e l i a b l e .  To f a c i l i t a t e  sta-  interpretation  o f t h e r e s u l t s t h e d a t a were c o m b i n e d f o r - t h i s f a c t o r a n d r e a n a l y s e d . The  r e s u l t s o f t h i s a n a l y s i s - a r e p r e s e n t e d i n - T a b l e 13 o f A p p e n d i x " A  and  t h e means f o r e a c h  g r o u p a r e p r e s e n t e d i n F i g u r e 22.  groups d i f f e r e d i n r a t e o f a c q u i s i t i o n o f t h e response df =  The l e s i o n  r  (F =  3.21;  3, 105; £ = .001). T h e DP l e s i o n e d a n i m a l s d i f f e r e d r e l i a b l y  f r o m SH a n i m a l s i n s e s s i o n 2 a n d t h e DP a n d SG l e s i o n e d r e l i a b l y d i f f e r e d f r o m S H a n i m a l s i n s e s s i o n 3-  animals  T h e ST a n d S P a n i -  m a l s d i d n o t d i f f e r r e l i a b l y f r o m SH a n i m a l s i n a n y o f t h e s e s e s s i o n s (Dunnett's  t , <* = The  i n Figure sections.  23.  .05/2, 5, 35,= 3«4l).  h i s t o l o g i c a l results f o rthis study are presented The e x t e n t o f t h e damage i s d e p i c t e d i n r e p r e s e n t a t i v e  Damage s u s t a i n e d b y t h e a n i m a l s i n e a c h o f t h e l e s i o n  g r o u p s was a s e x t e n s i v e a s t h a t r e p o r t e d i n t h e p r e c e d i n g  studies.  92 A.  F i g u r e 2 2 ( a - e ) . Mean number o f l i c k s d u r i n g t h e 5 s e c b a s e l i n e ( B ) a n d d u r i n g t h e p r e s e n t a t i o n o f t h e s t i m u l u s ( S ) w h i c h was f o l lowed by an unavoidable f o o t shock, ( a ) SH, ( b ) ST, ( c ) SC, ( d ) SP a n d ( e ) DP l e s i o n e d a n i m a l s .  •a  z6  93  A .  F i g u r e 23(A-D). Representative sections d e p i c t i n g the extent of damage t o SC a n d s u r r o u n d i n g t i s s u e f o r ( A ) SC, ( B ) S P , (c) DP a n d (D) a s u r f a c e v i e w o f c o r t i c a l damage a n d c o r r e s p o n d i n g t h a l a m i c d e g e n e r a t i o n f o r ST l e s i o n e d a n i m a l s . The s m a l l e s t l e s i o n a t e a c h r e p r e s e n t a t i v e s e c t i o n i s d r a w n i n "black a n d t h e l a r g e s t i s s t i p p l e d .  93 B.  The SG lesions always included damage to the s u p e r f i c i a l and deep layers of the SG, p r e t e c t a l nuclei, branchium of SG, dorsal tegmentum, -.and overlying white matter of the cortex.  Some of the animals  i n this group also sustained damage to the central grey and hippocampus.  The SP lesions were r e s t r i c t e d primarily to the s u p e r f i c i a l  layers of SC and a l l the lesions damaged the branchium of SC.  The  DP lesions were confined to the l a t e r a l edge of the deep layers of SC and dorsal tegmentum. The ST lesions varied i n s i z e and placement f o r the animals i n this study.  Half the animals had lesions confined p r i m a r i l y to  area 17 and the remainder had lesions which included damage to area 17,  18, 18A,and 7«  The behavioral results varied markedly depending  upon the extent of the lesions. small portion of area 17, the bordering areas 18,  Animals with lesions confined to a  o r . a l l . o f area 17 and small portions  of  18A, and 7 d i d not d i f f e r from SH animals on  the t r i a l s to c r i t e r i o n measure or when the data from the f i r s t 4 sessions were analysed. 18,  The rats with extensive damage to area 17,  18A, and 7 required many more t r i a l s to reach the suppression  criterion.  These animals d i d not, however, d i f f e r from SH animals  during the f i r s t k sessions but did require more t r i a l s to reach the s t r i c t performance c r i t e r i o n of almost perfect suppression.  9 5.  Discussion These d a t a a g a i n demonstrate  t h a t SG l e s i o n e d a n i m a l s a r e  - n o t b l i n d t o t h e v i s u a l d i s p l a y s .that they- ^no-^ed;'4n-_..tfe-i-.pt.ey^u^ e x ^ v  periments  a n d ' i n p h a s e 1 .of .the. 'pE.es-e.nt --expe^i^ent.,:'.' / A l ' . l • tfi£- a.n$ma,ls-  disrupted  l i c k i n g when t h e l i g h t s  were f o l l o w e d b y a n u n a v o i d a b l e  f o o t shock.  T h e t h i r s t y S P a n d DP l e s i o n e d a n i m a l s , i n f a c t ,  fewer  to reach a rather s t r i c t  trials  performance  p e r f e c t suppression o f l i c k i n g i n the presence The  of almost  of the l i g h t s .  a c c e l e r a t e d a c q u i s i t i o n o f c r i t e r i o n performance  t h e SG a n d DP l e s i o n e d a n i m a l s may-be d u e ' t o to the shock  criterion  required  differential  o r to the d e p r i v a t i o n o f these animals.  d e p r i v a t i o n and shock  by  sensitivity  Manipulation  of  i n t e n s i t y do a f f e c t t h e a c q u i s i t i o n o f c o n d i -  tioned suppression f o r i n t a c t animals  ( M a c k i n t o s h , 1977)•  The  influ-  e n c e o f t h e s e v a r i a b l e s c a n not./ o f c o u r s e , b e e l i m i n a t e d s i n c e t h e DP l e s i o n e d a n i m a l s d i d r e q u i r e s u p p l e m e n t a l a c c e s s t o a d d i t i o n a l water and  t o m a i n t a i n body weight  c o m p a r a b l e t o t h e SH c o n t r o l  animals  t h e SC l e s i o n s damaged t h e p r o p r i o c e p t i v e f i b e r s o f t h e c e n t r a l  grey thought  t o be i n v o l v e d i n r e s p o n s e s  to painful stimuli  (Marx,  1976). A s e p a r a t e a n a l y s i s o f t h e SC a n d DP l e s i o n e d a n i m a l s ' does.,, h o w e v e r , s u g g e s t s a n o t h e r - i n t e r p r e t a t i o n .  It-i s p o s s i b l e  data  that  t h e e n h a n c e d a c q u i s i t i o n o f s u p p r e s s i o n was r e l a t e d t o t h e f a c t t h a t SC a n d DP l e s i o n e d a n i m a l s d i d n o t o r i e n t t o t h e l i g h t d u r i n g phase 1 o f t h e experiment.  display  An e x a m i n a t i o n o f t h e i m p o r t a n c e  o f o r i e n t i n g d u r i n g phase 1 o f t h e experiment  on t h e a c q u i s i t i o n  96-  of c o n d i t i o n e d  s u p p r e s s i o n was  the  a n i m a l s who  who  d i d ( t e s t e d i n E x p e r i m e n t V and  r e s u l t s of  d i d not  p r o v i d e d by  comparing the  o r i e n t i n phase 1 of t h i s study w i t h reported  t i o n of s u p p r e s s i o n to the The  a t t a i n conventional  l i g h t s by  the  The  towards f a s t e r a c q u i s i -  a n i m a l s who  d i d not  e f f e c t , however, approached but  statistical reliability  for  those  in.Appendix B).  t h i s comparison suggested a trend  t o t h e m i n p h a s e 1.  results  (F =  1.92;  orient  did  df =  not 9,  £ = .055). An question.  experiment c u r r e n t l y i n p r o g r e s s a l s o examines t h i s  This experiment involves  a c q u i s i t i o n of s u p p r e s s i o n to the with the  the  Preliminary  during  pre-exposure of  p h a s e 1.  I f the  absence of o r i e n t i n g to the a p p a r e n t l y moving stimulus  animals oriented  l i g h t s ) i n p h a s e 1, enhanced and  the  was  to the  These f i n d i n g s are  r e s p o n s e and  capable of u s i n g a s i g n a l of  and  DP  SH  control  only preliminary  r e s p e c t to the  light  display in  (approaching not  animals. but  have . i n t e r e s t i n g  r e l a t i o n s h i p between the The  orienting  t h r u s t of  the  h o w e v e r , was  t o d e t e r m i n e i f SC  lesioned rats  a stimulus,  which t h e y d i d not  readily orient  shock.  were c a p a b l e of u s i n g  The  r e s u l t s demonstrate that  a v i s u a l d i s p l a y as  that  lesioned  display  light display  other v i s u a l l y guided behaviors.  present report,  display  a c q u i s i t i o n o f c r i t e r i o n p e r f o r m a n c e was  equivalent  implications with  to the  of  r e s u l t s suggest  e n h a n c e d a c q u i s i t i o n o f c r i t e r i o n p e r f o r m a n c e b y SC the  rate  a p p a r e n t l y moving l i g h t  approaching l i g h t display.  animals c o r r e l a t e d with  as  a comparison of the  these  were to,  animals  a s i g n a l of shock even  though they had w i t h shock.  ignored the  Further,  t h e SC  response i n fewer t r i a l s  l i g h t d i s p l a y p r i o r to i t being and  DP  t h a n t h e SH  t i o n of c o n d i t i o n e d suppression  may  o r i e n t i n g d u r i n g pre-exposure of the ship w i l l  l e s i o n e d animals  acquired  controls.' Accelerated be  paired  acquisi-  r e l a t e d to the absence  l i g h t d i s p l a y s but  require furtherinvestigation.  this  this  of relatio:  GENERAL -DISCUSSION The  parameters o f o r i e n t i n g The  o r i e n t i n g response geherallyishas been t r e a t e d as a  simple r e f l e x i v e and u n i t a r y b e h a v i o r which occurs i n response t o the' p r e s e n t a t i o n o f a l m o s t a n y s t i m u l u s . not and does n o t respond t o a l l  s t i m u l u s changes.  i s a s e l e c t i v e behavior and t h i s number o f p a r a m e t e r s i n t r i n s i c  An a n i m a l , h o w e v e r , c a n Rather,  orienting  s e l e c t i v i t y i s determined by a  and e x t r i n s i c  o r i e n t i n g i s comprised of a s e r i e s  t o the animal.  Further,  o f b e h a v i o r a l components.  c r i p t i o n o f the o r i e n t i n g response t o a v i s u a l stimulus  A des-  includes  the c e s s a t i o n o f ongoing b e h a v i o r , t h e eye, head,and p o s t u r a l ments r e q u i r e d t o l o c a l i z e a n d f i x a t e  adjust-  the stimulus, and the reaching,  t r a c k i n g , a n d l o c o m o t o r a c t i o n s made t o w a r d s t h e s t a t i o n a r y o r m o v i n g stimulus.  These b e h a v i o r a l components a r e o n l y subsumed b y t h e gen-  e r a l t e r m " o r i e n t i n g " when t h e y o c c u r i n a s e q u e n c e . of t h i s  sequence,  i nfact,  Each  represents a discrete response.  p a r a m e t e r s w h i c h i n f l u e n c e o r i e n t i n g a p p e a r t o have t h e i r  component The effect  on t h e d u r a t i o n d f each component a n d w h e t h e r o r n o t t h e e n t i r e sequence  of behaviors occurs. An a t t e m p t was made t o d e t e r m i n e i f t h e e n t i r e  of behaviors involved i n o r i e n t i n g employed trial.  sequence  occurred i n response t o the s t i m u l i  i n t h i s i n v e s t i g a t i o n b y o b s e r v i n g t h e a n i m a l s on t h e f i r s t D i s r u p t i o n o f o n g o i n g b e h a v i o r w a s , h o w e v e r , t h e p r i m a r y mea-  sure used i n t h i s  i n v e s t i g a t i o n ' s t h i s component o f t h e r e s p o n s e  99  is  n e c e s s a r y i f t h e o t h e r components o f t h e sequence a r e t o o c c u r .  A novel  stimulus  can i n f l u e n c e o r g a i n c o n t r o l o f subsequent  only i f the animal d i s r u p t s i t s ongoing behavior  (i.e.,  behaviors  shifts i t s  attention). Previous  conclusions  t h a t SC l e s i o n e d a n i m a l s w e r e  o f t h e o r i e n t i n g r e s p o n s e have been b a s e d on paradigms t h a t  incapable ignore, the  d i s r u p t i o n component o f t h e o r i e n t i n g r e s p o n s e a n d r e q u i r e , t h e a n i mals t o l o c a l i z e a n d engage i n p r o l o n g e d e x p l o r a t i o n , o f t h e v i s u a l stimulus  1974; S c h n e i d e r ,  (Kirvel et al.,  d i d not take  1967, 1969). T h e s e s t u d i e s  i n t o c o n s i d e r a t i o n the f a c t that t h e o r i e n t i n g response  i s a sequence o f b e h a v i o r s  i n v o l v i n g s e v e r a l components a n d have  i n a p p r o p r i a t e l y c o n c l u d e d t h a t o r i e n t i n g was a b s e n t b e c a u s e t h e l a s t component d i d n o t o c c u r . argument w i t h r e s p e c t  W i l k i e a n d Masson  (1976) h a v e made a s i m i l a r  to studies of attention.  (See Note  While the paradigm used i n t h i s study animals t o l o c a l i z e o r explore  the stimulus,  1.)  d i d not require the  i t was s e n s i t i v e t o  small but r e l i a b l e responses t o the l i g h t d i s p l a y s .  Some o f t h e  l i g h t d i s p l a y s employed i n t h i s . i n v e s t i g a t i o n c l e a r l y - . c o n t r o l l e d t h e SC  l e s i o n e d animals'  behavior.  The l o c a l i z a t i o n a n d e x p l o r a t i o n  component o f t h e o r i e n t i n g r e s p o n s e were o f t e n s o b r i e f t h a t a measure based o n l y on o b s e r v a t i o n  o f t h e animals'  e y e , head, a n d p o s t u r a l  a d j u s t m e n t s would have been d i f f i c u l t t o o b t a i n . Manipulation  of stimulus  c h a r a c t e r i s t i c sand i n t r i n s i c  p a r a m e t e r s had- t h e i r e f f e c t o n t w o f a c e t s o f o r i e n t i n g  behavior.  These were t h e amount o f d i s r u p t i o n o f l i c k i n g on e a c h t r i a l a n d  100  the  number o f p r e s e n t a t i o n s  reliable  response  (i.e.,  measurement o f the o r i e n t i n g was  not  of the  the  light  rate  duration  purpose of t h i s  animals' response to the  lus  c h a r a c t e r i s t i c s a f f e c t e d w h e t h e r any  the  o r i e n t i n g response occurred ( i . e . , and  The with ous  the  the  light  duration  components o f  that  the  SH  localization  of  All  the  response from the various  different.  rate  "circling" and  SH  the  not  light displays  of habituation.  display,  the  "approaching" The  salience  combination of stimulus  of  components  closely  of  and  correlated  the f i r s t  perfect.  to the  In addition,  light displays lights  vari-  trial. observa-  revealed  ceased f i r s t ,  then  dimensions examined e l i c i t e d the  a n i m a l s and  was:  of  stimu-  l i g h t s , a n d , f i n a l l y , d i s r u p t i o n of l i c k i n g  stimulus  of h a b i t u a t i o n  t h a t the  or a l l of the  o r i e n t i n g r e s p o n s e on  Responding to the  terms of r a t e  components  disruption, localization  b e h a v i o r s towards the the  systematic  a n i m a l s a c t u a l l y engaged i n the  animals' habituation  exploratory  t o the  display revealed  a  o f e a c h component.  T h i s c o r r e l a t i o n , h o w e v e r , was t i o n of the  of a l l the  a m o u n t o f d i s r u p t i o n o f l i c k i n g was  amount o f t i m e t h e  While  investigation, observation  the  exploration)  that resulted i n  of h a b i t u a t i o n ) .  o c c u r r e n c e and the  displays  on  orienting  the  amount o f d i s r u p t i o n o f  the  early trials  displays The  can,  was  not  h o w e v e r , be  order from lowest to  display,  the  licking  markedly  ranked i n highest  t h e ' " s o l i d " nine l i g h t d i s p l a y , "stationary"  ceased.  "moving"  the display,  display. of  the  displays  appeared to r e s u l t from  characteristics.  The  amount o f  a  responding  101. e l i c i t e d b y a p a r t i c u l a r d i s p l a y was i n t e n s i t y or absolute  not determined s o l e l y by  number o f c h a n g e s ,  t h e amount o f a c t i v i t y i n  the d i s p l a y , i n c l u s i o n of apparent motion, o r the distance apparent motion.  F o r example, the approaching l i g h t s  w e r e more e f f e c t i v e t h a n t h e m o v i n g l i g h t s t h e i n t e n s i t y a n d amount o f a c t i v i t y  the  of  the  (Experiment  (Experiment i ) ,  even  IV) though  i n v o l v e d i n t h i s d i s p l a y were  less. The  pattern  or s p a t i a l configuration of the l i g h t s  display c l e a r l y influenced  t h e s a l i e n c e o f t h e d i s p l a y f o r SH  m a l s a n d s h o u l d be i n c l u d e d behavior (Experiment I V ) .  as a p a r a m e t e r  ani-  or determinant of o r i e n t i n g  I n a s i m i l a r manner, t h e o c c u r r e n c e o f  magnitude o f d i s h a b i t u a t i o n t o changes i n the l i g h t d i s p l a y s to r e s u l t from a combination of f a c t o r s i n c l u d i n g : m o t i o n , and  i n the  the s p e c i f i c pattern  of the display.  and  appeared  the i n t e n s i t y , F o r example,  change i n the d i r e c t i o n o f t h e a p p r o a c h i n g t o r e c e d i n g  the  lights  more  r e l i a b l y e l i c i t e d d i s h a b i t u a t i o n (Experiment IV) t h a n the change from the moving t o the s t a t i o n a r y l i g h t s The  e f f e c t s o f SG The  or  "apparently"  SG  l e s i o n s on  orienting  l e s i o n e d animals d i d not o r i e n t to a moving s t i m u l u s .  These s t i m u l u s  s a l i e n t f o r SH a n i m a l s a n d r e q u i r e d habituation b y t h e SC  (Experiment i ) .  to occur.  The  "flickering"  d i s p l a y s were  a number o f p r e s e n t a t i o n s  quite for  e l i m i n a t i o n of o r i e n t i n g to these s t i m u l i  lesioned animals could  n o t be a t t r i b u t e d t o a  general  i n a b i l i t y to d i s r u p t o r s h i f t the d i r e c t i o n of t h e i r behavior. T h e s e same a n i m a l s c l e a r l y c e a s e d l i c k i n g when a n  auditory  stimulus  was p r e s e n t e d a n d l o c a l i z e d t h e s o u r c e o f t h e t o n e  ment I I ) .  T h e SC l e s i o n e d a n i m a l s a l s o o r i e n t e d t o t h e l i g h t s  t h e p h y s i c a l i n t e n s i t y o f t h e d i s p l a y was i n c r e a s e d  Further,  when  (Experiment I I I )  o r when a d i f f e r e n t p a t t e r n o f t h e d i s p l a y was e m p l o y e d IV).  (Experi-  (Experiment  t h e SC l e s i o n e d a n i m a l s w e r e shown t o h e c a p a b l e o f  orienting to the previously  ignored  l i g h t d i s p l a y when g i v e n  t o w a t e r p r i o r t o t e s t i n g ( E x p e r i m e n t .V.) a n d d i s r u p t e d  access  licking  when  It.was p a i r e d w i t h shock (Experiment V i ) . E v e n t h o u g h t h e SC l e s i o n e d a n i m a l s d i d o r i e n t t o some o f t h e v i s u a l d i s p l a y s t h e i r b e h a v i o r d i f f e r e d from t h a t trol in  animals i n three  ways:  o f t h e SH  ( l ) T h e amount o f d i s r u p t i o n o f l i c k i n g  r e s p o n s e t o t h e l i g h t s a n d t h e number o f t r i a l s t o h a b i t u a t e  d i f f e r e n t d i s p l a y s d i f f e r e d markedly animals.  b e t w e e n t h e SC a n d SH  A l l t h e SC l e s i o n e d a n i m a l s h a b i t u a t e d  repeated presentation  con-  to  lesioned  more q u i c k l y t o t h e  o f t h e v i s u a l d i s p l a y s t h a n t h e SH a n i m a l s a n d  t h e y g e n e r a l l y d i d not d i s h a b i t u a t e t o t h e changes i n t h e v i s u a l d i s plays.  (2) When SC l e s i o n e d a n i m a l s o r i e n t e d t o t h e l e s s s a l i e n t  d i s p l a y s , o n l y t h e d i s r u p t i o n and l o c a l i z a t i o n components were o b s e r v e d and t h e s e were o f r e d u c e d d u r a t i o n trol  animals.  r e l a t i v e t o t h o s e o f con-  O r i e n t i n g t o t h e more s a l i e n t d i s p l a y s a l s o  involved  o n l y t h e d i s r u p t i o n a n d l o c a l i z a t i o n c o m p o n e n t s f o r t h e SC  lesioned  animals although the durations  o f t h e s e components were p r o l o n g e d  relative to the less salient displays.  (3) U n l i k e  SC l e s i o n e d a n i m a l s w e r e n e v e r o b s e r v e d t o a p p r o a c h play  o r t o f o l l o w t h e apparent  control animals, the light  motion o f t h e d i s p l a y .  dis-  103  The can  "behavioral-deficit  d e m o n s t r a t e d b y SG l e s i o n e d  be s u m m a r i z e d a s v i s u a l " n e g l e c t "  or "inattention"  animals  to novel  v i s u a l s t i m u l i which capture the normal-animals' a t t e n t i o n and provoke a "dramatic,"-reaction-." " . T r a d i t i o n a l  m o d e l s .of t h e n e u r a l - b a s i s  of v i s u a l l y g u i d e d b e h a v i o r have s u g g e s t e d a d i r e c t between "the"  orienting  suggested that Clearly, the  r e s p o n s e a n d t h e SG.  t h e SC was e s s e n t i a l  relationship  These models  further  to the e l i c i t a t i o n of orienting.  t h e SC n e e d n o t b e i n t a c t f o r a v i s u a l s t i m u l u s t o e l i c i t  disruption  o f ongoing behavior and the l o c a l i z a t i o n o f a  Superior c o l l i c u l u s lesions  stimulus.  d i d r e s u l t i n an impairment o f o r i e n t i n g  b e h a v i o r i n terms o f t h e d u r a t i o n o f these components, t h e r a t e o f habituation stimuli. sive  o f o r i e n t i n g , and d i s h a b i t u a t i o n  I n summary, t h e SC l e s i o n e d  a n i m a l s were o n l y " l e s s "  suggested that  SG l e s i o n e d  (1974) a n d S p r a g u e e t a l .  included  i n this report are consistent  however, t h e f i n d i n g s inattention stimuli.  in  withothis  emphasize t h e f a c t t h a t  The  deficit studies  interpretation-,  visual neglect or  need n o t r e f l e c t a n i n a b i l i t y t o o r i e n t  o r respond t o v i s u a l  The v i s u a l n e g l e c t o r i n a t t e n t i o n , m a n i f e s t e d " b y SC  was s e l e c t i v e  (1977)  animals manifest a behavioral  which they described as v i s u a l neglect o r i n a t t e n t i o n .  rats  respon-  to novel v i s u a l stimuli, but not incapable o f orienting. Gasagrande a n d Diamond  also  t o changes i n v i s u a l  and appeared t o r e p r e s e n t a q u a n t i t a t i v e  lesioned change  t h e animals' response t o n o v e l s t i m u l i a n d t o changes i n v i s u a l  stimuli.  104  The animals were not simply inactive and unresponsive to s t i m u l i or change per se. following findings:  This point i s c l e a r l y i l l u s t r a t e d by the  ( l ) SG lesioned animals d i d not d i f f e r from SH  animals i n response to an auditory stimulus.  (2) Manipulation of  the amount of water accessible to the animals p r i o r to t e s t i n g resulted i n disruption of l i c k i n g equivalent to that of the intact animals.  (3) The SC and DP lesioned animals were capable of using  the onset of the previously ignored l i g h t displays as a signal of shock, and further, they acquired t h i s response i n l e s s t r i a l s than SH animals.  (4) F i n a l l y , the SC and DP lesioned animals were much  more active than SH animals tested i n an open f i e l d These r e s u l t s are reported i n Appendix D.  situation.  The SC and DP lesioned  animals crossed more squares i n the f i e l d and reared l e s s often than SH animals.  The SC lesioned animals' excessive a c t i v i t y i n  the open f i e l d appeared to be due i n part to the f a c t that they were not d i s t r a c t e d by the peripheral s t i m u l i which the intact animals appeared to respond to by rearing and s n i f f i n g , but instead, persisted i n t h e i r locomotor a c t i v i t y .  These r e s u l t s  supplemented  the interpretation outlined above and c l e a r l y demonstrated that SC lesioned animals d i d not s u f f e r a general malaise which would have interfered with t h e i r responsiveness to v i s u a l s t i m u l i . The data reported above suggest that the s e l e c t i v e v i s u a l neglect or inattention demonstrated by SC lesioned animals d i d not r e s u l t from a simple, passive neglect of v i s u a l s t i m u l i .  Rather,  the animals were l e s s e a s i l y distracted by the l e s s salient s t i m u l i  105  in  t h e i r environment and d i d n o t s h i f t o r r e d i r e c t t h e i r behavior ( o r  a t t e n t i o n ) t o t h e l i g h t s and n e g l e c t t h e water spout. o f t h e SG a n d DP l e s i o n e d a n i m a l s of a c q u i s i t i o n of suppression  The p e r s i s t e n c e  i n t h e open f i e l d and enhanced r a t e  t o t h e l i g h t s when p a i r e d w i t h s h o c k s u p -  port this interpretation.  Results of other studies are also consistent  with this interpretation.  Jane," L e v e y , a n d G a r l s o n  t t t h a t SC l e s i o n e d a n i m a l s t  had d i f f i c u l t y  with reversals i n a pattern  c r i m i n a t i o n t a s k and p e r s i s t e d i n responding stimuli.  Goodale and M u i r i s o n  did  (1975) f o u n d t h a t SG a n i m a l s t o o k more  i r r e l e v a n t v i s u a l and a u d i t o r y s t i m u l i .  and were n o t d i s t r a c t e d  A l s o , r a t s w i t h SG l e s i o n s  n o t d i s r u p t b a r p r e s s i n g when a n i r r e l e v a n t l i g h t was  (Goodale & L i s t e r , stimulus  presented  1974), a n d w e r e l e s s s u s c e p t i b l e t o a s t a r t l i n g  than c o n t r o l s (Goodale, M i l n e r & Rose,  G o o d a l e , Foreman, and M i l n e r evant,  dis-  t o the p r e v i o u s l y rewarded  d i r e c t paths t o a goal box than c o n t r o l animals by  (1972) d e m o n s t r a t e d  1975)-  More r e c e n t l y ,  (1977) f o u n d t h a t v i s u a l n e g l e c t o f i r r e l -  d i s t r a c t i n g , a n d n o v e l s t i m u l i was r e s t r i c t e d t o t h e p e r i p h e r y  of the visual f i e l d s i n colliculectomized rats.  These animals  were,  h o w e v e r , d i s t r a c t e d b y a n i r r e l e v a n t s t i m u l u s when i t was p r e s e n t e d i n the  c e n t r a l v i s u a l f i e l d i n c l o s e r p r o x i m i t y t o the g o a l box.  salience of a v i s u a l stimulus likely  and i t s p o t e n t i a l t o be d i s t r a c t i n g a r e  a function of i t s p o s i t i o n i n the v i s u a l f i e l d ,  c i a t i o n with aversive o r rewarding sic  i t s prior  consequences, and t h e o t h e r  parameters o u t l i n e d i n t h i s r e p o r t .  ther systematic  The  asso-  extrin-  These v a r i a b l e s warrant  fur-  measurement t o d e t e r m i n e t h e i r r e l a t i v e c o n t r i b u t i o n  as p a r a m e t e r s o f t h e o r i e n t i n g r e s p o n s e .  106. The e f f e c t o f l e s i o n s  o f t h e s u p e r f i c i a l a n d deep l a m i n a e o f t h e  SG o n o r i e n t i n g . L e s i o n s o f t h e e n t i r e SC r e s u l t e d tention"  to a light display  that  l e s i o n s were c o n f i n e d t o o n l y a s m a l l  the  deep l a y e r s  demonstrated.  tegmentum,  As was t h e c a s e f o r a n i m a l s  orienting behavior.  These animals  with  disrupted  l i c k i n g a n d l o c a l i z e d t h e more s a l i e n t l i g h t d i s p l a y s . they oriented  previously  t o and  with  shock.  When l e s s  localized a light display  i g n o r e d and they responded t o t h i s d i s p l a y  when i t was p a i r e d of  visual  o f t h e e n t i r e S C , l e s i o n s o f t h e d e e p l a m i n a e d i d n o t com-  pletely eliminate  thirsty,  When  area a t the junction of  o f t h e SC a n d t h e a d j a c e n t d o r s a l  n e g l e c t was a l s o  or "inat-  normal animals responded t o .  the  lesions  i n "neglect"  Unlike  as a s i g n a l  t h e animals with  t h e deep l a m i n a e o r t h e e n t i r e SC, a n i m a l s w i t h  they  lesions  lesions  confined  t o o n l y t h e s u p e r f i c i a l l a m i n a e o f t h e SC a n d t h e b r a n c h i u m o f t h e SC o r i e n t e d  t o and l o c a l i z e d a l l o f t h e novel v i s u a l  displays.  Recently, i t has been popular t o attempt t o d i s s o c i a t e the as  r o l e o f t h e s u p e r f i c i a l l a m i n a e a n d t h e d e e p l a m i n a e o f t h e SC discrete  f u n c t i o n a l and a n a t o m i c a l systems (Casagrande & Diamond,  1974; I n g l e & S p r a g u e , 1974).  C a s a g r a n d e a n d Diamond a l s o  that  lesions  with  orienting t o v i s u a l s t i m u l i by tree  that  included  gested that  found  c o n f i n e d t o t h e s u p e r f i c i a l laminae d i d n o t i n t e r f e r e s h r e w s . "However,  b o t h t h e s u p e r f i c i a l and deep l a y e r s  d i d . They s u g -  t h e s u p e r f i c i a l l a y e r s • w e r e not. i n v o l v e d  b e h a v i o r except as t h e source o f v i s u a l i n f o r m a t i o n  lesions  i n orienting t o t h e deep  107  layers of the c o l l i c u l u s .  I t was the deep layers i n conjunction  with other (presumably non-visual) inputs that were responsible f o r i n i t i a t i n g the orienting response to v i s u a l s t i m u l i . The data presented i n t h i s report support t h i s interpreta^ t i o n i f one considers only the l e s s s a l i e n t l i g h t displays (which the DP lesioned animals d i d not orient to while the SP lesioned animals d i d ) .  I t i s also i n t e r e s t i n g i n t h i s regard that the SP  and  DP lesioned animals d i f f e r e d with respect to t h e i r performance i n the open f i e l d and a c q u i s i t i o n of the v i s u a l display-shock-'.association.  The SP lesioned animals did not d i f f e r from the SH operated  controls i n either of these tasks, while the DP lesioned animals were more a c t i v e , i n the open f i e l d and acquired the v i s u a l displayshock association f a s t e r than SH operated controls. However, other data are not supportive of Casagrande and Diamond's interpretation, since:  ( l ) Orienting to the more s a l i e n t  displays was not eliminated f o r the DP lesioned animals and, i n r e s ponse to these displays, they behaved l i k e the SP lesioned animals. ( 2 ) The DP and-SP lesioned animals were also a l i k e i n that they gene r a l l y d i d not dishabituate to the changes i n the l i g h t displays. F i n a l l y , ( 3 ) the DP and SP lesioned animals did not rear i n the open f i e l d , nor were they observed to engage i n the intense  explora-  tory behavior that SH operated animals demonstrated i n response to some of the moving l i g h t d i s p l a y s .  These data suggest that the  s u p e r f i c i a l and deep laminae of the superior c o l l i c u l u s are not d i s c r e t e functional and anatomical systems.  108  The  e f f e c t of " c o r t i c a l lesions or. orienting Lesions r e s t r i c t e d to the s t r i a t e cortex (area 17)rand the  extrastriate cortex (areas 18 & 18A) tion, or dishabituation.  did not impair orienting, habitua-  These animals were i d e n t i c a l to the SH oper-  ated control animals i n a l l respects. as well as a l l of areas 17,  Lesions which included area 7  18, and 18A did not i n t e r f e r e with the  disruption and l o c a l i z a t i o n components of the orienting i n response to any of the novel l i g h t displays; however, these animals required fewer t r i a l s to habituate to the l i g h t displays and d i d not  disha-  bituate to the changes i n the l i g h t displays. Only a few rats, however, sustained  a l e s i o n which removed  area 7 and a l l of the s t r i a t e and extrastriate cortex i n t h i s report; consequently, additional animals were tested and the r e s u l t s are reported  i n Appendix E.  The r e s u l t s of t h i s study confirmed the  above findings and demonstrate that lesions of the cortex l i k e l y require the loss of both the geniculo-striate system and the from the s u p e r f i c i a l layers of the SG to the cortex ( v i a NLP)  input to  y i e l d a behavioral d e f i c i t comparable to that caused by lesions of the superficial'-'.SC laminae.  Lesions of the s u p e r f i c i a l layers of  the SC (SP l e s i o n s ) , the terminal area of the geniculo-striate and tecto-pulvinar system (large c o r t i c a l lesions), or the geniculo-striate and tecto-pulvinar pathways to cortex (NLP  and area 17)  do not a f f e c t  the disruption or l o c a l i z a t i o n components of orienting to the novel l i g h t displays.  However, animals with any of these lesions habituate  more quickly and do not dishabituate to the changes i n the l i g h t d i s plays .  109  On cluded  t h e b a s i s o f t h e d a t a s u m m a r i z e d a b o v e , i t c o u l d be  that the behavioral d e f i c i t  i s simply  of v i s u a l neglect  t h e deep l a y e r s o f t h e terminal to the  area of the  SC,  the  considered  g e n i c u l o - s t r i a t e and  involved  i n o r i e n t i n g to a novel  Indeed, the  v i s u a l stimulus-.and  Both involve the  (shifts i n attention).  SC.,  and  those  involved  are not  likely  r e d i r e c t i o n of b e h a v i o r towards  Dishabituation  i s the recovery  t o t h e d i s r u p t i o n and ponse to the occurred a shift  novel  localization  s t i m u l i on t h e  to the novel  early t r i a l s .  s t i m u l i on t h e  l i c k i n g the  of the  o f one  SC  had  c o r t e x and  t o be  o r i e n t i n g to the.novel  modality  involved  stimuli.  i n res-  response which represented  to a  stimulus  cues i n v o l v e d  in  visual stimuli). s u p e r f i c i a l laminae of the  eliminated dishabituation i n this  l a y e r s of the  restricted  early trials likely  from the p r o p r i o c e p t i v e  water spout to the  Lesions generally  (e.g.,  The  by  stimulus  components w h i c h o c c u r r e d  i n a t t e n t i o n from a stimulus  of another modality  t e r m o r i e n t i n g was  of  and  d e f i n i t i o n i n v o l v e s s h i f t s i n a t t e n t i o n t o changes w i t h i n a In t h i s i n v e s t i g a t i o n the  the  behaviors  o r i e n t i n g t h a t o c c u r s i n response t o changes i n a s t i m u l u s  modality.  that  t e c t o - p u l v i n a r pathways  i n d i s h a b i t u a t i o n t o changes i n a v i s u a l s t i m u l u s separate behaviors.  SC.  i t appears  s u p e r f i c i a l l a y e r s of the  c o r t e x are a l l i n v o l v e d i n o r i e n t i n g .  stimuli  or inattention  a r e s u l t o f the removal o f the deep l a y e r s o f t h e  However, i f t h e d i s h a b i t u a t i o n d a t a a r e  con-  investigation.  i n the l e s i o n to  T h e s e r e s u l t s may  ence i n t h e s e a n i m a l s ' ^ a b i l i t y t o a t t e n d  The  SC deep  eliminate  reflect a  t o changes w i t h i n  differ-  and  1 10  between m o d a l i t i e s .  Jane e t al...  i n t e r p r e t a t i o n with, r e s p e c t that  (1972) h a v e p r o p o s e d a s i m i l a r  t o attentional behavior.  They  i n t r a n o d a l a t t e n t i o n i s mediated by t h e cortex  a t t e n t i o n i s mediated by t h e c o l l i c u l u s .  while  intermodal  The data, o f t h e - p r e s e n t  i n v e s t i g a t i o n , however, suggest t h a t  intermodal  the  extrastriate cortex,  cial  connections between t h e s t r i a t e ,  attention  intramodal  deep l a y e r s appear t o be i n v o l v e d attention.  i n both  I n t h i s i n v e s t i g a t i o n t h e DP  animals d i d not s h i f t from t h e s t i m u l i associated  and s u p e r f i -  in the visual display. species  Page & S u t t e r l i n ,  1970)  also  mouse, Dr'ager, 1975, suggest t h a t  197°;  i n other goldfish,  an important f u n c t i o n o f  d e e p SC l a y e r s may b e t h e i n t e g r a t i o n o f i n f o r m a t i o n  sense m o d a l i t i e s .  lesioned  t o t h e changes  Electrophysiological recordings  ( c a t , G o r d o n , 1973;  intermodal  with drinking t o  those o f t h e v i s u a l d i s p l a y and d i dn o t d i s h a b i t u a t e  the  involves  layers of the colliculus. The  and  suggested  i n several  C e l l s i n t h e s u p e r f i c i a l l a y e r s o f SC o n l y  res-  pond t o v i s u a l s t i m u l i w h i l e  c e l l s i n t h e deep l a y e r s r e s p o n d t o  s t i m u l i from every modality.  The f u r t h e r enhancement o f v i s u a l  neglect  b y i n c l u d i n g t h e d e e p l a y e r s i n t h e l e s i o n may b e t h e r e s u l t  of the elimination of the v i s u a l input (and  from t h e s u p e r f i c i a l  perhaps other v i s u a l areas) i n combination with  o f t h e many c o n v e r g e n t n o n - v i s u a l The Figure  Zk.  the destruction  pathways.  above l e s i o n - b e h a v i o r  This  layers  r e l a t i o n s h i p s a r e summarized i n  summary s u g g e s t s t h a t  a different  o f t h e SC's i n v o l v e m e n t i n o r i e n t i n g i s r e q u i r e d .  conceptualization Behaviorally,  I l l A.  Figure 24. A schematic diagram of the relationships between the behavioral impairment of orienting and lesions of the v i s u a l system.  1 12  such a model would have t o account f o r t h e s e l e c t i v i t y o f o r i e n t i n g behavior i n terms o f t h e i n f l u e n c e o f i n t r i n s i c  and e x t r i n s i c  m e t e r s o n t h e number o f components o f t h e o r i e n t i n g r e s p o n s e occur,  parathat  and t h e d u r a t i o n o f each component. I t was somewhat s u r p r i s i n g t o f i n d t h a t l a r g e l e s i o n s o f  c o r t e x o r SC d i d n o t e n t i r e l y other  eliminate o r i e n t i n g behavior.  words, n e i t h e r o f t h e " c l a s s i c a l "  In  v i s u a l systems played  a  " p i v o t a l " , r o l e i n t h e d i s r u p t i o n and l o c a l i z a t i o n components o f t h e o r i e n t i n g response b u t r a t h e r appeared t o only modulate these ors  i n terms o f t h e d u r a t i o n  behavi-  o f the responses, rate o f habituation,  d e m o n s t r a t i o n o f d i s h a b i t u a t i o n , and the p r o b a b i l i t y o f t h e animal i n i t i a t i n g further exploratory  a c t i v i t i e s towards t h e l i g h t s .  Any  model o f t h e n e u r a l b a s i s o f o r i e n t i n g b e h a v i o r would have t o i n c l u d e b o t h t h e s u p e r i o r c o l l i c u l u s and t h e t e c t o - p u l v i n a r p r o j e c t i o n s t o cortex  i n conjunction  with t h e g e n i c u l o - s t r i a t e projection,, as a l l  t h e s e pathways appear t o modulate o r i e n t i n g There a r e three  questions  behavior.  a r i s i n g from t h i s i n v e s t i g a t i o n  t h a t warrant f u r t h e r d i s c u s s i o n and study:  ( l ) What s y s t e m o r  s y s t e m s do c o n t r o l t h e f i n a l m o t o r p a t h w a y s n e c e s s a r y f o r of t h e motor responses i n v o l v e d  initiation  i n t h e components o f o r i e n t i n g and  w h a t i s i t s r e l a t i o n s h i p t o t h e SC?  (2) What i s t h e r e l a t i o n s h i p  o f t h e SC t o t h e a p p r o a c h a n d f o l l o w i n g c o m p o n e n t s o f o r i e n t i n g ? (3) What a r e t h e i m p l i c a t i o n s f o r m o d e l s o f v i s u a l l y g u i d e d b e h a v i o r ?  I n i t i a t i o n o f 'orienting The  s u p e r i o r c o l l i c u l u s and t h e c o r t e x appear t o p l a y  only modulatory  r o l e s i nt h e o r i e n t i n g response.  Hence, t h e n e u r a l  a c t i v i t y r e q u i r e d t o i n i t i a t e t h e motor responses d i s r u p t i o n and l o c a l i z a t i o n :  „• - a n o t h e r ,  neural The  components o f o r i e n t i n g must o c c u r i n  structure(s).  known c o n n e c t i o n s o f t h e r a t s 1  points o f i n t e r a c t i o n arepresented i n c l u d e d i nt h e diagram order r e t i n a l  involved i n the  " v i s u a l systems" and  i n F i g u r e 24.  However, n o t  a r e o t h e r t e r m i n a l s o f t h e r e t i n a and second  connections which  may m e d i a t e t h e d i s r u p t i o n a n d l o c a l -  i z a t i o n components o f o r i e n t i n g  (Huhel & W i e s e l ,  1977)-  Any o f t h e s e  structures could he responsible f o r t h e i n i t i a t i o n o f t h e d i s r u p t i o n and/or l o c a l i z a t i o n components i n v o l v e d i n o r i e n t i n g b e h a v i o r . v e n t r a l geniculate nucleus, accessory optic nucleus & Webb, 19°2; Hayhow, Webb & J e r v i e , the cerebellum, receives r e t i n a l All  i960), a n d i n some s p e c i e s , . e v e n  or indirect  1976).  c o n n e c t i o n s t o t h e SC,  t h e tegmentum, o r d i r e c t a c c e s s t o t h e o c u l o m o t o r cord.  (Hayhow, S e f t o n  i n p u t s (Maekawa & T a k e d a ,  t h e s e s t r u c t u r e s have d i r e c t  The  nucleus and s p i n a l  The r o l e o f these s t r u c t u r e s h a s n o t been i n v e s t i g a t e d t o d a t e . A  second  possibility  i s that t h e connections t o the oculo-  motor nucleus and s p i n a l cord a r ed u p l i c a t e d throughout systems.  Anatomically this i scertainly feasible.  the visual  The v i s u a l l y  r e s p o n s i v e a r e a s o f c o r t e x h a v e numerous c o n n e c t i o n s t o s p i n a l and  m u l t i p l e i n d i r e c t p r o j e c t i o n s t o t h e oculomotor  nucleus.  cord In  a d d i t i o n , a number o f t h a l a m i c n u c l e i i n o t h e r s p e c i e s r e c e i v e  1 14  d i r e c t p r o j e c t i o n s from r e t i n a and these n u c l e i i n t u r n  project  t o t h e oculomotor and s p i n a l t r a c t s ( C a s t i g l i o n i , Galloway, & Coulter,  1978;  Edwards & H e n k e l , 1978;  GouldHall  ,-"&  Ebner,  1978). A model o f o r i e n t i n g might i n c l u d e connections as i n i t i a t i n g neural  commands t o t h e m o t o r m e c h a n i s m s  necessary t o d i s r u p t ongoing a c t i v i t y stimulus  some o r a l l o f t h e s e  i n response t o a stimulus  c h a n g e (.-the d i s r u p t i o n component).,  The d u r a t i o n  t i o n o f ongoing b e h a v i o r and t h e i n i t i a t i o n o f f u r t h e r  or  of disrup-  activity  d i r e c t e d t o w a r d s t h e s t i m u l u s may d e p e n d u p o n t h e i n f l u e n c e o f t h e modulatory areas o u t l i n e d i n t h i s i n v e s t i g a t i o n . (SC a n d c o r t e x )  These  structures  may a l s o f u r t h e r m o d u l a t e t h e o r i e n t i n g r e s p o n s e b y  e i t h e r d i r e c t l y i n i t i a t i n g o r i n h i b i t i n g t h e motor systems subsequent It  components ( e x p l o r a t i o n & f o l l o w i n g )  involved  underlying  i n orienting.  i s t h e s e components o f t h e o r i e n t i n g r e s p o n s e t h a t a r e most a f f e c t e d  b y SC l e s i o n s . stimulus  The d i r e c t i o n o f t h e head and l i m b s  i n space r e q u i r e s  towards a v i s u a l  a c l o s e correspondence between s e n s o r y and  m o t o r p r o c e s s e s i n t h a t t h e m o t o r a p p a r a t u s must b e c o n s t a n t l y with respect  t o p o s i t i o n o f t h e muscles r e l a t i v e t o a stimulus.  SC i s i d e a l l y o r g a n i z e d d a t a from recording  The  f o r t h i s f u n c t i o n and t h e e l e c t r o p h y s i o l o g i c a l  and s t i m u l a t i o n experiments suggest i t s i n v o l v e -  ment i n d i r e c t e d e x p l o r a t o r y h e a d 1972).  monitored  T h e SC i s l i k e l y ,  a n d eye movements (Wurtz & G o l d b e r g ,  however, o n l y  involved  head motions as t h e t e c t o - s p i n a l t r a c t o n l y  i n t h e neck and  extends t o t h e c e r v i c a l  l e v e l o f t h e s p i n a l t r a c t ( N y b e r g & H a n s e n , 1964) , a n d g r o s s p o s t u r a l  1 15  a d j u s t m e n t s and SC  limb  coordination  and  l e s i o n s ( N y b e r g & H a n s e n , 1964;  1975,  and  head and  1978).  Marshall,  The  d i r e c t i o n are unaffected  see SC  n e c k movements r e q u i r e d  a l s o Goodale &  t h e r e f o r e may  f o r the  be  s t r u c t u r e ( s ) may in this  involved  sense t h a t the  p o s s i b l y be The  be  coordination  i n gross p o s t u r a l adjustments.  It is  substrates  to the  while  the  neural  of o r i e n t i n g behavior  d u p l i c a t e d throughout the nervous SC  involved i n  other  neural  r e l a t i o n s h i p of the  Muirison,  r e f i n e d muscle  necessary to d i r e c t a c t i v i t y towards a stimulus  by  may  system.  a p p r o a c h and  f o l l o w i n g components  of orienting. The  r e l a t i o n s h i p between l e s i o n s o f the  t i o n o f f o l l o w i n g , and salient  s t i m u l i i s of i n t e r e s t .  (Marshall,  1978)  have not  are  incapable  the  animals simply  that normally  do  do  elicit  This  not  and  established  not  activity  animals  emit them i n r e s p o n s e t o v i s u a l s t i m u l i  such i n v e s t i g a t o r y b e h a v i o r s by  c e l l s of the  SC  SC,  which destroy On  involved  the  constant  these  animals.  However, t h e s e SC  the  responsive connections  projections  refinement of the  i n smooth f o l l o w i n g o r p u r s u i t and  connect  o t h e r hand,  visually  correspondence of the  necessary f o r the  intact  have c o n n e c t i o n s t o c e l l s c o n t r o l l i n g  receive p r o j e c t i o n s from other  h a v e t h e d i r e c t 1:1 be  elimina-  investigations  whether thc-SC l e s i o n e d  v i a c o r t i c a l motor connections.  w h i c h may  previous  e l i m i n a t e the motor responses.  n e c k m u s c l e s do regions  the  or approach behavior towards •  neck musculature, l e s i o n s o f the  tions, should  and  o f t h e s e components o f t h e o r i e n t i n g ' r e s p o n s e o r i f  Since the  exploratory  SC  muscle  approach •  1  movements o f e y e a n d h e a d . to respond  T h e SC l e s i o n e d a n i m a l s w e r e  16  observed  w i t h s m o o t h h e a d movements when a n a u d i t o r y s t i m u l u s was  p r e s e n t e d a n d e n g a g e d i n n e c k a n d h e a d movements r e q u i r e d f o r g r o o m i n g (Experiment  Ii).  A s was t h e c a s e f o r t h e d i s r u p t i o n a n d l o c a l i z a t i o n  components o f o r i e n t i n g ,  i t i s l i k e l y t h a t t h e SC l e s i o n e d  animals  a r e c a p a b l e o f t h e s e responses.,- b u t t h e y , a r e n o t e l i c i t e d by. v i s u a l s t i m u l i t h a t normal  animals tend t o explore.  c o u l d be examined i n s t u d i e s which explore v i s u a l  These  relationships  r e q u i r e a n i m a l s t o f o l l o w and  stimuli.  I m p l i c a t i o n s f o r models o f v i s u a l l y guided b e h a v i o r . The models o f v i s u a l l y g u i d e d b e h a v i o r r e v i e w e d I n t r o d u c t i o n suggested s t r i a t e system  t h a t p a t t e r n v i s i o n i s mediated  by t h e geniculo-  w h i l e t h e s u b c o r t i c a l systems were r e s p o n s i b l e f o r  simple r e f l e x i v e behaviors.  They a l s o suggested  of the behavioral significance of visual mation  i n the  of visual  that the evaluation  s t i m u l i and t h e t r a n s f o r -  i n f o r m a t i o n i n t o a d a p t i v e m o t o r b e h a v i o r s were a l s o  a function o f the geniculo-striate's connections t o the l i m b i c system. The f i n d i n g s o f t h i s i n v e s t i g a t i o n o f o r i e n t i n g  behavior  a r e a t odds w i t h t h e s e b r o a d e r models o f v i s u a l l y g u i d e d b e h a v i o r . T h e s u p e r i o r c o l l i c u l u s was f o u n d t o i n f l u e n c e t h e e a s e w i t h o r i e n t i n g b e h a v i o r was e l i c i t e d b y n o v e l s t i m u l i . c o l l i c u l u s appears  which  The s u p e r i o r  t o be i n v o l v e d i n a process by which t h e  behavioral s i g n i f i c a n c e of a p a r t i c u l a r v i s u a l stimulus i s assessed  I  and  the n e c e s s i t y of motor responses  determined  (i.e.,  whether  any  o r a l l o f t h e components o f o r i e n t i n g a r e w a r r a n t e d by a  particular  visual stimulus).  visual  F o r example, the p r o c e s s e s by which  s t i m u l u s i s e v a l u a t e d as r e q u i r i n g  any o r a l l o f the components  o r i e n t i n g b e h a v i o r i s i n f l u e n c e d by parameters organism, lus.  and-by the m o t i o n ,  a  intrinsic  to  of  the  i n t e n s i t y , and p a t t e r n o f a v i s u a l s t i m u -  I n p a r t i c u l a r , t h i s i n v e s t i g a t i o n found that the p a t t e r n of  stimulus  (Experiment I V ) i s an i m p o r t a n t d e t e r m i n a n t  F o r t h i s r e a s o n i t may  be  of  a  orienting.  counterproductive to separate the n e u r a l  s u b s t r a t e s o f v i s u a l l y g u i d e d b e h a v i o r i n t o one v i s i o n and  system f o r p a t t e r n  another system f o r o r i e n t i n g b e h a v i o r .  The  relationship  between the n e u r a l s u b s t r a t e s of v i s u a l l y guided b e h a v i o r are f a r more c o m p l e x t h a n t h o s e i m p l i c i t i n t h e b r o a d e r m o d e l s .  Figure  summarizes the l e s i o n - b e h a v i o r r e s u l t s o f t h i s i n v e s t i g a t i o n some of- the- c o n n e c t i o n s w h i c h m u s t be c o n s i d e r e d i n a n y account  o f o r i e n t i n g b e h a v i o r and, q u i t e p o s s i b l y ,  v i s u a l l y guided behavior.  17  24  and  adequate  other aspects  of  J I8  Note  1. A version of this  present investigation.  argument' c o u l d a l s o be a p p l i e d t o t h e  I f measures  o f autonomic nervous system  c h a n g e s , r e s p i r a t o r y c h a n g e s o r s m a l l e y e movements h a d b e e n r e c o r d e d , evidence o f o r i e n t a t i o n t o even t h e l e s s s a l i e n t v i s u a l d i s p l a y s and d i s h a b i t u a t i o n t o t h e changes i n t h e l i g h t d i s p l a y s b y a n i m a l s might have been o b t a i n e d .  lesioned  [ S i n c e n o r m a l r a t s do n o t s h i f t  t h e p o s i t i o n o f t h e eyes i n d e p e n d e n t l y o f changes i n head and body position  ( D r a g e r & H u b e l , 1975)  e y e movements a r e n o t l i k e l y t o  have o c c u r r e d i n d e p e n d e n t o f head and p o s t u r a l a d j u s t m e n t s w h i c h w o u l d l i k e l y h a v e b e e n i n c o m p a t i b l e w i t h l i c k i n g t h e w a t e r s p o u t .J I f f u r t h e r r e s e a r c h demonstrated t h a t autonomic o r o t h e r  physio-  l o g i c a l c h a n g e s do o c c u r i n r e s p o n s e t o v i s u a l s t i m u l i i t w o u l d reinforce the general conclusion of this report that is  n o t e n t i r e l y e l i m i n a t e d b y SG  lesions.  orienting  119. 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R e t e n t i o n o f t h r e e b r i g h t n e s s discriminations by rats following posterior cortical lesions. Journal o f C o m p a r a t i v e a n d P h y s i o l o g i c a l P s y c h o l o g y , 1 9 7 4 , 8 6 , 637-647V a l l e , F . P., & B o l s , R. J . Age f a c t o r s i n s e x d i f f e r e n c e s i n o p e n field activity ofrats. Animal L e a r n i n g and B e h a v i o r , 1976, 4, 457-460. W e l s k r a n t z , L. The i n t e r a c t i o n b e t w e e n o c c i p i t a l a n d t e m p o r a l c o r t e x i n v i s i o n : An overview. I n F . - , 0 . S c h m i t t & F. G. W o r d e n ( E d s . ) The N e u r o s c i e n c e s T h i r d S t u d y P r o g r a m , 1 9 7 4 , 1 8 9 - 2 0 4 , C a m b r i d g e , M a s s a c h u s e t t s , MIT P r e s s . W i c k e l g r e n , B., & S t e r l i n g , P. I n f l u e n c e o f v i s u a l c o r t e x o n r e c e p t i v e , f i e l d s i n t h e s u p e r i o r c o l l i c u l u s . o f - the c a t . 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J o u r n a l o f N e u r o p h y s i o l o g y , 1976, 22, 7^5-%5. W u r t z , R. H., & G o l d b e r g , M. E. A c t i v i t y o f s u p e r i o r c o l l i c u l u s i n b e h a v i n g monkey. . I V . E f f e c t s o f l e s i o n s o n e y e m o v e m e n t s . J o u r n a l o f N e u r o p h y s i o l o g y , 1972, 35-j 587-596.  APPENDIX A Analysis of Variance F  Tables.  129  Table 1 Analysis  o fVariance F Table  T r i a l s ,1-5 f o r S I , . S 2 , " S 3 and,S4, E x p e r i m e n t I G e i s s e r Greenhouse Conservative F test  Conventional F t e s t  Source  Degrees o f Freedom  Mean Square  Mean G Error  1 4 35  1264473.00000  P PG Error  3 12  513.20825 24.0.09863  105  137.19604  4 16  174.54883 142.59644 78.06718  T TG Error  140  12  PT PT.G Error  48  420  2395-84668  F  1293.43115 2.45071  Prob. F Exceeded  Degrees o f Prob. F Freedom Exceeded  '0.000 • 0.064  977-61133 3.75069 1.75004  2.23588 1.82659  0.013 0.066  1, 35 4, 35  P P  .05 .10  : 0.068 0.033  1, 35 4, 35  P P  .10 .10  1, 35 4, 35  P P  .10 .25  4 ,  1, 35 35  P P  .00 .00  0.000 0.011  1, 35 4, 35  P P  .01 .10  110.97266  1.86828  53-775^  0.90534  0.036 0.655  61.78020 11.35395  • 0.000 0.000  59-39815  S SG •Error  1 4 35  7351.92578 1351.13477 119.00133  PS PSG Error  3 12 105  397-92822 106.96094  TS TSG Error  4 16  425.78320  7.48886  110.14868  1.93734  0.000 - 0.022  1, 35 4, 35  P P  .05 .10  I.54063 1.22726  0.106 - 0.151  1, 35 4, 35  • P P  .10 .25  140  PTS PTSG Error Note.  = = = =  2.33327  56.85551  12  64.77994  48  51.60318  420  G P T S  45.84174  8.68048  42.04758  L e s i o n group. Stimulus pattern. Trial. Stimulus versus baseline.  130  Table 2 Analysis of Variance F Table Trials  1-30 f o r S I a n d S2, E x p e r i m e n t I G e i s s e r Greenhouse Conservative F test  Conventional F test  Source  Degrees y of Freedom1  Mean Square  F  Prob.. F Exceeded  Degrees o f Prob. F Freedom Exceeded  Mean G Error  1 4 35  2025994.00000 I836.71875 1044.64697  1939.40527 1.75822  -- 0.000 = 0.159  P PG Error  1 4 35  0.0 119.35590 112.85408  0.0 1.05761  • 1.000 •• 0.392  T TG Error  14 56 490  322.70776 100.56284 57.30560  5.63135 1.75485  0.000 0.001  1, 35 4, 35  •P- < .05 P > .10  PT PTG Error  14 56 490  77.24748 67.41168 61.35704  I.25898 1.09868  0.229 0.298  1. 35 4, 35  P > .25 P > .25  S SG Error  1 4 35  1886.95508 345.95166 91.75206  20.56580 3.7705.O  0.000 0.012  PS PSG Error  1 4 35  3.78170 1.87641  0.060 0.136  TS TSG Error  14 56 490  439.91357 90.50703 39.45749  11.14905 2.29379  = 0.0 • 0.000  1, 35 4, 35  p p  PTS PTSG Error  14 56 490  65.61133 49.94370 38.18611  1.71820 1.30790  • 0.049 - 0.074  1, 35 4, 35  p  Note.  G P T S  = = -= =  148.09595' 73.48230 39.16119  ' l e s i o n group. Stimulus pattern. .Trial. Stimulus versus baseline.  < .01  >.05  >..10 P > -25  131  Table  3  Analysis of Variance F Table f o r Experiment I I G e i s s e r Greenhouse Conservative F test  Conventional F test  Source  Degrees o f Freedom  Mean Square  F  Prob. F Exceeded  Degrees o f Prob. F Freedom Exceeded  Mean G Error  1 4 67  1541673.00000 1102.12793 536.86475  2871.62256 2.05290  0.0 0.097  P PG Error  2 8 134  4429-30469 62.05311 129.19458  34\28398 0.48035  0.000 0.868  1, 67 1, 67  p p  < .01 > .25  >T TG Error  4 16 268  2348.20508 48.38062 59.20955  39.65923 0.81711  0.000 O.389  ^ >  1, 67 67  p P  < .01 > .25  FT PT.G Error  8 32 536  199-02002 56.93457 54.01616  3-68445 1.05403  - 0.000 0.389  1, 67 4, 67  P > .05 P ? .25  S SG Error  1 4 67  28727.78125 205-46777 116.79880  245.95955 1.75916  0.0 0.147  PS PSG Error  2 8 134  2687-30664 46.33594 85.52274  31.42212 0.54180  0.000 0.823  1, 67  p > .01  4, 67  P  TS TSG Error  4 16 268  3285.36328 49.46265 47.36026  69.36961 1.04439  0.000 0.410  1, 67 4, 67  p u .01  PTS PTSG Error  8 32 536  344,17090 34.08765 40.95763  8.40303 0.83226  0.000 0.732  1, 67 4, 67  P £- .01  Note.  G P T S  = = = =  l e s i o n group. Stimulus pattern. Trial. Stimulus versus baseline.  < .25  P ^ .25  .25  132  Table Analysis Trials'1-5  4  o f Variance F Table  f o r S I , S 2 , S3 a n d S4, E x p e r i m e n t I I I G e i s s e r Greenhouse Conservative F test  Conventional F test  Source  Degrees of Freedom  Mean G Error  1 4 35  P PG Error  3  12 105 4 16  T TG Error  140  12  PT PTG Error  48 420  1 4 .35  S SG Error PS PSG Error  3  12 105 4 16  TS TSG Error  140  12  PTS PTSG Error Note.  48 420  G P T S  = = = =  Mean Square  F  Prob. F Exceeded  Degrees o f Prob. F Exceeded Freedom  1047163.37500 1553.69531 692.76172  1511.57788 2.24275  0.000 0.084  2046.07813  19.28630  1, 35 4, 35  p ^ .01  232.12955 106.08965  2.18805  0.000 0.017  622.87695 76.99609 50.93225  12.22952 1.5H73  0.000 0.103  1, 35 4, 35  p = .01 p = .10  133.45215  2.54463 1.02271  0.003 0.436  1, 35 4, 35  P * -05 P ^ .25  13791.12500 1310.72363  152.33879 14.47845  0.000 0.000  1, 35 4, 35  p .01 p = .01  1765.04297  34.11252  0.000 0.014  1, 35 4, 35  p = .01 p =• .05  131.97778 37.80292  3 . 4 9 1 2 1  0.000 0.000  1, 35 4, 35  p = .01 p ^ .05  147.56216  4.52343 , - 0.000 1.05178 0.385  1, 35 4, 35  p = .01 p ^ .25  53.63557  52.44452  90.52930  116.16243  2.24504  P ^ -05  51.74178  836.51593  34.31079 32.62173  22.12843  L e s i o n group. Stimulus pattern. Trial. Stimulus versus baseline.  133  Table 5 Analysis o f Variance F Table Trials  1-30 f o r S I a n d S 2 , E x p e r i m e n t  G e i s s e r Greenhouse Conservative F test  Conventional):- F t e s t  Source  F  Prob. F Exceeded  1709706.00000 974.76953 1097.83618  1557-34145 0.88790  ^0.0 . 0.481  26.30316 6.92009  0.000 : 0.000  Degrees o f Freedom 1 4  Mean G Error  35  Degrees o f Prob. F Exceeded Freedom  P PG Error  35  2533.57227 666.55615 96.72193  T TG Error  14 56 490  601.82935 90.02084 58.31429  10.32044 1.54372  0.0 0.617  1, 3 5 4, 3 5  P p  PT PTG Error  14 56 490  235.77065 54.08545 58.05476  4.06118 0.93163  0.000 0.617  1, 3 5 4, 3 5  P < .05 p >,25  S SG Error  1 4 35  7408.89063 523.55835 71-77959  103.21722 7-29397  0.000 0.000  PS PSG Error  1 4  22.51860 2.10436  0.000 0.101  35  1191.18823 III.3I622 52.89796  TS TSG • Error  14 56 490  796.08862 93.56082 33-97095  23.43439 2.75414  0.0 0.000  1, 3 5 4, 3 5  PTS PTSG Error  14 56 490  229.16656 40.90227 29.81012  7.68754 1.37209  0.000 0.044  1, 35 4, 3 5  Note. ' G P T S  1 4  Mean Square  III  = = = =  L e s i o n group. Stimulus pattern. Trial. S t i m u l u s 'versus b a s e l i n e .  <:.01 > .10  P > .01 P < .05  p < .01 p > .25  134  Table Analysis Trials  6  o f Variance F Table  1 - 5 f o r S I , S2, S 3 a n d S4, E x p e r i m e n t I V A G e i s s e r Greenhouse Conservative F test  Conventional F test  Source  Degrees o f Freedom  Mean Square  F  Prob. F Exceeded  Degrees o f Prob. F Exceeded Freedom  Mean G Error  1 4 19  .613145.50000 678.36816  2011.78638 2.22579  0.000 0.105  P PG Error  3 12 57  1870.96216 75.53107  39-64734  0.000 0.117  1, 19 4, 19  P P  T TG Error  4 16 76  434.98315 48.08046  II.05209  0.000 0.272  1, 19 4, 19  P i. .01 P ->.25  FT PTG Error  12  71.74576  1.78936 1.03420  0.051  1, 19 4, 19  P P  5.10 >.25  17150.29297 671.76367 166.59167  102.94807 4.03240  0.000 0.016 0.000 0.008  1, 19 19 >  P P  < .01  104.14813  50.78313 2.58990  735.61230  22.11537 1.27786  0.000 0.233  1, 19 4, 19  P P  2.03379 1.05325  0.022 0.389  1, 19 4, 19  P > .10 P » .25  48 228  1  S SG Error  19  PS PSG Error  3 12 57  TS TSG Error  4  4  PTS PTSG Error Note.  = = = =  47.19009  1.60057  1.22163  c.01  >.10  39-35753 41.46704 40.09573  2042.15234  40.21320  16 76  42.50491  12  66.'35774  48  34.36499  228  G P T S  304.77661  0.421  4  >.05  i..01  >-.25  33.26247  32.62759  L e s i o n group. Stimulus pattern. Trial. Stimulus versus baseline.  1 35  Table 7 Analysis of Variance F Table T r i a l s 1-30 f o r SI and S2, Experiment IVA Geisser Greenhouse Conservative F test  Conventional F t e s t Source  Degrees of Freedom  Mean Square  F  Prob... F Exceeded  Degrees of Prob. F Freedom Exceeded  Mean G Error  1 4 19  629630.87500 724.39453 239.40674  2175.59155 2.50303  0.0 0.077  P PG Error  1 4 19  2183-24878 67.64032 52.60526  41.50247 1.28581  0.000 0.311  T TG Error  9 36 171  554.18994 58.10774 31.04771  17.84961 1.87156  0.000 0.004  i , 30 4, 30  p 4-.01 p ->.10  PT PTG Error  9 36 171  191.85025 35.23784 30.75040  6.23895 1.14593  0.000 0.278  1, 30 4, 30  P  S SG Error  1 4 19  13157•12891 646.07397 212.57506  61.89403 3.03927  0.000 0.043  PS PSG Error  1 4 19  2359.37036 141.44482 40.95830  57.60420 3.45339  0.000 0.028  TS TSG Error  9 36 171  624.25903 41.10156 27.47084  22.72441 1.49619  -• 0.000 • 0.047  1, 30 4, 30  p ^..01 p >.10  PTS PTSG Error  9 36 171  289.94995 36.90442 23.40471  12.38853 1.57679  0.000 0.029  1, 30 4, 30 "  P  Note.  G P T S  = = = =  l e s i o n group. Stimulus pattern. Trial. Stimulus versus baseline.  P  ^.05 *.25  p <..01 *.io  136 Table 8 Analysis  o f Variance F Table  Experiment IVB G e i s s e r Greenhouse Conservative F test  Conventional F test  Source  Degrees o f Freedom  Mean Square  F  Degrees o f Prob. F Exceeded Freedom  0.000 0.057  Mean G Error  1 4 23  P PG Error  2 8  924.51636 125.67377 57-30966  16.13194 2.19289  0.000 0.046  1, 23 4, 23  p <i..01 p V .10  T TG Error  9 36 207  269.24292 34.58127 42.66112  6.31120 0.81060  0.000 0.771  1, 23 4, 23  P t~ -05 p .25  PT PTG Error  18  300.06616 27.38715 44.81671  6.69541  72  0.61109  0.000 0.994  1, 23 4, 23  p <L .05 p ^ .25  1 4 23  3348.76855 52.21161 32.56474  102.83417 1.60332  0.000 0.207  1436.43604 58.12714  44.31200 1.79314  0.000 0.103  1, 23 4, 23  p p  '356.20605 23.82291 29.07950  12.24939 0.81293  0.000 0.758  1, 23 4, 23  p *--.01 p ^.25  251.40016 20.73459 27.19446  9.24454  0.000 0.921  1, 23 4, 23  p i-.Ol p J*. .25  46 •  414  S SG Error  2 ' 8  PS PSG Error  46  TS TSG Error  9 36 207  PTS PTSG Error  72  Note.  18 414 G P T S  = = = =  1296232.00000 4490.42969 2.67917 773-38477 288.66528  Prob. F Exceeded  c.Ql  ^-25  32.41641  0.76246  L e s i o n group. Stimulus pattern. Trial. Stimulus versus baseline.  137  Table 9 Analysis of Variance F Table Experiment V Geisser Greenhouse Conservative F t e s t  Conventional F t e s t Source  Degrees of Freedom  Mean Square  Mean G Error  1 3 12  333328.81250 382.09717 - 130.57547  P PG Error  3 9  524.59375  T TG Error PT PTG Error.  •  3  F 2591.05933 2.92626  132.84119  Prob. F Exceeded 0.000 0.077  8.58772 ' 0.000 2.17464 '0.048  61.08653  6  ' 1  P < .01 .25 P  14.89722 0.87130  0.000 0.580  12 36  •133.89517 24.80371 39.88976  3.35663 0.-62181  0.000 0.951  15750.85547 . 451.61987 192.76462  81.71030  0.000 0.125  l 3 12 .  .01 P y .10 P  10.46177  0.000 0.098  1 3 12  P P  1 3 12  P < .01 P .25  48  144  PS PSG Error  3 9 36  583.60132 101.60066  4 . 12  974.86572 33.97491 37-50841  25.99059 0.90579  0.000  12 36 '  74.94661 29.26898 38.25179  1.95930 0.76517 O.76517  0.032 0.825  Note.  P < .05 P 7 .10 P  769.04590 44.97955 51.62344  1 ' 3 12  PTS PTSG Error  1 3 12  4 12  S SG Error  TS TSG ,Error  Degrees of Prob • K Freedom Ex ceeded  1.82132  55-78419  48  144  G P T S  2.34286  = = = =  Lesion group. Stimulus pattern. Trial. Stimulus versus baseline.  0.548  3 12 1 3 16  1 3 12  P P  P .P  < >  c.  >  .05 .25  .01 ,10  .10 > .25  >  138  T a b l e 10 Analysis o f Variance F Table Experiment I Versus Experiment V G e i s s e r Greenhouse Conservative F t e s t  Conventional F test  Source  Degrees of Freedom  Mean Square  F  Prob. F Exceeded  Mean E G Error  1 1 3 39  1154153-00000 22684.33203 1592.32666 685.39258  1683.92969 33.09683 2.32323  0.000 0.000 0.739  P PE PG PEG Error  3 3 9 9 11?  645.60010 301.10547 264.23438 80.58594 117.11514  5.51252 2.57102 2.25619 0.68809  0.001 0.058 0.023  T TE TG TEG Error  4 4 12 12 156  611.19629 402.51660 120.93262 52.57129  8.68986 5.72290  PT PTE PTG PTEG Error  12 12 36 36  168.76724  3-22181  20.66644  1.60960 0.39453 0.90019  S SE SG SEG Error  1 1 3 3 39  18373•23047  173.46249  194.48828  38.37549 13.22502 I.83617  PS PSE PSG PSEG Error  3 3 9 9 117  767.37231 136.82031 135.15451 64.56683 50.03792  468  70.33440  84.31543 47.15451 52.38278  4064.75000 1400.80078 105.92047  1.71939  0.74745  15-33582 2.73433 2.70104  1.29036  Degrees o f Prob. F Exceeded Freedom  0.718  1, 1, 3, 3,  39 39 39 39  P < .05 P > -05 p > .10 P > -25  0.000 0.000 0.067 0.704  1, 1, 1, 3,  39 39 39 39  P P P P  0.000 0.085 0.999 0.638  1, 1, 3, 3,  39 39 39 39  P > .05 p > .10 P > .25 P y .25  1, 1, 3, 3,  39 39 39 39  P < .01 p > .10 P > .05 p > . 10  :  < < > >  .01 -05 .10  .25  0.000 0.000 0.000 0.157 0.000  0.047  0.007 0.249  139  G e i s s e r Greenhouse Conservative F  Conventional F test  Source  Degrees o f Freedom  Mean Square  F  TSTSE TSG TSEG Error  4 4 12 12 156  1095-66699 292.-33887 73.28548 51.88638 49.47372  22.14644  PTS PTSE PTSG PTSEG Error  12 12 36 36  99.00098 44.12695 37.16254 34.01476 39-98340  Note.  468  Prob. F Exceeded  D e g r e e s o f Prob...'F Exceeded Freedom  1.04877  0.000 0.000 0.136 0.408  1, 1, 3, 3,  39 39 39 39  P < .01 P < .05 p > .10 p > .25  2.47605  0.004  0-355 0.589 0.717  39 39 39 39  p > .10  1.IO363  1, 1, 3, 3,  5-90897  1.48130  0.92945 0.85072  E = Experiment. G = . L e s i o n group*. Pir= S t i m u l u s p a t t e r n . T = Trial. S = Stimulus versus baseline.  P  > -25  P p  > .25  > -25  140  Table 1 1 "Analysis of-Variance F Table Trials  t o C r i t e r i o n , Experiment VI  Conventional F  Source Mean G S GS Error Note.  Degrees o f Freedom  Mean Square  1  175562.43750  4  2281.23633  1  1 1 0 2 . 4 9 6 0 9  4  2 4 6 . 2 4 7 0 7  30  370.83301  G = L e s i o n group. S = Stimulus display.  test  F  473.42700  Prob. F Exceeded 0.000'-  6 . 1 5 1 6 5  0 . 0 0 1  2.97303  0.095  0 . 6 6 4 0 4  0 . 6 2 2  1.41  Table  12  A n a l y s i s o f Variance F Table A c q u i s i t i o n o f Conditioned Suppression,  P h a s e 2, E x p e r i m e n t V I G e i s s e r Greenhouse ConservativesF test  Conventional F test  Source  Degrees of Freedom  Mean Square  F  Mean G L GL Error  1 4 1 4 30  1229020.00000  2935-41455  243.14453  927.75391 162.75781  0.58073 2.21586 0.38873  D DG DL DGL Error  3 12 3 12 90  10520.89844 335.55273  66.68654 2.12689  192.28384 98.63184 157-76645  0.62518  T TG TL TGL Error  9 36 9 36 270  168.64670 44.17935  3.74184 0.98023  27  71.26634 49.80373  DT DTG DTL DTGL Error  108  27  108 810  418.68701  42.08289 26.53189 45.07050  1.21879  0.93371 0.58868 1.65173 1.15429  47.43619 43.42468  1.09942  43.14656  1.00645  S SG SL SGL ' ' Error  1 4 1 4 30  229823.56250 521.72168 18.44922 652.55273  494.93945  DS DSG DSL DSGL Error  3 12 3 12 90  10026.03125 365.05811 17.81250 106.23209 117.61514  85.24438 3.10384  464.34668  I.12356 0.03973 1.40531  0.15145 0.90322  Prob. F Exceeded  Degrees o f Prob. F Exceeded Freedom  0.000 0.679 0.147  0.815 .01  0.000 0.023 0.308 0.816  1, 4, 1, 4,  30 30 30 30  P P P P  0.000 0.506 0.496 0.972  1, 4, 1, 4,  30 30 30 30  P P P P  i .05 i. .25  0.020  1, 4, 1, 4,  30 30 30 30  P P P P  * .10 > .25 x .25 25  1, 4, 1, 4,  30 30 30 30  P P P P  L.01  0.148  0.332 0.468  L.  .i. .10  * .25 ^ .25  .25 i.25  i.  0.000 0.364 0.843  0.256 0.000 0.001 0.929 0.548  t- .05  A .25  \ .25  Continued...  142  Geisser Greenhouse Conventional F test  Conventional F test Degrees of Source . Freedom  Mean - Square  F -  Prob. F - Exceeded  Degrees of Prob. F Exceeded •.Freedom  TS TSG TSL TSGL Error  9 36 9 36 2?0  141.18011 44.85036 67.61371 39.34288 33.98759  4.15387 1.31961 1.98936 1.15757  0.000 0.114 0.041 0.256  1, 4, 1, 4,  30 30 30 30  P P p P  DTS . • DTSG DTSL DTSGL Error  27 108 27 108 810  29.87036 31.37474 47.41072 34.87178 33-75862  0.88482 0.92938 1.40440 1.03297  O.636 0.679 0.084 0.397  1, 4, 1, 4,  30 30 30 30  P > .25 p > .10 P >-.25  Note.  G L D T S  = = = = =  Lesion group. Light display. Session. Trials. Stimulus versus baseline.  > .05 > .25 > .10 > .25  P > .25  Table Analysis  13  Degrees o f Freedom  2, A n a l y s i s  Mean " Square  2,'Experiment-VI G e i s s e r Greenhouse Conservative F test  F  Prob. F Exceeded  1229020.00000 243.14453 403.98315  3042.25537 0.60187  0.000 0.664  3 12. 105  10520.89844 335.55273 151.99496  69.21872 2.20766  0.000 0.016  T TG Error  9 .36 315  168.64670 44.17924 42.86670  3.93421 1.03062  0.000 0.426  DT DTG Error  27 108 945  71.26619 49.80363 43.30116  1.64583 1.15017  S SG Error  1 4 35  229823.56250 521.72168 473.11670  DS DSG Error  3 12 105  TS TSG Error DTS DTSG Error  Mean G Error  1 4 35  D DG Error  Note.  3  Suppression  Conventional F test  Source  4  o f Variance F Table  Acquisition of Conditioned Phase  1  Degrees o f Prob. F Exceeded Freedom  1, 35 4, 35  P P  < .01 > -05  1, 35 35  P P  .05 > .25  0.021 0.152  1, 35 4, 35  P P  > .25 > .25  485-76489 1.10273  0.000 0.371  1, 35 4, 35  P c P >  10026.03125 365.05811 113.46301  88.36386 3.21742  0.000 0.001  1, 35 ^, 35  P c .01 P ^".05  9 36 315  141.17924 44.85025 35.56061  3.97010 1.26123  0.000 0.152  1, 35 4, 35  P P  4-.05 > .25  27 108 945  29.87022 31.37474 34.27618  0.87146 0.91535  0.656 0.716  1, 35 4, 35  P P  > .25 > .25  .G= D = T = S =  L e s i o n group. Session. Trials. Stimulus versus  baseline.  4  '  .01 .25  144  Table 14 Analysis of Variance F Table Experiment B Geisser Greenhouse Conservative F test  Conventional F test  Source  Degrees o f Freedom  0.000 0.322  3 9 36  904.50293 76.53297 62.05225  14.57647 1.23336  0.000 0.306  1, 12 3, 12  P P  L  4 12 48  151.13422 67.25970 37,79749  3-99853 1.77948  0.007 0.079  1, 12 3, 12  P P  > .05 *..10  12 36 144  75.17934 45.24249 24.50761  3.06759 1.84606  0.001 0.006  1, 12 3, 12  P P  y  1 3 12  4080.38062 336.00146 75.24042  54.23123 4.46570  0.000 0.025  3 9 36  575.98389 43.00241 53.19720  10.82733 0.80836  0.000 0.612  1, 12 3, 12  P P  4..01  4 . 12 48  271.36401 68.24973 25.88504  10.48343 2.63665  0.000 0.009  .1, 12 3, 12  P P  t.01 A . 10  12 36 144  84.40443 48.35378 24.75693  3.40933 1.95314  0.000 0.003  1, 12 3, 12  P  .05 .10  Error  T TG Error  S SG Error  PS PSG Error  Error  PTS PTSG Error  Note.  G P T S  Degrees o f Prob. F Freedom Exceeded  3094.12988 1.29174  P PG  TS TSG  Prob. F Exceeded  502206.37500 209.66129 162.30940  Error  Error  F  1 3 12  Mean G  FT PTG  Mean Square  = = = =  Lesion group. Stimulus pattern. Trial. Stimulus versus baseline.  P  .01 ^.25  .05 *.10  145  T a b l e 15 A n a l y s i s o f V a r i a n c e F Table Appendix G G e i s s e r Greenhouse Conservative F t e s t  Conventional F t e s t  Source  Degrees o f Freedom  Mean Square  F  Prob. F Exceeded  Degrees o f P r o b . F Freedom Exceeded  Mean G E  1 1 10  574998.75000 1245.58325 • 242.48444  2371.28101 5-13675  0.000 0.047  P'  2 2 20  195-93469 51-51758 89.61803  2.18633 0.57486  0.138 0.572  1, 10 1, 10  P < -25  PG Error T TG Error  9 9 90  95.80034 104.73914 50.72156  1.88875 2.06498  0.064 0.041 ,  1, 10 1, 10  p < . 10 p < . 10  PT PTG Error  18 18 :180  43.92273 48.54578 43.93810  0.99965 1.10487  0.462 0.351  1, 10 1, 10  p < .25 P < .25  S SG Error  1 1 10  2956.48657 371.23169 34.09782  86.70601 10.88725  0.000 0.008  PS PSG Error  2 2 20  275-14111 26.35950 82.35588  3.34088 0.32007  0.056 0.730  1, 10 1, 10  P .25 P < .25  TS TSG Error  9 9 90  298.00488 98.87589 31.04611  9-59878 3.18481  0.000 0.002 "  1, 10 1, 10  P > .05 p < .10  18 18 180  77.17101 18.I6296 29-59142  2.60788 0.61379  0.001 0.886  1, 10 1, 10  p < .10 P < .25  PTS PTSG Error/ Note.  G P T S  = = = =  L e s i o n group. Stimulus pattern. Trials. Stimulus versus b a s e l i n e .  P  <  .25  <  146. APPENDIX B Counterbalanced P r e s e n t a t i o n of S t a t i o n a r y and " A p p a r e n t l y " M o v i n g l i g h t D i s p l a y s . The  f o l l o w i n g study  d i s r u p t i o n o f l i c k i n g on t h e  was  conducted to determine i f the  first  t r i a l s b y SC,  g r o u p s d e m o n s t r a t e d i n E x p e r i m e n t I I I was  first at  The  trials  1 per  SC  and  DP  SP  lesioned  the  specific  moving 1 per  i n response to p r e s e n t a t i o n of the apparently  l / l O sec  l i g h t s but  d i d not  d i s h a b i t u a t e to the  To  of the  of stimulus  s t i m u l u s , the order  a d d i t i o n a l n a i v e SH,  l/lO  l e s i o n e d a n i m a l s d i s r u p t e d l i c k i n g on  i n pattern of t h e l l i g h t s .  for  and  i n f l u e n c e d by  p a t t e r n of t h e . d i s p l a y used (the "apparently" display).  DP,  SC,  evaluate  SP,  and  DP  lesioned  the  moving  changes  the s i g n i f i c a n c e of the p r e s e n t a t i o n was  sec  motion  reversed  animals.  Method Subjects Sixteen naive e i t h e r SC,  SP,  DP,  o r SH  a n i m a l s were t e s t e d . lesions.  Four animals  Maintenance of the  s u r g i c a l p r o c e d u r e were i d e n t i c a l t o t h a t d e s c r i b e d  sustained  animals  i n the  and  previous  studies. Apparatus The previous  a p p a r a t u s was  i d e n t i c a l to that described  in  the  i d e n t i c a l to that described  i n Experi-  studies.  Procedure The  p r o c e d u r e was  ment I ; h o w e v e r , t h e o r d e r The  s t a t i o n a r y 1 per  l/5  of the s t i m u l u s  sec  p r e s e n t a t i o n was  l i g h t d i s p l a y ( S i ) was  presented  reversed. on  147. the f i r s t 15 t r i a l s , followed by the "apparently" moving 1 per  1/5  sec l i g h t display (S2) on t r i a l s 16-30, the stationary 1 per l/lO sec l i g h t display (S3)  on t r i a l s 31-35, and the "apparently" moving 1 per  l/lO sec l i g h t display (S4)  on t r i a l s 36-40.  A l l the animals i n the SC and DP lesioned groups were tested with the red f i l t e r s removed.  Half the animals i n the  SP  and SH lesioned groups were tested with the f i l t e r s removed and half with them on. Results The results of the analysis of variance f o r the f i r s t f i v e t r i a l s of l i g h t displays SI, S2, S3, Table 14 of Appendix A. X stimulus X group was  The four way  and S4 are presented i n  i n t e r a c t i o n of pattern X t r i a l  s t a t i s t i c a l l y r e l i a b l e (F = 1. 95, df = 36»  p_ < .01) with the conventional F t e s t . determine i f disruption of l i c k i n g was  144,  T tests were conducted to r e l i a b l y d i f f e r e n t from base-  l i n e f o r each of the lesioned groups on each t r i a l included i n the analysis.  T r i a l s on which disruption of l i c k i n g was r e l i a b l y d i f -  ferent from baseline ( t , c r i t i c a l , <* = .05/2, = 10.75) are marked by an asterisk i n Figure  25.  The SH animals; r e l i a b l y disrupted l i c k i n g on the f i r s t three t r i a l s to the stationary 1 per 1/5 sec l i g h t display,  habitua-  ted, and dishabituated to the change from one l i g h t display to another. Responding to the l i g h t display (Si) was not as marked ( i n terms of amount of disruption) as to the moving l i g h t display presented,, but the o v e r a l l pattern of r e s u l t s i s very s i m i l a r to that of the p r e v i ous studies f o r t h i s group.  148 A.  Figure 25(a-d). Mean number of l i c k s per 5 sec during baseline (B) and during presentation of the stimulus (S) f o r l i g h t displays SI, S2, S3, and S4. (a) SH, (b) SG, (c) SP, and (d) DP lesioned animals. The a s t e r i s k indicates the t r i a l s on which disruption of l i c k i n g was-.statistically r e l i a b l e .  149  A.  Figure 26(A-C). R e p r e s e n t a t i v e s e c t i o n s d e p i c t i n g the e x t e n t o f damage t o t h e S G a n d s u r r o u n d i n g t i s s u e f o r ( A ) S G , ( B ) S P a n d ( C ) D P lesioned animals.  149 B.  150. The  S C , S P , a n d DP l e s i o n e d a n i m a l s a l l r e l i a b l y d i s r u p t e d  l i c k i n g on a t l e a s t t h e f i r s t sec  t r i a l when t h e s t a t i o n a r y 1 p e r l / 5  l i g h t d i s p l a y was p r e s e n t e d f i r s t .  Disruption of licking d i d  not r e l i a b l y o c c u r t o any o f t h e l i g h t d i s p l a y changes The  l e s i o n s s u s t a i n e d by animals  presented.  i n t h e s e groups were  very s i m i l a r t o those o f t h e preceding s t u d i e s .  Representative  s e c t i o n s i l l u s t r a t i n g t h e e x t e n t o f damage t o t h e SC a n d s u r r o u n d i n g t i s s u e a r e i n c l u d e d i n F i g u r e 26.  The l e s i o n o f one s u b j e c t i n t h e  SC g r o u p , h o w e v e r , was n o t a s e x t e n s i v e a n d d i d n o t i n c l u d e damage to  t h e d o r s a l tegmentum o r p r e t e c t a l n u c l e i .  r e s p o n s i v e on t h e f i r s t group and accounts second of  trials  two t r i a l s  T h i s a n i m a l was more  than the other subjects i n t h i s  f o r t h e enhanced r e s p o n d i n g on t h e f i r s t and  r e l a t i v e to the preceding studies.  (Compare p a n e l 1  F i g u r e s 12(b) a n d 2 6 ( b ) ) . Discussion The  s t a t i o n a r y l i g h t s were l e s s s a l i e n t t h a n t h e m o v i n g  l i g h t s f o r t h e SH c o n t r o l a n i m a l s .  T h e SH a n i m a l s d i d n o t d i s r u p t  l i c k i n g f o r a s l o n g on any one t r i a l a n d t h e y r e q u i r e d f e w e r to  h a b i t u a t e t o t h i s l i g h t d i s p l a y than t o t h e moving l i g h t  in  Experiment  of  responding t o the l i g h t s  I.  T h e SC, S P , a n d DP l e s i o n e d a n i m a l s w e r e when f i r s t  presented.  trials display  capable  The p a t t e r n o f  the d i s p l a y d i d n o t appear t o i n f l u e n c e t h e magnitude o f t h e r e s p o n s e t o t h e l i g h t s o r t h e number o f t r i a l s to  required to habituate  i t s r e p e a t e d p r e s e n t a t i o n b y t h e SC l e s i o n e d a n i m a l s .  These  a n i m a l s , i n f a c t , a p p e a r e d t o h a b i t u a t e more q u i c k l y t o t h e m o v i n g l i g h t s i n Experiment  1 than to the stationary l i g h t s presented  first  J. 5.1  in this animal's  study. lesion  This finding  i s , h o w e v e r , somewhat a m b i g u o u s a s  i n t h e g r o u p was i n c o m p l e t e .  When t h i s  .  one  animal's  d a t a w e r e i g n o r e d , t h e SG l e s i o n e d a n i m a l s d i d n o t d i f f e r i n r e s p o n s e to  t h e moving and s t a t i o n a r y l i g h t  displays.  152. APPENDIX C The E f f e c t o f I n c r e a s e d on O r i e n t i n g The SG l e s i o n e d to disrupt  animals  Intensity  i nExperiment  t h e i r ongoing b e h a v i o r i n response  that  been important i n e l i c i t i n g lesioned  animals.  stationary animals ary  the pattern  The s t u d y d e s c r i b e d  o f t h e l i g h t s may n o t h a v e  t h e o r i e n t i n g response  T h e SC l e s i o n e d  observed  to thevisual stimuli  when t h e i n t e n s i t y o f t h e l i g h t was i n c r e a s e d . i n Appendix B suggested  I I I were  animals  f r o m t h e SC  a l s o responded t o t h e  d i s p l a y when i t was p r e s e n t e d f i r s t .  T h e c o n t r o l SH  w e r e more r e s p o n s i v e t o t h e m o v i n g d i s p l a y t h a n t h e s t a t i o n -  when i t was p r e s e n t e d f i r s t .  f u r t h e r evaluate t h e importance  The f o l l o w i n g s t u d y a t t e m p t s t o o f stimulus c h a r a c t e r i s t i c s by focus-  s i n g on t h e i n t e n s i t y o f t h e l i g h t s p e r s e . Method Subjects S u b j e c t s w e r e 6 n a i v e SC l e s i o n e d and  6 n a i v e SH l e s i o n e d  Long-Evans hooded r a t s  animals.  Apparatus The p r o c e d u r e except  that  was i d e n t i c a l t o t h a t d e s c r i b e d i n E x p e r i m e n t  t h e f o l l o w i n g s t i m u l i were p r e s e n t e d :  were i l l u m i n a t e d f o r 5 s e c .  (S2)  ( S i )A l l nine l i g h t s  A l l n i n e l i g h t s were i l l u m i n a t e d a n d  f l i c k e r e d a t 1 per l / l O sec i n t e r l i g h t i n t e r v a l .  (<S3)  A l l nine l i g h t s  were i l l u m i n a t e d a n d f l i c k e r e d a t 1 p e r l / 5 s e c i n t e r l i g h t L i g h t d i s p l a y S I was p r e s e n t e d o n t r i a l s S3 o n t r i a l s  21-30.  I  1-10, S2 o n t r i a l s  The r e d p l a s t i c f i l t e r s w e r e n o t u s e d .  interval. 11-20, a n d  153  Results The SC  r e s u l t s of the a n a l y s i s of v a r i a n c e comparing  l e s i o n e d animals are presented i n Table  15  of Appendix  t h e SH A.  and  The  b e h a v i o r a l a n d h i s t o l o g i c a l r e s u l t s a r e p r e s e n t e d i n F i g u r e 2?.  The  g r o u p s d i f f e r e d r e l i a b l y i n amount o f l i c k i n g d u r i n g t h e p r e s e n t a t i o n of  the l i g h t s .  The  o n l y the f i r s t three t r i a l s  SC  trial.  l e s i o n e d animals r e l i a b l y d i s r u p t e d l i c k i n g The  SH  animals d i s r u p t e d , l i c k i n g - o n the  first  t o S I , h a b i t u a t e d , and d i s h a b i t u a t e d t o the changes o f  stimulus display.  The  trials  on w h i c h  the  the animals r e l i a b l y d i s r u p t e d  l i c k i n g a r e marked by an a s t e r i s k i n F i g u r e df  on  2? _(jt, oc = .05/2, =  6.99,  10).  =  Two ducted.  a n i m a l s i n t h e SC  group d i e d b e f o r e h i s t o l o g i e s were  F o r t h e r e m a i n i n g a n i m a l s the h i s t o l o g i c a l r e s u l t s were  s i m i l a r to those presented i n the p r e v i o u s s t u d i e s . always  The  m o s t c a s e s t h e damage e x t e n d e d w h i t e m a t t e r of the c o r t e x , and  o f SC,  i n t o the c e n t r a l grey o v e r l y i n g t h e , hippocampus..  the  The b e h a v i o r a l d i d not vary i n  w i t h t h e e x t e n t o f damage t o e x t r a c o l l i c u l a r  i n c l u d e d I n the  SC,  and d o r s a l tegmentum. I n  r e s u l t s were q u i t e s i m i l a r f o r a l l t h e a n i m a l s and a n y ..obvious way  quite  lesions  i n c l u d e d damage t o t h e s u p e r f i c i a l a n d d e e p l a y e r s o f  p o s t e r i o r p r e t e c t a l n u c l e i , branchium  eon-r  areas  lesion. Discussion  In each  t h i s s t u d y , t r i p l i n g t h e number o f l i g h t s p r e s e n t e d  t r i a l r e s u l t e d i n o r i e n t i n g t o the l i g h t d i s p l a y s by  lesioned animals.  The  d i s r u p t i o n was,  the  SC  however, o n l y r e l i a b l e  on  on  the  154  A .  F i g u r e 27(A-C). ( A ) Representative sections depicting the e x t e n t o f damage t o t h e SC a n d s u r r o u n d i n g t i s s u e , ( B ) Mean number of l i c k s p e r 5 c d u r i n g the b a s e l i n e ( B ) and d u r i n g the p r e s e n t a t i o n o f the stimulus (S) f o rthe s o l i d ( S i ) and f l i c k e r i n g l i g h t d i s p l a y s S2 a n d S3, f o r SC l e s i o n e d a n i m a l s a n d ( C ) SH l e s i o n e d animals. The a s t e r i s k i n d i c a t e s t h e t r i a l s o n w h i c h d i s r u p t i o n o f l i c k i n g was s t a t i s t i c a l l y r e l i a b l e . - . s  e  SOL ID S 1  FLICKERING 1 SEC. S2 10  FLICKERING 1 SEC. S3 5  15 5  first  trial.  T h e r e was no f u r t h e r e n h a n c e m e n t o f r e s p o n d i n g f o r  these animals r e l a t i v e t o the responding demonstrated i n the p r e v i ous s t u d i e s . facilitate  The i n t e n s i t y o f t h e l i g h t  d i s p l a y p e r se appears t o  the e l i c i t a t i o n of o r i e n t i n g independent of the p a t t e r n  of the d i s p l a y .  156. APPENDIX D E f f e c t of V i s u a l and S u b c o r t i c a l L e s i o n s o n Open F i e l d A c t i v i t y . S m i t h a n d W e l d o n (1976) h a v e f o u n d t h a t a n i m a l s w i t h lesions  are excessively  examined r a t s w i t h deep l a y e r s  SC  o f t h e SC  active  lesions  i n an open f i e l d . that  overlying  t o t h e SC b u t r a t h e r  l y i n g tegmentum and The  t h e s u p e r f i c i a l and  c e n t r a l grey  t o t h e damage o f t h e  under-  l e s i o n groups employed i n the p r e v i o u s experiments  l e v e l o f l o c o m o t o r a c t i v i t y , and extracollicular structures.  o f t h e SC  examination of habituation  of  involve-  i n change,  t o examine the i n v o l v e m e n t  In addition,  animals by.comparing  a t the end  appro-  areas.  ment o f t h e s u p e r f i c i a l a n d . d e e p l a y e r s  lesioned  The  n o t have been  t h i s i n v e s t i g a t i o n p r o v i d e d an o p p o r t u n i t y t o examine the  plementary  tegmentum,  posterior,.cortex.  t h e y o b s e r v e d i n t h e s e a n i m a l s may  priately ascribed  authors  a n d s u b s t a n t i a l damage t o t h e d o r s a l  c e n t r a l grey, p r e t e c t a l n u c l e i , and hyperactivity  included  These  SG  i n the  of  the  t h i s study provided a  or waning of a c t i v i t y of  supthese  a c t i v i t y a t the s t a r t of t e s t i n g  and  of t e s t i n g . Method  Subjects S u b j e c t s w e r e 12 r a t s w i t h with  SC  l e s i o n s , 12 w i t h  operated controls. ment I , I I I , o r I V .  SP l e s i o n s ,  s t r i a t e cortex-ablations,.12 12 w i t h  A l l of these subjects  DP  l e s i o n s , and  had been t e s t e d  They were a l l o w e d a d l i b a c c e s s  f o r a t l e a s t 2 weeks p r i o r t o  testing.  in  12  SH Experi-  to f o o d and  water  157Apparatus A wooden open-field, 1.22 m square and  .3 m high and painted  white was divided into 16 equal squares by black l i n e s (described previously by Valle and Bols, 1976).  Illumination was provided by  a 15 watt overhead lamp positioned i n the center of the f i e l d providing an i l l u m i n a t i o n l e v e l of .29 cd/m  and  as measured by a Weston  l i g h t meter i n the center of the f l o o r of the f i e l d . Procedure The animals were dark adapted f o r at l e a s t 4 hours p r i o r to testing (tested during the dark phase of the colony light-dark cycle between 2100-2400 h r s ) , and moved from the colony to t e s t i n g room i n l i g h t - t i g h t carrying cases.  The animals were placed i n the  center of the open-field, f a c i n g the corner opposite the  experimenter.  The number of squares entered with both front paws and the number of rearing responses (both front paws o f f the f l o o r ) were counted f o r 10 min scored i n two 5 min blocks. was also recorded.  The number of f e c a l b o l i deposited  The f l o o r of the f i e l d was cleaned with a d i l u t e  vinegar s o l u t i o n a f t e r each animal's t e s t session. Results An analysis of variance compared the a c t i v i t y of the lesioned animals on the number of squares crossed and the number of rearing responses made i n the two 5 min blocks of the session.  A  separate analysis of variance compared the number of b o l i f o r each of the lesioned groups.  Differences between the lesioned and  SH  animals on these measures were assessed by t tests or be Dunnett's t  158. for  non-orthogonal comparisons. T h e r e w e r e no s t a t i s t i c a l l y r e l i a b l e  l e s i o n e d a n i m a l s f o r t h e number o f b o l i The means w e r e SH = 4.00,  S P = 5-25,  d i f f e r e n c e s between the  ( F = 1.24,  ST = 4.11,  d f = 1, 37;  SC = 2.92,  p ^  a n d DP =  The SH, S P , _ a h d - S T a n i m a l s ; - d i d t e n d t o h a v e - h i g h e r s c o r e s o n ' t h i s t h a n - t h e SC a n d DP l e s i o n e d a n i m a l s ; h o w e v e r , t h e v a r i a b i l i t y the  g r o u p s was q u i t e h i g h a n d t h e d i f f e r e n c e s w e r e n o t  .25). 2.67-  measure  within  reliable.  The l e s i o n e d g r o u p s d i f f e r e d m a r k e d l y i n t o t a l amount o f activity in  ( n u m b e r o f s q u a r e s c r o s s e d a n d number o f r e a r i n g  t h e o p e n f i e l d ( F = 2.62,  d f = 4,  37; £ -  .05).  responses)  The SH a n i m a l s  a v e r a g e d a t o t a l o f 116.3, SC a n i m a l s 205.0,- S P a n i m a l s 116.5, DP a n i m a l s 151.0, a n d ST a n i m a l s 172.7 responses i n the e n t i r e  squares c r o s s e d and r e a r i n g  10 m i n o f o b s e r v a t i o n .  The SC, DP, a n d ST  a n i m a l s w e r e much more a c t i v e i n t h e o p e n f i e l d t h a n t h e SH o p e r a t e d and SP l e s i o n e d a n i m a l s .  The SG, DP, a n d ST l e s i o n e d a n i m a l s w e r e  s t a t i s t i c a l l y d i f f e r e n t f r o m SH a n i m a l s , w h i l e t h e S P l e s i o n e d a n i m a l s were n o t ( D u n n e t t ' s t,  =  .05/2, 5, 35 = 49-15).  The number o f s q u a r e s c r o s s e d -and r e a r i n g r e s p o n s e s made i n the  first  and second h a l f o f t h e s e s s i o n d i f f e r e d markedly between  g r o u p s ( F = 8.04,  d f = 1, 37, £ -  S P , DP, a n d S T ) a c t i v i t y  .01).  The l e s i o n e d a n i m a l s ' ( S C ,  l e v e l s habituated, i n that they  reliably  crossed fewer squares i n the second h a l f of the s e s s i o n , but activity  (ty.  was n o t r e l i a b l y  d i f f e r e n t i n the 2 halves of the session  = .05/2, = 10.98, d f = 1, 37).  appeared  their  to habituate a c t i v i t y  A l l the lesioned  animals  i n t h e o p e n f i e l d more q u i c k l y  than  159. t h e SH o p e r a t e d a n i m a l s .  A d i f f e r e n c e between animals w i t h  large  l e s i o n s o f cortex which i n c l u d e d a l l o f area 1 7 , e x t r a s t r i a t e , and p a r t o f area 7 and those w i t h in habituation of activity.  lesions confined  t o a r e a 1 7 was o b s e r v e d .  The a n i m a l s w i t h l a r g e r l e s i o n s  were l e s s a c t i v e i n t h e s e c o n d h a l f o f t h e s e s s i o n . of animals with  lesions confined  clearly  The a c t i v i t y  t o a r e a 1 7 o n l y was d i s t r i b u t e d  more e q u a l l y b e t w e e n t h e t w o h a l v e s  of the session.  The n u m b e r o f r e a r i n g r e s p o n s e s was d i s t r i b u t e d e q u a l l y b e t w e e n t h e two h a l v e s statistically  a n d t h e d i f f e r e n c e s were n o t  r e l i a b l e f o r any o f t h e groups.  lesioned animals, the  of the sessions  h o w e v e r , made v e r y  entire session.  The SC,'SP,  a n d DP  few r e a r i n g responses  throughout  The S T l e s i o n e d a n i m a l s a n d SH o p e r a t e d  animals  made f a r more r e a r i n g r e s p o n s e s t h a n SC l e s i o n e d a n i m a l s .  The S T  l e s i o n e d a n i m a l s d i d n o t d i f f e r r e l i a b l y f r o m SH o p e r a t e d  animals,  while  a l l t h e SC l e s i o n e d a n i m a l s d i d o n t h i s m e a s u r e ( D u n n e t t ' s t ,  -05/2, 5 , 3 5 = 13.88). Discussion Lesions activity not  of the superior  i n t h e open f i e l d .  The s u p e r f i c i a l l a y e r s w e r e , h o w e v e r ,  involved i n this behavioral  d o r s a l tegmentum  were.  colliculus resulted i n increased  change, while  t h e deep l a y e r s and  This f i n d i n g supports the notion that the  deep l a y e r s ' r o l e i n b e h a v i o r c a n be d i s s o c i a t e d f r o m t h e s u p e r f i c i a l layers'  ( C a s a g r a n d e & Diamond, The a c t i v i t y  all  197^; I n g l e & S p r a g u e ,  1975)-  l e v e l s o f t h e S P , DP, a n d SC l e s i o n e d  changed as a f u n c t i o n o f time ( i . e . ,  there  was a m a r k e d  animals reduction  16 0  in  a c t i v i t y during  the second h a l f of the s e s s i o n ) .  The SH  opera-  t e d a n i m a l s were n e v e r a s a c t i v e a s t h e l e s i o n e d a n i m a l s h u t t h e i r l e v e l s o f a c t i v i t y was s u s t a i n e d ing,  throughout the session.  This  of course, p a r a l l e l s the r e s u l t s f o r f a s t e r habituation  o r i e n t i n g t o s p e c i f i c v i s u a l s t i m u l i f o r SC, SP, a n d l a r g e cortex  lesions reported  i n t h e main body o f t h i s  findof  posterior  report.  The SC l e s i o n e d a n i m a l s d i f f e r e d m a r k e d l y f r o m t h e SH c o n t r o l s a n d ST l e s i o n e d a n i m a l s i n t h e amount o f r e a r i n g i n t h e open f i e l d . field.  The SC l e s i o n e d a n i m a l s v e r y r a r e l y r e a r e d  The SH_and ST l e s i o n e d a n i m a l s s p e n t a g r e a t  i n the open  deal  o f time  r e a r i n g a n d t h i s a p p e a r e d . t o be i n r e s p o n s e t o e x t r a n e o u s n o i s e s was o f t e n c o r r e l a t e d w i t h b o u t s o f s n i f f i n g . mals' excessive  a c t i v i t y i n the open f i e l d  The SC l e s i o n e d  and  ani-  relative to control  a n i m a l s may h a v e b e e n due t o t h e f a c t t h a t t h e y were n o t d i s t r a c t e d by extraneous noises  and perhaps o l f a c t o r y s t i m u l i t h a t the i n t a c t  animals appeared t o respond t o by r e a r i n g and s n i f f i n g . the  SC l e s i o n e d a n i m a l s p e r s i s t e d i n t h e i r l o c o m o t o r  Marshall the  activity.  (1978) a l s o f o u n d SC l e s i o n e d a n i m a l s w e r e more a c t i v e i n  open f i e l d  a n d t h a t , • u n l i k e t h e SH o p e r a t e d ' a n i m a l s , t h e y d i d  no.t e x p l o r e . o b j e c t s i p l a c e d \ i n . t h e making l a t e r a l l y  t e s t c h a m b e r by r e a r i n g and  d i r e c t e d i n v e s t i g a t o r y head  movements.  I n summary, t h e s u p e r f i c i a l l a m i n a e o f t h e c o l l i c u l u s were n o t i m p l i c a t e d i n t h e e x c e s s i v e field  Rather,  superior  a c t i v i t y i n t h e open  d e m o n s t r a t e d f o r a n i m a l s w i t h l e s i o n s o f t h e deep  and. a d j a c e n t t e g m e n t u m ,  laminae  B o t h l e s i o n s , however, r e s u l t e d i n f a s t e r  161  habituation  of a c t i v i t y  and i n t h e l o s s o f r e a r i n g i n t h e open  Large lesions of the cortex  which included  cortex,and area 7 of the cortex, a r e a 17 r e s u l t e d i n i n c r e a s e d  or lesions confined  activity  impairment o f r e a r i n g i n t h e open  a r e a 17,  field.  the e x t r a s t r i a t e primarily to  i n t h e open f i e l d b u t nob  field.  162. APPENDIX E The E f f e c t of Geniculo-Strlate and Tecto-Pulvinar Inputs to the Cortex on Orienting The e f f e c t of c o r t i c a l lesions on orienting.behavior dishabituation were d i f f i c u l t to evaluate i n the preceding as the behavioral e f f e c t was l e s i o n s i z e and placement.  and  studies  not systematically correlated with Animals whose lesions included a l l of  areas 17, 18, and 18A d i d not d i f f e r from control animals; however, i f the l e s i o n included a l l of areao7, as well as., areas 17, 18A,  the animals oriented to the novel l i g h t display but  18,  and  habituated  within a few t r i a l s and did not dishabituate to the changes i n the l i g h t display.  Large lesions of the cortex which include  areas 17,  18, 18A,and 7, as well as lesions of the s u p e r f i c i a l or deep laminae of the SC, mayrresult  i n f a s t e r habituation to the l i g h t displays and  the absence of dishabituation to changes i n the l i g h t displays. The area of cortex removed by the lesions of the posterior cortex includes the terminals of the geniculo-striate system and major projection of the SC to the cortex v i a the NLP pulvinar system).  This study was  the  (the tecto-  conducted to determine i f the  changes i n habituation and dishabituation seen a f t e r large c o r t i c a l lesions were due to the loss of the input from the s u p e r f i c i a l laminae of the  SC. Method  Subjects Twelve naiveJ animals were tested.  Two  animals received  large b i l a t e r a l lesions, 2 received s t r i a t e cortex lesions, 4 received  163  nucleus l a t e r a l i s posterior (NLP) lesions, and 4 received NLP and s t r i a t e cortex (NLP+ST) l e s i o n s .  Animal maintenance and housing  were i d e n t i c a l to Experiment I . Apparatus The apparatus was i d e n t i c a l to that described i n Experiment I.  The "apparently" moving and stationary l i g h t displays with the  red p l a s t i c f i l t e r s were presented as i n Experiment I . Procedure H i s t o l o g i c a l and testing Experiment I .  procedures were i d e n t i c a l to  Surgical procedures were d i f f e r e n t from Experiment I  i n the following ways: L a r g e s b i l a t e r a l cortex (LC) lesions were aspirated as i n Experiment I and an attempt-was made to include all-of- areas 17, 18, 18A,and 7. S t r i a t e cortex (ST) lesions were aspirated as i n Experin ment I . The coordinates were those described by Hughes (1977). Nucleus L a t e r a l i s Posterior (NLP) lesions were made b i l a t e r a l l y with an e l e c t r o l y t i c l e s i o n maker by a twisted wire electrode insulated except f o r the area of the t i p (approximately Tissue  .5 mm).  destruction was accomplished by passage of an anodal DC current  (.2 mamp) f o r 20 seconds.  The coordinates were those, described by-  Hughes (1977). Nucleus l a t e r a l i s posterior and s t r i a t e cortex (NLP+ST) lesions were made as described above.  164  Results The e f f e c t s of the l e s i o n s on orienting, habituation, and dishabituation i n response to the "apparently" moving l i g h t display were presented i n Figure 24. on these data.'  S t a t i s t i c a l analyses were not conducted  The i n d i v i d u a l animals' performance was  comparison to the averaged r e s u l t s of Experiment I.  assessed by  The rate of  habituation was determined by a ratio.. (the number of l i c k s during baseline - the number of l i c k s during the l i g h t displays '/ the number of l i c k s during baseline).  The animal was  ted to the display when a r a t i o of zero was  considered to have habituaattained on two  successive  trials. The animals with lesions which included a l l of areas 17,  18,  18A,and 7 ( i - e . , complete p o s t e r i o r decortication) habituated to the repeated presentation of the l i g h t s on approximatelythe t h i r d t r i a l did not dishabituate to any of the l i g h t displays-changes.  and  The ani-  mals with lesions confined to area 17 only disrupted l i c k i n g i n response to l i g h t display SI, habituated to i t s repeated presentation, and dishabituated to each of the changes i n the l i g h t display.  These-  animals d i d not habituate as quickly to l i g h t display SI as the  SH  animals of Experiment I.  They required an average of 9 t r i a l s com-  pared to an average of 6 f o r the ST animals i n Experiment I. The animals with l e s i o n s of the NLP, were quite s i m i l a r to the ST lesioned animals i n t h i s study.  They disrupted l i c k i n g i n  response to l i g h t display SI, habituated to i t s repeated presentation, and dishabituated to the changes i n the l i g h t display.  These animals  165  habituated to SI i n an average of 8 t r i a l s . Unfortunately  2 of the animals which sustained NLP+ST  lesions died p r i o r to the behavioral t e s t s .  The remaining animals  with NLP+ST lesions behaved l i k e the SC lesioned animals.  They  disrupted l i c k i n g i n response to l i g h t display SI, habituated to the repeated presentation of the l i g h t display i n an average of 4 t r i a l s , and d i d not dishabituate to any o f the changes i n the l i g h t display. A l l of the animals i n t h i s study oriented to the presenta"-s t i o n of SI on t r i a l 1 .  The animals disrupted l i c k i n g , l i f t e d t h e i r  heads from the water spout,and looked at the l i g h t display.  The  extent of the head l i f t , postural adjustment," and duration of looking at the l i g h t s was quite s i m i l a r to the ST animals observed i n Experiment I . Discussion As can be seen i n Figure 24, complete NLP lesions d i d not impair dishabituation to the changes i n the v i s u a l display.  There-  fore the projections from the s u p e r f i c i a l layers of the SC to the cortex per se are not responsible f o r the behavioral change. I t appears from these preliminary r e s u l t s that both the s t r i a t e cortex, the s u p e r f i c i a l laminae of the SC,and i t s c o r t i c a l projections are involved i n dishabituation. animals.  This was confirmed by the NLP+ST lesioned  Like the SP lesioned animals and the large c o r t i c a l l e s i o n  group, these subjects oriented on the f i r s t t r i a l s but d i d not d i s habituate to any of the stimulus changes.  The same r e l a t i o n s h i p held  f o r the rate of habituation f o r these animals.  The SP and large  1:66  cortical lesioned fewer t r i a l s  a n i m a l s and  to habituate  rate of h a b i t u a t i o n m a l s was  not  posal  that  f o r NLP  first  stimulus  presented. f o r ST  controls,but  The  lesioned  they  ani-  appeared  trials. of i n t e r e s t i n l i g h t  i n t e r a c t i o n s between the  which the  s t r i a t e animals' r e q u i r e d  l e s i o n e d a n i m a l s and  above f i n d i n g s are  of considerable in  to the  plus  m a r k e d l y d i f f e r e n t f r o m SH  t o r e q u i r e more The  t h e NLP  two  of the  pro-  m a j o r v i s u a l s y s t e m s may  importance i n these f u n c t i o n s .  be  Lesions of the  areas  g e n i c u l o - s t r i a t e systemcand t e c t o - p u l v i n a r system  over-  l a p r e s u l t e d i n an e l i m i n a t i n g one dishabituation.  impairment of d i s h a b i t u a t i o n ; however,  of the  simply  systems' i n p u t s t o t h e s e a r e a s d i d not  affect  167.  APPENDIX F:  Figure  28.  168.  Figure 28. A h i s t o l o g i c a l reconstruction of the superior c o l l i c u l u s and surrounding structures. Abbreviations: SN = substantia nigra, FOR = r e t i c u l a r formation, HI ^hippocampus, GD = dentate gyrus, CG = c e n t r a l grey, GCS = commisure of the superior c o l l i c u l u s , SGS = stratum griseum s u p e r f i c i a l , SO = stratum opticum, SGM = stratum griseum mediale, SAM = stratum album mediale, SGP = stratum griseum profundum, and SAP = stratum album profundum.  CCS  SGS] soj  S U P E R F I C I A L L A M I N A E  SGM SAM  D E E P  SGP  L A M I N A E  SAP  ON vO  

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