CONDITIONED REFLEXES ESTABLISHED BY COUPLING 

 ELECTRICAL EXCITATION OF TWO CORTICAL AREAS^ 



R. W. Doty and C. Giurgea 



Is the mere coincidence of action of two stimuli sutiicient to form a 

 learned association between them, or is some motivational factor also 

 required? This has been a persistent question in psychology (and psy- 

 chiatry) and is of major importance in any attempt to solve the riddle of 

 the neural mechanisms subserving learning. Human experience is too 

 complex to provide an answer despite the long history of 'associationism' 

 as a science. In animal experimentation, on the other hand, it has been 

 difficult to demonstrate learning or establish conditioned reflexes when 

 motivation or 'drive reduction' have been unequivocally absent. 



The pertinent evidence has been reviewed elsewhere (Giurgea, 1953a). 

 The experiments of Loucks (1935), however, are of special interest since 

 they are the direct antecedents of our own. In several dogs Loucks 

 stimulated the 'motor' cortex through permanently implanted electrodes 

 effecting a movement of one of the animal's limbs. With each animal on 

 as many as 600 occasions over several days he preceded the motor stimula- 

 tion with an auditory conditional stimulus (CS). The CS never came to 

 evoke the movement with which it was so thoroughly paired, nor any 

 other movements. A food reward was then introduced to follow the CS 

 and the induced movement. Within a few trials the animal began moving 

 to the CS. Loucks drew the justifiable conclusion from these experiments 

 that the motivational element was essential to the formation of conditioned 

 reflexes and these results have had a wide and well-deserved influence on 

 psychological theory since that time. 



Louck's position was apparently conhrmed by Masserman (1943) who 

 failed to obtain any signs of conditioning when stimulation of the 

 hypothalamus was used as US. However, Brogden and Gantt (1942) were 

 able to produce movements by presenting a CS alone after repeated pair- 

 ing of CS and stimulation of the cerebellum. In some animals the 'condi- 

 tioned response' (CR) so elicited was very similar to the movement 

 induced by cerebellar stimulation. Motivation seemed to be absent here. 



1 New research reported here was supported by grants to R. W. Doty from the Foundations' 

 Fund for Research in Psychiatry and the National histitutcs of Neurological Diseases and Blind- 

 ness (B-1068), and by a travel grant to C. Giurgea from the Academy of the Rumanian 

 Peoples Republic. 



