424 



BRATN MECHANISMS AND LEARNING 



US to consider the possible existence of an independent control for these 

 phenomena: size of potentials and EEG synchronization or desynchroniza- 

 tion. 



The results already described regarding the elementary plastic processes, 



HABITUATION 



NORMAL CAT 



1«J FLASHES 



ROSTROPONTINE CAT 



• 1«» FLASHES 



1 100 _vV 



Fig. 5 

 Study of habituation associated to a synchronized EEG 

 Rostropontiiie cat. No habituation during stimulation period 

 ahnost twice as long as that of the normal cat. 



attention and habituation, open a new line of research for studying the 

 central mechanism of Pavlovian 'internal' and 'external inhibition' 

 (Pavlov, 1928). The second concept corresponds to attention and the first 

 to sensory discrimination and habituation. Habituation as negative 



