210 



BRAIN MECHANISMS AND LEARNING 



obtained from most diverse papers in which the authors themselves did 

 not intend to study precisely this problem. 



We may cite data from the work oi Jasper who points out that in a 

 number of cases the secretomotor area of the cerebral cortex exhibits a 

 depression of its rhythm much ahead of the real movement of the arm, 

 this desvnchronization sometmics appearing in the person tested at the 

 thought of the forthcoming movement alone ( lasper, 1958). 



A 



o — o 



o — o 



'il' 



8. 



• — o 



II 



• — o 



II 



• --o 



--0 



1 



d' 



c' 



*-^' 



Fig. 10 

 Schematic representation of the 'anticipatory' spread of excitation 

 and its significance in the formation of the acceptor of action. 



A, a, h, c, d, -^ successively developing action of the external stimu- 

 lations of which d is the reinforcement with food. Orienting reactions 

 a^, b^, c^ and d^ emerge correspondingly. 



B. Correlation of the processes after training. The action of the one 

 initial stimulus a is enough for the process of excitation immediately 

 to spread along the afferent traces to d which is the 'acceptor of action' 

 in this case. 



We fmd indications of similar facts 111 the studies oi Gastaut concerned 

 with depressing the rolandic rhythm (Gastaut, 1957). 



hi his recent detailed review of the stuciies of the reticular formation 

 O'Leary also cited data to the effect that the 'idea' of the forthcoming 

 movement alone may lead to a desynchronization of the electrical activity 

 of the cerebral cortex (Fig. 10). 



All the data culled from the literature, as well as our own observations, 

 indicate that after the application of a stimulus or the reading of instruc- 

 tions the selective impulse process of excitation, which ensures the 



