132 BRAIN MECHANISMS AND LEARNING 



Anokhin. I should like to make two comments on Dr Konorski's very interest- 

 ing report. The brain, as a specific substance has two possibilities for 'remember- 

 ing', each of which can be related to what Dr Konorski relates to 'recent memory'. 

 There is first of all the ability of a nervous substance to associate any successive 

 stimuli coming trom the inner or outer world ot the organism. On account of its 

 ability to conduct stimuli rapidly and multilateralK' and oi its ability to retain in 

 the synaptic systems the molecular changes which have taken place, the nervous 

 tissue 'remembers' any succession of stimuli brought upon it. That is the most 

 direct and universal memory which fits under the name of 'recent memory'. 



Tliis memory, however, represents a specific advance effected by the nervous 

 system in relation to the acting agents of the outside world. 



For a given association to become stable, it has to end by a strong emotional 

 discharge, i.e. has to end by some event which is meaniiigtul for the life of the 

 organism. 



Thus in my view, to study the physiological mechanisms of 'recent memory' 

 consists basically in discovering those concrete processes which occur as a result of 

 emotional discharges and spread in the direction of the cerebral cortex, retaining 

 there fleeting temporary associations. 



As is shown by the unavoidable extinction of desynchronization when training 

 for the association 'sound-light', a final consolidation of such ephemeral associa- 

 tions is indispensable. 



AsRATYAN. Food boxcs are very important factors in recent memory. Do you 

 think the rule of the tonic conditional reflex, as we name it, plays a role in this 

 recent memory? 



BusER. I wish to ask Dr Konorski if he has some information on the thalamic 

 connections of the cortical areas which were ablated in his experiments. 



Konorski. I tliink that Asratyan's 'tonic conditioned reflexes' are based on the 

 same principles as ordinary conditioned reflexes, i.e. when firmly established, they 

 are due to stable memory traces. 



Our lesion producing the loss of delayed responses comprised gyrus proreus, 

 subproreus and the anterior part of gyrus orbitalis. The vessels in presylvian sulcus 

 were usually spared. These lesions produce degeneration in dorso-medial nucleus 

 of the thalamus. Other desenerations were not so far studied. 





