JERZY KONORSKI I3I 



One must be precise with terms and when one says centre, for instance, one 

 must not think that the centre of the spoken word means that the spoken word is 

 venerated there. If a cortical area is destroyed and the spoken word is perturbed or 

 disappears, all that one can say is that the cortical area is necessary but not surticient 

 for the reproduction of the spoken word. 



The fact that neurones are incapable ot reproducing themselves is perhaps the 

 price we have to pay to have memories and habits and other learned capacities 

 which persist throughout life. If neurones died and were substituted by others, it 

 is hard to conceive how these functions could be preserved. 



Reverberation circuits may be the basis of learning but perhaps they are not 

 enough. Do vou, Dr Konorski, conceive as diiferent phenomena: habits, organic 

 memory and memory itself? 



Konorski. As far as I know in dogs and in monkeys the loss of recent memory of 

 directions after prefrontal ablations is irreversible. JVIoreover, in some of our 

 annuals, there was only a partial deficit of recent memor)', due perhaps to smaller 

 lesions. Why in Dr Rosvold's chimpanzee the deficit of recent memory is rever- 

 sible, should be explained by further experimentation. As far as patients with pre- 

 frontal lesions are concerned, they are able to solve the delayed response test very 

 well. We believe that it is so because their memory of directions is supported, or 

 even based, on visual cues and also on verbal recent memory which in man, is very 

 powerful. 



I agree that we are not able so tar to state definitely which sorts ot cues are 

 responsible in delayed response tests, although it seems that this problem may be 

 solved by further experimentation. 



To answer Professor Estable, I would like to stress once more that, according to 

 our view, conditioned reflexes, including habits as a particular form, are chiefly 

 based on stable or static, or organic memory, while such forms of behaviour which 

 are involved in delayed responses are based on transient or dynamic memory. 



Olds. I wish to address myself to the experiments where the so-called auditory 

 association areas were removed, and where Dr Konorski says his experiment was 

 on recent memor\-, for an auditory stimulus. I wish to suggest the possibility that 

 these were not experiments on recent memory at all, but possibly on the animal's 

 ability to compare two stimuli. It seems to me that the way this could be tested is 

 to have the stimulus and the comparison stimulus (another S^ or Sy) presented 

 somehow simultaneously. If the deficit is hi the animal's ability to compare, he 

 will fail this test. If it is in recent memory, he will pass. One might also ask the 

 question of the delayed response technique again here and ask if it is really fair to 

 reject the delayed response as a test for recent memory of a particular (e.g. auditory) 

 stimulus. One might develop some text in which a given tone Sx would not signify 

 a direction but an abstract contingency and find whether excision o( the auditory 

 association areas prevented an auditory memory which involved no comparison. 



Konorski. As to the first question of Dr Olds I agree that the test proposed b)' us 

 is based on comparison of two stimuli, wliich is rendered impossible by the loss of 

 recent memor)-. Whether or not there is any special function which may be called 

 'comparison' — I do not know. 



As to the second question I would remind that, as shown in my paper, the 

 removal of pre-frontal areas did not impair the recent memory of particular 

 auditory stimuli, as proved by our recent memory test. 



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