CHAPTER LIX 



Neurophysiological basis of the higher functions 

 of the nervous system — introduction 



WILDER PENFIELD Montreal Neurological Institute, Montreal, Quebec 



CHAPTER C O N T E N T S 



The Mountain Top 



Higher Functions 



Clinical .Surmises 



Sensory and Motoi Responses 



Ccntrcnccphalic Organization 



Flash-back Memory and Comparative Interpretation 



Higher Functional Mechanisms 



NEUROPHYSIOLOGISTS endowed with widely varied 

 skills have joined together in the common enterprise 

 of composing ihis hook. Their eontrihntions have 

 advanced along .1 rising scale from neuron and brain 

 potential to sensory mechanisms, motor mechanisms 

 and transactional mechanisms. Thus the patient 

 reader hears a swelling chorus of some 60 voices. Now 

 that we have come to the neurophysiological basis <>l 

 higher function we must turn our attention to man 

 himself and to the mind of man. Here there is no full- 

 toned harmony and the physiological voices are few 

 and faltering. 



I III MOUNTAIN TOP 



Those who hope to solve the problem of the neuro- 

 physiology of the mind arc like men at the foot ol a 

 mountain. Thev stand in the clearings thev have made 

 on the foothills, looking up at the mountain they 

 hope to scale. Bui the pinnacle is hidden in eternal 

 clouds and many believe il can never be conquered 

 Surely if the day does dawn when man has reached 

 complete understanding of his own brain and mind, 

 it may be his greatest conquest, his final achievement. 



In the meantime, what are scientists to say of the 

 things unseen, the problems yet to be solved? Are 

 they entitled to a special privilege as prophets? Whal 

 should thev sav in advance about the nature ol the 

 mind, the existence <>! the spirit.' What about monism, 

 dualism, Cod.' 



In his Rede Lecture at Cambridge in 1933, v n 

 Charles Sherrington said: "I reflect with appre- 

 hension that ,1 great subject can revenge itself shrewdl) 

 for being too hastily touched To the question of the 

 relation between brain and mind the answer given 

 bv a physiologist 60 years ago was Tgnorabimus.' .. . 

 The problem lodav has one virtue a1 least, it will long 

 oiler in those who pursue ii the comfort that to journe) 

 is better than to arrive; but thai comfort assumes 

 arriv al. Some of us perhaps because we are too old 

 or is it, too young think there mav be arrival at 

 last." 



There is onl) one method that a scientist may 

 use in his scientific work. This is the method of ob- 

 servation of the phenomena of nature followed by 

 comparative analysis and supplemented by experi- 

 mentation in the light of reasoned hypothesis. Neuro- 

 physiologists who follow the rules of the scientific 

 method in all honesty will hardly pretend that their 

 own scientific work entitles them to answer these ques- 

 tions. 



Ivan Pavlov described the learning process, elabo- 

 rating the mechanisms of conditioned reflexes. Sher- 

 rington explored the basic mechanisms of subcon- 

 scious reflex action. Both were good scientists, and 

 neither claimed that he had solved ultimate truths 

 ouiside the confines of an animal laboratory. 



Those who assert lodav that the work of Pavlov 

 proved the truth of materialism draw a premature 



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