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HANDBOOK OK PHYSIOLOGY 



NKTROPHYSIOLOGY III 



conclusion. Those who hail Pavlov as the great 

 mollis and set Sherrington up against him as the 

 leader of dualism go far beyond the evidence. 



Sherrington in his laboratory was a cautious scien- 

 tist who worked without preconceived prejudice. His 

 pupils hardly suspected that outside the laboratory 

 he was a poel and a philosopher. His book of poems 

 u.is published when he was 68 years of age, and his 

 philosophical monograph, Man on Hi* Nature, when 

 he was 80! At the age of go, when he wrote the intro- 

 duction to a new edition of his scientific magnum 

 opus, he ventured no farther than to s.i\ : "That our 

 being should consist of two separate elements, offers, 

 I suppose, no greater inherent improbability than 

 that it should rest on one only." 1 



Although in the laboratory he adhered to critical 

 objectivity, he had faith that "the relation between 

 brain and mind" would be solved the mountain 

 would be scaled in some distant day. Until then, he 

 pointed out, neurophysiologists must cam - on using 

 the "language of separation" without prejudice as 

 to what the final truth may prove to be. To speak of 

 mind and brain is to employ the language of the com- 

 mon man, the language of dualism. But we can do 

 nothing else if we would get on with the job. 



Outside the laboratory, lew scientists are to be con- 

 red poets or philosophers. But, nevertheless, most 

 reasonable men must wonder about (hose mysteries 

 which are not to be solved by the scientific method in 

 their lifetime; such mysteries as: what lies beyond the 

 e? what is the origin of life, the design of the uni- 



\ else, the nature of truth 3 



Scientists are men as well as workers. They enter 

 and leave life like other men. "There is a season and a 

 time to every purpose under the heaven," and all 

 must play, in turn, the role of child, husband, lather 

 .mil cldci Good scientists may well conclude that 

 there is virtue in the concepts of life that have been 

 passed along from father to son within the memory of 

 in. in Christian, Jew, Moslem and Hindu may have 

 an intelligent faith in God .md still be completely 

 objective in scientific thought. The atheist can do the 

 same, il he is also .1 good scientist. 



I hus eat h man should turn to his workshop in his 

 own 'clearing' without prejudice, and without linger- 

 ing too long on the street corner to debate with 

 Berkleian philosopher, or materialist or dualist. And 

 I hasten now to return to my problem of writing an 

 introduction to the chapters oi this section on "The 

 Neurophysiology ol Higher Function." 



From the Introduction to the second edition ol / ' / 

 iivr Action "I th London Cambridge, 1947. 



HIGHER Ft Nl I [i iNS 



Man is said, by man, to lie higher in the evolu- 

 tionary scale than all other creatures. But how are we 

 to define "higher" as applied to the neurophysiology 

 of the nervous system? Let us say that the neuronal 

 mechanisms that are essential to consciousness are 

 high, higher than certain reflex mechanisms. It is 

 clear that in the central nervous system there are 

 many involuntary mechanisms that have little or 

 nothing to do with conscious states. The manifold 

 activities of the decerebrate animal bear witness to 

 this. Above this there is the neuronal activity asso- 

 ciated with "consciousness" and with the preparation 

 for voluntary action, an activity that is essential to 

 the very existence of these things. 



Voluntary activ its is produced by a flow of poten- 

 tials along a well-known pathway from cerebral cor- 

 tex to muscle. And the paths of sensory inflow that 

 carry related information inward are well known as 

 far as the cerebral cortex. But the cortex is not the end 

 of the sensory pathway nor is it the beginning of the 

 motor pathway. 



It is the organizing and integrating activity that 

 comes between this 'CiiMin input and this motor out- 

 put that constitutes the physiological basis of the mind. 

 Here is the "higher function.' Here, the highest levels 

 of integration are to be sought. 



Physiologists have contributed little .it this level, 

 although the work of MagOUn on the reticular acti- 

 vating system, and such contributions .is those in the 

 preceding chapters by Bremer, Brookhart, French, 

 Jasper, Pribram, Kaada, Green, Pampiglioni and 

 Gloor constitute a promising beginning. 



However brief it may lie, each sta^e must have .1 

 sequential time value. I here is a time allowance for 

 a) afferent conduction, h\ centrencephalic organiza- 

 tion, (i volitional efferent conduction and d) motor 

 contraction. A man's awareness oi environment dur- 

 ing any moment ol time cannot be present during the 

 afferent conduction of that moment. It must follow. 

 It must precede the Outgoing volitional conduction. 

 if appropriate action is taken. 



This sequence must hold although preparation and 

 overlap are, no doubt, important in such processes. 

 In borrow from the thinking of William James, 

 consciousness is continuous during our waking hours, 

 but its content is never the same. Like a mountain 

 brook it tumbles p.ist in iis rocky bed but the watei 

 cannot return nor be held in its place, from the 

 standpoint of the physiologist too, the electrical poten- 

 tials pass in swift and everchanging variation through 

 the higher circuits of organization. 



