NEUROPSYCHOLOGY 



By Karl S. Lashley 

 Yerkes Laboratories of Primate Biology and Harvard University 



The ultimate purpose of studies of the 

 nervous system is to gain a better under- 

 standing of the mechanisms of behavior. 

 However, neural anatomy and physiology 

 have developed in alliance with medical 

 science; psychology has only recently es- 

 caped from administration with philosophy. 

 There has been relatively little direct con- 

 tact between students of the two discip- 

 lines. In consequence, many investigations 

 and interpretations in neurology fail to con- 

 sider the problems that are raised by com- 

 plex behavior. Conceptions of integrative 

 mechanisms tend to be oversimplified and 

 of little aid in understanding the major 

 problems of psychology. Psychological 

 studies too often fail to recognize the lim- 

 itations set by neurological facts and make 

 frequent use of explanatory conceptions, 

 such as that of free nervous energy, for 

 which no physiological counterpart exists. 

 There is a mutual dependence between 

 psychology and neurophysiology. Psy- 

 chology can formulate descriptive laws of 

 behavior, but the explanation of those 

 laws must be sought in the activities of 

 the nervous system, and the laws must be 

 consistent with the facts of neurology as 

 well as of behavior. The student of neu- 

 rology must take into account the integra- 

 tion of the whole organism, as revealed by 

 behavior, as well as the functioning of par- 

 tial systems. 



There is thus an urgent need for closer 

 integration of studies of the nervous sys- 

 tem with studies of behavior, for more fre- 

 quent contacts and exchange of ideas be- 

 tween investigators in the two disciplines, 

 and especially for the training of investiga- 

 tors who will have an adequate apprecia- 

 tion of the problems in the two fields. 



COOPERATIVE RESEARCH 

 Research on the borderline between neu- 

 rology and psychology requires an integra- 



tion of numerous specialties; neural anato- 

 my and histology, physiology, psychologi- 

 cal techniques of measurement, and fre- 

 quently biochemical, endocrine, neuropath- 

 ological, and clinical methods. No one 

 individual can be competent in the tech- 

 niques desirable for such investigations. 

 Team work is becoming a requisite of in- 

 vestigations in neuropsychology just as it 

 has been found essential in clinical diag- 

 nosis and many branches of medical re- 

 search. Such team work is always expen- 

 sive and considerable sums must be avail- 

 able to make it possible. At the present 

 time there are not more than five institu- 

 tions in America in which there is def- 

 initely organized experimental research 

 combining neurological and behavioral 

 studies, and even these are heavily weight- 

 ed toward one side or the other. 



In clinical neurology also, although the 

 need for coordination of neurological and 

 psychological studies is receiving some rec- 

 ognition, especially in connection with the 

 lobotomy problem, adequate provisions for 

 psychological studies of patients have been 

 made in few places. 



Cooperative research requires more than 

 provision of funds and employment of spec- 

 ialists. There must be stimulating and in- 

 sightful leadership; this is the greatest lack 

 in the borderline field between neurology 

 and psychology. Few individuals have 

 broad training and comprehension of the 

 problems in both fields. The primary need 

 of neuropsychology is some provision for 

 development of leadership in research. 



STUDENT TRAINING 



Except for the highly specialized fields 

 of sensory physiology there are few places 

 in the country where a student is likely to 

 be encouraged to work in the borderline 

 field between neurology and psychology 



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