Neuropsychology — Karl S. Lashley 



19 



and where he can receive adequate train- 

 ing in both discipHnes. This is not a 

 question of courses or opportunity for study. 

 Courses in neural anatomy, physiology, 

 and psychology are offered in many places. 

 But the departments are usually as separate 

 as if in different institutions, and students 

 are encouraged to specialize within depart- 

 mentalized boundaries rather than to cross 

 departmental lines. The history of science 

 indicates that borderline fields are likely 

 to develop only when interest is directed 

 to them by some outstanding discovery or 

 through the application of new and prom- 

 ising techniques. Nevertheless the tre- 

 mendous progress of studies of sexual phy- 

 siology and sexual behavior under the sup- 

 port and encouragement of the National 

 Research Council Committee for Research 

 in Problems of Sex shows what can be 

 done toward developing a neglected field 

 by the wise administration of limited funds. 

 In the beginning adequate support was 

 given to a few investigators whose work 

 seemed promising. Important results of 

 their work aroused general interest, at- 

 tracted additional investigators, and led 

 to special training of students for work in 

 the field. 



It is doubtful that any direct means, such 

 as support of special instruction or of fel- 

 lowships, will contribute greatly to the de- 

 velopment of the borderline field. En- 

 couragement of research and successful 

 outcome of the research is the more prom- 

 ising method of developing interest and 

 eventual leadership in the field. 



GENERAL PROBLEMS 



Attempts to find explanation of behavior 

 in terms of neurology have been largely 

 restricted to studies of localization of spec- 

 ial functions. Although of diagnostic value, 

 such localization has little or no explana- 

 tory value; the conclusion that the cortex 

 of the angular gyrus is especially con- 

 cerned in the use of language throws no 

 light on the physiology of language struc- 

 ture. The concept of the conditioned re- 

 flex was an attempt at real explanation but 

 is as inadequate as was the association 

 psychology of J. S. Mills, upon which it 



was modeled. Psychological analysis of 

 functions is approaching a point where the 

 problems of neurological correlates can be 

 more clearly formulated. Psychological 

 processes can be described as structure 

 having definite organization or relations 

 among elements. Thus perception is the 

 organizing of sensory elements in certain 

 definite ways. The task for neurophysiol- 

 ogy is to discover the mechanisms which 

 produce such organization. With such an 

 approach it is possible to foresee at least 

 the kind of physiological explanations 

 which will account for the organization of 

 adaptive behavior, for the structure of lan- 

 guage and thought. Such a goal is far re- 

 moved, but some directions of research 

 can be sketched which have special rele- 

 vance to the problem. 



Evolution of Structure and Behavior. 

 Comparative anatomists have worked out 

 in some detail the evolution of nervous 

 structures. Although in general the degree 

 of centralization and the size and com- 

 plexity of the central nervous system cor- 

 relate roughly with the level of behavioral 

 development, it is not possible to specify 

 the structural characters responsible for 

 various phases of behavioral evolution. The 

 chief lack is of a comparative psychology 

 comparable to comparative anatomy. There 

 are comprehensive studies of the behavior 

 of the rat, of the chimpanzee, and of man, 

 but little is known of any other species. 

 Capacity for simple learning has been test- 

 ed through a wide range of forms, but even 

 for this function quantitative data are lack- 

 ing or not suitable for comparison of 

 species. There is need for systematic stud- 

 ies of the development of many behavioral 

 characteristics throughout the evolutionary 

 series, with comparable techniques applied 

 at different levels, before insight into the 

 neural basis of behavioral evolution will be 

 possible. 



Genetics of Nervous Structure and of 

 Behavior. Studies of inheritance of be- 

 havior traits have been most successfully 

 carried out on pathological conditions be- 

 cause of their more certain indentifiability, 

 the weight of medical interest and support, 

 and the availability of medical records. 



