1932] Poliak: Afferent Fiber Systems, Primate Cerebral Cortex 17 



Chapter III 



MATERIAL AND METHODS 



The above mentioned and many other deficiencies and contradic- 

 tions in our knowledg^e of the central nervous mechanisms and the 

 belief that only palpable and reliable data, so far as these can be 

 obtained, can solve the discussed problems induced me to attempt to 

 attack by experiment some of the more important problems of the 

 fiber anatomy of the forebrain, and thus of the functions of certain 

 fiber systems and cortical reg'ions, or areas, connected with these. 

 There can be no doubt as to the advantages of experimental anatomical 

 methods of investigation provided a suitable procedure is chosen and 

 the application of the method is sufficiently accurate and the inter- 

 pretation of the results sufficiently critical. Attention has already 

 been called to the relative value of most of the argnments upon 

 which the prevalent modem views on brain organization and function 

 are founded. Mention has also been made of the slender exact anatom- 

 ical data on the afferent fiber systems of the fore-brain. Nowhere 

 have we detailed and exhaustive descriptions of these systems sup- 

 ported by sufficiently numerous and accurate illustrations. Most of 

 the evidence hitherto used has been derived from physiological and 

 pathological observations without adequate anatomical control, or this 

 control was carried out in a superficial, summary way. It is also true 

 that there exist only a few dependable anatomical investigations on the 

 central portions of the somatic sensory, auditory, and visual systems, 

 none of them giving a full and complete analysis of the finer, internal 

 or functional organization of the fiber systems in question (in man 

 and in primates). No satisfactory experimental anatomical investiga- 

 tion of the three main afferent fiber systems of the cerebral cortex 

 from their subcortical origin to their cortical termination has as yet 

 been undertaken in primates ;^ all data has been derived from normal 

 human and mammalian or from pathological human material, the 

 latter, because of the extensiveness of the destruction, being usually 

 unsuitable for any finer analysis. It will be admitted that the con- 

 trollable results of experimental anatomical inquiries ■v\all be much 

 more persuasive than deductions made from physiological, clinical, 



1 The only exception is the visual system, thaaiks to experiments of Brouwer and 

 Zeeman, and of Heuven. 



