CEEEBRAL FUNCTION IN LEARNING 59 



a particular part of the cerebrum, (Sollier, '00; Franz, '07). 

 Many of these and similar statements are based upon purely 

 metaphysical grounds, as Morgan's doctrine of the cerebrum 

 as the seat of consciousness. Others are based upon an inade- 

 quate experimental analysis of the problem, and much more 

 experimental data must be accumulated before we can sub- 

 scribe fully to any of the theories of nervous function in learning. 



Before we outline the problems of nervous localization in 

 learning and methods for attacking them it is necessary to 

 recognize clearly that learning and retention may result fronTl 

 the activity of distinct nervous mechanisms. It is conceivable 

 that the conditioned-reflex paths which mediate the learned 

 reaction are established in one portion of the nervous system, 

 under the directive influence of some other part of the nervous 

 system which functions only during the learning process and is ; 

 unnecessary for the production of the learned reaction. The f 

 hypotheses which imply that learning requires the conscious /7) 

 direction of the cerebrum although learned reactions may be 

 carried out altogether at subcortical levels imply such a con- 

 dition. On the other hand the attempts made by Max Meyer/ 

 ('11), Watson ('14), and others to account for learning in terms 

 of reintegration of simple reflex arcs assume that no other nervous' 

 organization is necessary for learning than that included in the 

 reflex arcs which are reintegrated and communicating cells 

 between them. There is no certain evidence to support either 

 one of these hypotheses and the question can be settled only by , 

 a detailed examination of the function of every part of the nervous 

 system during learning and in the performance of learned reac- 

 tions. Before this is carried out extreme care in distinguishing 

 learning and retention in interpreting experimental data will! 

 be necessary. 



The greater part of the existing experimental and theoretical 

 work centers about the problem of the function of the cerebrum 

 in learning. Since the present investigation deals with certain 

 aspects of this problem a brief review of the experimental work 

 which has been done upon cerebral function in learning may 

 serve to connect the somewhat detached sections of the paper 

 and bring them into relation to the fundamental problems. 



