62 K. S. LASHLEY 



upon which his fore feet were supported. These alterations in 

 behavior may have been merely a result of gradual recovery 

 from shock but they may with equal justice be interpreted as 

 cases of simple learning. 



The one outstanding experiment upon decerebrate animals 

 is that of Burnett ('12), who failed to obtain the formation of 

 the maze-habit by decerebrate frogs. His experiments were 

 well controlled and seem to demonstrate that the decerebrate 

 frog is incapable of forming so complex a habit, but they do not 

 rule out the possibility of learning of a simpler type. As Franz 

 the writer have pointed out, the disorganization which 

 follows decerebration is so great that many of the factors which 

 are ordinarily effective in inducing learning (for instance, the 

 sexual impulses) are no longer present and unless the training 

 methods are adjusted very carefully to the condition of the 

 animal negative results of training can have little significance. 

 The experimental work does seem to show that destruction of 

 the cerebrum abolishes the vast majority of learned reactions 

 ;and that decerebrate animals have a greatly reduced capacity 

 for learning, but it does not show conclusively that it completely 



Eliminates all ability to learn. This insistance upon the possi- 

 bility of learning in the absence of the cerebrum may seem 

 needless quibbling when there is so little evidence that non- 

 cerebral learning plays any important part in the behavior of 

 higher animals, but the point is one of the greatest importance 



" for learning theory since upon it hinges the question of whether 

 learning is the product of some particular kind of nervous organi- 



zation or is a capacity of all integrated nervous tissue; whether 



the cerebrum is a highly specialized organ or is merely a mass 

 of reflex paths comparable in all save complexity to the spinal 

 cord. 



A^The evidence from comparative anatomy suggests that the 

 (cerebrum is not essential for reintegration of reflex arcs^and 

 data upon the vicarious function of various parts of the cerebrum, 

 upon retention of habits after destruction of any given part of 

 the cerebrum, and upon learning in partially decerebrate animals 

 all tend to substantiate this view. A final judgment of the 

 matter must await further evidence. 



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