THE EFFECTS OF CEREBRAL DESTRUCTION UPON 



HABIT-FORMATION AND RETENTION IN THE 



ALBINO RAT 



K. S. LASHLEY AND S. I. FRANZ 



Department of Psychology of the Johns Hopkins University and the Government 



Hospital for the Insane 



INTRODUCTION 



It has long been known that the cerebrum is anatomically 

 complex and it is recognized that its functions are diverse. 

 There is also the appreciation of the failure to correlate the 

 known anatomical facts with the functional observations. There 

 are many reasons for the last. The variation in cerebral struc- 

 ture in different species of animals is one of the greatest of the 

 difficulties in the correlation of the anatomical and the func- 

 tional, for two animals with obviously dissimilar brain struc- 

 tures may appear in the main to be functionally similar, and 

 conversely two animals with obviously dissimilar activities may 

 have quite similar cerebral structural arrangements. The di- 

 versity of structures in the same brain has been more recently 

 emphasized. Differences in the arrangements or in the method 

 of combination of cells and fibers have been described as points 

 of major importance, and many cortical areas, a score or more, 

 have been described as different organs. They have also been 

 assumed to represent equal functional differences. On the func- 

 tional side, especially when man has been under consideration, 

 the diversity has been exaggerated, and this has probably been 

 carried over into modern neurology from the mental faculty 

 aspect of GalPs phrenological system, although the anatomical 

 part of Gall's work is totally discarded. The differences of 

 emotions, hate, joy, fear, anger, of sensations such as color, tone, 

 and the taste and smell qualities, of movement and of will, of 

 desire, of interest, and of all mental states, have led to assump- 



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