488 



BRAIN MECHANISMS AND LEARNING 



poorer than chance, and in the other two it was significantly better than 

 chance. The first cat, Brd, was taught discrimination I-ab through the right 

 eye and Ill-ba through the left eye. Performance on transfer tests of 

 discrimination I-ab through the left eye was only 13 correct in 40. This 

 below chance performance indicated not only lack of transfer but revealed 

 also a definite preference for the negative, I-b pattern. Inspection of the 

 patterns of the two responses made it seem likely that the preference for 

 I-b, while using the left eye was due to its resemblance to the positive 

 pattern of discrimination Ill-ba already established through this eye. 



Table II 



INTEROCULAR TRANSFER IN CATS WITH OPTIC CHIASMA AND CORPUS CALI OSUM 



SECTIONED 



* Priiir training experience (see Table I). 



Bij^w appeared to recall discrimination V-ab on tests through the un- 

 trained right eye. This cat had earlier been taught discrimination Il-ab 

 through this same eye (see Bgw, Table I). The preference for pattern V-a 

 expressed during the transfer testing may have been due to a previously 

 unsuspected similarity between this pattern and positive pattern Il-a of 

 discrimination Il-ab. This interpretation was strongly supported when 

 subsequent work with a normal cat showed a near 100 per cent generaliza- 

 tion from discrimination Il-ab to discrimination V-ab. In such a generaliza- 

 tion the cats presumably responded to some general feature of the two sets 

 of patterns such as smallness versus largeness or concentration versus 

 diffuseness (see Fig. 4). 



