Abstract: | Specialization of the right cerebral hemisphere in man for analysis of spatial relations suggests that a similar specialization may exist in macaques. This possibility is being examined in animals first trained to negotiate a maze and then subjected to transection of optic chiasm and forebrain commissures. In the one successful experiment to date, clear evidence of such specialization was obtained for the left hemisphere in a monkey consistently using its left hand for retrieval of food. Provisional evidence for the existence of unilateral engrams in such circumstances was also obtained by limiting input during training to one eye and hemisphere and testing the other before and after completion of transection of the forebrain commissures. Finally, it was found that in the split brain macaque, a lesion in the parietal-occipital area of one hemisphere initially disrupted maze performance using either hemisphere. |