Enhancement of discrimination learning following unilateral lesions of posterior neocortex in guinea pigs

Monocular acquisition and interocular transfer of a horizontal-vertical discrimination were measured in 16 male albino guinea pigs which were restricted to using either the contralateral or ipsilateral primary visual fibers; restriction was accomplished by introduction of a unilateral striate lesion coupled with monocular occlusion. Eight sham-operated animals served as controls. The animals restricted to use of the contralateral fibers showed reliably enhanced rates of acquisition as compared to the controls, while the animals restricted to the ipsilateral fibers were unable to master the discrimination. The control animals learned readily, but demonstrated fairly low levels of interocular transfer. The data suggest that there is some form of interhemispheric interference which is eliminated by the introduction of unilateral ablations of the posterior neocortex.