Extravisual Plasticity of Posterior Cortex in Rats as a Function of Variations in Proximal and Distal Input during Development 1,2

Abstract

Posterior cortex ablations, sham ablations, and enucleations were performed on 65-day-old Ss reared from 10 days of age. A combination of 2 enriched and 2 impoverished conditions were used. These conditions were (1) proximal impoverishment (normal lab-cage), (2) distal impoverishment (enucleation at 10 days), (3) proximal enrichment (large special cage), and (4) distal enrichment (use of vision until 65 days of age). All testing was done post-operatively. Proximal enrichment positively enhanced maze learning and tactual discrimination. Distal impoverishment increased running time on the tactual maze. Ablations of posterior cortex interfered with maze learning (Lash-ley III) but not tactual discrimination. Even though an hypothesis of the plasticity of posterior cortex function suggests the likelihood of interactions of early experience variables, none were found.