Effect of Visual Pattern Restriction in Early Life on Brain Enzyme, Body Weight and Learning in the Rat

Abstract

VISUAL pattern restriction or enrichment in early life can induce significant differences in body weight gain, performance on a visual sensory reinforcement test and brain enzymatic activity in adult rats¹. Rats raised in an enriched visual environment, however, perform better on the visual reinforcement test than rats raised in a restricted visual environment only when light-onset is used as reinforcement; if light-termination is used as reinforcement, performance differences are completely reversed². Thus the effects of early visual experience may be beneficial only in some highly specific learning situations. Our experiments test the effect of visual input in early life on learning tests other than those previously used; we also looked at possible differences in body weight and brain enzymatic activity induced by early visual experience after a period of extensive handling, a food deprivation schedule and learning experience.