Postweaning environmental stimulation and somesthetic performance in rats sustaining cortical lesions at maturity.

Rats were enucleated at 28 days of age and were assigned to complex or relatively barren tactile environments for the duration of the experiment. Approximately half of the animals in each group received large, bilateral lesions of the somatosensory cortex when they were 60 days of age, and the remainder underwent sham operations. Twenty days later all groups were tested for the ability to master a series of tactile discriminations. Statistical tests revealed a highly significant lesion effect, but no environment or lesion x environment interaction effects. These sensory discriminative findings stand in contrast to some earlier reports which have shown that environmental complexity provided prior to or following other forebrain lesions can minimize error scores on simple learning tasks.