Abstract
26 rats, with unilateral lesions in the area striata and adjacent cortex, were tested for the retention of a pattern discrimination habit, of complex order, on the Lashley jumping apparatus. The extent of lesion correlated with postoperative relearning + .55 [plus or minus] .09 for trials, and + .48 [plus or minus] .10 for errors. Loss of retention was not mainly dependent on destruction in the area striata or the posterior cortex. The results were interpreted as indicating extra-striate functions in the discrimination of complex visual patterns.