The effect of cortical lesions upon visual discriminations in binocularly deprived cats.

Four cats were raised with binocular eyelid suture and, after their eyes were opened, were trained on a series of discrimination tasks. They performed at normal rates on the brightness task but indicated some difficulty with the pattern tasks. They then received large, bilateral occipito-temporal cortex ablations. Postoperatively, this in no observable way affected their visually guided orienting behavior, but it did destroy their capacity to perform the preoperatively learned pattern tasks. Postoperative performance on the brightness task remained good. These data indicate that, in these deprived cats, there is little or no cortical development for visual orienting, but cortex is necessary for visual discrimination learning.