Effects of occipital neocortical lesions upon visual discriminations in the cat

Cats were trained on flux, equal-contour-pattern, unequal-contour-pattern and visual cliff discriminations. The stimuli used in the pattern discriminations either increased or decreased in the number of intersections. Subsequently, the animals were subjected to surgery with the intent to remove the neocortex from the lateral, posterolateral, suprasylvian, suprasplenial and splenial gyri. Postoperatively, all cats relearned the flux, visual cliff and unequal-contour-pattern discriminations. The most medial portions of area 17 were spared in these animals. Two of the cats also relearned the equal-contour-pattern discriminations. Different but additional sparing was noted in area 19. The results in terms of varying the number of intersections were equivocal.