Response characteristics of single cells in the monkey superior colliculus following ablation or cooling of visual cortex.

that the characteristics of single cells in the superior colliculus depend to a considerable extent on cortical input. In the cat, the majority of studies reveal a dramatic loss of binocularity and direction selectivity in superficial collicular units following ablation of the visual cortex (1, 18, 25). In the ground squirrel, removal of the visual cortex renders most cells in the intermediate and deep layers of the superior colliculus unresponsive to visual stimuli (14); this also appears to apply to the cat (22). Work on the rabbit, however, indicates that in this species, ablation of visual cortex produces no discernible effects on collicular