Visual activation of neurons in the primate pulvinar depends on cortex but not colliculus.

Superior colliculus lesions had little effect on the visual response of neurons in the monkey inferior pulvinar. By contrast, striate cortex lesions eliminated the visual response of all inferior pulvinar neurons for a period of 3 weeks after the lesion. At longer survival times, a few pulvinar neurons responded to small light spots, but sensitivity to orientation and direction of movement never returned. Thus striate cortex, rather than the colliculus, appears to be responsible for the visual properties of pulvinar cells.