Responses to direction of stimulus movement are different for somatosensory and visual cells in cat superior colliculus

Abstract

Direction selectivity is prominent among visual cells in the superior colliculus (SC). Its presumptive behavioral role raises the question of whether SC cells representing other sensory modalities involved in parallel behaviors also exhibit this property. The present experiments demonstrate that, apart from cells activated by vibrissae displacement, this property is poorly represented among somatosensory SC cells. Some somatosensory cells do exhibit movement asymmetries yet these asymmetries are not in opposite directions along the same axis, but rather among different axes (axis selective). These findings may reflect a fundamental difference in how SC cells representing these sensory modalities code movements across their respective receptor organs.