Visuospatial and Motor Deficits Following Pulvinar Lesions

Abstract

Abstract Most concepts of goal-directed behavior and cognition emphasize cortico-cortical interactions within large-scale networks. However, many, if not all, direct connections between cortical areas are paralleled by a trans-thalamic cortico-pulvino-cortical route, whose importance has been demonstrated by electrophysiological and lesion studies in monkeys and humans. In most literature, the pulvinar is conceived as a “visual” thalamic nucleus, with proven contributions to higher-order visual functions related to visual attention, feature binding, and processing of emotional stimuli. At the same time, the expansion of its dorsal portion in primates, in particular in humans, and its anatomical connectivity with frontoparietal regions suggests an important role in higher-order motor functions such as eye-hand coordination and manual prehension. In this chapter, the authors review electrophysiological, imaging, lesion, and human patient studies showing that pulvinar function goes well beyond its subscribed role in visual attention and might be more appropriately conceived as a multimodal integrator underlying visually guided saccades and reach-grasp behavior. A specific focus will lie on lesion-induced visuospatial and reach-grasp deficits in monkeys and humans.