The Visual Pathways Mediating Perception and Prehension

Publisher Summary The higher primates, especially humans, are capable of reaching out and grasping objects with considerable accuracy. Vision plays a critical role in the control of this important skill. Accumulating evidence from both neuropsychological studies of patients and electrophysiological and behavioral work in the monkey suggests that these pathways, particularly at the level of the cerebral cortex, may be quite distinct from those underlying. The initial evidence for this reinterpretation of the functional distinction between the dorsal and ventral streams came from a series of investigations of visually guided behavior in neurological patients in which damage appeared to be largely confined to one stream or the other. The ventral stream delivers the perceptual and cognitive representations underlying knowledge of objects and events in the world, and the dorsal stream. The dorsal and ventral streams work in a highly integrated fashion in the behaving organism and there is considerable anatomical evidence for a complex interconnectivity between the two streams.