Perception and Action Interactions: Evidence from Neuropsychology, Neuroimaging, and Transcranial Magnetic Stimulation
Although prominent theories of vision have emphasized dissociations between two visual streams specialized for perception and action, in some situations, the two streams must interact. One such situation is the performance of actions upon remembered objects. Neuropsychological evidence from two patients with occipitotemporal lesions suggests that while immediate actions can be performed using only the dorsal vision-for-action stream, delayed actions require integrity of the ventral vision-for-perception stream. My lab has investigated the interactions between the two streams during delayed grasping using functional magnetic resonance imaging and transcranial magnetic stimulation. Our results suggest that delayed actions re-recruit information about object properties such as shape, size and orientation from the ventral stream and early visual areas at the time the delayed action is performed.