Reaching and grasping

Abstract

When the hand meets an object we confront the overlapping worlds of sensorimotor and cognitive functions. We reach for objects, grasp and lift them, manipulate them and use them to act on other objects. Prehension entails two motor processes: «reaching» and «grasping.» Reaching refers to the extension of the arm in order to touch a distant target, whereas grasping refers to the progressive opening of the hand grip, with straightening of the fingers followed by a gradual closure of the grip until it matches the object’s size and shape. The present article separately examines these two distinct but interconnected processes, and reviews core findings in the fields of neuropsychology, neuroimaging and electrophysiology on the neural correlates of these two actions.