Abstract

This article reviews studies of the kinematics of prehension movements in terms of Jeannerod's (1981, 1984) widely accepted suggestion that these movements are controlled by two separate visuomotor channels: one which controls the "transport" (or "reach") and a second which controls the "manipulation" (or "grasp"). The transport component extracts information regarding the spatial location of the object and allows for the transformation of this information into motor commands that are appropriate for bringing the hand towards the object. The manipulation component exctracts information regarding the size and the shape of the object, thus allowing for the implementation of the distal movement pattern necessary to grasp the object. This review describes the processes underlying the programming and execution of these two components, and how these components are coordinated depending on target features or task requirements.