Hand kinematics during reaching and grasping in the macaque monkey

In this paper, we develop an animal model of prehension movements by examin ing the kinematics of reaching and grasping in monkeys and by comparing the results to published data on humans. Hand movements were recorded in three dimensions in monkeys who were trained to either point at Visual targets u nder unperturbed and perturbed conditions, or to reach and grasp 3-D object s. The results revealed the following three similarities in the hand kinema tics of monkey and man. (1) Pointing movements showed an asymmetry dependin g on target location relative to the hand used; in particular movements to an ipsilateral target took longer than those to a contralateral one. (2) Pe rturbation of target location decreased the magnitude of the velocity peak and increased the duration of pointing movements. (3) Reaching to grasp mov ements displayed a bell-shaped wrist velocity profile and the maximum grip aperture was correlated with object size. These similarities indicate that the macaque monkey can be a useful model for understanding human motor cont rol. (C) 2000 Elsevier Science B.V. All rights reserved.