The influence of aging and target motion on the control of prehension.

The purpose of this study was to examine age-related differences in reaching behavior when younger (mean age = 26.0 years) and older (mean age = 70.1 years) individuals were required to reach toward and grasp both small and large targets that were either stationary or moving. The older subjects had shorter movement times, and smaller within-subject movement time variability than younger subjects. Also, the deceleration of the reach was shorter for older subjects, indicating that they were not making extensive use of on-line feedback, and were instead utilizing anticipatory control strategies. There were no age differences in the size of the maximum grasp around the target, but the timing of the grasp was influenced by target motion for the younger subjects, suggesting on-line control for the younger subjects only.