Use of vision in manual aiming by young and older adults

This study was designed to examine the influence of age and the availability of vision on the performance and kinematic characteristics of discrete aiming movements. Twelve young adults (19-25 years old) and 12 healthy older adults (62-82 years old) performed 130-mm aiming movements to targets with diameters of 5, 10, and 20 mm. On half the trial blocks, visual feedback about the aiming movement was eliminated upon movement initiation. Surprisingly, older adults were both as fast and as accurate as young adults regardless of the vision or target condition. While the velocity profiles of young and older adults were also similar, older adults exhibited a greater number of deviations in acceleration in both the vision and no-vision situations. Since these deviations are thought to reflect adjustments to the movement trajectory, older adults may rely more on visual and kinesthetic feedback for the control of goal-directed movement.