Intermittent Vision and Discrete Manual Aiming

This study was designed to assess how the precision requirements of discrete aiming movements affect the utility of brief visual samples provided during execution of movement. Subjects pointed with a hand-held stylus to targets with indices of difficulty of 3, 4, 5, and 6 bits with full vision, no vision, and in conditions in which 20-msec. visual samples were provided every 80, 140, or 200 msec. While intermittent vision required slightly …