Self-selected visual information during discrete manual aiming.
The authors examined strategic selection of visual samples during manual aiming. Participants (N = 12) wore liquid-crystal goggles while performing discrete movements to a small target. Initially, participants controlled a 40-ms visual sample via a switch in their nonaiming hand. Subsequently, experimenter-imposed strategies required participants to take visual samples before movement initiation or early or late in the movement. Although participants adopted a variety of strategies to optimize the use of vision, they were more likely to select a sample during the early stages of the movement. Experimenter-imposed early and late instructions resulted in longer movement times than did self-selected sampling. Compared with late sampling, early sampling resulted in a temporal advantage with similar accuracy.