MOVEMENT TIME AS A DETERMINER OF TIMING ACCURACY

In a task in which Ss tried to move a slide so that an attached pointer hit a moving target, movement time was varied by having Ss move at maximal or at moderate speed, by changing the starting position so that S moved 15, 30, 45, or 60 cm., and by adding or not adding an additional load. 160 male right-handed undergraduates were assigned to 1 treatment combination in a 2 * 4 * 2 design, and 20 trials with knowledge of results were given. Absolute timing error was decreased by maximal speed in instructions when the movements were unloaded, by shorter movement distances under all conditions of speed and load, and by the added load when the movements were at maximal speed, supporting the hypothesis that factors affecting movement time partially determine timing accuracy. Evidence indicated that the responses were preprogramed, and that Ss tended to hold movement time constant and correct the error on the previous trial by adjusting starting time. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.