Reaching movements: Programming time course is independent of choice number

THE present study was undertaken to assess the effect of varying the number of choices on the time needed by human subjects to program the correct direction of reaching arm movements. Subjects were required to reach for visual targets presented in two, four or eight different directions. In none of these subjects was the time needed to program response direction correctly prolonged by increasing the number of choices. In the present experimental situation, the time course of the process by which information derived from a visual target is used to accurately set the direction of reaching arm movements is uninfluenced by the number of possible targets.