The utilization of visual information in the control of rapid sequential aiming movements

Two experiments were conducted to examine the role of vision in the executi on of a movement sequence. Experiment 1 investigated whether individual com ponents of a sequential movement are controlled together or separately. Par ticipants executed a rapid aiming movement to two targets in sequence. A fu ll vision condition was compared to a condition in which vision was elimina ted while in contact with the first target. The size of the first target wa s constant, while the second target size was varied. Target size had an inf luence on movement time and peak velocity to the first target. Vision condi tion and target size did not affect the time spent on the first target. The se results suggest that preparation of the second movement is completed bef ore the first movement is terminated. Experiment 2 examined when this prepa ration occurred. A full vision condition was compared to a condition in whi ch vision was occluded during the flight phase of the first movement. Movem ent initiation times were shorter when vision was continually available. To tal movement time was reduced with vision in two-target condition, but not in a control one-target condition. The time spent on the first target was g reater when vision was not available during the first movement component. T he results indicate that vision prior to movement onset can be used to form ulate a movement plan to both targets in the sequence [Fischman & Reeve (19 92). Journal of Human Movement Studies, 22, 131-144]. The plan can then be refined on-line using whatever visual feedback is available [Chamberlin & M agill (1989). Research Quarterly for Exercise and Sport, 60, 256-267]. (C) 1999 Elsevier Science B.V. All rights reserved. PsycINFO classification: 23 30.