Vision-to-event and movement-to-event coordination in an unimanual circling task.

Coordination of actions with events in extracorporeal space is essential for many everyday tasks. In the present study, we investigated how transformations, like in tool use, and varying the spatial context affect action coordination. For this aim, we used a circling task that required participants to coordinate the visual feedback of hand movements with a clockwise circling stimulus (event). The trajectories of stimulus and visual feedback were presented horizontally aligned (group horizontal), within each other (group interleaved) or vertically aligned (group vertical). Within groups, we varied the instructed rotation direction of stimulus and visual feedback (same and different), and y-direction of visual feedback relative to the stimulus (same and different). To dissociate movements and the associated proprioceptive/kinesthetic feedback from visual movement feedback, participants performed the tasks under regular and transformed visual feedback (180° angular shift). Results indicated that action coordination follows the principle of vision-to-event coordination (similar data patterns with regular and transformed feedback), but subtle effects of movement-to-event coordination were also observed (larger difference in performance between same y-direction and different y-direction conditions with regular than with transformed feedback). The presence of a transformation affected performance negatively. The different visual layouts affected the different conditions differentially, pointing to the importance of the visual context. In conclusion, vision-to-event coordination dominates unimanual action coordination. The quality of performance is influenced by perceptual processes based on differential processing of the horizontal and vertical axis, and based on Gestalt principles.