When visuo-motor incongruence aids motor performance:the effect of perceiving motion structures during transformed visual feedback on bimanual coordination

Two experiments are reported in which bimanual coordination tasks were performed under correct and transformed visual feedback conditions. Participants were to generate cyclical line-drawing patterns, with varying degrees of coordinative stability, while perceiving correct or transformed visual information of the trajectories on a screen. Visuo-motor transformations that dissociated the perceived movement direction from the actually generated direction, were applied to one or both limbs, resulting in varying degrees of perceptual grouping power. The transformed feedback did not influence the most stable coordination patterns (in-phase) whereas the accuracy and/or stability of the less stable coordination patterns (anti-phase and particularly orthogonal) benefited from particular visual feedback manipulations, i.e. when coherently grouped visual motion structures emerged, the quality of coordination improved significantly. These findings indicate that perceptual transformations aid the production of more complex coordination patterns, thereby underscoring the importance of perception-action coupling in bimanual coordination. (C) 2002 Elsevier Science B.V. All rights reserved.