Ladwig, S. , Sutter, C. , Müsseler, J. , Wendler, K. & Bade, F.
Department of work and cognitive psychology. RWTH Aachen University. Aachen. Germany.
In tool use non-corresponding proximal and distal action effects appear to have solid impact on motor performance. Recent findings show motor behaviour assimilates towards perturbed visual feedback. In the present experiments we investigated if and to what extend these deviations will also occur in a cross-modal task of sensorimotor control. Different gains for the x-axis perturbed the relation between hand movements on the digitizer tablet and cursor movements on a display. The covered hand movement was held constant while the cursor amplitude was shorter, equal or longer, and vice versa in the other condition. Participants were asked to replicate either their initial hand amplitude (hand judgement) or the displayed cursor amplitude (display judgement) without gaining visual feedback. First, the replicated hand amplitudes varied in accordance with the non-corresponding distal effect, showing the expected solid impact of visual distractors. Furthermore, deviations remarkably increased in the cross-modal task. When participants were asked to replicate the initially seen cursor movement judgements assimilated by 56% towards the proximal distractor. To sum up, in the cross-modal task kinaesthetic/proprioceptive feedback dominated action control and overruled the visual predominance.