Action control while seeing mirror images of one's own movements: effects of perspective on spatial compatibility.

It is examined whether and how the perspective of seeing one's own movements exerted an influence on action control. Such change in the perspective challenges an information processor, as she or he has to handle successfully the discrepancies between the tactile/proprioceptive feedback and the visual feedback on a projection screen. In the experiments participants responded to visual stimuli, but saw their responses either from the top or with an x-axis reflection, a y-axis reflection, or a reflection about both axes. The results showed that a change in perspective did not impair performance as long as the left-right relations corresponded with the body space (e.g., with visual feedback reflected about the x-axis). By contrast, performance was drastically reduced when visual feedback was reflected about the y-axis or about both axes, so that performed left-side (right-side) movements were seen as right-side (left-side) movements. It is concluded that an actor preferably relies on the information of the visual system, but refers to the tactile/proprioceptive information when it facilitates the task demands.