Experimental design and setup.

A) Participants were seated in front of a touch screen on which targets were displayed. Participants performed pointing movement either towards the touch screen with their index finger or on a graphics tablet using a stylus. To control for visual feedback participants wore shutter glasses that were only transparent as long as a mouse button was being held. A chin rest restricted head movements. B) The complexity of the visuomotor mapping depends on the response mode (direct–touch screen vs. indirect–graphics tablet). Direct condition (top): for touch screen responses the pointing movement is directly towards the visual target location. Indirect condition (bottom): for tablet responses the pointing movement is on the horizontal plane of the tablet involving an additional mapping from the vertical image screen to the horizontal response plane. C) Sequence for a single trial. Participants initiated stimulus onset and shutter glasses transparency by pressing the right mouse button, such that with the onset of the movement visual feedback was prevented. After movement completion participants indicated whether they thought they had landed left or right of target. At the end of each trial they received a score based on absolute pointing accuracy.