Figure 2 illustrates the sequence of events in each trial. For reasons of clarity, not all items are shown at the correct scale. At the start of each trial an arrow was presented on the monitor that guided the participant to a randomly chosen initial position within a rectangular area of 1-cm height and 4-cm width, with its midpoint 1.5 cm below the center of the semicircular workspace (
Figure 2a). The arrow disappeared when the stylus held by the participant was in the initial position (with a 4-mm margin) for 1 s. Next, we instructed the range of movement directions of the outward movement for the current trial by displaying a WiFi-like symbol (three circular arcs of 25° width at 18-, 24-, and 30-mm radial distance from the center position) for 1 s (
Figure 2b). The color of the symbol indicated the type of trial: It was red for
UniCursor trials (signaling participants not to move their hand), green for
UniHand trials, and light gray for bimodal trials. Directly after the WiFi symbol disappeared, the center position was shown (a 7-mm diameter outline circle) as well as visual feedback of the hand position (a 6-mm filled circle;
Figure 2c). This allowed participants to reach the center position swiftly. After maintaining this position for 250 ms (with a 2.5-mm margin), the center position circle disappeared and an auditory beep was presented as a cue to begin the outward movement to the stopper ring. If the cursor was shown (all trial types except
UniHand), it was visible until 97% of the 15-cm distance between the start position and the stopper ring was covered. Its direction was rotated according to the magnitude of the visuomotor rotation selected for each specific trial (
Figure 2d). The 97% criterion was required to detect all movement endpoints because, due to the thickness of the stylus and depending on its exact orientation in the hand, a slightly variable radial distance between 97% and 100% was reached. Immediately after hitting the stopper ring, participants moved the stylus back to the remembered start position of the outward movement without visual feedback (
Figure 2e). They pressed the button on the stylus, which triggered an auditory beep, to confirm being back. Immediately thereafter the word CURSOR or HAND was presented on the monitor to instruct participants to judge the remembered cursor movement endpoint or hand movement endpoint, respectively (
Figure 2f). 500 ms later the appearance of the response cursor (
Cursor response task) or the arrow (
Hand response task) signaled that participants could report their position judgment.