Figure 1.

Method. (a) Depiction of the setup for the interception task. The white and red dots represent the target and the hand’s starting position, respectively. In the judgment task the setup was identical except that the participant’s hand was next to a keyboard rather than being equipped with a marker, and the starting position for the index finger was absent. (b) Paradigm of a single trial in the judgment (left) and interception (right) tasks. After an initial fixation of 600 ms the fixation point (black dot) disappeared and 50 ms later the target appeared with an offset either to the left or to the right. The magnitude of the offset (target crossing time, TX) was manipulated so that the target would pass the initial fixation location after 100 or 240 ms. Thus, the size of the step depended on the target’s velocity and the target crossing time. The target kept moving for 600, 650 or 700 ms. In the judgment task participants had to decide whether they had been presented with a fast or slow target on each trial. In the interception task they had to try to tap on the target with their right index finger before it disappeared.