were presented 70.3 mm to the left of the target. The lines were 0.38 mm thick and 1.52 mm apart from each other. The participant was asked to press a button on the keyboard to indicate which of the two lines was closer to the position of the target. Pressing of the upper/lower arrow key changed the color of the further/closer line from gray to yellow. The position estimate was confirmed by the enter key. In response to this key press the target and the comparison lines disappeared and the start position appeared. This was a signal to move the stylus back to the start position that was constant through the experiments. --------- Figure 2 about here --------- Participants were encouraged to perform rather slow movements and to stop the movement immediately after the stop signal. An error feedback was presented and the current trial was repeated when the stylus key was pressed before the stop position was reached or when the distance between the end position of the stylus and the position at which the stop signal was presented exceeded 38 mm. In those cases, the following text appeared at the screen for made a wrong movement. The trial will be 1000 ms (in German): “Error! You repeated”. Experiment A and Experiment B differed only in visual feedback accompanied forward movements of the stylus. In Experiment A, the current stylus position was continuously presented during the forward movement (green dot, 2 mm in size). Note, however, after movement stopping (i.e., before the position judgment) the feedback disappeared. In Experiment B, forward movements were performed in the absence of visual feedback. In both experiments, the current stylus position was displayed during the backward movement when the y-distance between the stylus and the start position fell below 38 mm. There were three possible target positions. Related to the y-coordinate the target was located either approximately in the middle between the two comparison lines (middle target),
were presented 70.3 mm to the left of the target. The lines were 0.38 mm thick and 1.52 mm apart from each other. The participant was asked to press a button on the keyboard to indicate which of the two lines was closer to the position of the target. Pressing of the upper/lower arrow key changed the color of the further/closer line from gray to yellow. The position estimate was confirmed by the enter key. In response to this key press the target and the comparison lines disappeared and the start position appeared. This was a signal to move the stylus back to the start position that was constant through the experiments. --------- Figure 2 about here --------- Participants were encouraged to perform rather slow movements and to stop the movement immediately after the stop signal. An error feedback was presented and the current trial was repeated when the stylus key was pressed before the stop position was reached or when the distance between the end position of the stylus and the position at which the stop signal was presented exceeded 38 mm. In those cases, the following text appeared at the screen for 1000 ms (in German): “Error! You made a wrong movement. The trial will be repeated”. Experiment A and Experiment B differed only in visual feedback accompanied forward movements of the stylus. In Experiment A, the current stylus position was continuously presented during the forward movement (green dot, 2 mm in size). Note, however, after movement stopping (i.e., before the position judgment) the feedback disappeared. In Experiment B, forward movements were performed in the absence of visual feedback. In both experiments, the current stylus position was displayed during the backward movement when the y-distance between the stylus and the start position fell below 38 mm. There were three possible target positions. Related to the y-coordinate the target was located either approximately in the middle between the two comparison lines (middle target),
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