Fig. 1.

MSIT task. The subjects had to respond to the different number in the series, with their index (1), middle (2) or ring (3) fingers. During the control trials, the distractor stimuli were zeros (0) and the target number was placed in the position congruent with its position on the response box where the participant should respond. During interference trials, distractors were other numbers (1, 2 or 3) and the target was never placed in a position congruent with the position in the response box. In the first example the correct answer would be to press the “1” button with the index finger; and in the second example the correct answer would be to press the “2” button with the middle finger.