Fig 1. Experimental setting.

(A) Originality in the current study. (B) Experimental task. The study used four conditions for the initial state of cursor and target: the two-target condition, the two-cursor condition, the one-target condition, and the one-cursor condition. In the two-target condition, at the beginning of the task, a cursor and two potential targets were presented along a vertical line. In this condition, after movement onset, one of the two targets disappeared, and the other remained at the initial position. The participants were required to reach and keep the cursor on the remaining target within a time constraint (500 or 750 ms in the fast and slow groups, respectively). In the two-cursor condition, at the beginning of the task, two potential cursors and a target were presented along a vertical line. In this condition, after movement onset, one of the two cursors disappeared, and the other remained at the initial position. The one-target condition and the one-cursor condition were the control conditions for the two-target and two-cursor conditions, respectively. (C) Start positions of cursors and targets. In the analyses, the distance between the cursor and the target was classified into three categories: long (L: 18–22 cm), middle (M: 14–18 cm), and short (S: 10–14 cm), starting with the farthest one. The probability of appearance of these areas was set to be equal. Thus, the one-target and one-cursor conditions included the three distance conditions, L, M, and S, with 16 trials performed for each condition. However, the two-target and two-cursor conditions included six distance conditions, namely, LL, MM, SS, LM, LS, and MS, each of which was also assessed over 16 trials.