Figure 2.

Experimental setup. (A) Lateral view of the target arrangement with respect to the participant's body. (B) Top view of the target arrangement in the peripersonal space. The participants performed reaching movements with their right hand toward one of the nine dots projected on the screen at different depths (near, intermediate, and far) and in different directions (left and right positions). Reaching movements were performed in a dimly lighted room, starting from the initial hand position located next to the body and marked by a squared surface (white square). (C) Time sequence of the visually guided reaching in the peripheral reaching configuration. The small white dot represents the fixation target; the filled black dot represents the reaching target. The fixation target stayed on for 1.5 s and then the reaching target was turned on in one of the nine locations. As soon as the reaching target appeared on the screen, a sound indicated to the participant to reach with his or her right hand the position of the target while maintaining fixation on the fixation target. The fixation target lasted until the participant completed the movement. (D) Top view of the two task configurations. (Top) Peripheral reaching: reaching movements were performed toward one of the nine targets (hands). The spatial position of the target changed trial to trial, but gaze was kept constant at the central position (eye). (Bottom) Foveal reaching: reaching movements were performed toward one of the nine targets. During the task, the participant had to fixate and reach the same target (eye and hand on the panel). (E) Representation of real and straight trajectories in a control participant. (Left) Distribution of the real (shaded traces) and straight (dotted lines) two-dimensional trajectories toward left and right targets (direction dimension). (Right) Distribution of the real (shaded traces) and straight (dotted line) two-dimensional trajectories toward the near, intermediate, and far targets (depth dimension).