Figure 1.

(a) Schematic of the video-game display with left and right gates represented by pairs of squares and a final common goal represented by an opening in a virtual wall at the top of the display. The black hand icons represent the initial position of the left and right cursor, respectively. The cross represents the location of initial gaze fixation. Icons are not to scale and the screen background was black, not white, with gray objects. (b) Location of gates and goal of each scene for experiment 1. Each scene had a field-of-view of 45 deg, with azimuth and elevation running from –22.5 to 22.5 deg and consisting of one final goal (circle). Scenes 2-13 included two gates (squares) located at various positions. In scene 1 no gates were present. The size of the gate openings was 4.2 deg (scene 2), 6.2 deg (scene 3), 3.8 deg (scenes 4, 6, 8, 11), 7.2 deg (scenes 5, 7, 9), 4.6 deg (scene 10), and 6.6 deg (scenes 12, 13). Icons are not on scale. Each pair of lines with the same grayscale represents the left and right cursor trajectories of a single trial, for S2. Traces only show the trajectory between movement onset of the left (right) cursor until the time when gaze moved away from the left (right) gate. (c) Same as (b) for experiment 2. In scene 1, only one gate was present; scenes 2-7 included two gates. The size of the gate openings was 2.5 deg in all scenes.