Figure 1

Antisaccade task. In each trial, a stimulus (black dot) is presented at a distance x from the fixation point (colored dot); the stimulus disappears; two targets appear (gray dots) and the subject responds by making an eye movement (arrow) to one of them. The color of the fixation spot indicates whether the movement should be a saccade or an antisaccade. a: In context 1 the fixation spot is red and the movement is to the target at x. b: In context 2 the fixation spot is green and the movement is to the opposite target, at -x. In the model, x is between -15 and +15, with distance in arbitrary units.