Figure 1.

Icon-selection task. (A) After the monkey fixated a central fixation point for 300 ms, 2 icons appeared that were connected by curves (black lines) to 2 red disks. The monkey had to make a saccade (green arrow) to the target disk (T) that was connected to the target icon (yellow icon). The other icon, curve, and disk were distractors (D). The lower panel shows examples of target and distractor icons used in different sessions. (B) For easy and intermediate stimuli, the target icon was on top of or closer to the fixation point than the distractor icon. In the difficult condition, the distance between the icons and the fixation point was identical so that the monkeys could only rely on icon identity to make a correct choice. RF, receptive field; FP, fixation point.