Figure 1.

Experimental paradigms. Each window represents what the monkey sees chronologically ordered from top to bottom. Red filled circles represent targets, green filled circles represent distractors, and unfilled green circles represent potential distractor locations. (A) Two-target trials. Both targets are displayed but the reward outcome for choosing a target is probabilistic (%). (B) Single-target trials. Only one of the two potential targets appears, but reward is certain. Note that during a particular prospect block, the probability of target presentation at a particular location in single-target trials equals the probability of receiving a reward for choosing that target during two-target trials. (C) Distractor trials. These trials follow the same pattern as single-target trials, with the addition of an irrelevant green distractor being displayed prior to target appearance. Directing a saccade toward a distractor aborts the trial and reward is withheld.