Spatial aspects and timing of task. (a) Spatial layout: Each trial consisted of two stages—a decision stage (top) and a bet stage (bottom). In the decision stage, monkeys foveated a fixation spot. A target appeared at one of four locations in the periphery, and after a variable time (stimulus onset asynchrony [SOA]), masks appeared at the four locations. A correct decision was made (shown) if a saccade went to the location of the target. A saccade to any other location was an incorrect decision. In the bet stage, monkeys foveated a new fixation spot, then the two bet targets appeared in the periphery. A bet was made when a saccade went to one of the two targets, completing a single trial. (b) Timing: Top bracket shows when stimuli were visible (gray shading) and invisible (flat line) during each trial. Bottom bracket shows a hypothetical eye trace and actions performed by monkeys during the sequence of events.