Study task and longitudinal structure.

A. Go-NoGo task. Modified with permission from (26). Participants are presented with four stimuli for 36 trials each in fully randomized order. After a short ‘wait’ interval, they implement a decision of either to press or not press a button. Subjects discover by trial and error the two possible outcomes for choice of each stimulus (win/nothing or nothing/loss) and across trials learn which decision, ‘Go’ or ‘NoGo’, most often (with probability 0.8) leads to the best outcome. B. Longitudinal study structure, summarizing and illustrating the stages described in Methods.