a, Schematic illustrating the influences of feedback on a decision process. The lighter grey boxes indicate a theoretical process that is a specific focus of the present study, with a corresponding measure of interest indicated in parentheses (e.g., EV is a measure of decision evidence). The color-shaded areas represent a theoretical mapping of the two intersections of reinforcement learning and drift-diffusion parameters in the present study. EV, expected value; RPE, reward prediction error. b, Regions of interest corresponding to the Threshold + RPE (red) and Drift-rate + EV (blue) intersections. Z coordinates indicate the position of the axial slice in mm from ACPC line in Talairach space.