The experimental task was a modified version of Gehring and Willoughby’s (2002) gambling task in which the participant chose between two monetary options on each trial and then received feedback indicating whether the choice resulted in winning or losing money on that trial. The modification was that feedback was presented 100 ms after the button press to have the feedback occur more immediately following the choice. The target stimuli consisted of two adjacent squares, each enclosing a number (5 or 25) representing a monetary value (in cents). The target stimulus remained on the screen until a choice was made between the square on the left and the one on the right, after which a blank screen appeared for 100 ms, followed by a feedback stimulus that indicated the outcome of the participant’s decision. That is, the chosen box turned either red or green to signify either a win or a loss (with red or green as the winning color counterbalanced across participants), and the unchosen box turned the other color (either green or red) to indicate what the outcome of
