Fig. 1

Behavioral paradigm and performance. a Monetary incentive delay task: A bet (a dollar, a cent, or no money) appeared at the beginning of each trial. After a randomized interval between 1 and 5 s, a target box appeared on the screen, then disappeared after a short period (response window). Subjects were told to press a button as quickly as possible to collect the money in the target box (win) before it disappeared. Otherwise, subjects lost the bet, with the amount deducted from their total winnings. A premature button-press prior to the appearance of the target box terminated the trial, and similarly resulted in loss. A feedback window was shown on the screen after each trial to indicate the amount of money won or lost. b Accuracy rate and c RT of dollar, cent and no money (nil) trials (mean ± SD) for men and women