Experimental Task: In each trial, participants first viewed either a high or low motivation incentive cue that indicated the opportunity to earn a monetary bonus (reward group) or avoid an electrical stimulation (punishment group). In control trials, the cue was followed by serial repetitions of a trial-unique, color object image. After 10 or 11 repetitions that image became gray-scale, to which participants were to make a speeded button press. In surprise trials, serial presentation of the trial-unique color object image was interrupted by a novel, yet highly similar, object image at a temporally unpredictable time. Following the button press to the target, participants were presented an outcome screen that indicated their performance (i.e., whether they earned a monetary bonus or avoided a shock).