A gambling task modeled after Holroyd et al. (2003) presented the participant with four lifelike balloon images of different colors (red, green, orange, blue) that randomly appeared in different serial positions along a row centered on the screen. The object of the game, called “Money Maker,” was to select balloons, one at a time, to win money. Participants responded with their right and left middle and index fingers on a four-button response pad. Participants were told to try to win as much money as possible and that they would receive this money at the end of the game. After each selection, all the balloons disappeared, and either a green dollar sign (indicating a reward of 10 cents), or a white square (indicating a non-reward) appeared. Subsequent to balloon selection on each trial, feedback was delayed 1 to 1.2 seconds. Feedback lasted 1,000 msec followed by a 1,000–1,200 msec crosshair, and a 100 msec blank screen before the balloons reappeared. Participants made balloon choices at self-paced intervals.
