The monetary gambling task (MGT) used in this study is illustrated in Figure 1. Each trial begins with a choice stimulus (CS), with two numbers (representing monetary values in US cents) of 10 (left box) and 50 (right box), displayed for 800 ms. The participants select a bet of either 50¢ or 10¢, and receive feedback of either loss or gain for the selected amount (outcome stimulus, OS). The task details have been described in our previous publications (Kamarajan et al., 2008; Kamarajan et al., 2012; Kamarajan et al., 2015a; Kamarajan et al., 2015b). The inter-stimulus interval between a CS and OS, and between an OS and the next CS is 1500 ms. The task involves a total of 172 trials, each with one of four possible outcomes: Loss 50, Loss 10, Gain 50, and Gain 10. The number of outcome events for loss/red and gain/green trials (OS) are equal (i.e., 50% loss and 50% gain trials regardless of the amount within each outcome), and the order of trial sequence is predetermined, pseudo-randomized, and identical for all participants. However, the
