Brain response during anticipation of incentive stimuli was probed during fMRI using a modified version of the Monetary Incentive Delay task 30. Modifications were designed to eliminate the memory component from the original task, by replacing symbols for “reward” and “loss” trials with text stating trial type. A schematic of the modified paradigm is presented in Figure 1. Each 6 second trial consisted of four events. First, subjects were presented with an incentive cue (2000 ms) of five possible values (gain of $0.2, $5.0; loss of $0.2, $5.0; or no change $0). This was followed by a 2000 ms anticipation delay. Next, a target appeared for a variable length of time (200 to 300 ms) during which, subjects made a button press response in an attempt to gain or avoid losing said incentive. Subjects were instructed to respond to neutral targets despite the lack of incentive value. A feedback message then informed subjects of the trial outcome. The incentive trials were presented contiguously in a pseudorandom order. Subjects performed two runs of the task, each lasting 5 minutes. A total
