Figure 1.

Block design of (A) cue-induced cocaine craving task (CCT) and (B) cue-induced food craving task (FCT). Briefly, a fixation cross appeared on the screen to engage attention at the beginning of each block. After 2 seconds, 6 pictures displaying cocaine/food-related cues (cocaine/food block) or neutral scenes (neutral block) were shown for 6 seconds each. Participants were asked to look at the pictures and think about how they might relate to the scenes. At the end of each block participants were asked to report how much they craved cocaine/food on a visual analog scale from 0 (no craving) to 10 (highest craving ever experienced) by pressing a button on the hand-held box in the scanner. A total of 12 cocaine/food and 12 neutral picture blocks were interleaved in two 9-minute runs of fMRI.