In Study 1, participants first saw a fixation cross for 2 seconds, followed by an image (methamphetamine, methamphetamine smoking, intranasal use, or food) for 6 seconds, followed by another fixation cross. At the end of each trial, they were asked to report their craving for methamphetamine or food on a 1–5 scale (1= not at all and 5 = very much). In Study 2, participants first saw a fixation cross for 2 seconds, then received instructions for 2 seconds: LOOK, POSITIVE, or NEGATIVE, followed by an image (of methamphetamine, methamphetamine smoking, or food) for 6 seconds, followed by a fixation cross. At the end of each trial, they were asked to report their craving for methamphetamine or food on a 0–10 scale (0= not at all and 10 = very much).