Brain activity during anticipation of smoking-related and emotionally positive pictures in smokers and nonsmokers: A new measure of cue reactivity

Previous studies have shown that a brain wave pattern known as stimulus preceding negativity (SPN) can index the anticipation of motivationally relevant events. The present study was the first to use SPN as an index of the motivational significance of smoking-related pictures. Emotionally positive and neutral pictures served as controls. The paradigm involved the following sequence: (a) presentation of a picture (S1) for 500ms, (b) a fixation cross for 3,500ms, (c) a second presentation (S2) of the same picture for 2,000ms, and (d) another fixation cross signifying the beginning of a new S1-S2 trial using a different picture. The participants (N=24, half smokers and half nonsmokers) viewed pictures from three categories (smoking-related, emotionally positive, or emotionally neutral). Consistent with predictions, smokers exhibited significantly greater mean SPN amplitudes in anticipation of smoking-related pictures relative to neutral pictures. Among nonsmokers the SPN was significantly smaller in anticipation of smoking pictures compared with neutral pictures. These findings are consistent with the incentive sensitization theory of addiction and other conditioning and cue-reactivity models.