Each laboratory session involved the presentation of 48 slides, 12 each from the categories of pleasant, unpleasant, neutral, and cigarette. Each slide was presented for 6 s followed by a randomly determined inter-slide interval that varied from 10 to 20 s. Four separate slide orders, one for each session, were pseudorandomized such that no slide valence was shown more than twice consecutively. The pleasant, unpleasant, and neutral slides were selected from the International Affective Picture System (IAPS; Center for the Study of Emotion & Attention, 1999),1 with the unpleasant slides selected from the negative valence, high arousal dimensions; the pleasant slides from the positive valence, high arousal dimensions; and the neutral slides from the neutral valence, low arousal dimensions. The cigarette slides, consisting of smoking cues such as slides of burning cigarettes and people smoking in a social context, were created for this experiment and are validated elsewhere (Carter et al., 2006). A PC using Psychology Tools’ E-Prime software (v1.1; Pittsburgh, PA) presented a 91.5 cm × 122 cm image of the slides using a digital projector, on a screen
