We found no significant differences between participants in the two argument conditions in any demographic, individual differences, or smoking behaviors assessed in the study; none of these variables were controlled in subsequent analyses.
Simple hypothesis tests
A significant quadratic main effect of smoking cue, F(1, 94) = 4.2, p < .05, partial η2 = .04, and a marginally significant linear interaction between smoking cue and argument strength, F(1, 94) = 3.8, p = .06, partial η2 = .04, were found on smoking urges. The results are graphed in . Smoking urges started at a relatively high level for smokers in both argument conditions (M = 3.4, SD = 1.2). Urges decreased after participants watched the no-cue advertisements (M = 3.3, SD = 1.3) and increased slightly after they watched smoking cue advertisements (M = 3.4, SD = 1.4), which produced a significant quadratic effect. The linear interaction resulted from the smoking urge after watching smoking cue advertisements. Whereas smokers in the weak argument condition significantly increased their smoking urge after watching smoking cue advertisements, Mpre cue = 3.3, SDpre cue = 1.3 vs. Mpost cue = 3.5, SDpost cue = 1.4, t(47) = 2.6, p = .01, smokers in the strong argument condition did not, Mpre cue = 3.3, SDpre cue = 1.3 vs. Mpost cue = 3.2, SDpost cue = 1.5. Thus, smoking cues increased smoking urges only for advertisements with weaker arguments.
Interaction between argument strength and smoking cue on smoking urge (p < .06).
Smoking cue had a significant main effect on heart rate change (measured in beats per minute). Advertisements with smoking cues were associated with a larger heart rate reduction (M
= –1.2, SD
= 1.9) than advertisements without smoking cues (M
= –0.4, SD
= 1.6), F
(1, 88) = 14.4, p
< .001, partial η2
= .14. Argument strength interacted with smoking cues on heart rate change, F
(1, 88) = 6.1, p
< .02, partial η2
= .07, such that the difference in heart rate change between no-cue and smoking cue advertisements was significant only for advertisements with weaker arguments, Mno cue
= –0.3, SDno cue
= 1.5 vs. Mcue
= –1.5, SDcue
= 2.1, t
(44) = 4.5, p
< .001. The magnitude of the heart rate change is consistent with previous literature (Carter & Tiffany 1999
; Kelly, Barrett, Pihl, & Dagher, 2004
). presents the results. This finding, paired with the finding that smoking cues elicited stronger smoking urges in the weak argument condition, suggests that stronger urges might be associated with a reduction in heart rate.
Interaction between argument strength and smoking cue on heart rate change scores (p < .02).
We did not find any significant main or interaction effects on skin conductance.
Our findings did not support the second hypothesis, according to the approach-based model. Instead, it revealed that smoking cues reduced heart rate in the weak argument condition, which was the same condition in which smoking cues had the strongest impact on smoking urges.
An overall urge change score was calculated as the difference between urge change during viewing no-cue advertisements and urge change during viewing smoking cue advertisements. A marginally significant effect for this urge change was obtained, F(1, 92) = 3.7, p < .06, partial η2 = .04, along with a main effect for gender, F(1, 92) = 7.0, p < .01, partial η2 = .07, and a significant interaction between gender and smoking cue, F(1, 92) = 5.0, p < .03, partial η2 = .05. Smoking cues significantly increased urge change only in male smokers, Mno cue = –0.4, SDno cue = 0.8 vs. Msmk cue = 0.1, SDsmk cue = 0.7, t(51) = 3.1, p = .003. presents the interaction.
Gender moderates the impact of smoking cues on smoking urge changes (p < .03).
Gender interacted with smoking cues on skin conductance change over baseline, F(1, 82) = 4.7, p < .05, partial η2 = .05. This effect was due primarily to the decreases in skin conductance for men, although the effect was not significant. Male smokers experienced a larger decrease in skin conductance during viewing smoking cue advertisements, M = –0.4, SD = 0.9, compared with viewing no-cue advertisements, M = –0.1, SD = 0.7, t(48) = 1.8, p < .08, whereas female smokers’ skin conductance reduction was not significantly different while viewing no-cue advertisements, M = –0.3, SD = 0.6, and smoking cue advertisements, M = –0.2, SD = 0.8.
Gender did not affect participants’ heart rate change during advertisement viewing.