Disgust but not Health Anxiety Graphic Warning Labels Reduce Motivated Attention in Smokers: A Study of P300 and Late Positive Potential Responses.

Background: Graphic health warning labels (GHWLs) on tobacco products attempt to leverage avoidance-promoting emotions, such as anxiety and disgust, to encourage cessation. Prior studies have relied on self-report or attentional metrics that may not accurately illuminate GHWLs' ability to motivate change. This report evaluates the impact of disgust- and anxiety-based GHWLs on electroencephalograph (EEG) measures of motivated attention among two groups of smokers-those that report higher versus lower cigarette dependence. We hypothesized that both anxiety and disgust GHWLs would reduce appetitive attention, as indexed by lowered P300 (P3) and late positive potential (LPP) activations.

Methods: Sixty-one smokers provided demographic and smoking history before completing an oddball paradigm consisting of three counterbalanced stimuli blocks. Each block (100 trials) contained a neutral, GHWL-anxiety, or GHWL-disgust frequent image and a smoking cue as the oddball image (20%). Oddball trials for each block were averaged, P3 and LPP were identified at midline electrode positions (Fz, Cz, and Pz), and mean amplitude was analyzed.

Results: Separate mixed-model ANOVAs of P3 and LPP reactivity revealed disgust-focused GHWLs reduced motivated attentional processing. Conversely, the anxiety-focused GHWL appeared to increase the salience of the smoking cue (Fz only). Less-dependent smokers showed lower P3 reactivity than those with higher dependence at Fz, but greater P3 reactivity at Cz and Pz.

Conclusion: These results extend prior work in demonstrating that disgust, but not anxiety-based GHWLs, may reduce EEG-assessed motivated attention to smoking cues. Disgust may thus represent a more fruitful target for public health cessation efforts.

Implications: Most GHWL evaluations have focused on fear (or anxiety) elicitation rather than disgust, an emotion that may have a unique link to smoking, having evolved specifically to facilitate the avoidance of contaminants via oral incorporation. Analyses of P300 and LPP responses to GHWLs suggest that disgust-focused images interfere with the EEG-indexed attentional processing of smoking cues and do so better than health anxiety-focused messages. However, interaction effects at different electrode sites indicated that GHWLs have complex effects in more versus less-dependent smokers and that an understanding of how smoking cues and anti-smoking imagery become associated over time is needed to identify relevant targets for public health efforts.