Neural mechanisms underlying visual attention to healthwarnings on branded and plain cigarette packs

Aims To (1) test if activation in brain regions related to reward (nucleus accumbens) and emotion (amygdala) differwhen branded and plain packs of cigarettes are viewed, (2) test whether these activation patterns differ by smoking statusand (3) examine whether activation patterns differ as a function of visual attention to health warning labels on cigarettepacks.Design Cross-sectional observational study combining functional magnetic resonance imaging (fMRI) witheye-tracking. Non-smokers, weekly smokers and daily smokers performed a memory task on branded and plaincigarette packs with pictorial health warnings presented in an event-related design.Setting Clinical Research andImaging Centre, University of Bristol, UK. Participants Non-smokers, weekly smokers and daily smokers (n =72)were tested. After exclusions, data from 19 non-smokers, 19 weekly smokers and 20 daily smokers were analysed.Measurements Brain activity was assessed in whole brain analyses and in pre-specified masked analyses in theamygdala and nucleus accumbens. On-line eye-tracking during scanning recorded visual attention to healthwarnings.Findings There was no evidence for a main effect of pack type or smoking status in either the nucleusaccumbens or amygdala, and this was unchanged when taking account of visual attention to health warnings.However, there was evidence for an interaction, such that we observed increased activation in the right amygdalawhen viewing branded as compared with plain packs among weekly smokers (P = 0.003). When taking into accountvisual attention to health warnings, we observed higher levels of activation in the visual cortex in response to plainpackaging compared with branded packaging of cigarettes (P =0.020).Conclusions Based on functional magneticresonance imaging and eye-tracking data, health warnings appear to be more salient on ‘plain’ cigarette packs thanbranded packs.To (1) test if activation in brain regions related to reward (nucleus accumbens) and emotion (amygdala) differwhen branded and plain packs of cigarettes are viewed, (2) test whether these activation patterns differ by smoking statusand (3) examine whether activation patterns differ as a function of visual attention to health warning labels on cigarettepacks.Design Cross-sectional observational study combining functional magnetic resonance imaging (fMRI) witheye-tracking. Non-smokers, weekly smokers and daily smokers performed a memory task on branded and plaincigarette packs with pictorial health warnings presented in an event-related design.Setting Clinical Research andImaging Centre, University of Bristol, UK. Participants Non-smokers, weekly smokers and daily smokers (n =72)were tested. After exclusions, data from 19 non-smokers, 19 weekly smokers and 20 daily smokers were analysed.Measurements Brain activity was assessed in whole brain analyses and in pre-specified masked analyses in theamygdala and nucleus accumbens. On-line eye-tracking during scanning recorded visual attention to healthwarnings.Findings There was no evidence for a main effect of pack type or smoking status in either the nucleusaccumbens or amygdala, and this was unchanged when taking account of visual attention to health warnings.However, there was evidence for an interaction, such that we observed increased activation in the right amygdalawhen viewing branded as compared with plain packs among weekly smokers (P = 0.003). When taking into accountvisual attention to health warnings, we observed higher levels of activation in the visual cortex in response to plainpackaging compared with branded packaging of cigarettes (P =0.020).Conclusions Based on functional magneticresonance imaging and eye-tracking data, health warnings appear to be more salient on ‘plain’ cigarette packs thanbranded packs.