How real-life health messages engage our brains: Shared processing of effective anti-alcohol videos

Abstract

Health communication via mass media is an important strategy when targeting risky drinking, but many questions remain about how health messages are processed and how they unfold their effects within receivers. Here we examine how the brains of young adults-a key target group for alcohol prevention-'tune in' to real-life health prevention messages about risky alcohol use. In a first study, a large sample of authentic public service announcements (PSAs) targeting the risks of alcohol was characterized using established measures of message effectiveness. In the main study, we used inter-subject correlation analysis of fMRI data to examine brain responses to more and less effective PSAs in a sample of young adults. We find that more effective messages command more similar responses within widespread brain regions, including the dorsomedial prefrontal cortex, insulae and precuneus. In previous research, these regions have been related to processing narratives, emotional stimuli, self-relevance and attention towards salient stimuli. The present study thus suggests that more effective health prevention messages have greater 'neural reach', i.e. they engage the brains of audience members' more widely. This work outlines a promising strategy for assessing the effects of health communication at a neural level.

Keywords: alcohol; fMRI; health communication; inter-subject correlation; public service announcements; self.

Fig. 1.

Average inter-subject correlation (ISC) during all anti-alcohol PSAs. Raw ISC values > 0.1 were displayed on an inflated, anatomical rendering of the Colin27 Average Brain (Holmes et al., 1998). Statistical values were FDR corrected with q = 10⁻⁴, smoothed and a voxel contiguity threshold of 50 mm² was applied. L = Left hemisphere, R = Right hemisphere.

Fig. 2.

Differences in inter-subject correlation (ISC) during more compared to less effective PSAs. (A) Differential reach of ISC during more and less effective PSAs throughout the brain. Average raw ISC values > 0.1 were displayed for more (red) and less (blue) effective PSAs. FDR corrected with q = 10⁻⁴. (B) Illustration of significantly higher ISC during more (red/yellow) vs less (blue/green) effective PSAs. P-values were derived from two-sided, paired t-tests and FDR corrected with q = 0.05. All statistical values were overlaid onto a Talairach normalized, anatomical rendering of the Colin27 Average Brain (Holmes et al., 1998), and a voxel contiguity threshold of 50 mm² was applied. L = Left hemisphere, R = Right hemisphere, dmPFC = Dorsomedial prefrontal cortex, Ins = Insula, IPL = Inferior parietal lobe, Prec = Precuneus, STG = Superior temporal gyrus, Vis = Visual system.