Diminished valuation in the brain: how repeated exposure reduces health message engagement

Public health campaigns traditionally aim to maximize message reach, assuming that more exposure leads to greater intended effects. However, recent research on message fatigue suggests that repeated exposure can lead to diminished message engagement. The goal of the current study is to understand the neuropsychological processes involved in repeated health message exposure in key brain regions known to facilitate or inhibit persuasion.

This study examines how repeated exposure to health campaign messages is linked to neural activity in brain regions implicated in valuation, which is in turn linked to key processes of message engagement, including attention, elaboration, and counterarguing.

Thirty-seven adolescent nonsmokers viewed 12 public service announcements (PSAs) from The Real Cost anti-tobacco campaign in a functional magnetic resonance imaging scan session. We examined the relationship between the number of PSA exposures and neural activity in the hypothesized brain regions of interest (ROIs). We also investigated whether the observed neural activity, in turn, was associated with the levels of message engagement reflected in participants' subsequent verbal descriptions of the PSAs, assessed with automated linguistic coding.

Increased message exposure was negatively associated with neural activity in the valuation ROI, which was positively associated with activity in the attention, elaboration, and counterarguing ROIs. Neural activity in the attention ROI was linked to higher message engagement, while activity in the counterarguing ROI was negatively associated with message engagement. No significant link was found between neural activity in the elaboration ROI and message engagement. Mediation analysis suggested that increased exposure may indirectly reduce message engagement by diminishing positive valuation of the messages, thereby decreasing attention to and elaboration of the messages.

This study elucidates the counterproductive effects of repeated message exposure on message engagement by examining the neurocognitive and psychological processes involved when target audiences are repeatedly exposed to similar anti-tobacco campaign messages. These insights are crucial for planning and designing public health campaigns that typically are repeated via various media channels.