Self-affirmation alters the brain's response to health messages and subsequent behavior change

Abstract

Health communications can be an effective way to increase positive health behaviors and decrease negative health behaviors; however, those at highest risk are often most defensive and least open to such messages. For example, increasing physical activity among sedentary individuals affects a wide range of important mental and physical health outcomes, but has proven a challenging task. Affirming core values (i.e., self-affirmation) before message exposure is a psychological technique that can increase the effectiveness of a wide range of interventions in health and other domains; however, the neural mechanisms of affirmation's effects have not been studied. We used functional magnetic resonance imaging (fMRI) to examine neural processes associated with affirmation effects during exposure to potentially threatening health messages. We focused on an a priori defined region of interest (ROI) in ventromedial prefrontal cortex (VMPFC), a brain region selected for its association with self-related processing and positive valuation. Consistent with our hypotheses, those in the self-affirmation condition produced more activity in VMPFC during exposure to health messages and went on to increase their objectively measured activity levels more. These findings suggest that affirmation of core values may exert its effects by allowing at-risk individuals to see the self-relevance and value in otherwise-threatening messages.

Keywords: VMPFC; behavior change; fMRI; physical activity; self-affirmation.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.

Effect of affirmation on neural activity in VMPFC and on behavior change in the month following the scan. Participants who were affirmed showed (A) greater activity in VMPFC during exposure to health messages and (B) greater declines in sedentary behavior in the month following the scan than participants who were unaffirmed, controlling for baseline sedentary behavior and demographics.

Fig. 2.

(A) VMPFC ROI. (B) Participants who showed higher levels of VMPFC activity during exposure to health messages subsequently decreased their sedentary behavior more in the month following the scan, controlling for baseline sedentary behavior and demographics.

Fig. 3.

Overall study design.

Fig. 4.

fMRI task design.