It’s a persistent conundrum in the field of public health — how can we open people’s minds to positively receiving and acting on health information? Previous research has found that combining health tips with messages of self-affirmation may be a particularly effective strategy, but researchers weren’t entirely sure how self-affirmation worked at the neurological level. Now, a new study has found that self-affirmation’s effects on a particular region of the brain may be a major key to behavior change.

In even simpler terms, researchers involved this new study — which examined how self-affirmation alters the brain’s response to health messaging — found that precisely activating a certain region of the brain could be a central pathway toward positive behavior changes. The findings could point to a relatively low-cost way to yield behavioral changes that could impact some of the nation’s costliest conditions and risk factors, from obesity to tobacco use. Plus, the findings illustrate one way to deliver health messages in a fashion that allows those most at risk to see value in what might otherwise be viewed as judgmental and threatening.

“It seems like we can change neural activity using this simple intervention and it does relate to behavior change down the road,” said study lead author Emily Falk, an assistance professor of communication at the University of Pennsylvania Annenberg School for Communication. “Self-affirmation is a cheap, scalable intervention…and it turns out to have huge effects for a relatively low investment.”

To conduct the study, which was published in February in the Proceedings of the National Academy of Science, Falk and her fellow researchers used functional magnetic resonance imaging to study a region of the brain involved in processing self-relevance known as the ventromedial prefrontal cortex (VMPFC). To begin, sedentary study participants were first given a list of values — such as family and friends, religion or politics — and asked to rank them in order of meaningfulness. The study sample was then broken into two groups — both groups received the same behavioral health information, but only one group was first primed with a self-affirmation message based on their values ranking. The control group received similar self-affirmation messages, but they were based on values unimportant to them.

Study participants were also fitted with a device that measured their activity levels for a week prior to the study and for a month after the initial intervention. In addition, participants continued to receive text message reminders for a month following the initial intervention. The text reminders would include one self-affirmation message and one health tip. For example, Falk told me a self-affirmation text might prompt the person to think about a time in the future when friends and family might need advice; while the health tip would explain that inactivity puts a person’s health at risk or that the best parking spots are those furthest away from the store. Falk and study co-authors Matthew Brook O’Donnell, Christopher Cascio, Francis Tinney, Yoona Kang, Matthew Lieberman, Shelley Taylor, Lawrence An, Kenneth Resnicow and Victor Strecher write:

VMPFC has been consistently associated with behavior change in response to health messages in prior work. This prior research has suggested that the link between VMPFC activity during health message exposure and behavior change may stem from a recipient’s ability to process a health message as self-relevant or as having value to oneself. Thus, we hypothesized that if affirmation allows people to see otherwise-threatening information as more self-relevant and valuable, delivering self-affirmation before health messages should increase neural activity in VMPFC during message exposure.

And that’s exactly what researchers found. According to the study, people who received relevant self-affirmation messages before getting the health advice showed higher levels of activity in the VMPFC region of the brain at the time of receiving the health messages. However, study participants who were prompted to think about values not ranked as important to them, showed lower levels of activity in that particular part of the brain. And not only did the relevant self-affirmation messages light up the region of the brain associated with positive valuation, it also resulted in actual behavior change. Those who received relevant self-affirmation showed a steeper decline in sedentary behavior in the month following the initial intervention, while those who didn’t receive relevant self-affirmation maintained their baseline levels of sedentary behavior.

Falk told me that previous research has found that brain activity in the VMPFC region tends to be a complimentary predictor of behavior change — in other words, brain activity seems to provide additional information that goes above and beyond what researchers gain from simply asking people questions. However, researchers were somewhat stumped as to why that was the case. At the same time, self-affirmation was emerging as an effective health messaging strategy, but researchers didn’t really know how self-affirmation worked at the neurological level. Falk said this study helps bring all those pieces together.

“We wanted to find a way to precisely engage that region of the brain and self-affirmation is a good tool to do that,” she told me. “The next step in the research is figuring out how to do this at scale, and I do think that’s a possibility.”

To request a full copy of the study, visit the Proceedings of the National Academy of Science.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.