Social Media Use and 'Divergent' Brain Development

Posted January 24, 2023 | Reviewed by Vanessa Lancaster

There are plenty of indications that youth today are struggling quite a bit with their mental health, and people are looking hard to identify the primary cause or causes. Arguably, suspect number one is the screens, particularly excessive social media usage. Direct evidence implicating social media use, however, is mixed, so it isn't that surprising that a recent study that looked at the association between social media use and brain activation patterns over time caused quite a stir.

The study, published in the reputable journal JAMA Pediatrics, recruited 6th and 7th-grade students at three public schools in North Carolina. At baseline, the subjects completed a questionnaire that examined the frequency with which they checked their Facebook, Instagram, and Snapchat accounts. Based on this, the subjects were divided into low, medium, and high usage groups.

Then, the same subjects at up to three different time points in the future completed an activity called the Social Incentive Delay task, which involved reacting to anticipated social rewards, punishments, and neutral feedback in a way not unlike social media. While subjects were doing this task, they underwent a functional MRI scan which can measure the amount of brain activation that occurs in different brain regions.

The main finding was that in some key brain areas thought to be important in processing social rewards, the three groups of subjects had different brain activation patterns over time. Those who checked social media the most were found at age 12 to have the lowest brain sensitivity in these areas, but this sensitivity tended to increase at ages 14 and 16. Displaying the opposite pattern was the youth in the moderate group (not the low usage group, interestingly), while those who checked social media the least at age 12 had the highest sensitivity at age 12, which then tended to fall over time.

This is a confusing pattern to interpret, especially since there aren't standards to refer to regarding what these brain development patterns should look like. What the researchers would like to suggest is that compulsive social media checking alters adolescent brain development through sensitizing pathways involved in social rewards and punishments.

However, they realize they can't make firm conclusions with the data they have because there are brain activation differences at one time, suggesting that it is quite possible that these brain activity differences caused the social media behavior variations and not the other way around.

Yet despite the limited conclusions that can be drawn from the study, the media and the public jumped all over it, taking the more vague but still somewhat ominous finding of "divergent brain development" to infer the worst. There's also something about these brain imaging studies that sound so compelling and real, even though they basically just confirm that brain activity is behind our thoughts, feelings, and behavior (like how else was it supposed to work?).

Hopefully, someday, researchers will look at some of these brain activation patterns before kids have been exposed to social media to help us sort some of these questions out.

Don't get me wrong: this is a cool study that could contribute to understanding better how social media becomes a compulsion. And I'm far from a denier that excessive social media or general screen use can be a huge problem for many people. I don't think we need to wait for studies like this to tell us that.

Resources would be best spent testing educational content that can effectively teach children how to use screens (versus having screens use them), regardless of which brain regions light up when looking at various emoji responses on your Instagram post.

References

Marla MT, Fox FA, et al. Association of Habitual Checking Behaviors on Social Media with Longitudinal Functional Brain Development. (2022). JAMA Pediatrics. Published online January 3, 2023. doi:10.1001/jamapediatrics.2022.4924