From an everyday habit to a research question
It is an increasingly familiar routine: we pause what we are doing, open social media for a few minutes, scroll through a feed, and then return to studying, working, or another task that requires our attention.
But do we return to that task in exactly the same cognitive state?
Much of the discussion around social media has focused on long-term screen time, problematic use, mental health, or academic performance. We wanted to ask a more immediate question: what happens to executive functioning shortly after a brief period of social media use?
Executive functions are the cognitive processes that help us hold information in mind, resist inappropriate responses, stay focused on a goal, and adapt our behavior. These abilities are particularly important when we are studying, solving problems, making decisions, or trying to resist distractions.
The challenge was finding a way to study this question without removing social media from the context in which people actually use it.
Making the experiment feel more like real life
A major consideration in designing the study was ecological validity.
Instead of bringing participants into a highly constrained imaging environment and showing everyone the same artificial collection of social-media images, we wanted the experience to resemble ordinary scrolling as closely as we reasonably could.
Participants assigned to the social-media condition therefore opened their own Instagram accounts and scrolled through their personal “Following” feed for 15 minutes.
There was, however, an important restriction: they could scroll, but they could not like, comment, message, or post.
This distinction mattered. Active social interaction introduces many additional factors—anticipating a response, communicating with another person, receiving feedback, or making decisions about what to post. By limiting the session to passive scrolling, we could focus more specifically on the experience of consuming a personalized social-media feed.
For comparison, participants in the control condition scrolled through a feed containing neutral black-and-white nature images and silent videos. The goal was to preserve the basic act of viewing and scrolling through a feed while reducing the emotionally and personally salient characteristics of someone's own social-media content.
This design inevitably involved a trade-off. Allowing participants to view their own feeds meant that every person saw different content. From a traditional experimental perspective, that introduces variability. From a naturalistic perspective, however, that variability is part of the experience we were interested in studying. Real social-media feeds are personalized.
Taking neuroimaging outside the traditional scanner
Another important part of the study was where—and how—we measured the brain.
The sessions were conducted in a quiet private room in a student residence building rather than in a conventional neuroimaging scanner environment.
We used wearable functional near-infrared spectroscopy, or fNIRS, to measure changes in oxygenated blood associated with activity in the prefrontal cortex.
This portability allowed us to bring neuroimaging closer to the setting in which the behavior naturally occurs.
Before the scrolling period, participants completed cognitive assessments of working memory and inhibitory control while we measured prefrontal activity. After either the Instagram or control condition, they completed the assessments again.
This gave us an opportunity to ask not only whether performance changed, but also whether the brain appeared to approach the same cognitive demands differently after scrolling.
What caught our attention
The most interesting part of the results was that there was not one simple pattern of “more” or “less” brain activity.
Following social-media exposure, participants showed poorer change in inhibitory-control performance compared with the control group. In other words, they became less successful at withholding a response when a response should be suppressed.
The neuroimaging findings added another layer to this picture.
We observed increased activity in the medial prefrontal cortex, a region associated with processes such as performance monitoring and regulation of cognitive effort. At the same time, we observed reduced activity in other prefrontal regions, including areas of the dorsolateral and ventrolateral prefrontal cortex and inferior frontal gyrus that are important for working memory and response inhibition.
One possible interpretation is that after social-media exposure, participants needed to recruit some aspects of prefrontal processing more strongly while other executive-control systems were engaged less effectively.
Importantly, behavioral and neural measures did not always tell exactly the same story.
For the working-memory task, we did not observe a statistically significant group difference in behavioral change, despite observing differences in brain activation. That discrepancy was particularly interesting to us.
A person can sometimes maintain similar outward performance while the neural processes supporting that performance change. This is one reason combining behavioral testing with neuroimaging can provide information that performance measures alone may miss.
What this study does—and does not—tell us
It is tempting to turn findings about social media and the brain into dramatic conclusions. We think the more interesting interpretation is also the more careful one.
Our study does not show that 15 minutes of Instagram “damages the brain.”
It does not tell us that all forms of social-media use have the same effects, nor does it establish what happens after months or years of use.
Our sample included only 20 college students. We studied passive Instagram scrolling during one relatively brief experimental session. Active social interaction, different platforms, different types of content, individual patterns of use, and longer periods of exposure could produce very different results.
These limitations are important.
At the same time, the findings raise a question that deserves further investigation: could even short digital experiences temporarily influence the way we recruit cognitive-control systems immediately afterward?
That question may be particularly relevant because people rarely use social media in isolation. We often scroll between other activities—before returning to homework, writing, meetings, or tasks requiring concentration.
Moving beyond “How much screen time?”
For us, one of the broader lessons from this study is that the conversation about digital behavior may need to become more specific.
Rather than asking only:
“How much time do people spend on social media?”
we may also need to ask:
What type of content are they consuming?
Are they actively interacting or passively scrolling?
What were they doing immediately before and after?
And do different individuals respond differently to the same digital experience?
Future studies with larger and more diverse samples can begin to separate these factors. It will also be important to examine different platforms and content types, active versus passive engagement, and how long any changes in cognitive functioning persist.
Portable neuroimaging technologies such as fNIRS may make these questions increasingly possible to study outside traditional laboratories.
Ultimately, we hope this work contributes not to a simple message that social media is “good” or “bad,” but to a more precise understanding of how everyday digital experiences interact with cognition.
The next time a five-minute break becomes fifteen minutes of scrolling, the interesting scientific question may not simply be how much time passed.
It may be what happens when we put the phone down and ask our brain to switch back to work.
AI disclosure: Generative AI was used to assist with drafting and language refinement of this post. The authors reviewed the content and are responsible for its accuracy and final wording.