What Happens to the Brain When We Spend Hours Scrolling on Our Phones?

When people spend an excessive amount of time scrolling through their phones, it can have various effects on the brain and overall well-being. Studies have shown that constant exposure to short, unpredictable stimuli through the "infinite scroll" feature on social media platforms can impact attention, sleep, well-being, and impulse control.

The design of these platforms is key to understanding why excessive scrolling can be problematic. Each swipe of the screen brings the possibility of encountering something interesting, entertaining, or engaging. This uncertainty can make it difficult for users to stop scrolling, as they anticipate finding something even more interesting in the next post. As a result, what may start as a few minutes of entertainment can quickly turn into much longer sessions than initially planned.

One defining characteristic of infinite scrolling is the removal of a natural stopping point. Unlike reading a book, watching an episode of a series, or watching a movie, social media constantly presents new content, making it difficult for users to disengage. The brain is constantly exposed to novel stimuli and small rewards, such as an interesting video or a post that generates curiosity.

This constant search for novelty can make activities that require sustained attention, such as reading a long text or completing a repetitive task, feel less stimulating in comparison.

While social media does not necessarily "destroy" the ability to concentrate, research suggests that problematic use of smartphones and the internet can be associated with changes in cognitive control. A 2024 systematic review of studies using magnetic resonance imaging found associations between problematic internet use and changes in measures related to cognitive control, although more research is needed to establish the mechanisms and causality with greater precision.

Another area affected by excessive scrolling is sleep. The light emitted by phone screens can interfere with the brain's natural sleep-wake cycle, and the content consumed can keep the brain active when it should be preparing for rest. People often find themselves staying up later than planned, scrolling through their phones for longer periods, and delaying the moment when they finally put the device down.

Research consistently shows a relationship between problematic social media use and sleep problems, as well as negative impacts on well-being, anxiety, and depression.

The effects of excessive scrolling extend beyond sleep and cognitive function. Constant exposure to idealized images, achievements, and experiences on social media can lead to social comparison, which may have negative consequences for mental health. While social media can provide entertainment, provide a sense of community, and serve as a source of information, it can also interfere with other important activities such as work, studying, and maintaining personal relationships.

The key issue arises when the phone begins to replace activities that are essential for overall well-being. Warning signs may include frequently losing track of time, feeling the need to constantly check the phone without a specific reason, or interrupting conversations, meals, work, or sleep. Rather than focusing on the exact number of hours of social media use that is harmful, it is more productive to consider the role the phone plays in daily life and whether it is interfering with essential activities.