UNC Health Care
young woman lays under blanket, looking at smartphone

The Effects of Smartphone Usage on the Brain

Many of us can relate to spending too much time on our phones during the coronavirus disease 2019 (COVID-19) pandemic. Sometimes, your phone even tells you just how much time you’ve spent searching and scrolling with a weekly screen time report.

If your numbers aren’t pretty, you’re not alone. Even before the pandemic, the average American spent about 3 hours and 30 minutes a day using mobile internet in 2019, an increase of about 20 minutes from a year earlier, according to measurement company Zenith.

Smartphones are an integral part of our lives, but what effect does all this scrolling and staring at screens have on our brain? Here’s what we know.

Smartphones Affect How We Think

Research has shown that smartphones adversely affect cognition, said UNC Health neurologist Dan Kaufer, MD, who spoke to Health Talk prior to his death in July. Cognition is the process of acquiring and applying knowledge through thought, experiences and the senses.

“With smartphones, you have a whole encyclopedia and beyond of information at your fingertips at any point in time. But this results in a much more superficial or shallow way to access information,” Dr. Kaufer said. “The more we rely on these types of information aids or sources, the less work and processing our brains actually do.”

In other words, our brains do not have to work hard to obtain the information, so we don’t retain it as well either. For example, when you read a book, you generate the images described in the book with your mind.

“That involves making connections between different parts of your brain,” Dr. Kaufer said. But “when you look at a picture that is already there, it’s much more passive. You’re not working [as many] parts of your brain.”

This applies to smartphones as well as watching television or a computer screen.

Smartphones Can Impair Social and Emotional Skills

The more time you spend looking at a screen, the less time you spend interacting in person with others. This makes it more difficult to establish interpersonal connections and strong relationships, which are important for mental health and the health of the community at large.

“Before smartphones, all interaction was face-to-face, and there’s a richness of communication that gets lost when you have a conversation on the phone or through texting,” Dr. Kaufer said. Because smartphones and other devices give information and entertainment rapidly, they can make us less patient with real conversation with people in our lives.

Also, that lack of face-to-face interaction can lead to depression.

Smartphones Can Make Your Brain “Lazy”

With smartphones, you no longer need to memorize a phone number or find your way around town using a map—your smartphone does these things for you. Research shows this overreliance on your smartphone can lead to mental laziness.

“If you give people the ability to store information remotely, outside of their brain, they become more dependent on that, which actually can have a negative effect on people’s memory,” Dr. Kaufer said. “Because they become too dependent on that external aid, they lose that skill of being able to remember things as freshly as they could, absent that external aid.”

How to Protect Your Brain from Your Phone

You don’t have to swear off your smartphone completely to improve your brain health. The important thing is to be aware of how you use your phone and other devices and to prioritize other activities and in-person interactions whenever possible.

Some people find it helpful to delete social media apps from their phone or to download software that limits the time they’re permitted on that site. Others designate hours of the day “phone-free” to protect family time. It can be empowering to trade screen time for reading a book or working on a hobby.

As you scale back your phone time, the increase in your mental clarity or mental health might be motivation enough to keep it up.


Talk to your doctor if you have concerns about the effect your smartphone is having on your brain. If you need a doctor, find one near you.

Editor’s note: Dan Kaufer, MD, died July 2, 2020. He was the founding director of the UNC Memory Disorders Program. Renowned for his research and treatment of memory disorders, Dr. Kaufer was deeply devoted to his patients and their families.