How Do Smartphones Affect the Brain?

Woman using cell phone in bed
Your smartphone might be keeping you up at night. Adam Hester/Blend Images/Getty Images

If you were asked to go a day without your smartphone, do you think you could do it easily? Researchers who have asked participants to go without their phones for various periods of time have found that breaking the technology habit, even for a relatively short interval, can be exceedingly difficult. Walk into any public venue and you will probably find people using their phones for a variety of purposes, from conducting business calls to checking their email to updating their Twitter.

Our phones have become an inextricable part of our lives.

But does this reliance on smart phones have any impact on our brains?

Some recent research suggests that it might. Experts suggest that all of this phone use can have an impact on children’s social and emotional development, that it can impair our sleep patterns, and that it might even turn some people into lazy thinkers.

Phone and Tablet Use Might Impair Social-Emotional Skills

In commentary appearing in the journal Pediatrics, researchers from the Boston University School of Medicine took a closer look at the available literature on smartphone and iPad use among very young children. Using such devices to entertain or pacify children, they warn, might have a detrimental effect on their social and emotional development.

“If these devices become the predominant method to calm and distract young children, will they be able to develop their own internal mechanisms of self-regulation?” the researchers question.

Hands-on activities and those involving direct human interaction are superior to interactive screen games, the experts suggest. The use of mobile devices becomes especially problematic when such devices replace hands-on activities that help develop visual-motor and sensorimotor skills. The researchers note however, that there are still many unknowns about how the use of mobile devices influences child development.

They question whether overuse of smartphone and tablets might interfere with the development of social and problem-solving skills that are better acquired during unstructured play with interaction with peers.

Your Smartphone Might Be Keeping You Up at Night

Using your smartphone or tablet at bedtime might be interfering with your sleep, and not because you’re staying up late to check your email, scroll through your Facebook news feed, or play a game of Trivia Crack. Instead, some sleep experts warn, it is the type of light emitted from your mobile device’s screen that might just be messing up your sleep-cycle, even after you turn off your device.

In a study published in the Proceeding of the National Academy of Sciences, a dozen adult participants were asked to either read on an iPad for four hours each night before bed or read printed books in dim lighting. After five consecutive nights, the two groups switched. What the researchers discovered was that those who had read on an iPad before bedtime displayed a reduction in levels of melatonin, a hormone that increases throughout the evening and induces sleepiness.

It also took these participants more time to fall asleep, and they experienced less REM sleep throughout the night.

The culprit? The type of blue light emitted by most mobile devices. The cells at the back of the eyes contain a light-sensitive protein that picks up certain wavelengths of light. These light-sensitive cells then send signals to the brain's "clock" that regulates the body's circadian rhythms. Normally, blue light peaks in the morning, signaling your body to wake up for the day. Red light increases in the evening, signaling that it is time to wind down and go to bed. By interrupting this natural cycle with the blue light emitted by mobile devices, the normal sleep-wake cycles are thrown out of whack.

"There's a lot of skepticism out there; a lot of people think this is psychological," explained one of the study's authors, Charles Czeisler. "But what we showed is that reading from light-emitting, e-reader devices has profound biological effects."

The next time you’re tempted to play with your mobile device in bed, think about the possible effect you might have on your brain and your sleep and consider picking up a paperback book instead.

Smartphones Might Make Your Brain Lazy

Mobile devices don't just offer distraction these days. You no longer have to memorize phone numbers or keep a Rolodex on your desk - all that information is neatly stored on your phone’s contact list. Instead of mulling over questions you might have about the world around you, you can just grab your phone and Google the answers.

And some experts warn that this over-reliance on your mobile device for all the answers might lead to be mental laziness. In fact, one recent study has found that there is actually a link between relying on a smartphone and mental laziness. Smartphones don't necessarily turn people from deep thinkers into lazy thinkers, but it does suggest that people who are naturally intuitive thinkers - or those who act based on instinct and emotions – tend to rely on their phones more frequently.

"The problem with relying on the Internet too much is that you can't know you have the correct answer unless you think about it in an analytical or logical way," explained Gordon Pennycook, one of the study's co-authors.

“Our research provides support for an association between heavy smartphone use and lowered intelligence,” said Pennycook. “Whether smartphones actually decrease intelligence is still an open question that requires future research.”

The researchers warn, however, that the use of mobile devices has far out-paced the available research on the subject. Researchers are just at the beginning stages of understanding the potential short-term and long-term effects that smartphone use might have on the brain. Mobile devices are certainly bound to have their detriments, but the researchers also suggest that we have yet to fully understand the possible ways that they might also benefit the brain.


Barr, N., Pennycook, G., Stolz, J. A., & Fugelsang, J. A. (2015). The brain in your pocket: Evidence that smartphones are used to supplant thinking. Computers in Human Behavior, 48, 473-480. doi:10.1016/j.chb.2015.02.029.

Boston University Medical Center. (2015, Jan. 30). Mobile and interactive media use by young children: The good, the bad and the unknown. EurekAlert. Retrieved from

Dennis, B. (2014, Dec. 22). IPads, tablets, smartphones disrupt good sleep, study finds. The Washington Post. Retrieved from

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