Your Phone Impairs Your Brain Even When You're Not Using It

Updated 03/28/18
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We're well aware of the far-reaching psychological, sociological, and cultural affects of smartphones and social media—and we know that we could all stand to take a break from technology. But as Harvard Business Review reports, it's not enough to put your phone aside, face-down on your desk—its mere presence can still affect your ability to be productive throughout the day.

"Results from two experiments indicate that even when people are successful at maintaining sustained attention—as when avoiding the temptation to check their phones—the mere presence of these devices reduces available cognitive capacity," reads the study abstract. When the study participants had their smartphones on their desks, the researchers found a "small but statistically significant impairment of individuals' cognitive capacity—on par with effects of lacking sleep." In other words, keeping your smartphone on your desk at work can impact your ability to learn, reason, and develop creative ideas throughout the day.

Curious about this idea that the mere presence of one's smartphone may ultimately undercut cognitive performance, researchers Kristen Duke, Adrian Ward, Ayelet Gneezy, and Maarten Bos recruited nearly 800 people for two lab experiments. First, the participants completed math problems and memorized random letters so the researchers could measure how well they could keep track of task-relevant information. Next, the participants saw a set of images that formed an incomplete pattern and selected the image that best completed the pattern, which measured "fluid intelligence," or a person's ability to reason and solve novel problems.

During these two tests, participants were instructed to either keep their phones in front of them face-down on their desk, keep them in their pockets or bags, or leave them in another room. All phones were set to silent. In the end, those who had their phones on their desks while completing the tasks performed the worst and actually showed an impaired cognitive ability. Unsurprisingly, those who kept their phones in another room performed the best.

"Even a small effect on cognitive capacity can have a big impact, considering the billions of smartphone owners who have their devices present at countless moments of their lives," reads the resulting report. "This means that in these moments, the mere presence of our smartphones can adversely affect our ability to think and problem-solve—even when we aren't using them. Even when we aren't looking at them. Even when they are face-down. And even when they are powered off altogether. Consider the most recent meeting or lecture you attended: Did anyone have their smartphone out on the table? Think about the last time you went to the movies or went out with friends, read a book, or played a game: Was your smartphone close by? In all of these cases, merely having your smartphone present may have impaired your cognitive functioning."

Head over to Harvard Business Review for more on the new study.

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