You Asked: Is My Smartphone Making Me Dumber?

Your best friend’s birthday? Check Facebook. Directions? Fire up Waze. Want to tip 20%? Open your calculator app. Your smartphone makes these tasks and a zillion others nearly effortless. But more and more research suggests that this digitally lightened mental workload may be coming at a cost.

Relying on your phone or the Internet to lighten your mental workload is a lot like relying on a car—rather than your legs—to get you places, the latest research suggests. Driving is faster and easier than walking. But sitting in a car does your body little good. Likewise, media multitasking may be the cognitive equivalent of too much sedentary time.

Research from McGill University in Canada found that drivers who depend on GPS-style navigation to get around, as opposed to those who rely on their own spatial abilities, had less activity and gray matter volume in the hippocampus region of their brain—an area important for memory consolidation. Similarly, a 2011 paper in the journal Science found that people tend to have worse recall when they know a piece of information is stored somewhere online or on a computer. Instead of remembering the piece of information itself—like a sibling’s phone number—you instead remember how to find that piece of information on your device. That’s not a big deal if you’re searching for something simple and unambiguous, like your sister’s digits. But when your brain is confronted with a more complex or profound question, it may falter.

“If you’re always pulling facts from Google, you can answer a trivia question, but you’re not building up the knowledge base necessary to be a deep and deliberate thinker,” says Nicholas Carr, a technology writer and author of The Shallows, a book about the Internet’s effect on our minds. Like an atrophied muscle, your brain’s ability to perform heavy lifting may be compromised.

Your mind may also struggle to filter what’s important or real from what’s counterfeit, Carr says. A recent study from Stanford University backs him up. The Stanford researchers discovered that students struggled to differentiate real news from promotional stories—even when an article was clearly labeled with a term like “sponsored content.” An older Stanford study found that media multitaskers—those who juggle online tasks like email, texting, browsing blogs and posting on social media—have problems staying on task or sorting important info from background noise. “They’re suckers for irrelevancy,” said that study’s coauthor, Clifford Nass, in a 2009 press release. “Everything distracts them.”

“With these devices, when we’re always jumping from task to task, we have this perception that our constant activity is a sign of efficiency—like we’re getting a lot done,” says Dr. Gary Small, a professor of behavioral sciences at UCLA and author of the book iBrain. “But actually this process of jumping around is not economical.”

Every time you switch tasks, your brain needs a moment or two to find its bearings. And the more you engage in rapid task-shuffling, the harder it becomes for you to ignore distractions and stay focused, he says. That could be because media multitasking may weaken your brain’s anterior cingulate cortex, a region involved in high-level information and emotion processing, according to research from University College London.

Your brain may also suffer from a lack of downtime—those small breaks, like waiting in line at the grocery store, when we all used to daydream instead of staring at our phones.

When your brain has the opportunities to wander, it fires up a group of overlapping networks known as its “default mode,” shows research from Mary Helen Immordino-Yang, a neuroscientist at the University of Southern California. “When the brain has space to roam freely, its default mode is engaged in reliving recent experiences, connecting emotionally relevant information, and constructing narratives that make sense out of life,” Immordino-Yang explains. “This is why people often have big insights in the shower or doing the dishes.”

But as our increasingly portable and powerful devices insert themselves into more and more of our lives’ empty spaces, our brains may have fewer opportunities to make those connections and conjure those “a-ha!” insights. “Potentially, we’re sort of reshaping our brains’ networks so that they’re more inclined to look for stuff in our environment to entertain us, instead of thinking about the longer-term and broader and ethical and deeper considerations we would otherwise be having,” Immordino-Yang says.

“What we don’t realize when we opt for the convenience or ease technology offers is that we’re denying ourselves the ability to create rich talents,” Carr adds. “Without practice, our brains begin to lose these talents for deep thinking or maintained focus.”