Your Brain On: Your iPhone

Error 503. You've probably encountered that message while trying to access your favorite website. (It means the site is overloaded with traffic or down for repairs.) but spend too much time on your smartphone, and research suggests your brain may be next to crash.

Shades of Gray

People who spend a lot of time media multitasking-that is, switching frequently between apps, websites, and other types of tech-tend to have lower amounts of gray matter in their brain's anterior cingulate cortex (ACC) compared to non-multitaskers, shows a study from the U.K. and Singapore. Gray matter is composed mostly of brain cells. And lower amounts of it in your noodle's ACC has been linked to cognitive and emotional control disorders like depression and anxiety, says study coauthor Kep Kee Loh, a cognitive neuroscientist with the Duke-NUS Graduate Medical School.

Other studies suggest rapidly jumping between tasks lowers activity in your mind's focus centers, which reside in your limbic system. Since that part of your noodle also helps regulate your emotions and your body's levels of stress hormones like cortisol, it's possible that teaching your brain to shift rapidly from task to task (instead of focusing on one) may damage its ability to handle strong emotions and hormonal responses to those emotions, suggests research from the University of Pennsylvania. All of this research suggests your phone isn't necessarily the problem; but constantly shifting between tasks is bad news.

Your Phone Fix

Addiction is a tricky topic. The line between healthy and unhealthy behaviors is often tough to pinpoint. But researchers from Baylor University and Xavier University looked at the smartphone habits of men and women in an attempt to figure out what percentage of users displayed "addictive traits." They defined these traits as a strong or irresistible desire to spend time on your phone even if it interferes with your work or social life, or puts your health at risk (like texting while driving).

The findings: Women tend to display addictive cell behaviors at higher rates than men, the study authors say. Why? Typically, ladies are more socially connected than guys, and apps related to social networking tend to drive addictive behaviors. Specifically, Pinterest, Instagram, and texting apps were tied to the highest rates of cell phone addiction, the research shows.

Brain Drain

The more time you spend online, the more your brain struggles to recall information, indicates research from Columbia University. If you know your phone or computer can find a friend's birthdate or an actor's name for you, your brain's ability to remember those bits of info seems to suffer, the study authors say. That may not seem like a big deal. (You'll almost always have the Internet handy, so who cares, right?) But when it comes to solving major dilemmas, Google can't help with-like questions about your relationships or career path-your brain may struggle to come up with answers, the study suggests.

More bad news: The kind of light your phone emits has been shown to disrupt your brain's sleep rhythms. As a result, staring at a bright phone before bed could leave you tossing and turning, shows a report from Southern Methodist University. (Turning down your phone's brightness and holding it father from your face can help, the SMU researchers say.)

All of this is unfortunate, to say the least. But pretty much every brain problem linked to your smartphone is dependent on frequent or compulsive use. We're talking six or eight hours a day (or more). If you're not married to your phone, you probably don't have much to worry about. But if you get antsy or uncomfortable anytime you and your phone are separated, or you find yourself reflexively reaching for it every five minutes-even if there's nothing you really need it for-that's a sign you may want to tone down your habit.