By Markham Heid
April 15, 2014

Care about your brain? You should probably finish this entire article. Like the muscles in your legs or core, different brain regions grow stronger or weaker depending on how much you exercise them, studies show. [Tweet this stat!] And the ways you read (or don't read) information online-jumping quickly from paragraph to paragraph or link to link-could be wasting away your mind's facility for deep focus and in-depth processing.

There are benefits associated with learning to rapidly scan snippets of info, sure, but there may be detriments as well, says Gary Small, M.D., author of iBrain and professor at UCLA's Semel Institute. "People are strengthening the neural circuits that control the Internet experience, and neglecting others," he says. "And when you neglect circuits, they weaken." Here's what a lot of Internet time could mean for your noodle.

Immediate Effects

"Our brains are hardwired to crave novelty," Small says. "And the Internet provides a never-ending source of novelty." Some studies have even indicated your brain receives a small release of dopamine (the reward hormone that floods the brain of people in love, or those on drugs) as you switch from one webpage to another, and that feels good, he adds. The ease of jumping from one link to the next coupled with this dopamine release may explain why you tend to "surf" the Web, instead of sinking down into its content.

But the pleasure could backfire if you extend your surfing methods to other tasks, research suggests. For example: If you jump from reading emails to looking at a report, to chatting with a colleague, your brain is more likely to make mistakes. Your attention is constantly shifting from one chore to the next, muddling your focus and productivity, Small says. People who multitask like this believe they're working ultra-quickly and productively, but studies show they're kidding themselves, Small says. All that task switching undercuts your efficiency, he adds.

The Long(er)-Term Effects

Researchers from Stanford have studied the brains of men and women who tend to work in the quick-switch Internet style described above. And compared to people who stick to just one or two forms of stimuli, so-called "media multitaskers" struggle to separate the important (a work proposal) from th9 e irrelevant (the blinking G-chat message a friend sent you), explains Anthony Wagner, Ph.D., who led that Stanford team.

These media multitaskers can develop a staccato, distracted style of thinking, Small says. They become accustomed to things moving very quickly, which can cause them to feel impatient when reality or non-internet tasks (like reading a book, or having an in-depth conversation) force them to slow down. Memory also suffers among those accustomed to relying on the Internet for help recalling info, shows a study from Harvard and Columbia.

And although it's not widely accepted, there's some evidence that your brain can become addicted to the Internet. Small links this back to the reward system that fires up when you jump from one online link to the next. Young people who have the Internet or smartphones taken away show some of the same withdrawal symptoms as smokers denied access to cigarettes-mental and physical distress, panic, confusion, and a sense of extreme isolation, according to a University of Maryland study.

Interestingly, for people who don't use the internet as often-mostly seniors-Small says working with computers actually fire up old brain circuits and pathways, improving a person's memory and fluid intelligence, a scientific term for the general smarts you use to problem solve. That's because, since the task is new to them, their brains benefit.

If you find the opposite while online: your mind struggling to reach the end of an article without wanting to veer off, your brain may be experiencing that newness craving. You don't need to quit the Internet (please don't!) to solve the problem, but just as keep your body in shape, your mind may benefit from a long magazine article, or an overdue conversation on a topic you're passionate about-anything that switches up your day-to-day habits, Small's research suggests.