Computing The Cost, Nicholas Carr

Cooper: Is there any real evidence that the Internet is “rewiring” our brains?

Carr: There’s certainly a lot of evidence that the brain readily adapts to experience — that our neural circuits are “plastic,” as scientists say. And we’re starting to see direct evidence that Internet use alters brain function. There was a fascinating study done in 2008 by Gary Small, who heads the UCLA Memory and Aging Research Center and recently published a book called iBrain. He and two of his colleagues scanned the brains of two dozen people as they searched the Internet: half the subjects lacked online experience, and the other half were experienced Web users. The researchers found very different patterns of brain activity between the two groups. The subjects with little experience on the Internet showed activity in the language, memory, and visual centers of the brain, which is typical of people who are reading. The experienced Web surfers, on the other hand, had more activity in the decision-making areas at the front of the brain. Interestingly, after five consecutive days of Web surfing, the brain activity of the “inexperienced” group began to match the activity of the experienced Web users. That indicates that the brain adapts very quickly to Net use, just as it does to other repeated stimuli.

Now, there’s good news and bad news here. The good news is that, if you’re older, using the Net may help keep you mentally sharp. It “exercises” the brain in the way that, as Dr. Small observed, solving crossword puzzles does. On the other hand, neurology experiments demonstrate that decision-making consumes a lot of your mental resources, leaving less available for other modes of thinking. That may be why it’s so hard to read deeply when we’re online — our brains literally become overloaded. Imagine trying to read a book while simultaneously working on a crossword puzzle. That’s the intellectual environment of the Web.

Cooper: Do the different areas of activity that show up on the scan necessarily mean the brain is being “rewired”?

Carr: If everybody in the study had shown the same pattern of brain activity from the start, that would have told us that this is just the way your brain works when you surf the Web. But because the patterns differed between experienced and inexperienced users, and because they changed for the inexperienced group as they used the Web more, it means the brain is adapting. People used to think that after childhood your brain was basically hard-wired, but we know today that even the adult brain is very plastic. Throughout our lives our brains adapt to the way we gather and process information. Performing an action over and over changes the brain’s circuitry. The new firing patterns of neurons become more stable and push aside older patterns. If you give up performing an action, then neural circuits formerly dedicated to it get weaker and are eventually used for other activities.

Cooper: So this rewiring isn’t something unique to Google or the Internet.

Carr: That’s right. Anything we do on a regular basis rewires the brain. There’s a saying among neuroscientists that “neurons that fire together, wire together.” When you practice a certain skill, the circuits get stronger, and the area of your brain dedicated to performing the skill gets larger.

What that means is that, as the Internet becomes our universal medium for gathering information, we’re training our brains to take in information in the way the Internet supplies it — that is, with an emphasis on speed and with continual distractions. We’ve seen this with previous intellectual technologies like the alphabet, the clock, and the printing press: new modes of intelligence come into being that stress different aspects of our brain’s functioning. Some people would argue that, with the current change, we’re gaining a great deal, because we have access to all this information. And for most of us the obvious benefits of being online overwhelm any fears and concerns. This has been particularly true with young people who’ve grown up with this new technology. Because it’s become so natural, they don’t pay attention to what they might be losing. They might not even be aware of it. You don’t worry about losing something you never knew you had in the first place.