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Will teen multitasking give rise to ADD? Study may offer answer

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Whether they’re texting while talking to friends or plugging in to an iPod while studying, today's teenagers seem to be constantly multitasking.

Young people are spending at least seven-and-a-half hours a day with media -- computers, cell phones, TV or music -- and by frequently multitasking that means they're packing in the equivalent of nearly 11 hours hours of content, according to a 2010 study by the Kaiser Family Foundation. That's an increase from nearly six-and-half hours a day, or eight-and-a-half hours of media multitasking, just six years ago.

Parents who grew up in a world without all the technological chatter often find themselves wondering whether their kids will ever learn to focus on one thing at a time. They ask: Are we raising an entire generation of children with attention deficit disorder?

The answer to that question — and many others — may come from a groundbreaking study currently underway at the National Institutes of Health (NIH). Since 1991, researchers there have been scanning the brains of 1,000 kids’ brains every other year with functional MRI, a machine that shows in vivid colors exactly what the brain does while it’s thinking.

The study has given researchers their first look at how normal kids’ brains develop.

As part of the NBC Nightly News with Brian Williams series, "The Teen Brain: A Work in Progress," spoke with Jay Giedd, a neuroscientist in the child psychiatry branch of the NIH, about how all the digital distractions of our world are affecting young minds.

What makes teen brains tick? Join a Noon ET chat moderated by NBC's Dr. Nancy Snyderman

Q: As you looked at all these developing brains, was there anything that surprised you?
There were a couple of things that we didn’t see coming at all. First, was that the brain, especially the front part, doesn’t mature until age 25 or 30. We joke that the car rental companies had the best neuroscientists. They had it right — they said you had to be 25 to rent. And that’s because they had a lot of data showing that 24 year olds cost a lot more than people who are older.

Q: How are those two things connected? I mean, what do car accidents have to do with the fact that the front part of the brain is unfinished?
A: The front part of the brain ties everything together. It’s also involved in controlling impulses, judgment, wisdom, longer range planning. So this part of the brain is not totally defective, but it’s still under construction way longer than we used to think.

Q: And the other surprise?
The second big surprise was that the brain has reached 93 percent of adult size by the time we’re in the first grade.

Q: If kids’ brains aren’t getting much bigger after age 6, how is it that they seem to get so much smarter as they get older?
It’s like building a house. The frame is built early. But a lot of work goes on inside after that. In the brain, it’s the wiring. Different parts of the brain are being connected up.

So, it’s not the size or shape of the structures in the brain that is changing, but how the structures are connected to one another. This was a paradigm shift.

Q: With all the new technologies, from cell phones to ipods to the internet, kids’ brains are constantly being deluged with information in a way that ours never were. Will this cause their brains to wire up in ways that are different from ours?
That’s a great question — one that isn’t yet resolved. There’s definitely a generational divide. For better or for worse, kids these days have access to a world of information. To me, that’s overwhelmingly positive. Knowledge is power and these days you can look up anything — I think that outweighs the distractibility.

Q: But, are we raising a generation of kids who will look as if they have attention deficit disorder?
Well, first, I see ADD much more as something caused by biology and not as something caused by the environment.

Second, we know now that plasticity is the key feature of the adolescent brain. So, 10,000 years ago, which isn’t really that long in evolutionary terms, we were hunting and gathering berries. Now we’re texting and going on the internet reading and all those sorts of things.

The key thing is that the human brain can change. Reading is a very good example. People have been around about six million years and reading is only 5,000 years old. So, most people have lived and died without ever reading a single word.

Q: OK. So, the brain is built to be able to adapt to a changing world, which means our teens will be more adept at taking in all this new information. But is there a downside to this kind of adaptation?
That’s what’s still being debated: If you spend a lot of your time multitasking, then, when it is time to zero in just one thing, are you going to be better or worse at it? One camp says it’s like cross training.

You get good at handling a whole bunch of information and sorting through it so that when you want to zero in, it’s easy for the brain. The other people say, no, you only get good at what you practice.

I think the current generation can have the best of both worlds. They’ll get good at multitasking, which they’re likely to be doing in their adult jobs. But they can also develop the skills to zero in when they need to.

Q: So, it sounds like you’re saying that kids are going to have to consciously work at developing the ability to focus.
A: Yes. But it can come from things such as playing sports or music.