By CBSNews.com's Amy Sara Clark.
The high school sophomore who stays up all night adding to her blog. The 14-year-old who plays "Warcraft" for 12 hours at a stretch. The honors student who says she has no problem writing her English essay while IMing with her boyfriend and compiling iTunes play lists. Teens will swear up and down that the technology they won't turn off is harmless fun.
But what if they're wrong?
Only this much is certain: Teens are spending a lot of time hooked up — an average of 6½ hours a day, according to a survey by the Kaiser Family Foundation. Parents, researchers, and educators are trying to figure out what all these hours plugged in are doing to their brains.
The Teen Brain As Construction Site
When considering whether damage is actually being done, the first thing to understand is that the teenage brain is an unfinished product, explains David Walsh, a psychologist and author of "Why Do They Act That Way? A Survival Guide to the Adolescent Brain for You and Your Teen." The brain continues to develop in spurts until we're about 25 — something car insurance companies figured out a long time ago, and which you may have noticed when your rates dropped after your 25th birthday.
"Experiences that have the greatest impact on the wiring of the brain are those that happen during the brain's growth spurts," he says. During those spurts, the nerve endings grow rapidly, a process called blossoming. During that time, the cells that fire strengthen networks. The ones that don't die back — it's called pruning.
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Say a 2-year-old has chronic, untreated ear infections. Because his auditory functioning is being wired then, the child could end up with permanent hearing problems.
In the teenage years, says Walsh, one of the major circuits that's developing is the prefrontal cortex. "The circuits that are under construction during the teen years have to do with impulse control, management of aggression, emotional regulation, self regulation — a lot of 'executive functions' of the brain," he says. This might explain why your teen might suddenly to storm out during breakfast or pick fights at school.
It's also the reason teenagers are famous for having to pull all-nighters, not thinking through the consequences of downloading porn onto mom's computer, or piercing their tongues. That's because the prefrontal cortex also handles planning, reasoning and social skills, says Jordan Grafman, who heads the cognitive neuroscience section at the National Institute of Neurological Disorders and Stroke. "It's what makes us human," he says — and because it's still developing, "it's very susceptible to trends and changes that happen during the adolescent years."
Try our interactive to discover what each part of the brain does, and when in life these areas are wired.
Doing Too Much?
Perhaps this sounds familiar: Your daughter says she's doing her homework, but you keep hearing her IM chime. She swears she "only spent five minutes" updating her blog. . Those Mariah Carey songs she's downloading? That doesn't take any time at all.
Teens may think they're just taking little breaks, but David Meyer, a psychologist who directs the Brain, Cognition, and Action Laboratory at the University of Michigan, says they have no idea how much time they're really losing.
"I think there's a lot of mythology out there about how great multitasking is and that it's the sexy thing," Meyer says. He compares the image of the teen who can simultaneously IM with five friends while doing his homework with the Marlboro Man of the mid 20th century. "It's almost like smoking was in the '50s and '60s," he says. "It's a bunch of hype."
That's because multitaskers don't just lose the minutes they spend on sites such as Facebook; they also lose time getting reoriented with each interruption, says Meyer, whose lab has conducted experiments on multitasking for more than a decade. That means the homework itself can take between 25 and 400 percent longer depending on the complexity and similarity of the tasks.
Similarity? Yes. It turns out the worst kind of multitasking is between two related tasks, because they use the same parts of the brain. It's better, Meyer says, to switch from math to piano than, say, history to English.
That's why it's possible to fold laundry while listening to the stock report on the radio, he says. "They're relying on different kinds of information processing," he says, noting that the folding is a more automated task.
So how about talking on a cell phone and driving? While these may seem like different tasks, they both use the "talking" areas of the brain, Meyer says. Say you're driving in heavy traffic, he says. "You're reading signs and thinking what to do next. All this is talking to yourself."
Grafman, from the NIH, says his problem with multitasking goes beyond concerns about safety or inefficiency.
"If you're constantly shifting around between tasks, then it's likely you can actually get pretty good at learning visual motor requirements for that shifting," he says. "But what does that cost you in terms of depth of knowledge?"
"These are frivolous, leisure time activities" he says, adding that he'd "love to compete against those kids for jobs or anything else they're not going to have the knowledge."
GenTech Angst Overblown?
It's not just teens who need limits on media use. Find out why pediatricians say too much screen time — even if it's educational — can be harmful to a child.
Fifteen-year-old Cassandra Celestin wants you to remember that not every teen fits the GenTech stereotype. "We're not just some idle generation sitting at our desks and staring into cyberspace," she says.
Her favorite (and only) videogame is the educational "HangAroo," which seems to combine "Wheel of Fortune" with an angry kangaroo. She and her best friend both gave up IMing because it was too distracting. "I just found I don't have time with high school and all," she says.
She says she and her friends much prefer hanging out to chatting online. "I think we've come to the age now where we just want to come out and see each other," she says.
So perhaps parents should stop worrying, says Megan Boler, who teaches education and media studies at the University of Toronto.
"Every new era of technology causes social panics," she wrote via e-mail. "Teen tech overload may turn out to have some negatives for cognitive development. On the other hand, the Internet is less passive than the television or radio adults grew up with, and many of these new forms of media are encouraging self expression through blogs and Web pages." The popularity of blogs, in fact, may breed a generation of particularly active citizens who use the Internet for grassroots organizing and are used to routinely voicing their political opinions through blogging.
Kaveri Subrahmanyam, who teaches psychology at California State University in Los Angeles, agrees that these new forms of technology have benefits. Teens who don't fit in can use it to meet others like themselves, and teens can use it to organize extracurricular events.
Example: A recent study by the Kaiser Family Foundation found that 8- to 18-year-olds who spent the most time hooked up also spent the most time doing non-media activities.
"People like to think of the Internet as the Big Bad Wolf," says Subrahmanyam. "But it's almost like they're using the media to boost whatever else they're doing."
'Grand Theft Auto' Meets Real Life
Research on how technology affects the brain is still in its infancy. But one of the more studied areas is video games, especially the violent ones.
"What happens when a teen spends a lot of time playing violent videogames is the aggression center of brain activates but the emotional regulation center of brain deactivates," says teen brain specialist Walsh, who also directs the National Institute on Media and the Family. "Exactly the combination that we would not want to see."
Aggression researcher Bruce Bartholow adds that hundreds of studies have shown that people who are exposed to media violence become more aggressive.
Bartholow, a psychologist at the University of Missouri, likens the state of research to that of tobacco research in the '50s and '60s. The link between smoking and cancer was apparent, he says, but "while scientific evidence was mounting suggesting a link, the nicotine industry consistently and loudly protested that the evidence was still unclear."
Bartholow recently finished a study that found young men who played a lot of violent video games were more aggressive and less sensitive to violence than those that played fewer violent games. In the study, he questioned them about on how often they played violent video games and then gave them two tests. In the first test, they were shown pictures of violent scenes, such as a man holding a knife to a woman's throat, and their brains' responses to the photos was measured. Bartholow found that the brain waves of the frequent game players showed less response than the ones who played less often.
In the second test, the men were told they were testing their reaction times against other participants, but they were really competing against a computer. When they won, they were given the chance the chance to blast their "opponents" with noise. The men who played more violent video games blasted their opponent with louder noises for longer durations then the men who played for fewer hours.
And these effects, the study found, didn't fade away a few minutes after turning off the PlayStation. "This effect is cumulative over time as people are playing these games on their own," he says. "It's not just a short-term lab effect."
A study in Japan found that even non-violent games may increase aggression when played too often. Ryuta Kawashima at Tohoku University, found that excessive game playing may stunt development of the frontal lobes — including the cerebral cortex and its impulse control functions. Kawashima compared the brain activity of teens playing Nintendo games with that of teens doing arithmetic. He found that the Nintendo group only used the parts of the brain associated with vision and movement, while the math group had activity not only in the vision and movement areas, but throughout the frontal lobe — including the areas associated with learning, emotion, memory and impulse control. Kawashima argues that the study shows that teens who play video games at the expense of other activities, like math, reading aloud, or even just socializing or playing outside, will stunt their prefrontal cortex development end up more violent.
Other studies have shown that video games can be, says Walsh. "One out of seven develop all of the behavioral traits of a chemical addiction," he says, such as lying about time spent playing, craving the game when they're not playing and letting game playing get in the way of personal relationships.
These are the kinds of questions that new methods of looking at the brain in action may be able to answer. But it's clear the answers will be complicated.
For example, potential ill effects of violence in video games that doesn't mean that they aren't educational or skill-building, argues Steven Johnson, author of "Everything Bad is Good For You."
Take one of the very worst of the worst — and most popular — video games: the "Grand Theft Auto" series. This series gives players the opportunity to massacre police offices with chainsaws and kill prostitutes for fun. It has such a reputation for violence, in fact, that last year the families of two murdered police personnel filed a suit against the game's makers, claiming that it led a teen to murder two police department workers by hardwiring his brain toward violent scenarios.
"Kids are psychologically rehearsing for theft," says Walsh. But Johnson argues that playing the game teaches such skills as problem solving, resource management, identifying patterns and planning.
Eugene Fiume, a computer scientist at the University of Toronto, points out that games are moving away from the "single shooter" model to multi-player collaborative games that allow much more room for creativity and cooperation.
In fact, a study at Cornell University suggests that IQs have been going up in recent decades because of computers, video games, television and the Internet. According to this study, today's teens' scores are about 25 points higher than their grandparents and 15 points higher than their parents.
There are plenty of studies that show that video games, even violent ones, can improve visual and motor skills — useful for athletics, driving, and the military. And psychologists Mike Posner and Mary K. Rothbart at the University of Oregon, found that specially designed games can even improve impulse control in children.
"The real take-home message for me," says Craig Anderson, a psychologist who researches the effects of media violence at Iowa State University, "is that a well-constructed video game is an excellent teaching tool. But what it teaches depends on the content of the game."
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By Amy Sara Clark