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Theory says teens wired to take risks
Researchers think rebelliousness may be linked to brain changes
Washington Post
Tuesday, June 5, 2001
©2001 San Francisco Chronicle

URL: http://www.sfgate.com/cgi-bin/article.cgi?f=/chronicle/archive/2001/06/05/MN14265.DTL

Washington -- Neuroscientist Jay Giedd was studying the brains of healthy teenagers when he noticed something odd: The brains appeared to change in unexpected ways as the youths matured through adolescence.

When the National Institute of Mental Health researcher looked closer, he found that the most dramatic shifts around puberty occurred in the front of the brain, in an area believed crucial for advanced mental functions such as reasoning, making judgments and self-control.

Could the alterations account for the impulsive, erratic and sometimes irresponsible behavior often seen in teenagers?

"Some kids are more likely to take risks than adults, and those are the areas that are undergoing drastic changes," said Paul Thompson, a neurologist at the University of California at Los Angeles who helped Giedd produce striking images of changes in healthy teenagers' brains. "It mirrors cognitive changes."

Giedd and Thompson's work is part of a growing body of scientific evidence suggesting that rebelliousness and other stereotypical teenage behaviors commonly blamed on raging hormones may be partly caused by a burst of rapid change sculpting the developing brain.

The theory is speculative, but if it turns out to be true, it would underscore the importance of guiding children carefully through adolescence, because the right kinds of experiences might build the structures and connections necessary for a healthy adulthood.

"If the teens are doing music and sports and academics, that's how brains will be hard-wired. If they are doing video games and MTV and lying on the couch, that would be how they are hard-wired," Giedd said. "Teens are most likely to experiment with drugs and alcohol. I often show teens my data curve (and say), 'If you do this tonight, you may not be affecting your brains just this weekend but for the next 80 years of your life.' "

The theory is controversial because the roots of behavior are complex and cannot be easily explained by relatively superficial changes in the brain.

"The idea that because the frontal portions of the brain are immature and therefore children undertake risky behavior is nonsense," said John Bruer, president of the James S. McDonnell Foundation in St. Louis, which funds research in cognitive neuroscience. "The tendency here is to take our folk ideas and theories and prejudices about what adolescent behavior should and shouldn't be and make some biological explanation for that."

Giedd agreed that what scientists knew for sure was limited, but he added that the findings were intriguing. "The solid data is the gray matter thickens,

peaks around puberty and thins," he said. "The rest is pretty much speculation. . . . I don't mean to say that video games destroy the brain -- the real answer is we don't really know."

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