Articele: Teenagers' brains are still under construction

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Teenagers' brains are still under construction

Wednesday, November 29, 2006
By David Templeton, Pittsburgh Post-Gazette

Bill Wade, Post-Gazette

Dr. Beatriz Luna, director of the University of Pittsburgh's Laboratory of Neurocognitive Development, studies the brains of adolescents. Old film brain scans, which are not done anymore, are taped to her office windows, and old hand scans of her two children add to her office decor.

The adolescent brain always has puzzled adults. So University of Pittsburgh neuroscientist Beatriz Luna decided to try solving the age-old puzzle once and for all.

The native of Santiago, Chile, who serves as director of Pitt's Laboratory of Neurocognitive Development, has been using her own brain power to figure out the mysterious workings of adolescent brains.

What she's discovered might not be what parents, educators or government officials want to hear.

Teenagers 13 to 17 can do most things adults do. They play sports, drive, work puzzles and solve problems.

So why don't they do what they're told? Why can't they plan, focus, behave and control their emotions? And in a question that generates considerable media attention, why do they engage in risky behavior that could hurt or kill them?

In short, why can't adolescents act like adults?

Dr. Luna said they can't function like adults because they don't yet have adult brains. It's that simple.

"The brain of an adolescent is changing gears in the process of becoming an adult," she said. "The different parts of the brain are learning to work in collaborative fashion, which enables it to work in a more efficient manner."

In adults, the prefrontal lobe of the brain, right behind the forehead, orchestrates a cerebral symphony. It takes in information, and like a skilled director, assigns areas of the brain to complete different tasks.

To make this possible, the adult brain prunes unnecessary connections and fortifies the remaining connections of neurons with fat cells, in a process known as myelination.

But the adolescent brain has not completed maturation, and the prefrontal lobe has yet to learn the skill of directing the mental orchestra. Instead it functions more like a soloist, which limits its mental prowess.

Dr. Luna said when she scolds her adolescent children, Nick Childers, 16, and Elena Childers, 14, they use her science against her: "Mom, I'm not fully myelinated," they reply. "What do you expect?"

As the brain matures, any weakness, defect or injury in other parts of the brain may emerge, explaining why mental illness may crop up during adolescence.

Adolescents undertake risky behavior because they're preparing to leave the nest. Those that experiment and develop life experiences, sometimes at great risk to their well-being, are better able to survive as adults, Dr. Luna said. Those remaining under parental care and control are least able to adapt to adulthood.

So it's natural for adolescents to engage in some risk-taking behavior.

Based on preliminary data, rewards appear to work with adolescents better than punishment, although adults are more driven by fear of punishment, she said.

"It's made me more understanding, but it's also prompted me to lock the liquor cabinet," she said.

Dr. Luna, whose developed an international reputation in the trendy science of brain structure and function, turned her focus to the adolescent brain because it was little understood, prompting persistent social debate about the proper drinking, voting and driving age.

More recent debate has focused on whether adolescent murderers should face the death penalty.

But Dr. Luna said she's a scientist, not a [elected official], so she's reluctant to offer opinions on social topics.

But she does stress to policy makers that adolescent brains are not adult brains, so don't require them to act like adults.

In her research, she determined brain function by having people stare at a light on a screen. The subjects then were ordered not to look at any other light that flashed on the screen.

Measuring eye motions, she tested hundreds of people aged 8 to 25 to determine whether a flashing light distracted their attention, despite the admonishment.

Adults generally avoided looking at the flash of light. But adolescents more often failed, then quickly acknowledged their mistake. Dr. Luna also studied brain images to figure out what portions of the adolescent and adult brain were functioning at the time.

"Adolescents use the frontal cortex to a larger extent than adults," she said. For adults, that portion of the brain "acts like a conductor of an orchestra, telling other parts of the brain what to do."

It may help explain why adolescents can be more easily distracted by friends or iPods while driving, leading to a higher incidence of accidents.

Dr. Luna has been quoted extensively in scientific and popular literature about brain function. Her research, including more than 40 published articles in scientific journals, has inspired articles in Nature and Scientific American, among other publications.

In June, she was named a Presidential Scholar and received her award during a White House ceremony involving President Bush. That award added about $1 million in funding to her research in adolescent gray matter.

And speaking of gray matter, Dr. Luna's research reveals that young brains, indeed, are like balls of clay.

As they mature, the brain becomes more sculpted. Maturation involves pruning unnecessary portions.

"Adults lose what they don't need: the parts that made their brain less efficient," she said. "That way it gets more efficient."

Dr. Luna also is working to understand autism and attention deficit and hyperactivity disorder.

But she's yet to be distracted from her focus on the adolescent brain.

"I feel this knowledge could benefit the school system to understand ways to get better results with adolescents," she said. "Right now the attitude toward adolescents is a negative one, but we should realize they really are trying. Adolescence is a crucial time that influences how the brain will mature."

Her key message is that "adolescence is not a disease."

"Adolescents are not only normal, but it's an extremely important part of development," she said. "Their brains are working overtime to look like ours."

(David Templeton can be reached at [email protected] or 412-263-1578. )

hearts and roses

Mind Reader
My nephew was once throwing a little temper tantrum when he was about started with a request to unload the dishwasher and take out the garbage, just like every other Wednesday. He said he forgot, then he got mouthy and then when my sister lost her patience and screamed at him, "Why did you remember last week but all this week you are forgetting things? What's wrong with you??" My nephew responded with, "Mom, I know it's hard for your to understand, but my frontal lobe hasn't quite finished growing, so even though I'm capable to all that stuff, it doesn't mean I will be able to follow through..." and laughed.

My sister suggested a few things that would happen to his frontal lobe if he didn't get his b.u.t.t in gear and take out the garbage!

Good article, thanks for sharing it. It sure helps to understand a few things with my dds.

Wiped Out

Well-Known Member
Staff member
Thanks-a good article for me to read since my easy child is just beginning her teenage years.