Study Probes Child, Teen Brains

Preteen Brain Performs at Adult Level; Few Boy/Girl Differences

How do child and teen brains work? An ambitious U.S. study is trying to find out -- and the first results already are in.

The study enrolls only healthy children from birth to age 18. The kids undergo intensive neurological and psychological tests, as well as MRI brain imaging studies.

None of the kids will be followed for more than four years. But because the study enrolls a diverse sample of kids, it is giving researchers an unprecedented look at how kids' brains and minds develop.

The early results contain several surprises:

• By age 11 or 12, a child's mental and motor skills approach adult levels.

• Kids undergo rapid mental development from ages 6 to 10.

• Mental development drops off sharply during the teen years, suggesting that teenage development shifts from acquiring new skills to integrating what already has been learned.

• There were some differences between boys and girls but not as many as previously thought. There were no sex differences in verbal ability or math aptitude.

As expected, children from lower-income families performed less well than other children in IQ tests and social behaviors. But these healthy, low-income-family kids did much better than expected. This suggests that health disparities have a major impact on the gap in mental function seen in low-income kids.

"As we follow these children over time, we will have a better understanding of what's happening," study researcher Deborah Waber, PhD, of Children's Hospital Boston and Harvard Medical School, says in a news release.

Vastly more information will become available as the study progresses. Researchers will then be able to see how individuals develop over time. And they hope to be able to link skill acquisition to specific changes in the brain.

When finished, the study should greatly expand scientific understanding of normal human neuropsychological development.

Waber and colleagues report their findings in the current online issue of the Journal of the International Neuropsychological Society.

Reviewed by Brunilda Nazario, MD

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