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A peek into how the brain develops

Early findings from a study of kids' brains hold some surprises.

By ASSOCIATED PRESS
Published May 18, 2007


WASHINGTON - Can you get smarter than a fifth-grader?

Of course. But new research suggests some of the brain's basic building blocks for learning are nearing adult levels by age 11 or 12.

It is the first finding from a study of how children's brains grow. The most interesting results are yet to come.

About 500 super-healthy youngsters, from newborns to teenagers, recruited from super-healthy families, are having periodic MRI scans of their brains as they grow up. They also get a battery of age-appropriate tests of such abilities as IQ, language skills and memory.

The MRI images measure how different parts of the brain grow and reorganize throughout childhood. Overlap them with the children's shifting behavioral and intellectual abilities at each age, and scientists expect to produce a long-sought map of normal brain development in children representative of the diverse U.S. population.

Scientists are publishing a sneak peek at some surprising early results today.

Performance on a variety of cognitive tasks - working memory, vocabulary, spatial recognition, reasoning, calculation - rapidly improves from age 6 to 10, but then levels off.

"We don't honestly know why, " said Dr. Deborah Waber of Children's Hospital Boston, who led the analysis published in the Journal of the International Neuropsychological Society.

This is a snapshot of 6- to 18-year-olds' abilities during their first study visit, she said, and results may change after researchers observe each child's progress with age and compare their MRI scans.

The adolescent brain is still growing. Indeed, the region responsible for such things as impulse control and moral judgment is the last to mature, sometime in the early 20s, said Dr. Jordan Grafman of the NIH's National Institute of Neurological Disorders and Stroke.

The study, funded by the National Institutes of Health, did not evaluate those kinds of skills. "It's an incomplete picture, " he said.

The study also found that girls start with a slightly better verbal ability - but boys catch up by adolescence - and that they have an equal aptitude for math.