Scientists have developed a scan that can measure the maturity of the brain, an advance that someday might be useful for testing whether children are maturing normally and gauging whether teenagers are grown up enough to be treated as adults.

A federally funded study that involved scanning more than 12,000 connections in the brains of 238 volunteers ages 7 to 30 found that the technique appeared to accurately differentiate between the brains of adults and children and determine roughly where individuals scored in the normal trajectory of brain development.

While much more work is needed to validate and refine the test, the technique could have a host of uses, including providing another way to track children to make sure their brains are developing properly. The scan could, for example, identify children who might be at risk for autism, schizophrenia and other problems.

"If you are worried about a kid's development, in five minutes you could do a scan and it would spit out a measurement of their brain maturity level," said Nico Dosenbach, a pediatric neurology resident at St. Louis Children's Hospital who helped develop the technique described in Friday's issue of the journal Science.

But the test might be open to abuse, experts warn. Will overly anxious or competitive parents demand that their children be tested to see how they score compared with their peers? Will online dating services offer brain scans rating the maturity of potential mates? Will defense lawyers try to use it to prove their clients are too immature to be tried as adults?

"Ultimately, the question for all these kinds of studies is: Does the brain imaging tell us more than we would learn by observing or asking or examining the participants," said Anjan Chatterjee, a neuroscientist at the University of Pennsylvania. "Maybe this represents a step toward that possibility, but we are not there yet."

WASHINGTON POST