LOS ANGELES - Subtle deformities in a deep brain region vital for movement and learning have been linked to risks for attention deficit and other disorders among premature infants, according to a University of Southern California study.

The study for the first time mapped minute differences in specific areas of the putamen, a kind of crossroads deep in the brain where signals, including sensation and motor function, coalesce and connect with higher regions associated with more complex functions.

Injuries and deformities to the putamen have been linked to deficits in attention-based learning and executive function - deciding on appropriate action - among adolescents who had been born prematurely, according to the study, published online Wednesday in the journal PLOS One.

"It's sort of a pathway," said USC clinical pediatrician Dr. Douglas Vanderbilt, an author of the study. "These subcortical structures are where sensation and motor functions coalesce before they go to the association cortex, which is the higher brain structures. They're essential because they're the freeways that connect to those downtown areas. So if there's problems with that, information is not going to be delivered."

Researchers compared magnetic resonance images from 17 infants born one to three months prematurely with those of 19 infants born at full gestational age. The analysis showed differences in areas of the putamen that have been correlated with ADHD in older children, said lead author Natasha Lepore, a USC physicist and radiologist who spearheaded the analysis.

"We found that there's one area in the surface of the putamen that's different both in terms of surface area and thickness," Lepore said. "The interesting part of it, to us, is this is exactly the same area that is different in children that have ADHD."

Chiara Nosarti, a psychiatrist at Kings College, London who was not involved in the study, said the USC approach could offer insights into mood disorders and psychosis in adolescents.