WEDNESDAY, July 25, 2012 (HealthDay News) -- Severe social and physical neglect harms a child's brain development, but these effects can be partially reversed if the child is moved to a more positive environment, a new study indicates.
The researchers analyzed brain MRI scans from three groups of Romanian children aged 8 to 11. Some of the children were raised in orphanages, some were in orphanages and then moved to good foster homes and others lived in normal family settings for their entire lives.
Children who had been in an orphanage at any time in their lives had much smaller gray matter volume in the cortex of the brain than those who had never been in an orphanage. Even if children were placed in loving foster homes, the formerly institutionalized children's gray matter didn't catch up.
White matter, however, seemed to be more resilient. Children who remained in an orphanage had smaller white matter volume than those who had never been in an orphanage.
But orphaned children placed in high-quality foster care had the same white matter volume as those who were never in an orphanage.
Researchers said differences in how white matter and gray matter develop may explain why white matter was better able to catch up than the gray matter.
Growth of the brain's gray matter peaks at specific times during childhood and a child's environment can strongly influence brain development during these sensitive periods, the researchers said. Gray matter is involved in muscle control, emotions, memory speech and sensory perceptions such as seeing and hearing.
White matter -- which is necessary for forming connections in the brain -- grows more slowly over time. This may be what makes it more capable of recovering from the effects of social and physical neglect.
"Increasingly we are finding evidence that exposure to childhood adversity has a negative effect on brain development," study co-leader Margaret Sheridan, of the Labs of Cognitive Neuroscience at Children's Hospital Boston, said in a hospital news release. "The implications are wide-ranging, not just for institutionalized children but also for children exposed to abuse, abandonment, violence during war, extreme poverty and other adversities."
The study was published online July 23 in the Proceedings of the National Academy of Sciences.
At least 8 million children worldwide live in institutional settings, according to UNICEF.
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