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Children with autism show more activity in a brain region important for making decisions under changing circumstances, according to a poster presented Monday at the Society for Neuroscience annual meeting in San Diego.
The anterior cingulate cortex, a brain region that helps relay information crucial to decision-making to other parts of the brain, is more active in these children when they are confronted with a task that requires quick reactions.
The region is also part of a control network that regulates an individual’s ability to adjust behavior in response to new information — often compromised in people with autism, who are notoriously inflexible in thought and behavior.
Adults with autism have been shown to perform poorly on tasks that involve decision-making, but the children with autism in the study performed just as well as controls did. However, the researchers observed hyperactivity in the anterior cingular cortex of these children.
In the study, researchers scanned the brains of 17 typically developing boys aged 9 to 12, and 15 boys with autism in the same age range — all of whom have intelligence quotient scores above 80 — as they viewed a series of images of Pokemon cartoon characters. The children were asked to press a button when they saw one of the ‘good’ Pokeman characters, but to refrain from pressing the button when the ‘bad’ character appeared.
The researchers made the task more difficult by increasing the number of good characters the children saw before the bad character popped up. It becomes progressively harder to hold off on pressing the button the longer it takes to for the bad character to show up, says Tamar van Raaltern, a postdoctoral fellow in Sarah Durston‘s laboratory at the University Medical Centre Utrecht in The Netherlands. “It becomes a more automatic response that is difficult to suppress.”
The children with autism did slightly worse on this most difficult version of the task, but in general performed quite well, says van Raaltern. They just had to work harder to achieve a similar outcome.
Comparing the results of the Pokemon task with the children’s scores on the Repetitive Behavior Scale, a diagnostic test for autism that assesses rigidity in thought and behavior, the researchers found a correlation between hyperactivity in the cingulate and the severity of their symptoms.
“It is possible that children who have a fair amount of rigidity need to work harder to repress a response to certain stimuli,” says van Raaltern.
Studies on adults with autism have shown reduced activity in the anterior cingulate cortex and other regions involved in the cognitive control network. This suggests that the ability of children with autism to compensate is lost as they become older.
Another reason the children with autism may have performed almost as well as controls, van Raaltern says, is because the cognitive control network is not fully formed in childhood.
“It is possible that there are no big differences in performance in children with autism because the typically developing children are [also] still maturing,” she says.