Tuesday, October 31, 2006

Autistic Brain Has Difficulty Coordinating

Refreshingly jargon-free explanation of a current theory for autism:
"A growing number of scientists believe autism may be caused by a lack of coordination in the brain.
"Some people think that autism is a disruption of social function," says Marcel Just of Carnegie Mellon University in Pittsburgh. "But I think it's much more widespread. It's a disruption of many kinds of behaviors that require good cortical coordination."
For example, a conversation requires some areas of the brain to produce words. At the same time, Just says, other parts need to assess whether the listener understands those words. If those areas don't coordinate, there's no conversation.
Just says important skills require more than one part of the brain to work together.
"It's like the Internet," he says. "It's not one place. It's not Los Angeles. It's not Zurich. It's the network."

Michael Murias of the University of Washington presented a study on brain coordination. It compared 18 adults who have autism spectrum disorder with 18 typical adults.
All of them had electrodes attached to their scalps. Murias says the experiment itself was pretty easy: "We just instructed them to close their eyes and relax."
Then Murias and his team measured brain waves called alpha waves to see whether certain areas in the brain were communicating. In people with autism, they weren't -- at least not very well.
"The degree of communication within the brain was diminished," Murias says. "Particularly within the frontal lobes and particularly between the frontal lobes and the rest of the brain."
Murias says that's important because the frontal lobes are involved in so-called "executive functions," which help us recognize another person's intentions and avoid antisocial behavior. But only when the frontal lobes are connected to other parts of the brain.
In autism, the problem appears to be with the brain's connecting cables.
Those cables are contained in what scientists call white matter. Marcel Just, who has been studying white matter using a technique called diffusion-tensor imaging, says he's found that "the quality of the white matter is lower in autism. It's less coherently organized."

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