If gray matter is your brain cells, white matter is the connections between them. Too many of these connections, especially within the motor cortex, have been linked to poor motor skills in children with autism, according to research conducted by the Kennedy Krieger Institute in Baltimore.
On the other hand, increased white matter volume in typically developing children usually predicts improved motor skills, according to the study, published in the August issue of the journal Brain.
“Like any wiring ? phones in your home ? it?s not how many connections you have, but where it?s going and how it?s connected,” said Dr. Stewart H. Mostofsky, lead study author and a pediatric neurologist in the Department of Developmental Cognitive Neurology at the Kennedy Krieger Institute. In autistic children, “there seems to be an overgrowth in localized connections in the brain and an undergrowth in more distant connections.”
Mostofsky speculated that not having those long-range connections contributes to difficulty with more complex motor skills, as well as more complex social interactions.
Autism affects one in 150 American children today, according to the Autism Society of America. The ASA estimates that 1.5 million Americans and their families are now affected, costing the U.S. at least $35 billion annually.
Autistic children usually have difficulty with learning more complex motor skills, such as riding a tricycle, pumping their legs on a swing or tying shoelaces, according to the study.
Additionally, high-functioning children with autism often excel in academics rather than athletics. Since motor functions are highly measurable, with consistent results, they are much easier to study than measures of social behavior and communication. Motor signs can serve as markers for deficits in parallel brain systems important for control of socialization and communication.
