A research team led by Elizabeth Aylward, a University of Washington professor of radiology, report that brains of adults with autism are “wired” differently from people without the disorder. The researchers, who are affiliated with the University of Washington’s Autism Center, also found that this abnormal connection pattern may be the cause of the social impairments characteristic of autism in children.

The research team used functional magnetic resonance imaging in the study, which also revealed that the subjects with the most severe social impairment showed the most abnormal pattern of activity of connectivity in the brain regions that process faces. One of the earliest characteristics to emerge in autistic children is a deficit in face processing, and this study is the first to examine how the brain processes information about faces.

Lead author Natalia Kleinhans states that "This study shows that these brain regions are failing to work together efficiently" and that the “work seems to indicate that the brain pathways of people with autism are not completely disconnected, but they are not as strong as in people without autism."

The study’s participants were 19 high-functioning autistic adults from ages 18 to 44 with IQs of at least 85 and 21 age- and intelligence-matched typically developed adults. Within the autism spectrum disorder group were 8 individuals diagnosed with autism, 9 diagnosed with Asperger's syndrome, and 2 with an otherwise non-specified pervasive developmental disorder. Levels of social impairment were drawn from clinical observations and diagnoses.

Participants were shown 4 series of 12 pictures of faces and a similar series of pictures of houses, all while having their brains scanned. The pictures were viewed for 3 seconds, and occasionally they were repeated. The participants were instructed to press a button when a picture was repeated.

Because this was a basic task, the two groups’ performances revealed no difference in performance, but, according to co-author Todd Richards, “Differences might have shown up if they had been asked to do something more complicated."

While there was no difference in performance, the two groups exhibited different patterns of brain activity. The typically developing adults showed significantly more connectivity between the area of the brain involved in face identification and two other areas of the brain than did the autism group.

Those autistic participants with the largest social impairment demonstrated the lowest level of connectivity between the areas of the brain, leading the authors to conclude that "This study shows that the brains of people with autism are not working as cohesively as those of people without autism when they are looking at faces and processing information about them."