"Research suggests the brains of autistic children may indeed be "wired" differently "right from the beginning," Paterson says. A popular theory among researchers holds that autistic people have an abundance of "local connections," in one specific part of the brain, but not enough "long-distance connections" to coordinate complex tasks among various parts of the brain, such as interpreting emotions, says Geraldine Dawson, chief science officer for the advocacy group Autism Speaks.
"The changes lie not in the brain cells themselves but in the pathways that transmit messages between brain regions, Paterson says.
"These pathways aren't visible to the naked eye. But scientists can get a sense of these bundles of nerve fibers with technology that traces the path of water through the brain.
"Structural changes in these fiber tracts are evident in the brains of children later diagnosed with autism, even as young as 6 months old."