Among the 15 nerve-fiber tracts in the brain that linked various regions together, 12 showed aberrant growth patterns in the 6-month old babies who developed ASDs compared with those who didn’t. This suggests, says Dawson, that “there is a more global change in development of these tracts implicated in autism, and that functional connectivity, or the establishment of neural networks is clearly implicated in these findings.”
That means that whatever biological processes are driving autism, they aren’t limited to one region of the brain. And that makes sense, since the disorder’s hallmark behavioral symptoms involve language and social interactions, which require exquisite coordination of several different brain areas.