Contrast subgraphs catch patterns of altered functional connectivity in autism spectrum disorder

Despite the breakthrough achievements in understanding structural and functional alterations of brain connectivity in autism spectrum disorder (ASD), the exact nature and type of such alterations are not yet clear due to conflicting reports of hyper-connectivity, hypo-connectivity, and—in some cases—combinations of both. In this work, we bring order to the debate using a network comparison technique to capture mesoscopic-scale differential patterns of functional connectedness. In particular, we leverage recent algorithmic advances in extracting contrast subgraphs to identify maximally different mesoscopic connectivity structures between two sets of networks from typically developed individuals and ASD subjects across different developmental stages. A significantly larger connectivity among occipital cortex regions and between the left precuneus and the superior parietal gyrus was found in ASD subjects. At the same time, reduced connectivity characterized the superior frontal gyrus and the temporal lobe regions. More importantly, our results reconcile within a single framework multiple previous separate observations about functional connectivity alterations in ASD.