Altered global modular organization of intrinsic functional connectivity in autism arises from atypical node-level processing
Autistic spectrum disorder (ASD) is a neurodevelopmental condition characterized by restricted interests and repetitive behaviors as well as social-communication deficits. These traits are associated with atypicality of functional brain networks. Modular organization in the brain plays a crucial role in network stability and adaptability for neurodevelopment. Previous neuroimaging research demonstrates discrepancies in studies of functional brain modular organization in ASD. These discrepancies result from the examination of mixed age groups. Furthermore, recent findings suggest while much attention has been given to deriving atlases and measuring the connections between nodes, the within nodes information may be crucial in determining altered modular organization in ASD compared with TD. However, altered modular organization originating from systematic nodal changes are yet to be explored in younger children with ASD. Here, we used graph-theoretical measures to fill this knowledge gap. To this end, we utilized multicenter resting-state BOLD fMRI data collected from 5-10-year-old children - 34 ASD and 40 typically developing obtained from the Autism Brain Image Data Exchange (ABIDE) I and II. We demonstrated alterations in the topological roles and modular cohesiveness are the two key properties of the brain regions anchored in default mode, sensorimotor, and salience networks primarily relates to social and sensory deficits in ASD children. These results demonstrate atypical global network organization in ASD children arise from nodal role changes and contribute to the growing body of literature suggesting that there is interesting information within nodes providing critical marker of functional brain networks in Autistic children.