Atypical Social Behavior is Predicted by Overconnectivity Between Salience and Default Mode Networks in Autism Spectrum Disorder.

As Default Mode and Salience networks (DMN, SN) contribute to social behavior and switching between inner and outer attention, they are believed to function and develop differently in individuals with Autism Spectrum Disorder (ASD). However, it remains unclear what alterations of their interactivity are connected to certain autistic traits and how age influences these networks' maturing. Behavioral (social responsiveness, executive functions and communication skills) and resting-state functional connectivity (FC) data from the Autism Brain Imaging Data Exchange were analyzed comprising individuals with ASD (n = 144) and healthy controls (n = 99). We compared FC between the groups investigating DMN and SN separately and in combination. Finally, we assessed FC-behavior links in the ASD group and age effects on FC across these networks in both samples. Individuals with ASD exhibited increased FC between DMN and SN but decreased one within DMN compared to the control group. FC between right insular and medial prefrontal cortices predicted more severe social responsiveness impairments in ASD but there were no significant associations with executive functions nor adaptive behavior. Additionally, DMN and SN matured in ASD with partly different patterns than in typical development. Our results replicated and expanded previous findings on DMN and SN pointing to robust differences within and between these networks in ASD and their contribution to autistic traits regarding social responsiveness.