Functional gradient characteristics analysis of preschool-aged children with autism spectrum disorder

Abstract Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by social and behavioral impairments, emerging in early childhood with unclear causes. The primary aim of this study is to investigate shifts in the functional gradients underlying hierarchical brain network organization in ASD and to assess their potential contribution to clinical symptom severity. Resting-state functional magnetic resonance imaging was used to examine changes in functional gradients across seven major brain networks in a cohort of 52 individuals with ASD and 40 healthy controls. In the somatomotor network, neither the first nor third gradient showed significant group differences; however, two regions—right paracentral lobule and right postcentral gyrus—exhibited significant differences in the second gradient. In the frontoparietal network, only the left middle frontal gyrus in the second gradient showed a significant group difference. For the ventral attention network, only the primary gradient exhibited significant differences in the left insula, the right insula, and the right median cingulate and paracingulate gyri. In the default mode network, all three gradients showed statistically significant differences. These results suggest potential neuroimaging biomarkers for assessing the severity of ASD in preschool-aged children.