Abnormal resting-state brain network dynamics in toddlers with autism spectrum disorder.

Emerging evidence suggests aberrant functional connectivity (FC) of brain networks in children, adolescents, and adults with autism spectrum disorder (ASD). However, little is known about alterations of dynamic FC in toddlers with ASD. The aim of this study was to investigate the characteristics of brain network dynamics in ASD toddlers. We analyzed resting-state functional magnetic resonance imaging data of 41 ASD and 23 typically-developing (TD) toddlers aged 15-45 months using leading eigenvector dynamics analysis. The between-group differences in the temporal properties of state were evaluated, followed by correlation analysis of these differences with autistic factors in ASD. Compared with TD subjects, ASD toddlers had a lower occurrence rate and mean dwell time in the global state. The mean dwell time of this state was negatively correlated with the body and object use of the autism behavior checklist (ABC) score. The ASD group presented a higher occurrence probability in the state related to the visual network, and the dwell time of this state was positively correlated with the relationship building of the ABC score. Moreover, the occurrence probability of the state related to the dorsal attention network and default mode network was positively correlated with the body and object use of the ABC score. Our findings indicate that there are differences in the developmental patterns of large-scale brain functional networks in ASD toddlers, which may contribute to the early identification of ASD and provide meaningful insights into its potential neural mechanisms.