Developmental changes in neuromagnetic rhythms and network synchrony in autism.

ABSTRACT

OBJECTIVE: There is gathering consensus that altered connectivity is a hallmark of the autistic brain. This includes atypical neural oscillations and their coordination across brain regions, which are understood to mediate information processing and integration. It remains unclear whether and how connectivity in various neurophysiological frequency ranges develops atypically in autism spectrum disorder (ASD). METHODS: To address this in a cross-sectional sample, we recorded resting-state magnetoencephalography from 134 children and adolescents with and without ASD, and calculated resting spectral power and inter-regional synchrony (functional connectivity). RESULTS: Although no overall group differences were observed, significant alterations in linear and nonlinear age-related changes in resting oscillatory power and network synchrony were found. These differences were frequency- and region-specific and implicated brain systems thought to play a prominent role in ASD, such as the frontal cortex and cerebellum. We also found correlations between Autism Diagnostic Observation Schedule scores and the degree to which connectivity in cerebellar networks is "idiosyncratic" in an individual with autism. INTERPRETATION: We provide the first evidence that it is the curvatures of maturational changes in neurophysiological oscillations and synchrony, rather than disturbances in a particular direction, that characterize the brain function in individuals with ASD. Moreover, the patterns of idiosyncratic distortions of network synchrony relative to the group curve are associated with behavioral symptoms of ASD. Ann Neurol 2017;81199-211.