Altered Development of the Hurst Exponent in the Medial Prefrontal Cortex in Preschoolers With Autism.

Background: Atypical balance of excitation (E) and inhibition (I) in the brain is thought to contribute to the emergence and symptomatology of autism spectrum disorder (ASD). E/I ratio can be estimated from resting-state functional magnetic resonance imaging (fMRI) using the Hurst exponent, H. A recent study reported decreased ventromedial prefrontal cortex (vmPFC) H in male adults with ASD.

Reduced covariation between brain morphometry and local spontaneous activity in young children with ASD.

While disruptions in brain maturation in the first years of life in ASD are well documented, little is known about how the brain structure and function are related in young children with ASD compared to typically developing peers. We applied a multivariate pattern analysis to examine the covariation patterns between brain morphometry and local brain spontaneous activity in 38 toddlers and preschoolers with ASD and 31 typically developing children using T1-weighted structural MRI and resting-state fMRI data acquired during natural sleep. The results revealed significantly reduced brain structure-function correlations in ASD.