Functional connectivity of the inferior frontal cortex changes with age in children with autism spectrum disorders: a fcMRI study of response inhibition.

Unmasking the neural basis of neurodevelopmental disorders, such as autism spectrum disorders (ASD), requires studying functional connectivity during childhood when cognitive skills develop. A functional connectivity magnetic resonance imaging (fcMRI) analysis was performed on data collected during Go/NoGo task performance from 24 children ages 8-12 years (12 with ASD; 12 controls matched on age and intellectual functioning). We investigated the connectivity of the left and right inferior frontal cortex (IFC; BA 47), key regions for response inhibition, with other active regions in frontal, striatal, and parietal cortex. Groups did not differ on behavioral measures or functional connectivity of either IFC region. A trend for reduced connectivity in the right IFC for the ASD group was revealed when controlling for age. In the ASD group, there was a significant negative correlation between age and 2 right IFC correlation pairs: right IFC-bilateral presupplementary motor area (BA 6) and right IFC-right caudate. Compared with typical controls, children with ASD may not have gross differences in IFC functional connectivity during response inhibition, which contrasts with an adult study of ASD that reported reduced functional connectivity. This discrepancy suggests an atypical developmental trajectory in ASD for right IFC connectivity with other neural regions supporting response inhibition.

Are executive control functions related to autism symptoms in high-functioning children?

BACKGROUND: Linking autism symptoms to cognitive abilities can expand phenotypic descriptions and facilitate investigations into the etiology and treatment of this multiplex disorder. Executive dysfunction is one of several potential cognitive phenotypes in autism. METHOD: Archival clinical data on 89 children diagnosed with Autism Spectrum Disorders and administered a large neuropsychological battery were evaluated for relationships between executive functioning and autism symptoms. RESULTS: Significant relationships between both laboratory tasks and behavior rating scales of executive functions and autism symptoms were identified. Multiple regression analyses revealed that measures of semantic fluency, divided auditory attention, and behavioral regulation were significantly correlated with autism symptoms, even after accounting for the variance from correlated "nuisance variables," such as vocabulary and age. CONCLUSIONS: Executive dysfunction is related to all three clusters of behavioral symptoms in Autism Spectrum Disorders.