State-Dependent Differences in Functional Connectivity in Young Children With Autism Spectrum Disorder

Abstract

BackgroundWhile there is increasing evidence of altered brain connectivity in autism, the degree and direction of these alterations in connectivity and their uniqueness to autism has not been established. The aim of the present study was to compare connectivity in children with autism to that of typically developing controls and children with developmental delay without autism.MethodsWe assessed EEG spectral power, coherence, phase lag, Pearson and partial correlations, and epileptiform activity during the awake, slow wave sleep, and REM sleep states in 137 children aged 2 to 6 years with autism (n = 87), developmental delay without autism (n = 21), or typical development (n = 29).FindingsWe found that brain connectivity, as measured by coherence, phase lag, and Pearson and partial correlations distinguished children with autism from both neurotypical and developmentally delayed children. In general, children with autism had increased coherence which was most prominent during slow wave sleep.InterpretationFunctional connectivity is distinctly different in children with autism compared to samples with typical development and developmental delay without autism. Differences in connectivity in autism are state and region related. In this study, children with autism were characterized by a dynamically evolving pattern of altered connectivity.

Electroencephalogram Coherence Patterns in Autism: An Updated Review

“…Only one study from the past ten years has investigated resting-state as well as sleepbased connectivity in young children recently diagnosed with ASD [31]. This large study evaluated 137 two- to six-year-old children with either ASD, developmental delay matched with the ASD group by non-verbal intelligence (DD), or typical development [31].…”

“…This large study evaluated 137 two- to six-year-old children with either ASD, developmental delay matched with the ASD group by non-verbal intelligence (DD), or typical development [31]. The authors measured functional coherence across three states: awake, slow wave sleep (SWS), and Rapid Eye Movement (REM) sleep [31].…”

“…This large study evaluated 137 two- to six-year-old children with either ASD, developmental delay matched with the ASD group by non-verbal intelligence (DD), or typical development [31]. The authors measured functional coherence across three states: awake, slow wave sleep (SWS), and Rapid Eye Movement (REM) sleep [31]. After adjusting for multiple comparisons, the authors found relatively increased MSC between frontal-parietal regions during SWS and REM sleep across all frequency bands in toddlers with ASD relative to the TD group [31].…”

“…The authors measured functional coherence across three states: awake, slow wave sleep (SWS), and Rapid Eye Movement (REM) sleep [31]. After adjusting for multiple comparisons, the authors found relatively increased MSC between frontal-parietal regions during SWS and REM sleep across all frequency bands in toddlers with ASD relative to the TD group [31]. In contrast, there were no observed differences during the awake resting-state following multiple comparison correction [31].…”

“…After adjusting for multiple comparisons, the authors found relatively increased MSC between frontal-parietal regions during SWS and REM sleep across all frequency bands in toddlers with ASD relative to the TD group [31]. In contrast, there were no observed differences during the awake resting-state following multiple comparison correction [31]. There were also far fewer differences in MSC between ASD and DD groups, with the ASD group predominantly showing increased MSC in a small group of electrode pairs in the frontal/central-parietal region during SWS and REM sleep [31].…”