Resting State EEG Connectivity in Children with HFA

Background: There is a growing body of evidence indicating that autism is a biologically based disorder, related to atypical patterns of cortical connectivity. As distributed brain networks underlie higher cognitive, socio-emotional, and communication functions, impaired functional connectivity could relate to clinical manifestations of autism. Functional cortical connectivity can, in a non-invasive way, be studied by means of EEG coherence.

Objectives: To investigate functional cortical connectivity in children with high-functioning autism (HFA) during resting state, by means of EEG coherence.

Methods: Normally intelligent children (9 to 13 years) with HFA were compared with age-matched normally developing peers. Eyes-closed resting EEG was measured for three minutes, using a 128-channel EEG system. Inter- and intra-hemispheric coherence measures were calculated for delta, theta, alpha, and beta frequency bands.

Results: No main group differences were found for inter-hemispheric coherence measures. However, a significant group by hemisphere effect was found for slow wave EEG (delta and theta) coherence. This effect was caused by the combination of enhanced connectivity in the left hemisphere and reduced connectivity in the right hemisphere for the HFA group, indicating atypical lateralisation.

Conclusions: Differences in resting state EEG connectivity were noted between groups, suggestive of abnormal functional brain lateralisation in autism. The findings support the disturbed cortical connectivity model of autism.

Sponsor: Ghent University Research Fund