Organization of brain networks governed by long-range connections index autistic traits in the general population

Abstract

Background: The dimensional approach to Autism Spectrum Disorder (ASD) considers ASD as the extreme of a dimension traversing through the entire population. We use electroencephalography (EEG) functional connectivity to explore its potential utility as a biomarker. We hypothesized that individual differences in autistic traits of typical subjects would involve a long-range connectivity diminution within the delta band. Methods: Resting state EEG functional connectivity was measured for 74 neurotypical subjects. All participants also provided a questionnaire (Social Responsiveness Score, SRS) by an informant who knows the participant in social settings. We conducted multivariate regression between SRS score and functional connectivity in all EEG frequency bands. We explored modulations of network graph metrics characterizing the optimality of a network by SRS score. Results: Our results show a decay in functional connectivity mainly within delta and theta band (the lower part of the EEG spectrum) associated with increasing amount of autistic traits. When inspecting the impact of autistic traits on the global organization of functional network we found that optimal properties of the network are inversely related to the amount of autistic traits, suggesting that the autistic dimension, throughout the entire population, modulates the efficiency of functional brain networks. Conclusions: EEG functional connectivity at low frequencies and its associated network properties may be associated with some autistic traits in the general population.