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

Abstract

BackgroundThe dimensional approach to autism spectrum disorder (ASD) considers ASD as the extreme of a dimension traversing through the entire population. We explored the potential utility of electroencephalography (EEG) functional connectivity 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.MethodsResting-state EEG functional connectivity was measured for 74 neurotypical subjects. All participants also provided a questionnaire (Social Responsiveness Scale, SRS) that was completed by an informant who knows the participant in social settings. We conducted multivariate regression between the SRS score and functional connectivity in all EEG frequency bands. We explored modulations of network graph metrics characterizing the optimality of a network using the SRS score.ResultsOur results show a decay in functional connectivity mainly within the delta and theta bands (the lower part of the EEG spectrum) associated with an increasing number of autistic traits. When inspecting the impact of autistic traits on the global organization of the functional network, we found that the optimal properties of the network are inversely related to the number of autistic traits, suggesting that the autistic dimension, throughout the entire population, modulates the efficiency of functional brain networks.ConclusionsEEG functional connectivity at low frequencies and its associated network properties may be associated with some autistic traits in the general population.

Functional Connectivity and Temporal Variability of Brain Connections in Adults with Attention Deficit/Hyperactivity Disorder and Bipolar Disorder

“…Connections that were stronger in the BD group than in the CT group, while more diffusely distributed, showed a similar pattern. Our data are consistent with abnormal frontotemporal and fronto-occipital networks observed in several neuropsychiatric conditions [4,31,35,40,42]. These observations did not change qualitatively when changing the thresholds of the binary difference matrix or the activation mask.…”

“…This connectivity matrix produces a weighted graph in which each electrode corresponds to a node and each link is determined by the SL of an electrode pair. To calculate network measures, SL matrices were converted to binary undirected matrices by applying a threshold T. We explored a broad range of values of 0.01 < T < 0.2, with increments of 0.0005, and we repeated the full analysis for each value of T. Based on previous works [35,36,37,38,39,40], graph theory metrics [41] were performed on these thresholded matrices, measuring the clustering coefficient C, the characteristic path length L and the modularity index MI of brain networks, using the BCT toolbox [41]. Finally, we performed ANOVAs with group (CT or patients) and T (binned in 8) as independent factors.…”

Anatomic and Functional Connectivity Relationship in Autistic Children During Three Different Experimental Conditions

“…Barttfeld et al ( Barttfeld et al, 2013) have reported consistent differences in the connectivity patterns This article has been peer-reviewed and accepted for publication, but has yet to undergo copyediting and proof correction. The final published version may differ from this proof.…”

Dysfunction of sensory oscillations in Autism Spectrum Disorder

“…Determining the correspondence between resting and task based oscillatory networks by utilizing techniques such as graph theory remains a critically important step for future research. Such an approach is needed to better clarify the apparent links between resting oscillations, oscillatory responses to sensory stimuli, coupling across the oscillatory hierarchy, the autism phenotype (Cornew et al, 2012), and autism traits in the general population (Barttfeld et al, 2013). Methodological challenges are also imposed by the low-pass filtering effects of the skull.…”