Electrophysiological signatures of atypical intrinsic brain connectivity networks in autism

Abstract

Objective Abnormal local and long-range brain connectivity have been widely reported in autism spectrum disorder (ASD), yet the nature of these abnormalities and their functional relevance at distinct cortical rhythms remains unknown. Investigations of intrinsic connectivity networks (ICNs) and their coherence across whole brain networks hold promise for determining whether patterns of functional connectivity abnormalities vary across frequencies and networks in ASD. In the present study, we aimed to probe atypical intrinsic brain connectivity networks in ASD from resting-state electroencephalography (EEG) data via characterizing the whole brain network. Approach Connectivity within individual ICNs (measured by spectral power) and between ICNs (measured by coherence) were examined at four canonical frequency bands via a time-frequency independent component analysis on high-density EEG, which were recorded from 20 ASD and 20 typical developing (TD) subjects during an eyes-closed resting state. Main results Among twelve identified electrophysiological ICNs, individuals with ASD showed hyper-connectivity in individual ICNs and hypo-connectivity between ICNs. Functional connectivity alterations in ASD were more severe in the frontal lobe and the default mode network (DMN) and at low frequency bands. These functional connectivity measures also showed abnormal age-related associations in ICNs related to frontal, temporal and motor regions in ASD. Significance Our findings suggest that ASD is characterized by the opposite directions of abnormalities (i.e., hypo- and hyper-connectivity) in the hierarchical structure of the whole brain network, with more impairments in the frontal lobe and the DMN at low frequency bands, which are critical for top-down control of sensory systems, as well as for both cognition and social skills.

Editorial: Advanced Neuroimaging Methods for Studying Autism Disorder

“…This may pave the way to study differences in functionally defined networks. These studies confirm and extend results using Electroencephalography (Murias et al, 2007 ; Coben et al, 2014 ; Boutros et al, 2015 ; Shou et al, 2017 ).…”

What does scalp electroencephalogram coherence tell us about long‐range cortical networks?

“…Disruption of typical patterns of coherence between the EEG measured at scalp sites is observed in human patients with disconnection syndromes (Leocani et al , 2000; Spencer et al , 2003; Babiloni et al , 2016; Duffy et al , 2017; Schwartz et al , 2017; Shou et al , 2017). In experiments with non-human primates, coherence in local field potentials (LFPs) between brain areas measured with microelectrodes positioned intracranially near cell bodies has been linked to a number of cognitive functions such as selective attention (Gregoriou et al , 2009), working memory (Salazar et al , 2012), and decision-making (Nacher et al , 2013).…”

Differences in Clinical Characteristics and Brain Activity between Patients with Low- and High-Frequency Tinnitus

“…Resting-state network measurements revealed an association of tinnitus with alterations in a wide range of brain areas [ 76 – 79 ]. In our study, HFT was associated with increased alpha1 activity in the second auditory cortex (BA22) and angular gyrus (BA39) regions relative to that in the control group ( Figure 3 ).…”