The Imaginary Part of Coherency in Autism: Differences in Cortical Functional Connectivity in Preschool Children

Luis García Domínguez,José Luis Pérez Velázquez,Jim Stieben,Stuart Shanker,Carles Soriano-Mas

doi:10.1371/journal.pone.0075941

Abstract

Cognition arises from the transient integration and segregation of activity across functionally distinct brain areas. Autism Spectrum Disorders (ASD), which encompass a wide range of developmental disabilities, have been presumed to be associated with a problem in cortical and sub-cortical dynamics of coordinated activity, often involving enhanced local but decreased long range coordination over areas of integration. In this paper we challenge this idea by presenting results from a relatively large population of ASD children and age-matched controls during a face-processing task. Over most of the explored domain, children with ASD exhibited enhanced synchronization, although finer detail reveals specific enhancement/reduction of synchrony depending on time, frequency and brain site. Our results are derived from the use of the imaginary part of coherency, a measure which is not susceptible to volume conduction artifacts and therefore presents a credible picture of coordinated brain activity. We also present evidence that this measure is a good candidate to provide features in building a classifier to be used as a potential biomarker for autism.

Highlights

A significant challenge in the study of autism is to understand how the integration of brain activity occurring at multiple levels – cells and networks – results in the behaviors that are highly characteristic of the disorder
While advances have been made in our understanding of the genetic bases of autism and considerable effort has focused on neuroimaging the brains of individuals with Autism Spectrum Disorders (ASD), very little is known about the dynamics of the brains of individuals with ASD
If we could associate particular brain coordination dynamics with specific behaviors, this could result, in a basic understanding of how characteristic behaviors of ASD result from altered neurodynamics, and in the development of specific biomarkers that could help in the early diagnosis of ASD

Summary

Introduction

A significant challenge in the study of autism is to understand how the integration of brain activity occurring at multiple levels – cells and networks – results in the behaviors that are highly characteristic of the disorder. If we could associate particular brain coordination dynamics with specific behaviors, this could result, in a basic understanding of how characteristic behaviors of ASD result from altered neurodynamics, and in the development of specific biomarkers that could help in the early diagnosis of ASD. Such a mapping would afford the possibility of applying targeted interventions designed to enhance the integration of brain activity in young children with ASD. Most results from fMRI studies seem to support the thesis that reduced intracortical connectivity results in a lower degree of integration of information across certain cortical areas [3,4]

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Results

Conclusion