Reduced predictable information in brain signals in autism spectrum disorder.

Carlos Gómez,Christine M Freitag,Joseph T Lizier,Sven Bölte,Patricia Wollstadt,Michael Schaum,Michael Wibral,Roberto Hornero,Peter Uhlhaas,Christine Grützner,Sabine Schlitt

doi:10.3389/fninf.2014.00009

Abstract

Autism spectrum disorder (ASD) is a common developmental disorder characterized by communication difficulties and impaired social interaction. Recent results suggest altered brain dynamics as a potential cause of symptoms in ASD. Here, we aim to describe potential information-processing consequences of these alterations by measuring active information storage (AIS)—a key quantity in the theory of distributed computation in biological networks. AIS is defined as the mutual information between the past state of a process and its next measurement. It measures the amount of stored information that is used for computation of the next time step of a process. AIS is high for rich but predictable dynamics. We recorded magnetoencephalography (MEG) signals in 10 ASD patients and 14 matched control subjects in a visual task. After a beamformer source analysis, 12 task-relevant sources were obtained. For these sources, stationary baseline activity was analyzed using AIS. Our results showed a decrease of AIS values in the hippocampus of ASD patients in comparison with controls, meaning that brain signals in ASD were either less predictable, reduced in their dynamic richness or both. Our study suggests the usefulness of AIS to detect an abnormal type of dynamics in ASD. The observed changes in AIS are compatible with Bayesian theories of reduced use or precision of priors in ASD.

Highlights

It has been 70 years since Kanner (1943) and Asperger (1944) first described an intriguing disorder characterized by the children’s inability to relate themselves in the ordinary way to people and situations from the beginning of life
The symptom cluster described by Kanner has been called autism spectrum disorder (ASD), and it is clinically defined by a triad of deficits comprising impairments in communication, social interaction, and behavioral flexibility (Wing and Gould, 1979)
REDUCED ACTIVE INFORMATION STORAGE IN ASD Our results showed that active information storage (AIS) values were reduced in the neural signals obtained from the hippocampus/subiculum

Summary

Introduction

It has been 70 years since Kanner (1943) and Asperger (1944) first described an intriguing disorder characterized by the children’s inability to relate themselves in the ordinary way to people and situations from the beginning of life. Prevalence studies estimate that ASD affects 2–10 children per 1000 births (Yeargin-Allsopp et al, 2003; Baird et al, 2006). It is characterized by an early onset, since these typical behaviors show up before the age of 36 months. Due to the complexity and variety of the symptoms with which autistic individuals present to clinicians, it has been difficult to conceptualize a defining neurological mechanism that might underlie the core features of this disorder (Bauman and Kemper, 2005). New techniques are necessary to achieve a more detailed understanding of this disorder, and an earlier identification and more effective interventions and treatment (Bauman and Kemper, 2005)

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