An Investigation of the Behavioural and Neural Correlates of Repetitive Behaviour in Autism Spectrum Disorder

Abstract

The existing research on repetitive behaviour in Autism Spectrum Disorder (ASD) is sparse. The identification of biomarkers through the use of brain imaging is an important area of research that can provide information about the etiology and function of repetitive behaviour, which is poorly understood. To date, results from brain imaging studies have implied that there may be a common neurobiological substrate involved in social deficits and repetitive behaviour in ASD. At the same time, it is becoming increasingly apparent that ASD may be described as a spectrum of multiple ‘autisms,’ that vary in their behavioural presentation and genetic loci. As such, the identification of biomarkers of distinct repetitive behaviour subtypes across the autism spectrum is a priority. To date, several gaps in the literature remain, and the current body of research was completed to address these gaps. In this body of work, Chapter 1 offers an introduction to the subject matter. Chapter 2 presents a review of neuroimaging studies on repetitive behaviour in ASD and creates an organized framework for future research. In Chapter 3, the results of an eye-tracking study, which investigated the common neurobiological substrate in social deficits and repetitive behaviour, are presented. Chapter 4 outlines the results of a brain imaging study that investigated the association between repetitive behaviour and patterns of resting-state functional connectivity in ASD. In Chapter 5, the results of a pilot study that examined the association between inhibitory control and cortical gamma-amino-butyric acid (GABA) in ASD are presented. Last, chapter 6 offers a summary of these original research studies, and a discussion of implications and future directions.