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Abstract

A recent upsurge in the study of time perception in autism spectrum disorders (ASD) has suggested that atypical temporal processing may contribute to both phenotypical and clinically-defining aspects of ASD. The work presented in this thesis aimed to evaluate if atypical temporal processing does impact behaviour in autism and in particular whether it relates to core features of ASD. In the first part, we sought to establish whether time perception was indeed atypical in autism using a psychophysical short durations comparison task, and found that whilst a number of participants performed the task typically, a high proportion of autistic adults experienced difficulties to perform the task above-chance. In the second part, we turned our attention to temporal aspects of speech and gesture coordination in naturalistic productions. Focusing on a first set of data, we provided a progressive characterisation of successive levels of temporal organisation in communication, finding that autistic and non autistic adults differ mainly in terms of the structure of speech and pauses on the one hand, and gesture and holds on the other hand. Specifically, autistic adults showed similar asynchrony between speech and gesture (absolute delay between an event in speech and an event in gesture), but increased coupling (dependency between the speech and gesture signals) and diminished mutual information (repetition of patterns in the different communication channels), compared to their typically developing counterparts. Importantly, we showed that distinct temporal aspects of communication relate to phenotypical aspects (quality of communication ratings) and clinical severity (scores on the ADOS). Using machine learning algorithms, we found mixed evidence that acoustic and kinematic features of communication can predict a diagnosis of autism with high accuracy. However, an identical analysis on a second set of data failed to replicate the group differences at any level of the temporal structure of speech and gesture. We conclude with some recommendations for the most promising directions to explore in future research,

Publication Type:	Thesis (Doctoral)
Subjects:	B Philosophy. Psychology. Religion > BF Psychology
Departments:	School of Health & Psychological Sciences > Psychology School of Health & Psychological Sciences > School of Health & Psychological Sciences Doctoral Theses

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