Investigating profiles of attention and arousal in Autism Spectrum Condition (ASC)

Arora Fedyushkin, Iti (2020) Investigating profiles of attention and arousal in Autism Spectrum Condition (ASC). PhD thesis, University of Nottingham.

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The present doctoral project aimed to investigate profiles of arousal and attention in autistic individuals and identify how atypicalities in these relate with specific clinical symptoms of autism. I recruited children and young people between the ages of 7 and 15 years who were either neurotypical (n= 31) or had autism (n= 18). I included a clinical control group of children and young people with ADHD (n= 24) as well as those who had comorbid autism and ADHD (n= 33). I collected indices of arousal and attention by measuring heart rate, brain activity (using electrophysiology) and eye movements in response to experimental tasks requiring involuntary orienting of attention to auditory and visual stimuli, and also systematically manipulated characteristics of the stimuli used.

I found that there were no group-level differences in arousal profiles related to autism; but rather, that participants with ADHD (with or without autism) exhibited profiles of sympathetic underarousal. Given the heterogeneity in arousal profiles due to presence of ADHD in autistic participants, and due to heterogeneity apparent in the arousal literature in autism, I investigated the presence of subgroups with different arousal profiles in the autistic sample. This revealed that autistic participants could be stratified into distinct subgroups who showed tonic hyper- and hypo-arousal. These subgroups presented with different clinical profiles, such that the hyper-aroused subgroup showed worse autism symptom severity and higher rates of anxiety and sensory avoidance behaviours; while the hypo-aroused subgroup showed higher rates of hyperactive and impulsive behaviours as well as more sensory-seeking behaviours. I also found that autistic participants demonstrated intact abilities to orient to and habituate to simple auditory and visual stimuli. However, autistic participants (without ADHD) showed atypicalities in their profile of orienting to stimuli with higher complexity. These atypicalities in attention were related with social interaction symptoms of autism. Further, these atypicalities appeared to relate with presence of tonic hyperarousal. I verified the atypicalities observed in orienting to more complex visual stimuli in an independent sample of neurotypical children (n= 64) and found that neurotypical children with higher levels of subclinical autistic traits showed similar atypicalities in orienting attention to more complex stimuli.

The implications of these findings within the context of the literature on arousal and attention and recommendations for future research are discussed.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Groom, Madeleine
Ropar, Danielle
Hollis, Chris
Keywords: Arousal profiles; Attention to stimuli; Children with autism; Children with ADHD
Subjects: W Medicine and related subjects (NLM Classification) > WM Psychiatry
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Medicine
Item ID: 63962
Depositing User: Arora Fedyushkin, Iti
Date Deposited: 20 May 2021 10:52
Last Modified: 20 May 2021 10:52

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