Measuring the bias to look to the eyes in individuals with and without autism spectrum disorder

The overarching goal of this thesis was to investigate looking patterns in autism spectrum disorder (ASD), which is characterised by difficulties in modulating social eye gaze. Despite a large body of literature investigating where autistic individuals look when viewing a face, there is limited research into first fixation locations and into their capacity for altering looking patterns in line with an instruction. A novel prompting paradigm was used to investigate where individuals looked when viewing a face, how their eye tracking patterns changed in response to an instruction prompt, as well as behavioural performance throughout the task (accuracy and RT). The performance of individuals with ASD and neurotypical development (NT) was tested. In Study 1 I investigated how accurately and quickly autistic adolescents responded in a forced choice recognition paradigm, where either the eye or mouth region of a face had been changed between the target and foil images. Critically, the ASD group were less accurate overall when compared to the control group, but no group differences were seen between the eye and mouth conditions. In Study 2 eye tracking measures of dwell time and first fixation location were also included and the same paradigm was conducted with NT adults. This group had an initial, and difficult to inhibit, bias to look to the eyes, even when prompted to look to the mouth. In Study 3 the measure of time to first fixate was added to the paradigm, together with development of a control condition, and the same pattern of difficulty to inhibit looks to the eyes was found in typically developing (TD) children. Finally, Study 4 demonstrated that comparable eye tracking patterns were found in ASD and TD children, including this difficult to inhibit bias to look at the eyes. In summary, this thesis used a novel prompting paradigm and established an initial difficult to inhibit bias to look to the eyes, shown consistently across TD children, NT adults, and autistic children. Therefore, evidence from this paradigm indicates that initial spontaneous looking to the eyes might be an automatic response in autistic individuals