Forty-eight participants (25 with ASC) completed Experiments 1–3. Out of these 48, we excluded 13 participants in total from our analyses: six participants (five in the ASC group) based on poor performance during the thresholding procedure prior to the experiment, and seven participants (two in the ASC group) based on poor fixation during the experiment. For details of exclusion criteria, please see
Practice and
Thresholding and
Eye tracking below. It is important to note that excluding participants from the study based on poor performance during the thresholding procedure or poor gaze stability fixation, did not qualitatively affect the results reported here (all
p > 0.162). Participants were matched for age (Controls: 29.6 ± 8.6, ASC: 33.3 ± 12.3,
p > 0.31) and nonverbal IQ (Controls: 114.5 ± 22.3, ASC: 121.5 ± 8.8,
p > 0.22), as assessed using the Wechsler Abbreviated Scale of Intelligence (WASI). ASC participants all had clinical diagnoses of an autism spectrum disorder, as evaluated by qualified clinicians based on DSM-IV criteria, and were assessed using the ADOS-II (Module 4) by a research-reliable experimenter. Participants also completed the Autism Quotient Questionnaire (AQ; Baron-Cohen, Wheelwright, Skinner, Martin, & Clubley,
2001), the Sensory and Perception Questionnaire (SPQ; Tavassoli, Hoekstra, & Baron-Cohen,
2014), and the Glasgow Sensory Questionnaire (GSQ; Robertson & Simmons,
2013). All participants had normal or corrected-to-normal vision, and did not have a diagnosis of epilepsy or attention-deficit / hyperactivity disorder. All participants had normal or corrected-to-normal vision and no diagnosis of epilepsy or attention-deficit / hyperactivity disorder.