Date of Award

August 2020

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

Advisor(s)

Natalie Russo

Second Advisor

Beth Prieve

Keywords

Autism spectrum disorder, sensory processing, visual perception

Subject Categories

Social and Behavioral Sciences

Abstract

Individuals with autism spectrum disorder (ASD) demonstrate enhanced perceptual

abilities relative to typically developing (TD) peers, as evidenced by better detection and identification of visual targets. This enhanced ability to discriminate features has been replicated across spatial and temporal displays. Research also suggests that visual perceptual abilities are correlated with the severity of core autism symptoms in this population, with the exception of atypical sensory behaviors, including sensory seeking and aversion, in which the relationship has been understudied and remains poorly understood. The current study introduces a novel visual search task to assess identification accuracy of feature-based visual targets that concurrently manipulates the temporal and spatial presentation of targets and distractors among children with and without ASD. In the task, target and distractor stimuli were simultaneously presented over visual space on a computer screen, with the peripheral distance of target stimuli from the center of the screen manipulated across trials (close, medium, and far), and the presentation rate manipulated across blocks (39, 117, and 195ms). Results revealed a perceptual advantage in children with ASD when targets were presented close to the center of the display at a presentation rate of 195ms, but not at other rate/distance combinations. Several significant correlations were found between perceptual accuracy and core ASD traits, including atypical visual sensory behaviors. Conclusions are limited by the smaller than expected sample size (due to COVID-19 and abrupt discontinuation of data collection), and data collection will resume when possible to clarify findings. Nonetheless, results provide important insights into the nature of perceptual processing, both in individuals with ASD and TD individuals, in the context of simultaneous spatial and temporal constraints. Clinical implications, limitations, and future directions are discussed.

Access

Open Access

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