Accuracy, Response Time and Visual Search Strategies of Adolescents with and without Autism Spectrum Disorder during a Disembedding Task

Background:  The Weak Central Coherence Theory (WCC) and Enhanced Perceptual Functioning (EPF) are two main theories which described the differences in visuo-spatial processing among individuals with Autism Spectrum Disorders (ASD). It was purported that individuals with ASD process sensory information in a way that deviates from a top down manner and shows preference to local information. Disembeding tasks, or tasks that require the locating of hidden figure is one assessment to examine the presence of possible local processing in ASD. When comparing with typically developing (TD) counterparts, previous research found that children with ASD process information differently in visuo-spatial tasks. However, the performance and visual search strategies of adolescents with in disembedding figure tasks remain unknown.

Objectives:  The aim of the current study was to examine performance and visual search strategies of adolescents with and without ASD to provide insights in to the theories of WCC and EPF.

Methods:  An established experimental protocol was employed including a standardized assessment of visual perceptual skills, the Test of Visual Perceptual Skills 3^rd Edition to investigate disembedding performance of 27 adolescents with ASD and 30 matched peers.  The accuracy and time required to respond was measured. A remote eye tracker device was used to record the visual search strategies, i.e, number of fixations and duration of fixations of the participants.

Results: There were no differences in terms of accuracy in disembedding tasks among adolescents with and without ASD. However, adolescents with ASD were slower at completing the disembedding task. There were no differences in visual search strategies with the exception of an increased number of fixations and the duration of first fixations to the irrelevant white space.

Conclusions:  These results provide limited evidence for the notion of a local preference in ASD and contradict the WCC and EPF theoretical viewpoints that a local preference contributes to superior performance in disembedding tasks.