DOI:10.6129/CJP.202203_64(1).0002
Chinese Journal of Psychology 2022, Vol.64, No.1, 33-56
Comparing Face and Object Discrimination in Neurotypical Adults and Adults with Autism: A Morphing Paradigm
En-Yun Hsiung（Graduate Institute of Biomedical Sciences, China Medical University；Department of Pharmacy, Chang Gung Memorial Hospital）；Sarina Hui-Lin Chien（Graduate Institute of Biomedical Sciences, China Medical University；Graduate Institute of Neural & Cognitive Sciences, China Medical University）；Chien-Hui Kao（Woolcock Institute of Medical Research, University of Sydney）；Shin-Lei Peng（Department of Biomedical Imaging and Radiological Science, China Medical University）
Abstract
Recognizing faces and objects are essential perceptual skills for human survival. Previous studies exploring face and object perception in individuals with autism spectrum disorder (ASD) reported inconclusive results. Some studies suggested that adults with ASD exhibited impaired face processing but spared object perception; in contrast, other studies showed unimpaired face processing and enhanced object perception, suggesting superior featural- based processing in ASD. However, most studies did not control the task difficulties of face and object discrimination. Hence, we adopted the morphing technique to control physical similarities among the stimuli with equated task difficulties. Using computerized morphing face/object discrimination tasks, we investigated whether adults with ASD are impaired in holistic processing or enhanced in featural processing. We also explored the correlations between individual Autism-spectrum Quotient (AQ) scores and their task performances. Twenty-four adults with ASD and 24 NT adults received the morphing face/object discrimination task, and their accuracies were measured. The results showed that: For the morphing face discrimination task, the mean accuracies were not significantly different between the two groups; however, the estimated discrimination threshold of the ASD group (33.12%) was significantly higher than the NT group (25.87%). For the morphing object discrimination task, both groups had the same mean accuracies and estimated discrimination thresholds (ASD: 21.67%; NT: 23.12%). Lastly, the trend analyses revealed a significant linear component in the ASD group for both face and object tasks, while the NT group showed linear as well as quadratic components. In sum, the present study demonstrated that, compared to neurotypical adults, adults with ASD exhibited a larger discrimination threshold for morphing face, indicating impaired holistic processing. Additionally, the linear trend suggests that adults with ASD compensatorily relied on featural-based processing when differentiating among morphing images of faces and objects.
Keywords: autism spectrum disorder, face perception, object perception, morphing paradigm
