Brain idiosyncrasy during biological-motion perception is amplified in autistic individuals with intellectual impairment
Journal
Journal of Neurodevelopmental Disorders
Journal Volume
18
Journal Issue
1
ISSN
1866-1955
Date Issued
2026-03-25
Author(s)
Cheng, Michael
Hawco, Colin
Yang, Daniel
Ni, Hsing-Chang
Yeh, Chun-Hung
Chang, Jung-Chi
Tu, En-Nien
Hsu, Mei-Yun
Wu, Yu-Yu
Gau, Susan Shur-Fen
Lin, Hsiang-Yuan
Abstract
Background: Neuroimaging research in autism spectrum condition (ASC) often overlooks brain idiosyncrasy by focusing on group averages and frequently excludes individuals with co-occurring intellectual impairment (II). Methods: We investigated functional MRI correlates of passive biological motion (BM) perception, comparing typically developing controls (TDC; n = 33), autistic individuals without II (intellectually able; ASC-IA; n = 28), and autistic individuals with II (ASC-II; n = 19; defined by IQ or adaptive function < 85). Results: While standard group-average analyses revealed the expected BM-sensitive regions (e.g., bilateral posterior superior temporal sulci, cuneus) in the TDC and ASC-IA groups, the ASC-II group showed no consistent group-level activation pattern and exhibited greater activation in the right intraparietal sulcus compared to the ASC-IA group. Using a correlational distance-based metric, we quantified brain idiosyncrasy (“whole-sample brain variability”, VariabilityWhole), representing the deviance of an individual's activation pattern from others. Brain activity in the ASC-II group was significantly more idiosyncratic than the ASC-IA and TDC groups. Furthermore, VariabilityWhole showed significant transdiagnostic correlations with multiple cognitive and behavioural domains relevant to autism, including social difficulties, repetitive behaviours, non-verbal IQ, executive function, sensory hyper/hyposensitivity, ADHD symptoms, and adaptive function. Conclusions: Key limitations include the cross-sectional design and the use of a passive viewing task without a concurrent behavioral measure to directly link brain findings to task performance. These findings highlight substantial brain heterogeneity within the autism spectrum, particularly in the understudied ASC-II subgroup, and suggest that individual differences in brain processing patterns, rather than solely group-average differences, are critically linked to clinical and cognitive phenotypes.
Subjects
Autism spectrum condition
Biological motion
Brain idiosyncrasy
FMRI
Heterogeneity
Intellectual impairment
Social cognition
Publisher
Springer Science and Business Media LLC
Type
journal article