Morphological features of language regions in children with autism spectrum disorder and varying language abilities

-Previous studies have predominantly compared the brain morphological characteristics of individuals with autism spectrum disorder (ASD) to typically developing (TD) peers. However, language variability within ASD, particularly in preschoolers, remains understudied. Here, we investigated the morphological features of language-related regions and hemispheric asymmetry in children with ASD and varying language abilities compared to TD children.

We analyzed MRI data from a cohort of Chinese children with ASD (n = 68) and TD (n = 37) aged 1.5 to 6.5 years. The ASD group was classified into two subgroups based on language scores: ASD with moderate language deficits (ASD-MLD, n = 34) and ASD with severe language deficits (ASD-SLD, n = 34). We examined the asymmetry of morphological features in cortical language regions across the two ASD subgroups and TD children, explored between-group differences, and assessed brain-language correlations.

Significant hemispheric asymmetry in cortical volume and surface area was found across language regions in all three groups. Cortical thickness asymmetry was observed in certain regions of the ASD-MLD and TD groups. Both ASD subgroups exhibited enlarged gray matter volume within the frontal and temporal regions compared to the TD group. Additionally, significant associations between morphological features and language scores were present in the ASD-MLD and TD groups but absent in the ASD-SLD subgroup.

This study offers novel insights into the neuroanatomical basis of language deficits in children with ASD, highlighting structural brain differences associated with varying levels of language impairment.