Gray matter volume alteration is associated with insistence on sameness and cognitive flexibility in autistic youth

Abstract

Restricted and repetitive behaviors (RRBs) are hallmark characteristics of autism spectrum disorder (ASD). Previous studies suggest that insistence on sameness (IS) characterized as higher-order RRBs may be a promising subgrouping variable for ASD. Cognitive inflexibility may underpin IS behaviors. However, the neuroanatomical correlates of IS and associated cognitive functions remain unclear. We analyzed data from 140 autistic youth and 124 typically developing (TD) youth (mean age = 15.8 years). Autistic youth were stratified by mediansplit based on three current IS items in the autism diagnostic interview-revised into two groups (high, HIS, n = 70, and low, LIS, n = 70). Differences in cognitive flexibility were assessed by the Cambridge neuropsychological test automated battery (CANTAB). T1-weighted brain structural images were analyzed using voxel-based morphometry (VBM) to identify differences in gray matter (GM) volume among the three groups. GM volume of regions showing group differences was then correlated with cognitive flexibility. The HIS group showed decreased GM volumes in the left supramarginal gyrus compared to the LIS group and increased GM volumes in the vermis VIII and left cerebellar lobule VIII compared to TD individuals. We did not find significant correlations between regional GM volumes and extra-dimensional shift errors. IS may be a unique RRB component and a potentially valuable stratifier of ASD. However, the neurocognitive underpinnings require further clarification. Lay SummaryThe present study found parietal, temporal and cerebellar gray matter volume alterations in autistic youth with greater insistence on sameness. The findings suggest that insistence on sameness may be a useful feature to parse the heterogeneity of the autism spectrum yet further research investigating the underlying neurocognitive mechanism is warranted.

Towards Understanding Autism Heterogeneity: Identifying Clinical Subgroups and Neuroanatomical Deviations

“…While cerebellar differences in neuroanatomy have previously yielded inconsistent results in autism (Laidi et al, 2022) and associations with social functioning (Elandaloussi et al, 2023), a large body of research also points to the involvement of cerebellar neuroanatomy and neurocircuitry in the etiology of RRBs in autism (Tian et al, 2022). In line with our findings, autistic individuals with high RRBs were found to have increased GM volume in the vermis VIII and left cerebellar lobule VIII (Seng et al, 2022) and children with complex motor stereotypies have been shown to have increased GM volume in the anterior vermis (Dean et al, 2022). Such structural studies are corroborated by functional work showing for example atypical cerebellar-cortical connectivity being related to elevated RRBs in autistic individuals (Lidstone et al, 2021).…”

Unravelling Neurodevelopment: A Comprehensive Neuroimaging Exploration of Paediatric Disorders in a Tertiary Care Setting

“…The alterations in grey matter volumes in ASD and ID are in line with Seng et al research, emphasizing the relevance of these structural changes to the clinical manifestations of the disorders. [9] The nuanced pattern observed in white matter volumes further refines our understanding, suggesting potential unique characteristics within each diagnostic group.…”

Ventral temporal and posteromedial sulcal morphology in autism spectrum disorder

“…Understanding neuroanatomical features contributing to neurodevelopmental disorders is a major goal in cognitive and clinical neuroscience. Previous studies have identified cortical morphological differences between individuals with Autism Spectrum Disorder (ASD) and neurotypical controls (NTs), such as cortical thickness (Bethlehem et al, 2020; Hardan, Muddasani, Vemulapalli, Keshavan, & Minshew, 2006; Khundrakpam, Lewis, Kostopoulos, Carbonell, & Evans, 2017; Nunes et al, 2020; Smith et al, 2016; Yang, Beam, Pelphrey, Abdullahi, & Jou, 2016; Zielinski et al, 2014) and gray matter volume (Guo et al, 2021; Hazlett, Poe, Gerig, Smith, & Piven, 2006; Prigge et al, 2021; Sato et al, 2017; Seng, Lai, Goh, Tseng, & Gau, 2022; Yamasaki et al, 2010). Yet, very few have considered tertiary sulci, which emerge last in gestation and show a protracted development after birth (Armstrong, Schleicher, Omran, Curtis, & Zilles, 1995; Chi, Dooling, & Gilles, 1977; Petrides, 2019; Weiner, 2019; Welker, 1990).…”