UCLA

Introduction: Personality psychologists have made notable contributions to various clinical fields by incorporating an individual differences framework that is substantiated by neurobiological evidence. Recent autism research has employed this approach to explain the heterogeneity within the disorder; however, the neurobiological bases of personality in the ASD population remains unclear. In order to fully integrate this framework, it is necessary to investigate the neurological correlates of personality in autistic individuals and evaluate the extent it reflects findings in the normative population.Objectives: To identify resting-state functional connections associated with Extraversion and Neuroticism in autistic participants (ASD) in contrast to neurotypical peers (TYP). Method: The present study utilized secondary data from a longitudinal cognitive functioning study. After removing cases for excessive motion, 150 participants (ASD [n=73]: Mage=17.42, SDage=3.00; TYP [n=77]: Mage=16.92, SDage=3.10) had sufficient data for analyses. ROI-ROI connections associated with Extraversion or Neuroticism were identified in ASD and TYP independently, and the two groups were evaluated together to identify potential interaction effects between personality and ASD diagnosis. Results: In the ASD group, two connections (left parietal medial cortex – left retrosplenial cortex; left parietal medial cortex – right precuneus) were positively associated and one connection (left dorsal prefrontal cortex – right midcingulate cortex) was negatively associated with Neuroticism. The latter connection also presented differential associations with Neuroticism between ASD and TYP (p-FDR=.0250; TYP r=.207, ASD r=-.435). Exploratory analyses found that, in the ASD group, these connections were also associated with secondary measures of psychopathology, a relationship that was fully mediated by Neuroticism. Discussion: The identified connections were all related to functions of attention and memory, suggesting mechanisms linked to (over)sensitivity to negative stimuli and repetitive negative thinking. In particular, the left dorsal prefrontal cortex – right midcingulate cortex connection may be indicative of a compensatory mechanism biomarker in autistic individuals. This study serves as the first neuroimaging study in the emerging field of personality-related autism research, which aimed to tackle questions about the neural substrates of the endophenotypes of personality in the ASD population.