Unique deficit in embodied simulation in autism: An fMRI study comparing autism and developmental coordination disorder

Hum Brain Mapp. 2021 Apr 1;42(5):1532-1546. doi: 10.1002/hbm.25312. Epub 2020 Dec 15.

Abstract

A deficit in pre-cognitively mirroring other people's actions and experiences may be related to the social impairments observed in autism spectrum disorder (ASD). However, it is unclear whether such embodied simulation deficits are unique to ASD or instead are related to motor impairment, which is commonly comorbid with ASD. Here we aim to disentangle how, neurologically, motor impairments contribute to simulation deficits and identify unique neural signatures of ASD. We compare children with ASD (N = 30) to children with Developmental Coordination Disorder (DCD; N = 23) as well as a typically developing group (N = 33) during fMRI tasks in which children observe, imitate, and mentalize about other people's actions. Results indicate a unique neural signature in ASD: during action observation, only the ASD group shows hypoactivity in a region important for simulation (inferior frontal gyrus, pars opercularis, IFGop). However, during a motor production task (imitation), the IFGop is hypoactive for both ASD and DCD groups. For all tasks, we find correlations across groups with motor ability, even after controlling for age, IQ, and social impairment. Conversely, across groups, mentalizing ability is correlated with activity in the dorsomedial prefrontal cortex when controlling for motor ability. These findings help identify the unique neurobiological basis of ASD for aspects of social processing. Furthermore, as no previous fMRI studies correlated brain activity with motor impairment in ASD, these findings help explain prior conflicting reports in these simulation networks.

Keywords: action imitation; dyspraxia; functional magnetic resonance imaging; mentalizing; mirror neuron system.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Autism Spectrum Disorder / diagnostic imaging
  • Autism Spectrum Disorder / physiopathology*
  • Brain Mapping*
  • Child
  • Female
  • Humans
  • Imitative Behavior / physiology*
  • Magnetic Resonance Imaging
  • Male
  • Mentalization / physiology*
  • Motor Activity / physiology*
  • Motor Skills Disorders / diagnostic imaging
  • Motor Skills Disorders / physiopathology*
  • Prefrontal Cortex / diagnostic imaging
  • Prefrontal Cortex / physiopathology*
  • Social Perception*