Differences in cortical activation patterns during action observation, action execution, and interpersonal synchrony between children with or without autism spectrum disorder (ASD): An fNIRS pilot study

Abstract

Engaging in socially embedded actions such as imitation and interpersonal synchrony facilitates relationships with peers and caregivers. Imitation and interpersonal synchrony impairments of children with Autism Spectrum Disorder (ASD) might contribute to their difficulties in connecting and learning from others. Previous fMRI studies investigated cortical activation in children with ASD during finger/hand movement imitation; however, we do not know whether these findings generalize to naturalistic face-to-face imitation/interpersonal synchrony tasks. Using functional near infrared spectroscopy (fNIRS), the current study assessed the cortical activation of children with and without ASD during a face-to-face interpersonal synchrony task. Fourteen children with ASD and 17 typically developing (TD) children completed three conditions: a) Watch-observed an adult clean up blocks; b) Do-cleaned up the blocks on their own; and c) Together-synchronized their block clean up actions to that of an adult. Children with ASD showed lower spatial and temporal synchrony accuracies but intact motor accuracy during the Together/interpersonal synchrony condition. In terms of cortical activation, children with ASD had hypoactivation in the middle and inferior frontal gyri (MIFG) as well as middle and superior temporal gyri (MSTG) while showing hyperactivation in the inferior parietal cortices/lobule (IPL) compared to the TD children. During the Together condition, the TD children showed bilaterally symmetrical activation whereas children with ASD showed more left-lateralized activation over MIFG and right-lateralized activation over MSTG. Additionally, using ADOS scores, in children with ASD greater social affect impairment was associated with lower activation in the left MIFG and more repetitive behavior impairment was associated with greater activation over bilateral MSTG. In children with ASD better communication performance on the VABS was associated with greater MIFG and/or MSTG activation. We identified objective neural biomarkers that could be utilized as outcome predictors or treatment response indicators in future intervention studies.

Fig 1

Experimental setup (A) and task sequence (B). Written permission for publication of participant pictures has been taken.

Fig 2

Probe placement (A, B) and spatial registration output (C, D). Written permission for publication of participant pictures has been taken.

Fig 3

Data processing workflow (A) Filter, wavelet and GLM of NIRS signal and (B) Trial-by-trial view and average view of Oxy Hb (HbO₂), Deoxy Hb (HHb), and Total Hb (HbT) profiles for a given channel. (W, D, T) from 5 secs. before to 24 secs. after start of stimulation. Data have been averaged across trials and participants.

Fig 4

A visual representation of averaged HbO₂ concentration during Watch, Do, and Together conditions in children with ASD (left) and TD children (right). HbO₂ values on Y-axis range from 0 indicated by blue to 0.09 indicated by red and shades in between.

Fig 5. Group differences in HbO₂ concentration during watch, do, and together conditions.

*indicates significant differences (i.e., p < 0.05 and survived for FDR correction) between the ASD and TD groups.

Fig 6. Conditional and hemispheric differences in HbO₂ concentration for TD children, and children with ASD.

* indicates conditional differences with p < 0.05 and surviving FDR corrections. ↔ and * indicate significant hemispheric differences with p < 0.05 and surviving FDR corrections.