Evaluating the effectiveness of responding joint attention intervention on the level of brain synchronization using fNIRS hyper-scanning among Chinese ASD children

Abstract

Background: Joint Attention (JA), especially Responding to Joint Attention (RJA), is a prerequisite skill for the future acquisition of the essential abilities such as language and social processing skills. JA impairment is established to be one of the core symptoms of Autism Spectrum Disorders (ASD). JA Intervention based on the Discrete Trial Training (DTT) has delivered promising outcomes in terms of the behavioral measurements. Nonetheless, none of the previous work to date has examined the therapeutic effects of JA Intervention from a neurophysiological perspective, which is therefore the focus of the present study. Purpose: The aim is to offer a more comprehensive evaluation of the effect of JA intervention on the ASD children, by shedding light on the neural brain-to-brain synchronization of 10 clusters (10 x 10 clusters) between the experimenters and the children: both right and left side of DLPFC, IFG, TPJ, STS, temporal lobe. Participants and setting: Children diagnosed with ASD (n=26), who were selected by purposive sampling, took part. They were randomly assigned into the experimental condition (n=12) or the control condition (n=14). Those who were allocated to the experimental condition (n=12) received the JA intervention. Before and after the JA intervention, the RJA assessment would be carried out, during which the fNIRS neuroimaging would be acquired. Results: A two-way group (groups: experimental, control) x time (pre/post-test) repeated-measures (Z5, Z10,Z15) between-subjects multivariate analysis of variance (MANOVA) was performed for each inter-brain pair of the 10 clusters, consisting of bilateral sides of DLPFC, IFG, TPJ, STS, temporal lobe. The neural coupling is presented in the format: Adults’ Regions of Interest (ROI) x Children’s Regions of Interest (ROI). Interaction effect of the group and time has been established with medium effect sizes for a pair of inter-brain synchronization: Adults’ Cluster 8 (right TPJ) x Children’s Cluster 1 (left DLPFC). Thus, this elucidated that the effect of the intervention was efficacious for increasing the inter-brain coherence in the brain region affiliated with the RJA: Cluster 1 (left DLPFC). Conclusions: Our DTT JA intervention significantly increased a pair of inter-brain synchronization level: Cluster 8 (right TPJ) x Cluster 1 (left DLPFC). Thus, our study revealed that the left DLPFC are implicated in the RJA condition. Also, this underpinned the notion that the frontal-posterior coherence was initially impaired but improved as a result of the intervention. Given the role of left DLPFC in the social sensitivity, the increment in the neural coupling of children’s left DLPFC might infer that our RJA intervention was efficacious in increasing ASD children’s sensitivity to the social stimuli during the RJA. Importantly, incongruent with our hypothesis, it was found that the right TPJ was recruited in the IJA task whereas rTPJ were shown by other previous studies to be more involved in RJA, which thus need further research to confirm the function of the right TPJ. Future study would be benefit from incorporating both the behavioral and neural assessments.