Previous neuroscience studies exploring the neural mechanisms of social deficits of individuals with autism spectrum disorder (ASD) have mainly examined single participants' brain responses to pictures or video-clips displayed on a monitor from the perspective of a passive observer. The present study examined inter-brain communication between children with ASD and their parents in a socio-interactive context. We used a functional near-infrared spectroscopy (fNIRS)-based hyperscanning technique to simultaneously measure the prefrontal activations in 16 pairs of children with ASD and their parents in a two-person key-press task. The children's task was to press a key together with their parents in a cooperation condition when a "go" signal was present or to press a key as fast as possible under the observation by their parents in a single-person condition. We also measured children's severity of autism symptoms.We found that children with ASD showed increased interpersonal neural synchronization in the frontal cortex when engaging in cooperative interactions with their parents than when performing solo and non-interactive behaviors. Furthermore, this neural synchronization was modulated by the children's autism symptoms, which also covaried with their cooperation task performance. That is, children with severer autism symptoms showed lower level of action and neural synchronization with their parents during cooperation. Our study moved a major step forward in understanding the neural correlates underlying social deficits in ASD and provided important implications for the treatment and behavioral training of ASD.
Keywords: Autism spectrum disorder; Hyperscanning; Interpersonal neural synchronization; Parent–child interaction; fNIRS.