Brain-to-Brain Communication in Autism

Background: Given the relationship between mu modulation and MNS activity, recent literature has started to provide results concerning mu modulation during observation compared to execution of action in ASD, and their link with social impairments. Results however remain controversial, due to the lack of a truly interactive design testing online the hypothesis of differential involvement of mu according to the nature of the stimuli observed, self-related versus other-related stimuli.

Objectives: In search of brain markers of social interaction, we have designed an innovative EEG hyperscanning platform associated to a live imitation paradigm. This design allows recording simultaneously the brain activities of pairs of subjects while they interact online through hand gestures. In a previous paper reporting the results of 18 subjects paired as 9 dyads, we have shown for the first time that an interbrain synchronizing network emerges in the alpha mu band between the right centroparietal regions when two subjects freely synchronize their gestures. So doing, we have extended to an inter-individual level the classical intra-individual comparison between brain activity during observation and execution of action.

Methods: Our design appears to allow such a test in a social context, stating that when individuals with ASD perceive be synchronously imitated, they would modulate their mu and generate an inter-individual brain synchronization while they would not during the observation of another’s own gesture. We have compared the behavioural and brain data of 40 volunteer subjects recorded as 10 pairs composed of a HF young adult diagnosed with ASD meeting a neurotypical young adult of the same gender, and 10 pairs of young neurotypical adults. Three tasks were presented (an observation task, an imitation of a pre- recorded video and a free imitation leading to behavioural synchrony) to explore how the alpha mu band responds to the design in High Functioning individuals with ASD and which are the conditions for the emergence of a synchronizing inter-brain network. A frame-by-frame video analysis of the behavioural parameters allowed delineating the episodes of synchrony, imitation and be imitated for further brain analyses.

Results: Interbrain computation of oscillatory phenomena used cortical source reconstruction and coherence analysis. The presentation will focus on mu data during observation and free imitation tasks in the two kinds of dyads.

Conclusions: Discussion will include intra- and inter-individual levels.