Inter-brain similarity and connectivity based on EEG hyperscanning during patient‒acupuncturist interactions

The study of patient‒clinician relationships is a vital branch of interpersonal interaction research. Acupuncture attaches great importance to positive patient‒clinician interactions; thus, it serves as a typical example of patient‒clinician interaction research. Based on electroencephalography (EEG) hyperscanning, this study explored inter-brain similarity based on spatial correlations between two brains as well as inter-brain connectivity of different regions through different frequency bands. Regarding inter-brain similarity, both acupuncture and sham acupuncture significantly decreased spatial correlation during certain sessions during acupuncture. Regarding inter-brain connectivity, acupuncture enhanced not only the connectivity of the beta frequency band in the right temporoparietal regions but also the connectivity of the fast-ripple frequency band in the right and left temporoparietal regions. These results suggest that inter-brain similarity should be emphasized in patient–clinician relationship research. Moreover, high-frequency oscillations (HFOs) potentially play an important role in inter-brain connectivity in addition to the classical EEG low-frequency bands.