Limitations and future direction
INS, DISORDERS
This study should be reviewed with these two limitations. First, healthy subjects, not patients, were included in this study, which made it hard to analyze the impact of patient–acupuncturist interaction on therapeutic effects. Therefore, this study chose the needling sensation which is the key to obtain acupuncture effect as an “indicator” of acupuncture effect. Secondly, only one acupuncturist was recruited in this study to ensure standardized acupuncture manipulation, while the experience of acupuncturists might affect the patient–acupuncturist interaction. Future study could consider enrolling patients with recurrent disorders as well as acupuncturists with different years of clinical experience to further explore the relationship between INS of patient–acupuncturist dyad and acupuncture effect and to detect the influence of acupuncturist's experience on the INS of patient–acupuncturist dyad.In summary, this study first applied fNIRS hyperscanning to investigate the neurobiological mechanism of “patient”–acupuncturist interaction during acupuncture stimuli in a naturalistic clinical setting. The results identified the increase of INS between “patient” and acupuncturist, and found that PFC was important to the interaction of “patient”–acupuncturist. This study deepen our understanding on the patient–acupuncturist interaction, and provided a novel experimental approach for future studies on acupuncture mechanism.