Interpersonal neural synchronization in frontal-temporal regions as new neurophysiological index of interpretation quality: an fNIRS hyperscanning study

The evaluation of interpretation quality is fundamental to interpreting development. Previous interpretation evaluation studies focused solely on the interpretation itself, overlooking the interlocutors as recipients of the interpretation. We propose a novel approach by evaluating interpretation through mutual understanding between interlocutors. Using fNIRS hyperscanning, we examined neural activities of 20 interlocutor dyads communicating in Chinese-English context with interpreters. Results showed greater interpersonal neural synchronization (INS) in frontal-temporal regions during communication. Notably, INS in the left middle temporal gyrus (MTG) positively related to communication quality. Interpretation scores positively predicted INS in the left MTG, while mental load negatively predicted INS in the left inferior frontal gyrus, suggesting that INS in speech comprehension areas signifies interpretation quality at a semantic level. Moreover, the positive correlation between interpretation training time and INS in the left dorsolateral prefrontal cortex indicates that INS in mentalizing area reflects interpretation quality at a more advanced level.