Intersubject synchronization in the perception of a theatrical performance. Hyperscanning study

The study of neurophysiological characteristics in different types of interactions between two or more people has become possible relatively recently with the development of the “hyperscanning” methodology. This study aimed to evaluate how intersubjective EEG synchronization of bioelectric activity dynamically changes among spectators during a theatrical performance. Phase locking values (PLV) were calculated between all subjects in pairs (21 participants` pairs formed) in three time intervals of 5 minutes at the beginning, middle and near the end of the performance. Group-level statistical comparison of intersubject synchronization in real participant pairs was performed against data obtained from epoch permutations in each pair (1000 permutations). Intersubject synchronization measured by PLV increased in theta, alpha1, 2 frequency bands between parieto-occipital and central cortical areas and decreased between frontal and central areas (relative to randomly permuted data), predominantly during the second stage of viewing a performance, reflecting the involvement of the mirror neuron system in real-time action and emotion perception. Classification of EEG data at different stages of performance perception (by spectral power and time features) revealed high accuracy in classifying individual data (from 80 to 100% by SVM), but decreased accuracy in mixed samples.