Multimodal interpersonal synchrony: Systematic review and meta-analysis

This systematic review and meta-analysis examined the interplay among neural, physiological, and behavioral interpersonal synchrony. We included studies written in English, comprising human dyads, and reporting data that could be translated to correlation estimates between at least two modalities of synchrony, sourced from PsycINFO, PubMed, and Google Scholar. The initial meta-analysis, examining associations between neural and behavioral synchrony, assessed 37 samples with 1342 participants, revealed a significant medium effect size (r = 0.32, 95 %CI: [0.23, 0.41]) with higher correlations in studies measured frontocentral regions and used the same epoch size for synchrony calculations. The analysis on associations between physiological and behavioral synchrony included 13 samples (369 participants) and identified small effect size (r = 0.18, 95 %CI: [0.06, 0.30]). Due to the limited sample size of three studies involving 150 participants, we conducted a systematic review rather than a meta-analysis to examine the relationship between neural and physiological synchrony. This review revealed inconsistent results, underscoring the need for further research. Future inquiries address greater multimodal integration in certain brain regions and measures, such as frontal and central regions. A theoretical framework that will explain multimodal integration of synchrony will allow us to ascertain if it is a unique aspect of social experiences, or simply a description of synchrony across levels of organization.