Is It Easy to Synchronize Our Minds When We Are Forced to Cooperate?

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.

Multivariate model for cooperation: bridging social physiological compliance and hyperscanning

The neurophysiological analysis of cooperation has evolved over the past 20 years, moving towards the research of common patterns in neurophysiological signals of people interacting. Social physiological compliance (SPC) and hyperscanning represent two frameworks for the joint analysis of autonomic and brain signals, respectively. Each of the two approaches allows to know about a single layer of cooperation according to the nature of these signals: SPC provides information mainly related to emotions, and hyperscanning that related to cognitive aspects. In this work, after the analysis of the state of the art of SPC and hyperscanning, we explored the possibility to unify the two approaches creating a complete neurophysiological model for cooperation considering both affective and cognitive mechanisms We synchronously recorded electrodermal activity, cardiac and brain signals of 14 cooperative dyads. Time series from these signals were extracted, and multivariate Granger causality was computed. The results showed that only when subjects in a dyad cooperate there is a statistically significant causality between the multivariate variables representing each subject. Moreover, the entity of this statistical relationship correlates with the dyad’s performance. Finally, given the novelty of this approach and its exploratory nature, we provided its strengths and limitations.