When our hearts beat together: Cardiac synchrony as an entry point to understand dyadic co-regulation in couples

The degree to which romantic partners’ autonomic responses are coordinated, represented by their pattern of physiological synchrony, seems to capture important aspects of the reciprocal influence and co-regulation between spouses. In this study, we analyzed cou-ple´s cardiac synchrony as measured by heart rate (HR) and heart rate variability (HRV). A sample of twenty-seven couples (N = 54) performed a structured interaction task in the lab where they discussed positive and negative aspects of the relationship. During the interaction, their cardiac measures (HR and HRV) were recorded using the Biopac Sys-tem. Additional assessment, prior to the lab interaction task, included self-report measures of empathy (Interpersonal Reactivity Index and Interpersonal Reactivity Index for Couples) and relationship satisfaction (Revised Dyadic Adjustment Scale). Synchrony computation was based on the windowed cross-correlation of both partner´s HR and HRV time series. In order to control for random synchrony, surrogate controls were cre-ated using segment-wise shuffling. Our results confirmed the presence of cardiac syn-chrony during the couple´s interaction when compared to surrogate testing. Specifically, we found evidence for negative (anti-phase) synchrony of couple´s HRV and positive (in-phase) synchrony of HR. Further, both HRV and HR synchronies were associated with several dimensions of self-report data. This study suggests that cardiac synchrony, partic-ularly the direction of the co-variation in the partners´ physiological time series, may have an important relational meaning in the context of marital interactions