Exploring Dyadic Cardiovascular Synchronization in Response to High-Arousal Music

Interpersonal synchrony represents the ability of individuals to align temporally with others, fostering stronger social bonds and supporting emotional regulation. Previous research has shown that music can affect this process by shaping neural activity and enhancing group dynamics. However, the impact of different emotional contents within musical stimuli remains largely unexplored. In this pilot study, we aimed to examine how emotional classical music affects cardiovascular synchrony in dyads of unfamiliar participants. Twenty-four individuals were randomly paired and exposed to two high-arousal, two-minute musical stimuli: one positive, evoking joy, and the other negative, inducing tension. During the experiment, photoplethysmography (PPG) signals were recorded, and systolic-to-systolic time interval (SSI) series were extracted alongside time-varying frequency parameters, such as high-frequency (HF) power and the low-to-high (LF/HF) frequency power ratio. To quantify synchrony, we employed the Surrogate Synchrony (SUSY) method, a cross-correlation-based technique. Our results revealed a significant increase in SSI synchrony during the tension music compared to the resting state. Furthermore, synchrony in the LF/HF frequency series was notably higher during the tension piece than the joyful activation stimulus. These findings suggest that the neurophysiological processes associated with uncertainty and excitation - conveyed through music- can enhance the synchronizing effect on cardiovascular responses, highlighting the profound influence of emotional music on interpersonal synchrony.