Human heart rhythms synchronize while co-sleeping

Heenam Yoon, Sang Ho Choi, Sang Kyong Kim, Hyun Bin Kwon, Seong Min Oh, Jae Won Choi, Yu Jin Lee, Do Un Jeong, Kwang Suk Park

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Human physiological systems have a major role in maintenance of internal stability. Previous studies have found that these systems are regulated by various types of interactions associated with physiological homeostasis. However, whether there is any interaction between these systems in different individuals is not well-understood. The aim of this research was to determine whether or not there is any interaction between the physiological systems of independent individuals in an environment where they are connected with one another. We investigated the heart rhythms of co-sleeping individuals and found evidence that in co-sleepers, not only do independent heart rhythms appear in the same relative phase for prolonged periods, but also that their occurrence has a bidirectional causal relationship. Under controlled experimental conditions, this finding may be attributed to weak cardiac vibration delivered from one individual to the other via a mechanical bed connection. Our experimental approach could help in understanding how sharing behaviors or social relationships between individuals are associated with interactions of physiological systems.

Original languageEnglish
Article number190
JournalFrontiers in Physiology
Issue numberMAR
StatePublished - 1 Jan 2019



  • Causal relation
  • Co-sleeping
  • Heart rhythm
  • Non-linear dynamics
  • Phase synchronization

Cite this

Yoon, H., Choi, S. H., Kim, S. K., Kwon, H. B., Oh, S. M., Choi, J. W., Lee, Y. J., Jeong, D. U., & Park, K. S. (2019). Human heart rhythms synchronize while co-sleeping. Frontiers in Physiology, 10(MAR), [190].