The asymmetry of coupling between complex systems can be studied by conditional probabilities of recurrence, which can be estimated by joint recurrence plots. This approach is applied for the first time on experimental data: time series of the human cardio-respiratory system in order to investigate the couplings between heart rate, mean arterial blood pressure, and respiration. We find that the respiratory system couples towards the heart rate and the heart rate towards the mean arterial blood pressure. However, our analysis could not detect a clear coupling direction between the mean arterial blood pressure and respiration.
@article{arxiv.1306.0697,
title = {Estimating coupling directions in the cardio-respiratory system using recurrence properties},
author = {Norbert Marwan and Yong Zou and Niels Wessel and Maik Riedl and Jürgen Kurths},
journal= {arXiv preprint arXiv:1306.0697},
year = {2013}
}