Revealing the coupling directionality and synchronization between time series from physiological data by analysis of joint recurrences

Abstract

We applied methods for determining the recurrence based phase synchronization index and the coupling directionality based on conditional probabilities of recurrence to analyze the direction of coupling and synchronization of time series obtained from experimental data. The activity of brain neurons, fluctuations in arterial blood pressure, and the respiratory rhythm of anesthetized rats were used as experimental data. For the first time, variants of changing the direction of the coupling between the analyzed time series before and during pain exposure were revealed. The relationship of pain exposure with the adjustment of the frequency of the variability of neuron activity of the brain to the frequency of the variability of arterial blood pressure or with the adjustment of the frequency of the variability of blood pressure to the respiratory rhythm with the subsequent occurrence of phase synchronization has been established.