Change in the directional coupling between the heart beat and respiration during the Stroop test and mental arithmetic test

Purpose of the work is to study the influence of cognitive tasks on the interaction between the processes of autonomic regulation of the cardiovascular system and respiration. The low-frequency components (0.05-0.15 Hz) of the time intervals between heart contractions and photoplethysmogram signals were analyzed using a sensitive method for detecting directional coupling based on modeling the dynamics of instantaneous phases of oscillations. It was shown that the coupling coefficients in the frequency band of 0.05-0.15 Hz (associated mainly with the sympathetic regulation of blood circulation) decrease during the execution of the Stroop test and the mental arithmetic test. It has also been shown that the interaction of airflow signals and interbeat interval is reduced during the execution of a mental arithmetic test The results obtained allow us to better understand the features of the interaction of the elements of the autonomic regulation of blood circulation.