Directional couplings between the respiration and parasympathetic control of the heart rate during the cognitive tasks

The work is devoted to the study of directional couplings between the processes of autonomous control of circulation estimated from the signals of respiration and the sequence of RR intervals during the controlled cognitive tasks. The stressors were called stroop color word test and mental arithmetic test. The experimental sample included 63 healthy men. We calculated the phase coherence coefficient and indices for directional couplings, modeling of phase dynamics. The analysis was carried out in the so-called high-frequency (0.14-0.50 Hz) range associated with the process of parasympathetic control of circulation. As a result, high values of the bidirectional couplings indices between the studied processes were revealed, which changed during the controlled cognitive tasks.