Changes in the Interaction Between Brain Structures and Elements of the Autonomic Control of Blood Circulation During the Solution of Cognitive Tasks

The development of a new biomarker for diagnosing the psychophysiological state of a person based on the control of the characteristics of the interaction between brain structures and elements of the autonomous control of blood circulation is an important and open issue. For 30 healthy young men, we performed synchronous recording of electroencephalogram (EEG) and photoplethysmogram (PPG) signals during rest and episodic stress, implemented using Stroop color word test and mental arithmetic test. During episodic stress, a statistically significant $(\text{p}\lt 0.05)$ increase in the power of low-frequency (LF) oscillations (0.04-0.14 Hz) and a decrease in the power of high-frequency (HF) oscillations (0.14-0.40 Hz) of the EEG derivation signals of the left and right hemispheres were revealed; drop in coherence between EEG oscillations of the left and right hemispheres in the LF frequency range; an increase in coherence between the EEG oscillations of the left and right hemispheres and the PPG signal in the LF frequency range. The performance of the calculated characteristics for the classification of stress and rest situations is shown.