Vol 51, No 6 (2025)

We present the results of inter-brain synchronization analysis among the audience during a fairy-tale theater performance. The study examines synchronization between participants without external stimulus synchronization (i.e., without evoked potentials). The EEG (electroencephalography) data was synchronized via specialized technical signals that didn’t attract the attention of the participants and were used solely to ensure precise temporal alignment of EEG fragments across different stages of the performance. The obtained data were analyzed both individually and in pairs. Individual analysis assessed EEG spectral power during rest and before, during, and after the performance in Δ (1.5–4 Hz), θ (4–8 Hz), α₁ (8–10 Hz), α₂ (10–13 Hz), β₁ (13–18 Hz), and β₂ (18–30 Hz)-frequency bands. Pairwise analysis (21 pairs, where all participants were paired with each other) evaluated phase locking value (PLV) and circular correlation coefficient (CCorr). No differences in baseline spectral power (pre-vs. post-performance) were detected, suggesting an absence of viewers’ fatigue. However, a decrease of the EEG spectral power was observed in the α₁- and α₂-frequency bands, potentially connected with viewer engagement, selective attention, and emotional immersion in the narrative. Inter-brain synchronization metrics (both PLV and CCorr) revealed increased synchronization in θ-, α₁- and α₂-bands over centro-parieto-occipital regions, coupled with reduced frontal region synchronization (relative to artificially generated data) pronounced during the second stage of the performance. This likely corresponds to the narrative’s culmination.

The experimental study is dedicated to testing the hypothesis of the stability of cognitive style indicators, namely “analytic” and “holistic”, under conditions of moderate exogenous normobaric hypoxia, which serves as a model of biological stress. The study involved 32 individuals (22 women and 10 men) aged 18 to 30 years without chronic diseases. Participants completed the Analytic-Holistic (AH) questionnaire under normoxic and hypoxic conditions. The hypoxic phase was considered correctly completed if the questionnaire was filled out while blood saturation was in the range of 80–90% (on average 83–84%) during the administration of a gas mixture with a reduced oxygen concentration (FiO₂ = 0.11). Levels of trait (TA) and state anxiety (SA) were evaluated, along with cardiodynamic parameters before and after simulating a 10-minute period of breathing either normoxic or hypoxic gas mixtures (ReOxy device, AI Media S.A., Luxembourg). The interval between the normoxic and hypoxic phases averaged 30 days. Formation of the analyst and holist groups was performed retrospectively by dividing the sample according to the median distribution of the overall AH questionnaire scores obtained during the normoxic phase. Overall AH scores did not change when tested under hypoxic conditions relative to normoxic conditions. However, among the holists, there was a significant decrease in scores on the “focus of attention” subscale and a more pronounced increase in scores on the “causal attribution” subscale compared to analysts, reflecting some reduction in conscious attentional focus and an expansion of the subjective interpretation of individual events. A decrease in SA was noted in all groups of subjects in the post-hypoxic period without substantial dynamics in cardiommodynamic parameters. The analytic-holistic cognitive style is a fundamental characteristic of an individual and remains stable under conditions of moderate hypoxic stress. The changes observed in certain subscales among the holists are determined by the negative effect of hypoxia on the executive functions of the brain, and for clarification require further application of functional neuroimaging methods. The positive post-hypoxic dynamics of SA levels in both analysts and holists may be associated with the development of hormesis – a mechanism of adaptation caused by a post-stressor increase in parasympathetic nervous system tone, improved psychoemotional state, and mood.

Testing the maximum ability to maintain the balance of an upright body is in demand both in the physiology of posture regulation and, especially, in the diagnosis of athletic abilities. However, there is currently no technology for estimating maximum balance ability (MBA). The aim of the work was to develop and approbate a test for assessing MBA using eleven see-saws of decreasing radius of curvature movable in the sagittal plane in athletes of both sexes. Additional tasks were: 1) to compare the discriminating ability of the monopedal and bipedal test for MBA, 2) to evaluate the relationship of the MBA indicator with the area of fluctuations of the common center of pressure (ELS), determined on a stabiloplatform and simple see-saws, 3) to identify gender differences in MBA. To evaluate the MBA, a test has been developed with a stepwise increase in the difficulty of maintaining postural balance by the gradual reducing the curvature radius of see-saws. The MBA corresponded to the minimum radius of curvature of the see-saw, on which the subject could maintain balance for 15 seconds. In all the tasks of the test, the ellipse area of the center of pressure oscillations (ELS) was determined using a stabiloplatform (Stabilan 01-2). The application of the developed test on a sample of athletes (n = 78) showed that the discrimination index of the monopedal test was excellent (DI = 0.82) and significantly higher than the bipedal test (DI = 0.052). The MBA indicator in the bipedal test did not correlate with ELS in simple standing conditions, however, such weak and moderate correlations (r = -(0.27–0.48)) were established in the monopedal test. This indicates a weak predictive power of the stabilographic indicators defined in the usual stances. In both tests, the MBA indicator positively correlated with the maximum ellipse area of the center of pressure oscillations (ELSmax), showing the informative value of this indicator. The girls did not differ from the boys in MBA, but showed reduced ELS in stances on simple see-saws. To assess the maximum ability to balance, as well as the postural stability in submaximal conditions, a monopedal test with stepwise increasing complexity on movable see-saws can be used. Stablographic indicators obtained during usual quiet stances poorly predict MBA. The following indicators are the most informative about the MBA: the minimum radius of curvature of the see-saw and ELSmax, achieved in extremely difficult balance conditions. Gender differences do not affect MBA, but the postural stability on simple see-saws is higher for girls than for boys.

The article presents the results of a long-term study, the purpose of which was a comparative assessment of the impact of long-term exposure to weightlessness on indicators characterizing the functional state of the human musculoskeletal system. The study involved 18 cosmonauts (M ± SD: 44.1 ± 5.3 years, 81.6 ± 7.5 kg, 179.8 ± 5.1 cm) who had completed long-term space flights on the ISS lasting 178 ± 16 days (M ± SD). The functional state of the musculoskeletal system before and after space flights was assessed based on biomechanical characteristics of walking at a pace of 90 steps/minute: kinematic, electromyographic, and spatiotemporal. The article presents the results of the analysis of biomechanical characteristics of walking before and after space flights of the combined group of cosmonauts (n = 18). For the first time, an assessment was made of the dynamics of restoration of biomechanical characteristics of walking in the post-flight period of three groups of cosmonauts, distributed depending on the volume and intensity of physical training on a treadmill during long-term space flights. The results of the study revealed significant changes in the state of the musculoskeletal system as a result of being in conditions of weightlessness. During walking at a pace of 90 steps/minute in the post-flight period, the kinematic (joint angles, body tilt angle), electromyographic (EMG cost of muscle work) and spatiotemporal (length and duration of a double step) walking parameters changed. The key factor that determines the indicated changes in locomotion in the post-flight period is the reduction and elimination of the required level of support loads during the space flights. Analysis of the dynamics of recovery of some biomechanical characteristics of locomotion (EMG-cost of calf muscle work, double step length) depending on the volume and intensity of physical training during the space flights showed that prevention of negative consequences of the influence of weightlessness depends on rational use of physical training. The optimal combination of volume and intensity of training loads, as well as adherence to the principles of intervals and cyclicity are key factors in the positive dynamics of the recovery of walking characteristics after the return of cosmonauts to Earth.

A sample of 17 patients with resistant arterial hypertension combined with obstructive coronary atherosclerosis who had indications for coronary bypass surgery was examined. As part of a laboratory and instrumental examination, the patients underwent 24-hour blood pressure monitoring in a hospital setting. The reaction of isolated myocardial trabeculae isolated from intraoperative biopsies taken during coronary bypass surgery to the action of β-adrenergic receptor agonists (β-AR) was studied. The association of 24-hour blood pressure monitoring with the severity of the overall inotropic response of myocardial trabeculae to β-AR stimulation was assessed. It was shown that isolated myocardial trabeculae of patients with average daily systolic blood pressure < 130 mmHg had a statistically more pronounced (p = 0.03) overall inotropic response to β-AR stimulation than those of patients with average daily systolic blood pressure > 130 mmHg. The severity of the overall inotropic response of the trabeculae to β-AR stimulation has an inverse correlation with systolic and diastolic pressure. Significant correlations (p < 0.05) were found in the average daily, average nightly, and average daily formats of blood pressure assessment. It is suggested that the observed lack of difference between the daytime and nighttime periods is due to a more pronounced state of hyperexcitation of the autonomic nervous system in patients with resistant hypertension combined with obstructive coronary atherosclerosis.

The purpose of this work was to determine the effect of the level of nitric oxide in the blood on the function of external respiration and blood pressure in professional cross-country skiers during the performance of the test “until exhaustion”. The observation group included professional cross-country skiers (n = 59) who were current members of the national team of the Komi Republic (62°N) with normotensive (n = 27, group N) and hypertensive (n = 32, group H) reactions to the bicycle ergometric test “until exhaustion”. At rest, while at their anaerobic threshold level, during peak load, and during the recovery period (5th min) were determined the level of stable nitric oxide metabolites and cardiorespiratory parameters. In group N cross-country skiers, during the “until exhaustion” test and at the 5th minute of the recovery period, NO₃ is primarily involved in regulating the function of external respiration and arterial pressure. The development of hypertensive reactions to exercise in group H athletes and their lower physical performance are due to NO₃ deficiency. It has been shown for the first time that under the influence of physical exercise, the respiratory system in group N is more strained, while in group H, the cardiovascular system is more strained.

Urination is a complex physiological process of multilevel regulation, which determines both individual typological features in healthy young people and polypotent symptoms in its disorders, requiring a detailed analysis of the intersystem relationships in the implementation of the accumulative evacuation function of the bladder. Based on the results of current preventive examinations and recommendations of the American Society for Urinary Retention – ISC, three groups of young men were identified – with normal (n = 183), borderline (n = 52) and increased (n = 53) urination rhythm (Message 1). In the continuation of the conducted studies, the state of general and regional hemodynamics was additionally assessed at rest. To assess heart rate variability, a daily computer cardiointervalography (Inkart, Russia) was performed with a comparison of the indicators of the accumulative evacuation function of the MP in various phases – accumulation and retention of urine (NiUM), urge to urinate and during injection. It was found that with a rapid urination rhythm, higher cardiac output and blood pressure remain, but are accompanied by a decrease in blood flow in the detrusor and an increase in vascular resistance. HRV parameters in this group were shifted towards sympathicotonia (increased LF and VLF, decreased HF), whereas vagal influence prevailed in normal rhythm. In addition, individual typological features of the ratio of indicators of general hemodynamics and microcirculation in the detrusor were established. Such a complementary approach in studying the indicators of systemic and regional blood circulation, heart rate variability with an assessment of the cumulative evacuation function of the bladder will make it possible to establish additional mechanisms of intersystemic relationships, determine the normative boundaries of urination parameters necessary in the development of additional criteria for prenosological diagnosis and a deeper assessment of disorders of the lower urinary tract.

The aim of this article is to summarize current knowledge on the physiological basis of neurovascular coupling, highlight key aspects of its disruption in stroke, and consider the potential of integrating functional magnetic resonance imaging and arterial spin labeling methods for assessing these processes. The article describes in detail the mechanism of neurovascular coupling under normal conditions, as well as the impact of stroke on neurovascular uncoupling in the lesion site and in intact brain regions. Special attention is given to the use of functional MRI and arterial spin labeling as tools for evaluating perfusion changes and neuronal activity. Recent studies are reviewed to illustrate their application in clinical and research contexts, with an assessment of the strengths and limitations of these techniques in characterizing neurovascular coupling. The prospects of integrating these approaches for comprehensive assessment and monitoring of neurovascular coupling, and for the development of therapeutic strategies aimed at restoring neurovascular interactions in stroke patients, are discussed. This article provides a scientific basis for further studies in functional, quantitative, and noninvasive neuroimaging with a focus on evaluating neurovascular impairments.