Том 43, № 6 (2017)

We studied the effects of the acoustic context on active and passive discrimination of moving sound signals. Different contexts were created by reversing the role of standard and deviant stimuli in the oddball blocks, while their acoustical features were kept the same. Three types of sounds were used as standard or deviant stimuli in different blocks: stationary midline noises and two (smooth and abrupt) moving sounds moving to the left or right of the midline. Auditory event-related potentials (ERPs) were recorded during passive listening (the sound stimulation ignored), and mismatch negativity potentials (MMNs) were obtained. Active discrimination of sound movements was measured by the hit rate (percent correct responses) and false alarm rate, as well as the reaction time. The influence of the stimulus context on active and passive discrimination of the moving sound stimuli was reflected in the phenomenon known as the effect of deviance direction. The hit rate and MMN amplitude were higher when the deviant moved faster than the standard. The MMN amplitude was more responsive to the velocity of sound stimuli than the hit rate and false alarm rate. The psychophysical measurements in the reversed contexts suggest that smooth and abrupt sound movements may belong to the same perceptual category (moving sounds), while the stationary stimuli form another perceptual category.

The paper describes the results of studies aimed at evaluating the effect of interactive virtual environments on the visual system, including the magno-and parvo-systems. Analysis was conducted in patients diagnosed with paranoid schizophrenia diagnosed from one to five years ago. Comparative analysis of visual evoked potentials during the perception of images that differed in their semantic (animate/inanimate) and physical characteristics (filtration images at high/low spatial frequencies) was used for the assessment of the impact of virtual environments. The images of objects were filtered via digital filtration for selective effect on the magno-and parvo-channels of the visual system. To evaluate the function of visual perception, the measurement of contrast sensitivity using Gabor elements was used. At the early stages of schizophrenia, the patients exhibited a decrease in the amplitudes of the components of cognitive visual evoked potentials to stimuli filtered at high spatial frequencies and reduced contrast sensitivity at high spatial frequencies. The effect of virtual environments on the visual system resulted in a significant increase in the amplitude of the cognitive components of visual evoked potentials in the paradigm of presentation of images filtered at the high spatial frequencies, which allows the conclusion about a stimulating effect of the virtual environment on the parvo-system functioning. The activation of the magno-system occurred to a lesser extent. The present study represents the findings obtained by the studies of cognitive impairments in schizophrenia and the methods of their correction conducted at the Laboratory of Physiology of Vision of the Pavlov Institute of Physiology of the Russian Academy of Sciences and at the Laboratory of Neurobiology of Action Programming of the Bechtereva Institute of the Human Brain of the Russian Academy of Sciences.

The purpose of this study was to analyze sex-related differences in spontaneous and evoked brain activity. The study included 11 women and 10 men aged between 18 and 27 years; the subjects were adapted to the conditions of electrophysiological experiment. Differences in spontaneous activity were estimated by EEG spectral characteristics in frequency ranges corresponding to θ, α, β₁, β₂, γ₁, and γ₂ rhythms at rest with the eyes open and closed. The differences in evoked activity were estimated by the parameters of evoked potentials (EP) recorded upon the presentation of different types of stimuli (images and words) and categories (“fruits” and “vessels”). Behavioral differences were estimated by the efficiency of stimuli recognition. No gender differences were observed in the efficiency of stimuli recognition (number of errors, time of reaction). In the EEG of male subjects at rest, fast frequencies (β and γ) were less marked than in the female subjects, which may indicate a higher level of activation of CNS structures in women. Regardless of stimuli type and category, the amplitude of EP components in men is lower than that in women, which may be caused by lower level of CNS activation. However, the difference in the latency of EP components depended on the type of stimuli used. During the recognition of visual images, the latency of earlier EP components (N1, P2) in men was longer mostly on back and/or right electrodes. The latencies of the later EP components (P3, N3) in male subjects were longer on the back electrodes and shorter on the front electrodes than those in female ones. During the recognition of words, the latency of P1, N1, P2 and N2 components in men were shorter on temporal and temporoparietal electrodes of the left hemisphere. This may indicate that visual image in men are perceived slower but comprehended faster than in women. On the other hand, verbal stimuli in men were perceived faster but comprehended slower than in women.

The correlations between acoustic characteristics and lung function parameters measured by body plethysmography were revealed when analyzing the sample of 230 subjects consisting of subgroups of healthy subjects, subjects with risk factors, and patients with obstructive lung diseases. Multidirectional character of the correlations between acoustic characteristics of forced expiratory tracheal sounds and parameters measured by body plethysmography/spirometry was established in subgroups of healthy subjects, asthma patients with spirometrically confirmed and unconfirmed obstructive changes, and patients with chronic pulmonary disease.

The objective of this study is to identify markers of the addictive condition developing in athletes during exercise deprivation by analyzing electroencephalograms (EEGs), electromyograms (EMGs), skin temperature measurements, sympathetic nervous system activity, levels of anxiety and depression (by psychological tests). A cohort of professional football players (N = 50) voluntarily participated in the study. The athletes were tested under two test conditions: during active training sessions and during exercise deprivation (for seven days). The analyzed results have shown that the functional state of athletes with exercise addiction (due to exercise deprivation), compared with athletes showing no addictive behavior, was characterized by lower brain bioelectric activity (a decrease in the α-rhythm amplitude and power), growth in the muscular tension, increased sympathetic activity, and elevated levels of anxiety and depression. We have concluded that an athlete’s functional state during exercise deprivation is an important predictor for exercise dependence. A prolonged exercise deprivation causes intense psychophysiological changes in the body of athletes inclined to exercise addiction. The obtained results may be useful for experts in the field of sports medicine, as well as for further studies in different types of addictions.

The paper shows the possibility of using the laser Doppler flowmetry method for the assessment of system of blood microcirculation in the lower limbs of patients with diabetes mellitus. A series of experimental studies involving 76 patients with diabetes mellitus and 46 healthy volunteers was carried out. The state of peripheral blood flow was assessed during the local heating tests with different temperature regimes. The wavelet analysis of LDF-grams was used to evaluate the adaptive changes of microcirculation during the temperature tests. The data show that the proposed methodology in the form of heating tests and the use of the wavelet transform in the analysis of LDF-grams allows the evaluation of adaptation processes in the microcirculatory bed during thermal tests and the detection of the preclinical stage of trophic disorders.

The effects of kisspeptin, an important regulator of reproductive function, and leptin, a classical metabolic hormone, on the formation of inducible regulatory T cells (iTreg) and T helper cells that produce interleukin 17 (Th17), as well as on the activity of indoleamine 2,3-dioxygenase (IDO) have been studied. Both hormones are actively produced by the placenta and involved in the formation of a new hormonal profile during pregnancy. It was found that kisspeptin at concentrations typical for trimesters I–III of pregnancy stimulates the formation of iTreg and simultaneously inhibit Th17 induction. Regardless of the used concentration, kisspeptin increases the secretion of interleukin-10 (IL-10) and reduces the production of IL-17A in CD4⁺ T lymphocytes in women. At the same time leptin at physiological concentrations typical for pregnancy has the opposite effect, inhibiting the formation of iTreg without affecting the production of IL-10 in cultures of CD4⁺T lymphocytes and simultaneous stimulating the induction of Th17 and production of IL-17A in CD4⁺T lymphocytes. At the concentration corresponding to trimesters II–III of pregnancy both hormones significantly enhance lipopolysaccharide-induced activity of IDO in monocytes.

A method to estimate activity of subcutaneous thermogenic structures was developed on the basis of dynamical infrared thermography. The gist is comparing the dynamics of skin temperature changes for different body sites on exposure to factors evoking metabolic responses. The method can be used for investigating the mechanisms of changes in body temperature in response to various disturbing factors and, in certain cases, can help to differentiate metabolic and vascular responses.

We analyzed published data on the serum level of 25-hydroxyvitamin D (25(OH)D in healthy subjects in Russia, Ukraine and Belarus (lat. 45°–65° N). The primary list included 158 publications. Reports with insufficient sample size and incomplete statistical descriptions were excluded from the analysis. The review covers 41 publications comprising 8569 individual assessments. The meta-analysis showed that the average levels of 25(OH)D were the highest among children under the age of 5 years, varied slightly between the age of 6 and 60 years, and decreased in older adults (60+). Gender differences become apparent at the postpuberty stage. The level of 25(OH)D was higher in men. No correlation between the level of 25(OH)D and latitude was found, but the relationship with the season and the duration of daylight was significant. No differences were revealed between ethnic and social groups.