[Spatial organization of biopotentials and decision-making time during purposeful mental activity in humans].

Features of spatial organization of neocortical potentials were studied in subjects with different decision-making time during performing the task of memorizing and subsequently reproducing, on a monitor screen, a sequence of signals. The subjects with a short decision-making time differed from those with a long decision-making time in a higher level of the intra- and interhemispheric coherence in alpha EEG frequency band different neocortical areas during reproduction of a signal sequence (coherence in the frontal, central and parietal areas; coherence between the right central and the left frontal, central, parietal, occipital and temporal areas; coherence between the left occipital and both the frontal areas).

[EEG correlates of individual differences in performance efficiency of students during examination stress].

Performance of cognitive tests and EEG spectral power were evaluated in 39 students aged from 19-21 years in two conditions: during common educational process and immediately before examination (stress condition). Before examination, the performance was better in subjects with low level of spectral density in the delta band (in the occipital, parietal, central and frontal cortical areas) and high level of the alpha-rhythm spectral density in all the cortical areas, A decrease in performance scores before examination was correlated with an increase in the delta activity (in the right frontal and temporal cortical areas) and rise of the anxiety level (tested by Spielberger).

[Evaluation of systemic activity of the brain by means of an artificial intelligence model]. / Otsenka sistemnoi deiatel'nosti mozga s pomoshch'iu modeli iskusstvennogo intellekta.

The model based on the systems representation of informational brain mechanisms reproduces the principal stages of intellectual activities: afferent synthesis, decision making, acceptor of results of actions. The imitation of behavior of subjects in the special experimental environment with the model allows quantitative estimation of parameters of systemic stages in normal subjects of different ages and subjects with different brain dysfunctions, such as arteriosclerosis, schizophrenia, etc.

[Autonomic tone and energy metabolism in students during productive learning activities]. / Vegetativnyi tonus i énergozatraty u studentov v protsesse rezul'tativnoi uchebnoi deiatel'nosti.

Energy expenditures, autonomic functions, the severity of autonomic dysfunctions and personality traits were examined in 41 male students aged 18 to 23 years during their routine daily learning activities and after taking an exam in normal physiology. According to the characteristics of the baseline autonomic tone, all the examinees were divided into 3 groups: 1) those with elevated sympathetic tone EST; 2) those with elevated parasympathetic tone (EPT) and 3) an intermediate group with normal tone (NT). The EPT students showed the lowest energy exchange during routine daily learning activities. Examination-induced stress causes an elevation of mainly aerobic process in EST and EPT students. Anaerobic process increase in NT students at examinations. The parameters of autonomic functions due to examination stress also vary in students with different autonomic control. The students with EPT and worst marks showed significant changes in the measured parameters while these changes were significantly lower in EST students, but the changes in autonomic functions were much more profound in EST students who got good marks.

[Energy metabolism in students depending on motivation during exams]. / Energoobmen u studentov vo vremia ékzamena v zavisimosti ot urovnia motivatsii.

The energy metabolism (EM) was shown to significantly depend upon the motivation level in students during examination. Energy expenditure increased before the examination in low- and medium motivation groups but not in highly motivated students.

[Relaxing effects of local heat-air exposure under stresses in students]. / Relaksiruiushchie éffekty lokal'nogo teplovozdushnogo vozdeistviia v usloviiakh stressovykh nagruzok u studentov.

The relaxing effects of local heat-air exposures (TAE) on man (60 male students aged 19-21 years) were studied using a specially designed device which may control temperatures and time on an individual basis depending on the examinees' sensation of a positive emotion. On study days and under examination stress. TAE was shown to reduce situation-induced anxiety, to increase the duration and variability of R-R intervals on ECG, to make EEG right-frontal delta- and theta-indices lower and EEG right occipital and frontal alpha-index higher. The range of visual accommodation increased. The findings suggest that the proposed graded local heat-air exposure procedure is an effective tool of relaxation and prevention of negative effects of emotional stress.

Chaos theory: the transforming role of functional systems.

The review of applications of chaos theory in physiology shows, that this theory makes possible to get quantitative measure of degree of the order for such processes as neuronal activity, heart rate, electroencephalogram etc. The basic concepts of chaos theory--fractal dimension. Liapunov exponents, entropy, some algorithms for obtaining of quantitative characteristics of degree of the order for different processes--have been considered in this paper. The main areas for application chaos theory in physiology and medicine have been revealed and some examples of practical and theoretical achievements in this new region of investigation are given, as well as existing limitations and problems with results interpretation. Entirely new possibilities for understanding of the order in physiological processes are shown when estimation is made from the point of view of the functional system theory.

[Information model of systemic organization of human mental functions: new approach to the problem of artificial intelligence]. / Informatsionnaia model' sistemnoi organizatsii psikhicheskikh funktsii cheloveka: novyi podkhod k probleme iskusstvennogo intellekta.

The information model of systemic functions of the human brain reproduces important features of human intelligence: goal planning, prediction of needed results, behavior correction by feedback from the parameters of the results obtained and their comparison with the acceptor of action results. Human behavior imitation in the model is statistically proved by testing the model on a computer. An Adaptron apparatus based on the model quantitatively estimates the parameters of an important mechanism of the brain, namely human intuitive learning. With the Adaptron, the ade-dependent properties and some human intellectual dysfunctions are estimated, which reflect the mechanisms of prediction of future results, the building of memory traces in intuitive learning when the findings coincide with the planned results and the restructure of memory and respective behavior changes when the findings do not coincide with the planned ones.

[Physiological evaluation of the resultant activity of school children working with computers]. / Fiziologicheskaia otsenka rezul'tativnoi deiatel'nosti shkol'nikov pri rabote na komp'iutere.

The schoolchildren who had achieved high results in computer learning tasks showed a regular nature of changes in autonomic parameters, which was in concordance with steps taken in goal-oriented activity. Those with low results displayed higher and disconcorded changes in autonomic parameters, which were interpreted as a predisposition to emotional stress when learning computer tasks. The high-result schoolchildren made fewer errors in reaction-time tasks and signal differential tasks and spent less time in decision-making. They also differed from low-result schoolchildren by showing a higher frequency of beta-rhythm ECCG from forehead derivations and prevalent alpha-rhythm and also a higher proportion of teta-rhythm in the spectra of the forehead, central and parietal derivations as well as a higher coherence of alpha-rhythm from the forehead and parietal derivations of the left hemisphere.

[The individual characteristics of the physiological support for the activities of schoolchildren while learning to work on a computer]. / Individual'nye osobennosti fiziologicheskogo obespecheniia deiatel'nosti shkol'nikov pri obuchenii rabote na komp'iutere.

The ECG was recorded by telemetry in schoolchildren when they learned computer tasks. Successfulness of learning was estimated. The EEG was recorded with the same psychophysiological parameters (simple and complex reaction times, search for orders of numbers in special tables and others) under the laboratory conditions. Neuroemotional stress (NES) during computer learning as measured by the heart rate parameters was shown to depend on the stable individual characteristics. NES was significantly higher in introverts than in extraverts (determined by Eysenck's questionnaire). The most prominent physiological signs of NES were revealed at the stages of computer task learning when mistakes in computer programs were searched for and corrected. The speed of learning of computer tasks was found to be proportional to a lability of autonomic heart rate regulation and to be correlated with such psychophysiological parameters as decision making time, the number of false preliminary reactions and others.