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O M Razumnikova

Publications and source records attributed to O M Razumnikova.

At least 19 recordsLinked to original sources
PubMed2006

Frequency-spatial organization of brain electrical activity in creative verbal thought: the role of the gender factor.

Gender-related differences in the EEG correlates of creative thought were studied by mapping EEG power during performance of a Remote Associations Task as compared with verbal word-generation and simple association tasks. Right-handed students (18 male, 21 female) took part in the studies. Gender-related differences were seen in the factor structure of measures of verbal activity and in the larger number of words generated for a given letter in women than in men. In terms of the originality of the associations, men and women showed no significant difference, though the dynamics of the power of the beta-2 rhythm during creative thought differed. In males, the search for original associations was accompanied by increases in beta-2 power in both hemispheres at the initial stages of performing the task, with local increases in the beta-2 rhythm in the central parts of the cortex at the end of testing. In women, the increase in beta-2 power was initially greater in the right hemisphere than the left, while there was a relative decrease in beta activity in the parietal-temporal areas of the cortex and an increase in the left anterior frontal areas at the terminal stage of task performance. It is suggested that creative verbal thought is based mostly on an "insight" strategy in males, while women additionally use an "intellectual" strategy.

Adolescent↗
PubMed1999

Sex differences in EEG coherence during a verbal memory task in normal adults.

Coherence analysis was applied to the EEG of 15 female and 15 male subjects who had to memorise dichotically presented lists of concrete nouns. The EEG was recorded from 16 scalp electrodes placed in accordance with the 10/20 system. The results show significant gender-related differences in total coherence reactivity due to a greater increase of rest to task coherence in female than in male subjects. Women differed by showing higher coherence reactivity in the right hemisphere for all analysed (theta 1, theta 2, alpha 1, and alpha 2) frequency bands. They also had more extensive task-induced increases of interhemispheric coherence in theta bands in comparison with single changes in male subjects. In women these changes were mainly between the frontal electrodes of the left hemisphere paired with posterior electrodes of the other hemisphere. These findings indicate sex-related differences in functional cortical organisation during verbal memory tasks.

Adult↗
PubMed1989

[The hemodynamics of the lesser circulation and blood indices in rats under long-term high-altitude hypoxia].

Pulmonary hemodynamics in anesthetized rats was studied during long-term residence (2,5 and 10 months) at high altitude (3,200 m, Tien Shan). Transbronchial regional electroplethysmography and catheterization of pulmonary artery was used. It has been shown that at all periods of adaptation there was increased systolic pressure in pulmonary artery and practically unchanged diastolic one. Some regional redistributions of pulmonary blood flow and blood volume for five different lung parts were demonstrated. Hemoglobin content in erythrocytes was steadily increased while specific electric blood resistance, hematocrit, and number of erythrocytes did not change so significantly. The role of pulmonary arterial hypertension and changes of other studied indices of hemodynamics and red blood in adaptation to chronic high-altitude hypoxia are being discussed.

Adaptation, Physiological↗
PubMed1989

[The effect of high-altitude hypoxia on the lesser circulation in rats].

During ten-month stay at 3200 m altitude in the Tien Shan mountains a significant increase of systolic pressure and practically unchanged diastolic one in pulmonary artery were recorded in rats. A redistribution of the blood flow and volume occurred. An increased oxygen blood capacity was maintained through an elevated hemoglobin content in erythrocytes and an increase of their size but not of their number.

Altitude↗
PubMedDate not supplied

[Parameters of the spatial of organization of EEG in persons with various individual characteristics].

The relationships between some characteristics of EEG topographic maps and personality traits (extraversion-introversion, sensation-intuition, thinking-feeling, judging-impulsiveness) by the Keirsey's Type Inventory were studied in 46 17-20-year-old men). The most considerable distinctions in the spatial organization of the EEG were observed between the functions sensation and intuition. The high-sensation responders were characterized by higher EEG power in the theta 1, 2 and alpha 1-bands in all derivations and higher coherence (especially in the theta 1, 2 bands most expressed in the frontoparietal areas) as compared with the high-intuition responders. The expression of extraversion was positively correlated with coherence values in the theta 1, 2 and negatively correlated with coherence in the alpha 1, 2 bands. Characteristic EEG patterns for other types of personality traits were also described. The results suggest that some characteristics of brain maps reflect the individual psychological features determined on the basis of Jung's typology.

Adolescent↗
PubMedDate not supplied

[Dynamics of interhemispheric asymmetry during perception of verbal information in men and women: EEG analysis].

Neurophysiological basis of gender differences in the dynamics of asymmetry in retrieval of dychotically presented verbal information was studied by mapping of EEG power and coherence during a prolonged dychotical test. Right-handed students (20 men and 11 women) participated in the experiments. It was shown that gender differences in the EEG were absent at the initial stage of testing and appeared at the final stage. At this stage, the asymmetry of the theta 2 EEG power was lower in men than in women, while the interhemispheric coherence in the theta 2- and alpha 1-bands was more pronounced in women than in men, mainly, in the caudal cortical regions. Thus, different cortical electrophysiological processes underlie similar behavioral effects (the same values of asymmetry coefficients of retrieval of syllables at the final stage of dichotic testing) in men and women.

Adolescent↗
PubMedDate not supplied

[Differences in latent inhibition between men and women under conditions of nonverbal visually-spaatial masking].

In order to study gender differences in development of the latent inhibition (LI) and the influence of laterality (hemisphere) factor, two groups of subjects were examined. In the preexposure phase, subjects of the control group were presented with a pair of geometric figures, which appeared either in the right or in the left visual hemifield (at random) with the exposure time of 80 ms. A subject had to compare the figures in a pair and to press a button in case of their identity. In the preexposure (experimental) group, the subject solved the same task, but half of them was presented with the same set of stimuli which appeared in the right hemifield, another half of subjects received these stimuli in the left hemifield. Simultaneously with the target stimuli, the opposite hemifield was stimulated with a nonattended symbol "[symbol: see text]". In the test phase, all the subjects (both of the control and experimental groups) had to respond to the symbol "[symbol: see text]" (previously nonattended in the experimental group), which appeared in part of the trials, by pressing the button. Pairs of stimuli which had been target ones in the preexposure phase, became masking stimuli in the test phase. Correct responses were reinforced by presentation of a special sound. The number of trials required for acquisition of the instrumental contingency served as an index of the LI. Analysis of variance showed that significant strong effect of the LI was observed only in men (comparison between the control and preexposure groups), while there was no significant difference between women of the control and preexposure groups. There was no laterality effect. Gender differences and hemispheric asymmetry in the LI organization are discussed.

Adult↗
PubMedDate not supplied

[Lateral effects of emotional stimulation on verbal memory processes in men and women].

Effects of short-term changes in emotional state of men and women on hemispheric organization of verbal memory processes were studied in the model of emotional electrodermal stimulation. Retrieval of dichotically presented lists of words was analyzed. The lists of words included pairs of emotionally neutral word and pairs combined of a neutral and emotional or both emotional words. There were no gender differences in the immediate retrieval of the words. Electrodermal stimulation prior to presentation of list of word resulted in a lateralized reduction of the immediate report of neutral words presented to the right ear and of emotional words presented to the left ear. Gender-related differences were shown in the delayed retrieval. In women, the stimulation applied before word presentation induced a decrease in delayed retrieval of left-ear emotional words. In men, the stimulation applied after the word presentation improved the retrieval of word lists independently of the side of presentation. Mechanisms of gender-related differences in interhemispheric interaction in verbal memory processes are discussed.

Adult↗
PubMedDate not supplied

[Sex differences in EEG power changes in retention of dichotically and monaurally presented verbal stimuli].

EEG power mapping was used to study gender differences in hemispheric functional organization during memorizing dichotically and monaurally presented verbal information. Right-handed students (12 men and 14 women) participated in experiments. The EEG was recorded from 16 electrodes placed at homologous sites of the left and right brain hemispheres. Task-related changes in the thetal power in men differentiated between monaural presentations to different ears, i.e., situations of oppositely directed attention. In women the thetal power reactivity (the difference between the band power logarithms under baseline conditions and in task interval) differentiated between dichotic and monaural presentations of words, i.e., situations with different memory loads. Gender differences were also found in the alpha frequency band. Power changes in the alpha 1 band in all memory tasks and power changes in the alpha 2 were more evident in the right hemisphere in men but in the left hemisphere in women. In contrast, in the posterior temporal lead the alpha 2 power reactivity in men was higher in the right hemisphere, whereas in women the lateral differences were absent. As compared to men, the alpha 2 desynchronization in women was also more pronounced in posterior regions of both hemispheres. There were no gender differences in efficacy of memorizing. It is suggested that different processing strategies rather than different behavioral performance may be responsible for the revealed specific spatiotemporal EEG patterns.

Adult↗
PubMedDate not supplied

[Gender differences in resting EEG related to Eysenk's Personality Traits].

EEG mapping was used to study gender differences in hemispheric organization related to personality (40 male and 42 female subjects, the students 17-20 ages). The results showed, that each clearly defined personality trait (neuroticism, extraversion, psychoticizm and social conformity) characterized by special EEG pattern differenced on men and women groups. At the same time, more close interaction of gender and neuroticism was observed, but gender and extraversion were less connected. Neuroticism related patterns of coherence in the alpha2- and beta2-bands were associated with an activity changes in anterior cortex in men but posterior--in women, at that the positive correlations were observed in the beta2-band in the former case and negative ones in the second. There are two opposing tendencies of the interaction between extraversion and gender in a modulation of the resting theta-rhythm: an increase of cortex connections in men and decrease ones in women. The specificity of spatial-temporal EEG patterns in men associated mostly with a psychoticizm value but in women--with a social conformism. In either case these personality traits related to activity of frontal cortex in the left hemisphere.

Adolescent↗
PubMedDate not supplied

[Gender differences in EEG coherence during memorization of dichotically and monaurally presented verbal stimuli].

Gender differences in changes of coherence values in the theta and alpha frequency bands during encoding of dichotically and monaurally presented verbal information were studied. Right-handed students (14 male and 14 female subjects) participated in experiments. The EEG was recorded from 16 electrodes placed at homologous sites of the left and the right hemispheres. In male subjects, numerous differences in coherence values between conditions of dichotical and monaural word presentation were found in the theta2- and alpha1-bands, in females, the differences were most pronounced in the theta1- and theta2-frequency bands. Numerous differences in coherence values differentiated between dichotic and left-sided monaural presentations in males and between dichotic and right-sided monaural presentations in females. As compared to dichotic presentation, in condition of the monaural presentation, higher coherence values were observed in men and lower in women. The features of gender differences in frequency-spatial patterns of changes in EEG coherence values under conditions of bilaterally and unilaterally directed attention in male and female groups may testify that female subjects predominantly use right-hemispheric processing strategy, whereas male subjects use, mainly, left-hemispheric strategy for selection and memorization of concrete nouns.

Adult↗
PubMedDate not supplied

[Frequency-spatial organization of brain electrical activity in creative verbal thinking: role of the gender factor].

Gender differences in EEG patterns associated with verbal creativity were studied by EEG mapping. The EEGs of 18 males and 21 females (right-handed university students) were recorded during a performance of Remote Associates Task (RAT) compared with the letter-fluency and simple associate's tasks. Gender differences were found in a factor structure of the indices of verbal thinking and a score of generating words was greater in women than men. No significant gender differences in originality of associations were revealed, however, gender-related differences in the EEG-patterns were found at the final and initial stages of RAT. In men, the beta2-power was increased in both hemispheres at the beginning of test. To the end of testing, the power of oscillations in the beta2 band increased only in the central part of the cortex. In women, the beta2-power was increased to a greater extent in the right than in the left hemisphere at the initial stage of task performance, whereas the final stage was characterized by a relative decrease in beta-activity in parietotemporal cortical regions and increase in the left prefrontal region. It is suggested that the verbal creative thinking in men is based mostly on "insight" strategy whereas women additionally involve the "intellectual" strategy.

Beta Rhythm↗