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Biomedical subjects

N N Danilova

Publications and source records attributed to N N Danilova.

10 recordsLinked to original sources
PubMedDate not supplied

[Changes in heart rate variability under informational loading].

Three-dimensional vector spaces were constructed by the method of principal components from large sets of cardiac rhythm spectra obtained in the state of rest and under informational load. The individual and group spaces of cardiac rhythm revealed three common factors having the maximal factor loads within the domain of action of metabolic (0.02-0.04 Hz), vascular (0.06-0.08 Hz), and respiratory (0.12-0.16 Hz) oscillators. Each particular cardiac spectrum in this universal autonomic space can be represented by a three-dimensional vector. Changes in the functional state are reflected in a specific trajectory of this vector in the space. It was found that coactivation of the metabolic, vascular, and respiratory oscillators in combination with a decrease in the heart rate and index of tension is positively correlated with efficiency of task performance and appears to reflect the orienting reflex. The vector autonomic space, in which the metabolic, vascular, and respiratory oscillators act, may be a useful instrument for distinguishing the mechanisms underlying the orienting and defensive reflexes.

Adult↗
PubMedDate not supplied

[Human attention as a specific linkage of EEG rhythms with the wave modulators of the cardiac rhythm].

Two types of attention (active and passive) were described as specific correlations between central and peripheral oscillatory processes. The active attention was characterized by an enhance of the activity of the high-frequency respiratory heart rate modulator positively correlated with an increase in the EEG gamma-rhythm power. At the same time, the activity of the low-frequency heart-rate modulator was positively correlated with the depression of the low-frequency EEG and with phasic gamma-rhythm reactions (300 ms after stimulus presentation). During the passive attention, the power of the metabolic hear rate modulator increased, its positive correlation with the spectral power of the low-frequency EEG rhythms was observed. The sensory component of the gamma-rhythm was shown to increase with attention attraction.

Acoustic Stimulation↗
PubMedDate not supplied

[Heart rhythm indices during human solving of arithmetic tasks].

Heart rate and respiration were recorded in a group of 90 subjects (25 males and 65 females) aged 17-19 during rest and under informational load (arithmetical tasks) lasting 3 min each. Off-line spectral analysis was performed for all the subjects. Anxiety according to Spilberger and strength of excitation-inhibition according to Strelau were also tested. It was shown that heart rate increased significantly in the group as a whole, however, variability of RR-intervals remained unchanged. Then two subgroups of subjects who responded to information load by a decrease and increase of RR-interval variability were distinguished. These subgroups were characterized respectively by the high and low levels of personal anxiety. The decrease of RR-interval variability in the high-anxiety subgroup was associated with a decrease of power in all frequency bands of the rate spectrum. The increase of RR-interval variability in the low-anxiety subground was due to an increase of heart rate modulation in a low-frequency band of the heart rate spectrum. Fatigue is regarded as a cause of such heart rate modulation.

Adolescent↗
PubMedDate not supplied

[The dependence of the heart rhythm on anxiousness as a stable individual characteristic].

In 90 subjects (25 males and 65 females) aged 17-19 heart and respiration rates were telemetrically recorded with a "Sport" polygraph under conditions of rest and arithmetical load (periods of 3 min each). Spectral analysis of heart rate and respiration and statistical processing was performed off-line by an IBM PC XT with the software package PFE2. Anxiety was tested according to Spielberger State-Trait-Anxiety Inventory with Hanin modification and strength of excitation and inhibition according to Strelau Temperament Inventory. It was shown that the group characterized by the high trait-anxiety had significantly higher resting heart rate and Baevskiĭ index of strain than the group with low trait-anxiety. The groups differed also in R-R interval variability (standard deviation) under arithmetic load. In the group with high trait-anxiety R-R interval variability was lower than in the other group mainly in two frequency bands of R-R power spectrum, i. e., those of respiratory arrhythmia (RA) and Traube-Hering-Mayer waves (THM). Mental load evoked an increase in the heart rate and Baevskiĭ index and decrease in the power of RA and THM frequency bands. Such peculiarities of the heart rate in both groups during the periods of rest and informational load can be explained in the framework of reciprocal relationship between orienting (lower trait-anxiety, lower heart rate, higher R-R interval variability mainly in RA and THM bands of R-R power spectrum) and defensive reflexes (higher trait-anxiety, higher heart rate, lower R-R interval variability, in particular in RA and THM bands of R-R power spectrum.

Adolescent↗
PubMedDate not supplied

[The EEG rhythms and psychological indices of emotions in reactive depression].

Power and topographic distribution of the EEG rhythms (delta, theta 1, theta 2, alpha, beta 1, and beta 2) were compared with the reactive and personal anxiety levels (by Spilberger) and parameters of subjective emotional semantic space (obtained by the method of subjective scaling). A general decrease in the EEG power was observed in reactive depression, with the exception of the theta-rhythm, the power of which was higher than that in healthy persons. The increase in the theta 2 power in depression was correlated with activation of the right frontal area ("the zone of negative emotions"), and its decrease was associated with activation of the left frontal area ("responsible" for positive emotions), enhancement of positive emotions in semantic emotional space, and with a decrease in personal anxiety. High alpha activity in healthy persons was negatively correlated with the activation of the "zone of negative emotions" while a decrease in the alpha-rhythm power was associated with anxiety enhancement and decrease in contribution of positive emotions in the semantic space.

Adjustment Disorders↗