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Biomedical subjects

M V Slavutskaia

Publications and source records attributed to M V Slavutskaia.

At least 19 recordsLinked to original sources
PubMed1991

[The reflexotherapy at the hospital stage of the functional disorders following the surgical shutoff of the ovaries].

Basing on the parameters of psychoemotional status and vegetovascular reactions in 104 patients of a reproductive age after surgical castration, the authors assess the results of combined therapy, including reflex therapy. The postoperative treatment resulted in improvement of psychoemotional status and normalization of the vegetovascular reactions that may be regarded as early manifestations of the post-castration syndrome.

Adult↗
PubMed1991

[Reflex analgesia in the combined treatment of pregnant women with a pathological preliminary period].

The impact of reflex analgesia via transcutaneous electrical neurostimulation and electrical acupuncture was studied in 46 patients with an abnormal preliminary period by using tests of pain sensations and personal and reactive anxiety, ECG, hysterography, and computer-aided prediction of labor complications. Reflex analgesia was found to contribute to effective abolishment of preliminary pain sensations, to normalization of central nervous system function, autonomic reactions, uterine contractility, to reduction in pharmacological agent use and treatment duration, and to better delivery.

Adult↗
PubMed1983

[Functional indices of the human state and work capacity under monotonous conditions].

The operator's letter apprehension activity has been handled in the experimental conditions. Under monotonous conditions worsening of the capacity for work (the increase of decision time and number of mistakes) has been shown to be correlated with the value of such electrophysiological indices as longevity of alpha-rythm blockade, amplitude and frequency amplitude characteristics of electroencephalogram, interhemispheric and central-occipital asymmetry coefficients, frequency and variability of heart-rate. The character of changes of electrophysiological indices depends on the individual psychophysiological characteristics.

Adult↗
PubMedDate not supplied

[The effect of the visual stimulation of the leading and nonleading eye on the value of the saccadic latency period and on the peak latency of rapid presaccadic potentials].

Visual targets were presented monocularly to the leading and nonleading eyes. The complex of rapid positive and negative potentials was studied using the reverse summation from the onset of saccades. The latencies of saccades and peak latencies of the averaged presaccadic potentials were measured. The dependence of the saccade latencies and peak latencies of the complex of potentials on stimulation of the leading or nonleading eye and saccade direction was not simple and was largely determined by the individual profile of asymmetry. It is suggested that during stimulation of the leading eye the processes of attention fixation and switching as well as of the space visual processing are faster than during stimulation of the nonleading eye. Thus, the leading role of the right eye is reflected not only in fixation processes but also in movement anticipation.

Adult↗
PubMedDate not supplied

[Saccade latency during probability presentation of the visual targets in man].

The latent periods of saccadic eye movements in response to peripheral visual stimuli were measured in 8 right-handed healthy subjects using Posner's paradigm "COST-BENEFIT". In 6 subjects, the saccade latency in response to visual target presented in expected location in valid condition was shorter than that in neutral condition ("benefit"). Increase in saccade latency in response to the visual target presented in unexpected location in valid condition versus neutral condition took place only in 4 subjects ("cost"). A decrease in left-directed saccade latency in response to expected target presented in the left hemifield and increase in saccade latency in response to unexpected left target in comparison with analogous right-directed saccades were observed in valid condition. This phenomenon can be explained by the dominance of the right hemisphere in the processes of spatial orientation and "disengage" of attention.

Attention↗
PubMedDate not supplied

[Latent period of antisaccades in various conditions of visual stimulation in man].

The latent periods (LP) of normal saccades and antisaccades were studied in 10 right-handed healthy subjects in two series of experiments. Peripheral visual stimuli were located at an angle of 10 degrees with respect to the central fixation stimulus in the left and right visual semifields. Two standard schemes of visual stimulation: 1) SS (single step), i.e., switching the peripheral stimulus on immediately after switching the central stimulus of; 2) GAP, i.e., the same with the interstimulus interval in 200 ms. It was shown that in the GAP stimulation condition, the LP of both saccades and antisaccades was 30-50 shorter than in the SS condition. The LP of antisaccades was longer than that of saccades by 145-300 ms. The LP of the leftward antisaccades was by 10-100 ms shorter than that of the rightward ones. Probably, this phenomenon reflects the dominance of the right hemisphere in spatial attention.

Attention↗
PubMedDate not supplied

[Cortical slow negative potentials during eye fixation and preparing of visually triggered saccades in a man].

In 10 right-handed healthy subjects EEGs preceding saccades with mean latent periods were selectively averaged. Two standard schemes of visual stimulation were used: with immediate presentation of a peripheral target stimuli after the central fixation stimulus (a single step paradigm) and with the interval between the stimuli in 200 ms (GAP paradigm). Two waves of slow premotor negativity (early PMN1 and late PMN2) that appeared 930 +/- 79 and 609 +/- 82 ms, respectively, prior to a saccade onset were observed. The PMN2 was followed by the negative potentials N-3, N-2, and N-1 (saccadic initiation potential). It was found that in GAP stimulation condition the PMN1 was less pronounces and N-1 was increased as compared to the single step. These findings suggest that disengage of attention from the central point during the GAP period clears the saccadic system for decision making and initiation of a saccade. Under such conditions, the expectation of a visual target does not require a high level of nonspecific activation and motor attention.

Adult↗
PubMedDate not supplied

[Lateralization of saccadic latency during monocular presentation of stimuli to a leading and non-leading eye].

Saccadic latencies were studied in ten healthy subjects. Peripheral targets were presented monocularly to a leading and nonleading eyes in the right and left hemifields. SS (single step) and OVERLAP (200 ms) schemes of visual stimulation were used. Under OVERLAP conditions, the saccadic latency was longer by 30-39 ms and the number of long-latency saccades was higher than under SS conditions, especially in subjects with mixed asymmetry profiles. In the majority of subjects with right asymmetry profile, the latencies of saccades during stimulation of the leading eye were by 12 ms shorter than during stimulation of the nonleading eye, and the latencies of right saccades were by 24 ms shorter than that of the left saccades independently of the stimulated eye. The obtained results explain some characteristic features of hemyspheric asymmetry in organization of saccadic movements.

Brain↗
PubMedDate not supplied

[Positive potentials of the human brain at different stages of preparation of a visually triggered saccade].

The EEG of 10 right-handed subjects preceding saccades with mean values of latent periods were selected and averaged. Two standard paradigms of presentation of visual stimuli (central fixation stimulus-peripheral target succession): with a 200-ms inerstimulus interval (GAP) and successive single step (SS). During the period of central fixation, two kinds of positive potentials were observed: fast potentials of "inermediate" positivity (IP) developing 600-400 ms prior to saccade onset and fast potentials of "leading" positivity (LP), which immediately preceded the offset of the central fixation stimulus. Peak latency of the LP potentials was 300 ms prior to saccade onset in the SS paradigm and 400 ms in the GAP paradigm. These potentials were predominantly recorded in the frontal and frontosagittal cortical areas. Decrease in the latency by 30-50 ms in the GAP paradigm was associated with more pronounced positive potentials during the fixation period and absence of the initiation potential P-1' (or decrease in its amplitude). The obtained evidence suggest that the fast positive presaccadic potentials are of a complex nature related to attention, anticipation, motor preparation, decision making, saccadic initiation, and backward afferentation.

Adult↗
PubMedDate not supplied

[Potential of the human cerebral cortex prior to antisaccades].

Latencies and other parameters of presaccadic potentials preceding antisaccades and normal saccades to visual stimuli were studied in 10 right-handed healthy subjects. The EEG was recorded in F3, F4, Fz, C3, C4, Cz, P3, P4, O1 and O2 derivation. EEG records preceding saccades and antisaccades with mean latencies were selected and averaged. The latencies of the leftward antisaccades were shorter than of the rightward antisaccades. The slow presaccadic negativity (in the period of central eye fixations) and fast N -2 and P -1 potentials within the latent period were more prominent before antisaccades than normal saccades. Spatiotemporal analyses of presaccadic potentials showed that the right frontal cortex was activated to a greater extent before antisaccades than before saccades. These findings suggest that right-hemispheric dominance in the spatial attention and inhibition of automatic saccades to visual stimuli in the period of antisaccades preparation.

Acoustic Impedance Tests↗
PubMedDate not supplied

[Cortical positive potentials in the period of eye fixation prior to saccades and antisaccades].

The EEG of 10 right-handed healthy subjects preceding saccade and antisaccade with mean values of latency in the eye fixations period were selected and averaged. The positive potential P2 appearing on the fixation stimuly switching on and slow positive wave following after it were more prominent before antisaccades than normal saccades. Space-temporal analyses of presaccadic potentials showed that right frontal cortex was activated more before antisaccades. These findings suggest that right cortical hemisphere dominate in spatial attention and inhibition of automatic saccades to visual stimuli in the period of antisaccades preparing. During the period of central fixations "intermediate" positivity potentials, developing in 600-400 ms prior to saccade or antisaccade onset, were find out. These potentials were predominantly recorded in the left frontal and frontosagittal cortical areas. The obtained evidence suggest that "intermediate" positive potentials a period related to the process of motor attention, anticipation and decision making in the period of eyes fixation.

Adult↗
PubMedDate not supplied

[Positive potentials ot the human brain in the latent presaccadic period under conditions of stimulation of the leading and nonleading eye].

We used backward averaging method to study fast positive presaccadic EEG-potentials under conditions of the monocular stimulation of the leading and nonleading eye. Two schemes of the visual stimulus presentation ("no gap" and "overlap") were used. In the "no gap" condition, potential P1 dominated in the hemispere ipsilateral to a saccade direction. In the "overlap" condition, when the gaze was fixed at the central point, foci of this potential were localized in the sagittal derivations or in the same sites as in the "no gap" conditions. Irrespective on the stimulation scheme, the P2 foci were localized in the hemisphere contralateral to a saccade direction. We assume that the fast positive potentials involve both activation and inhibition processes in visuomotor structures and can be also associated with cognitive presaccadic processes (such as fixation disengage, attention lateralization and a preliminary extraction of motor programs from memory).

Brain↗
PubMedDate not supplied

[Directed attention influence on the human brain potentials under conditions of probability visual stimulation].

Saccadic latency and averaged EEG-potentials connected with switching on of the set and cue visual stimuli were examined in 12 right-handed healthy subjects in M. Posner's "cost-benefit" experimental paradigm. It was shown that attention was reflected in parameters of positive potential P100 evoked by switching on of set and cue stimuli and P300 and slow positive wave PMP1 evoked by switching on of the set stimulus in the relevant conditions. The spatiotemporal pattern of P100 probably reflects the involvement of the frontoparietal network of spacial attention in the perception of a relevant stimulus. Prevalence of the P300 and PMP1 potentials in the right parietal cortex suggests that these potentials reflect processes of space attention and visual fixation. Late positive potentials in a 600-900-ms interval after switching on of the set stimulus were found. Their amplitude was higher in backward averaging and they were predominantly localized in the left frontal cortex. These findings suggest that the late potentials reflect the anticipation and motor attention processes.

Attention↗