Search PubMed⌕ Search

Biomedical subjects

V I Shostak

Publications and source records attributed to V I Shostak.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

Topography of afferent and efferent flows in the mechanisms of auditory selective attention.

The auditory evoked potentials (AEP) were recorded in 10 healthy subjects under the conditions of simple rhythmic stimulation and in an attention task. The mid- (10-60 msec) and long-latency (up to 400 msec) AEP were analyzed by mapping the evoked potentials and by assessment of their spatial-temporal characteristics. It is hypothesized that the interaction of the parietal and left-sided temporal and frontal divisions exert an efferent influence on the brainstem structures in the 15-35 msec time segment. The amplitude of the P90 and P250 waves is reduced in the attention task. The amplitude of the late component P350 increases mainly in the central and anterior divisions of the brain.

Acoustic Stimulation↗
PubMedDate not supplied

[Color perception following intensive photic stimulation].

After a monocular effect of a short-term intensive light stimulation (of 80 mksec in duration with illuminance of 1600 cdl. sec) which followed complete dark adaptation, test subjects showed disorders in color perception. They included lowered decrease in the acuity of color discrimination measured in the AN-59 anomaloscope and significant distortion of the subjective evaluation of different color stimuli. The spectrum of an experimental intensive light effect was varied; it was thus shown that disorders in the color perception were associated with a nonuniform decrease of the sensitivity of color perceiving systems of the optic analyzer. The pattern and duration of these disturbances depended on the spectral composition and intensity of the light stimulus.

Adult↗
PubMedDate not supplied

[The thalamic integration of afferent flows in man during image recognition].

The article deals with the mechanisms of interaction of afferent flows at intrathalamic and thalamocortical levels of integration in humans identifying visual, auditory and tactile images. As the methodic model of thalamic block we used patients of surgical clinic with topically diagnosed volume process of the region of the third ventricle. Psychophysiological tests and multichannel EPs recording revealed functional significance of thalamus in the processes of perception and also mechanisms of compensation of these functions in pathological process.

Acoustic Stimulation↗
PubMedDate not supplied

[The characteristics of perceptive learning and memory in psychopathological states].

Dynamics is studied of visual images recognition in patients with schizophrenia under the influence of small doses of ionizing radiation used with therapeutic purpose. Functional state of the brain is evaluated by amplitude-temporal parameters of visual and auditory EPs. After conducted therapy no changes in responses to light flashes are found, and in auditory EPs in a part (the first group) of patients there is an increase of the component N1 amplitude in the frontal area. The same group is characterized by lower parameters of visual images recognition. Conclusion is made about the presence of non-specific changes of visual gnosis in patients with schizophrenia and about involvement of the associative frontal structures in pathologic process. Possible mechanisms of disturbance of the perceptive learning and memory processes in schizophrenia are discussed.

Acoustic Stimulation↗