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Biomedical subjects

S A Lytaev

Publications and source records attributed to S A Lytaev.

21 records · Page 2Linked to original sources
PubMedDate not supplied

[The negative components of visual evoked potentials in the mechanisms of the classification of incomplete images].

Event-related brain potentials were recorded in 16 young adult subjects in response to a short presentation of recognizable and nonrecognizable visual images with an incomplete set of signs. Sequential brain maps and amplitude-temporal ERP parameters in 1000 ms poststimulus epoch were estimated (BMDP 4M and 7M, 1987). The results suggested that the component N450 was specifically related to a perception of nonrecognizable visual images. N70 and N150 reflected voluntary attention during invariant recognition and the late negative waves (600-1000 ms) reflected an "exhaustive search" for categorization of new information.

Adult↗
PubMedDate not supplied

[The perception of targeted signals in the auditory and somatosensory systems with a lesion of the brain stem].

Auditory and somatosensory evoked potentials (AEPs and SEPs) were recorded in 8 patients with malignant processes in the brainstem region and 14 healthy persons under conditions of relevant and deviant stimulation. The spatial-temporal EP characteristics were evaluated and mapped. The low-voltage AEPs to simple rhythmical stimulation were recorded in patients over the whole cortical surface. During attention activation (solving selective attention tasks) there was an increase in the amplitude of the AEPs, mainly, of their mid-latency components. Under such conditions the N200 SEP components were well expressed in both hemispheres with the maximal amplitude in the medial and anterior derivations. The spatial distribution of N350 resembled that of the N200. There was an increase in N30 amplitude in both occipital derivations and its expressed reduction in the frontal areas as compared to the situation with the simple rhythmical stimulation. In patients with the brainstem pathology the increased amplitude of these components was observed mainly in the parietal and occipital cortical areas.

Acoustic Stimulation↗