Biomedical subjects

A Gourevich

Publications and source records attributed to A Gourevich.

4 recordsLinked to original sources

PubMed1989

Perception time and reaction time.

Two experiments were performed in order to examine the possible contribution of visual perception time in motor response time under conditions of pursuit eye movements. Subjects had to follow with their eyes a light spot moving horizontally along a reference scale at a constant velocity of 14 degrees/s. Stimuli (the disappearance of the moving spot) were presented randomly at distances of 11.3, 17.7 and 24.2 angular degrees from the onset of motion. In Experiment 1 subjects had to report verbally the scale division at which the stimuli were presented. In Experiment 2 subjects had to press a button as quickly as possible after stimulus presentation. No relationship between visual perception time and motor reaction time was found.

Adult↗

PubMed1987

In search of paintings influence on time judgement.

The influence of paintings on short time interval perception was studied. Three methods for time estimation were tested: direct scaling and two modifications of the method of reproduction with and without simultaneous presentation of the painting whose duration was, reproduced. The results show that short time interval perception is influenced by such complex stimuli as paintings. The motor reproduction with simultaneous presentation of the visual stimulus was the most effective in revealing the influence of paintings on short time interval perception.

Art↗

PubMed1984

Brief stimuli localization in visual periphery.

Experiments were carried out to establish the effect of stimulus eccentricity and the kind of reference structure on the localization of brief stimuli in the visual periphery. In Experiment 1 the effect of eccentricities up to 55 degrees to the left and to the right of the fixation point on stimulus localization was studied. Systematic errors were obtained, the stimuli being mislocated nearer the fixation point than they were actually presented. The angular size of errors increased with the increase of stimulus eccentricity. In Experiment 2 the subjects had to localize the stimuli against three different background structures (scales). The results showed that error magnitude decreased when scales with clearly visible cues were used. The possible involvement of stimulus direction perception and of the identification of the scale element nearest to the perceived event is discussed.

Adult↗

PubMed1983

Peripheral vision and perceived visual direction.

Experiments are described in which the subjects had to localize brief light stimuli presented up to 10 degrees from the fixation center. The localization was performed relative to a continuously illuminated scale with numbered or lettered divisions. Systematic errors were obtained, the stimuli being mislocated nearer the fixation point than they were actually presented. The angular size of errors increased with the increase of stimulus eccentricity. It appeared to be a characteristic of the stimulated retinal locus, independent of the viewing distance and the scale element corresponding to this locus. It is concluded that despite the presence of a visible background frame of reference, subjects prefer to base their reports on the perceived egocentric direction of the stimulus which does not coincide with the physical direction of the stimulus. A parallel is drawn between this study and the studies on serial position function for letter identification.

Cybernetics↗