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Biology subjects

Pyatin, V.

Publications and source records attributed to Pyatin, V..

2 recordsLinked to original sources

Dependence Of Heart Rate Variability On Immersion In A Virtual Game And Change Of Visual Content In The Flow Of Virtual Reality

A modern person constantly changes the environment of his mental activity, moving real into an immersive environment, for example, from the surrounding reality to the information environment of a smartphone and back. This kind of transition is needed to satisfy many of the cognitive and emotional needs of people. The transition from a real physical environment to virtual reality (VR) with the help of a special headset, for example, the Oculus Rift or HTC vive, occurs less often, causing less frequent emotional state. If at the same time the emotional state of a person is investigated, then, as a rule, the manifestation of heart rate variability (HRV) is used as an indicator. However, there are relatively few studies in the literature on physiological responses using HRV during the perception of VR content. The results of such studies are extrapolated to data evoked in HRV manifestations by stimuli of real and virtual environments. We studied HRV in 55 participants while they were in the flow of VR content of different dynamics. The results were analyzed by statistically testing the hypothesis of the effect of VR immersion and the effect of transitions between realities on HRV manifestations, as well as the effect of VR flow dynamics on HRV. The results showed that the perception of the VR flow and the content transitions made in it determine the change in HRV in the form of such parameters as LF and the Baevsky Index, which can be considered as markers of immersion in VR. An increase in emotional arousal with sequential participation in virtual games in one virtual stream determines the manifestations of HRV - HR, Moda and PAR. The results contribute to understanding the possibilities of using VR technology to recognize emotions during the transition between the natural environment and VR, as well as to determine the level of emotional arousal when immersed in the changing flow of virtual content. These studies are important for the study of the psychology of emotions in the VR flow paradigm.

physiology↗

A P300 brain-computer interface with a reduced visual field

A P300 brain-computer interface (BCI) is a paradigm, where text characters are decoded from visual evoked potentials (VEPs). In a popular implementation, called P300 speller, a subject looks at a display where characters are flashing and selects one character by attending to it. The selection is recognized by the strongest VEP. The speller performs well when cortical responses to target and non-target stimuli are sufficiently different. Although many strategies have been proposed for improving the spelling, a relatively simple one received insufficient attention in the literature: reduction of the visual field to diminish the contribution from non-target stimuli. Previously, this idea was implemented in a single-stimulus switch that issued an urgent command. To tackle this approach further, we ran a pilot experiment where ten subjects first operated a traditional P300 speller and then wore a binocular aperture that confined their sight to the central visual field. Visual field restriction resulted in a reduction of non-target responses in all subjects. Moreover, in four subjects, target-related VEPs became more distinct. We suggest that this approach could speed up BCI operations and reduce user fatigue. Additionally, instead of wearing an aperture, non-targets could be removed algorithmically or with a hybrid interface that utilizes an eye tracker. We further discuss how a P300 speller could be improved by taking advantage of the different physiological properties of the central and peripheral vision. Finally, we suggest that the proposed experimental approach could be used in basic research on the mechanisms of visual processing.

neuroscience↗