Effect of predictive sign of acceleration on heart rate variability in passive translation situation: preliminary evidence using visual and vestibular stimuli in VR environment

Evaluation of Tympanic Temperature, Heart Rate Variability and Finger-Foot Reaction Using VR in the Elderly

We evaluated tympanic temperatures, heart rate variability, as well as finger and foot reaction times in elderly using VR simulations of amusement park attractions. The subjects were 8 elderly people (mean age ± S.D., 75±7 year, range 61–85 year), including four females. A roller coaster, swing ride, and rotating cart were used for the amusement park attractions. Subjects were requested to wear VR headsets, rest for 3 minutes, and then were asked to run through the same virtual amusement ride 3 times in a row, which takes 3 minutes and 30 seconds. After another 3 minutes of resting, the subjects were requested to answer a simulator sickness questionnaire (SSQ). In addition, PVT and PS-PVT were performed before and after the attraction rides. Results showed that HRV were not significantly different, but time phase change of tympanic temperature showed increasing trend (P=0.095). As the results of SSQ, increasing trend of nausea was observed in roller coaster than rotating cart (P=0.097). The results of PVT and PS-PVT showed that finger reaction time was significantly faster after the swing ride (P=0.023) and foot reaction time was significantly faster after the rotating cart (P=0.034). It is considered that the tympanic temperature increases when VR sickness occurs. Work performance improved after using VR simulations of amusement park attractions. It is suggested that the moving stimulus of VR vehicles improves finger-foot reactivity and activates concentration in elderly people.

Psychophysiological effects of audiovisual stimuli during cycle exercise

Immersive environments induced by audiovisual stimuli are hypothesised to facilitate the control of movements and ameliorate fatigue-related symptoms during exercise. The objective of the present study was to investigate the effects of pleasant and unpleasant audiovisual stimuli on perceptual and psychophysiological responses during moderate-intensity exercises performed on an electromagnetically braked cycle ergometer. Twenty young adults were administered three experimental conditions in a randomised and counterbalanced order: unpleasant stimulus (US; e.g. images depicting laboured breathing); pleasant stimulus (PS; e.g. images depicting pleasant emotions); and neutral stimulus (NS; e.g. neutral facial expressions). The exercise had 10 min of duration (2 min of warm-up + 6 min of exercise + 2 min of warm-down). During all conditions, the rate of perceived exertion and heart rate variability were monitored to further understanding of the moderating influence of audiovisual stimuli on perceptual and psychophysiological responses, respectively. The results of the present study indicate that PS ameliorated fatigue-related symptoms and reduced the physiological stress imposed by the exercise bout. Conversely, US increased the global activity of the autonomic nervous system and increased exertional responses to a greater degree when compared to PS. Accordingly, audiovisual stimuli appear to induce a psychophysiological response in which individuals visualise themselves within the story presented in the video. In such instances, individuals appear to copy the behaviour observed in the videos as if the situation was real. This mirroring mechanism has the potential to up-/down-regulate the cardiac work as if in fact the exercise intensities were different in each condition.

Heart rate variability (HRV) during virtual reality immersion

The goal of the study was assessment of the hour-long training involving handling virtual environment (sVR) and watching a stereoscopic 3D movie on the mechanisms of autonomic heart rate (HR) regulation among the subjects who were not predisposed to motion sickness. In order to exclude predispositions to motion sickness, all the participants (n=19) underwent a Coriolis test. During an exposure to 3D and sVR the ECG signal was continuously recorded using the Holter method. For the twelve consecutive 5-min epochs of ECG signal, the analysis of heart rate variability (HRV) in time and frequency domains was conducted. After 30 min from the beginning of the training in handling the virtual workstation a significant increase in LF spectral power was noted. The values of the sympathovagal LF/HF index while sVR indicated a significant increase in sympathetic predominance in four time intervals, namely between the 5th and the 10th minute, between the 15th and the 20th minute, between the 35th and 40th minute and between the 55th and the 60th minute of exposure.