Identifying physiological correlates of cybersickness using heartbeat-evoked potential analysis

Abstract

Many studies have consistently proven that repeatedly watching virtual reality (VR) content can reduce cybersickness. Moreover, the discomfort level decreases when the VR content includes an unusual orientation, such as an inverted scene. However, few studies have investigated the physiological changes during these experiences. The present study aimed to identify psychophysiological correlates, especially the neural processing, of cybersickness. Twenty participants experienced two types of VR orientation (upright and inverted), which were repeated three times. During the experience, we recorded the participants’ subjective levels of discomfort, brain waves, cardiac signals, and eye trajectories. We performed a heartbeat-evoked potential (HEP) analysis to elucidate the cortical activity of heartbeats while experiencing cybersickness. The results showed that the severity of cybersickness decreased as the participants repeatedly watched the VR content. The participants also reported less nausea when watching the inverted orientation. We only found a significant suppression at the fronto-central HEP amplitudes in the upright orientation for the physiological changes. This study provides a comprehensive understanding of bodily responses to varying degrees of cybersickness. In addition, the HEP results suggest that this approach might reflect the neural correlates of transient changes in heartbeats caused by cybersickness.

Who says you are so sick? An investigation on individual susceptibility to cybersickness triggers using EEG, EGG and ECG

“…It's noteworthy that the decrease in Delta power contrasts with previous research [4,21]. Conversely, the increase in Beta wave power aligns with anxiety-related patterns [39].…”

“…It has been proposed as a potential indicator of a person's awareness of their internal bodily processes. Chang et al found that the magnitude of the HEP activity at the frontal area might reflect the level of arousal caused by cybersickness [5]. Park et al found a decrease of magnitude of HEP activity, and an increase in the Alpha power during cybersickness [36].…”

“…Electroencephalogram (EEG) has emerged as a promising tool for objectively assessing discomfort levels. However, reported changes in spectral power within different frequency bands have varied across studies [4,44]. In our investigation, we categorized EEG signals into four primary brain regions to ensure that potential changes would not be obscured by averaging signals from all electrodes.…”

BrainBeats, an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals

“…This approach examines how the brain processes cardiovascular activity with millisecond accuracy and requires that both time series are time-locked, the heartbeats be marked with events in the EEG signals, and the heart signal removed. This approach is the most popular [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] .…”