Recovery time from VR sickness due to susceptibility: Objective and quantitative evaluation using electroencephalography

Abstract

With the increasing use of virtual reality (VR) devices, interest in reducing their negative effects, such as VR sickness, is also increasing. This study used electroencephalography (EEG) to investigate participants' VR sickness recovery time after watching a VR video. We tested 40 participants in advance using a motion sickness susceptibility questionnaire (MSSQ). We classified the participants into two groups (sensitive group/non-sensitive group) depending on their MSSQ scores. We used a simulator sickness questionnaire (SSQ) and EEG to evaluate VR sickness. The SSQ score increased significantly after watching the VR sickness-inducing video (VR video) in both groups (p < 0.001). The recovery time based on the SSQ was 11.3 ± 6.6 min for the sensitive group and 9.1 ± 5.2 min for the non-sensitive group. The difference in recovery time between the two groups was not significant (p > 0.05). EEG results showed that recovery time took an average of 11.5 ± 7.1 min in both groups. The EEG data showed that the delta wave increased significantly across all brain areas (p < 0.01). There was no statistical difference between groups in recovering VR sickness depending on individual characteristics. However, we confirmed that subjective and objective VR recovery required at least 11.5 min. This finding can inform recommendations regarding the VR sickness recovery times.

Keywords: Electroencephalography (EEG); Recovery time; Simulation sickness questionnaire (SSQ); VR Sickness.

Fig. 1

Experimental working flow diagram. An EEG recording a four-condition experimental protocol: 1) Baseline condition: restings state without any action 2) Task condition: watching the VR video 3) Recovery condition: until induced VR sickness symptoms disappeared 4) End condition: comfortable state without any action. We divided the recovery conditions into four sections, R1, R2, R3, and R4, extracting every 10 s. Also, we extracted 10 s from the beginning and the end of the End section. We performed SSQ to check and compare their condition before watching the VR video.

Fig. 2

Results of total SSQ score between two groups. There are significant differences between the before-SSQ (SSQ-B), after-SSQ (SSQ-A), and final-SSQ (SSQ-F) in the sensitive group (p < 0.001) and the non-sensitive group (p < 0.001). There is a significant difference in the after-SSQ score between the two groups (p = 0.009).

Fig. 3

Results of Delta change over time. The graph shows an increase in delta after watching VR video and a decrease over time. The topography shows delta changes in all areas of the brain while recovering from VR sickness. B: baseline, R: recovery period, and E: end period.