  In this paper, we show that Virtual Reality (VR) sickness is associated with
a reduction in attention, which was detected with the P3b Event-Related
Potential (ERP) component from electroencephalography (EEG) measurements
collected in a dual-task paradigm. We hypothesized that sickness symptoms such
as nausea, eyestrain, and fatigue would reduce the users' capacity to pay
attention to tasks completed in a virtual environment, and that this reduction
in attention would be dynamically reflected in a decrease of the P3b amplitude
while VR sickness was experienced. In a user study, participants were taken on
a tour through a museum in VR along paths with varying amounts of rotation,
shown previously to cause different levels of VR sickness. While paying
attention to the virtual museum (the primary task), participants were asked to
silently count tones of a different frequency (the secondary task). Control
measurements for comparison against the VR sickness conditions were taken when
the users were not wearing the Head-Mounted Display (HMD) and while they were
immersed in VR but not moving through the environment. This exploratory study
shows, across multiple analyses, that the effect mean amplitude of the P3b
collected during the task is associated with both sickness severity measured
after the task with a questionnaire (SSQ) and with the number of counting
errors on the secondary task. Thus, VR sickness may impair attention and task
performance, and these changes in attention can be tracked with ERP measures as
they happen, without asking participants to assess their sickness symptoms in
the moment.
