Existing evidence suggests that cybersickness may be clinically different from "classic," motion-induced sickness; this evidence was, however, obtained in separate studies that focused on just one of the two conditions. Our aim was to bring clarity to this issue by directly comparing subjective symptoms and physiological effects of motion sickness induced by physical motion (Coriolis cross-coupling) and by immersion in virtual reality (ride on a roller coaster) in the same subjects. A cohort of 30 young, healthy volunteers was exposed to both stimulations in a counterbalanced order on 2 separate days ≥1 wk apart. Nausea scores were recorded during the exposure, and the Motion Sickness Assessment Questionnaire (MSAQ) was used to profile subjective symptoms postexperiment. Tonic and phasic forehead skin conductance level (SCL) was measured before and during exposure in both stimulation methods. We found that the nausea onset times were significantly correlated in both tests (r = 0.40, P = 0.03). Similarly, the maximum nausea ratings were significantly correlated during both provocations (r = 0.58, P = 0.0012). Symptom-profiling with the MSAQ revealed substantial and significant correlations between total symptom scores (r = 0.69, P < 0.0001) between each of 4 symptom clusters and between 15/18 individual symptoms assessed in both conditions. Both virtual reality and Coriolis cross-coupling provocations caused an increase in tonic SCL associated with nausea [mean difference (mean diff) = 5.1, confidence interval (CI) = (2.59, 6.97), P = 0.007 and mean diff = 1.49, CI = (0.47, 7.08), P = 0.0001, respectively], with a close correlation between the conditions (r = 0.48, P = 0.04). This was accompanied by a significant increase in the amplitude of phasic skin conductance transients in both visual stimulation and Coriolis cross-coupling when participants reported maximum nausea compared with no nausea [mean diff = 0.27, CI = (0.091, 0.63), P < 0.001 and mean diff = 0.235, CI = (0.053, 0.851), P < 0.006, respectively]. We conclude that symptoms and physiological changes occurring during cybersickness and classic motion sickness are quite similar, at least during advanced stages of these malaises.NEW & NOTEWORTHY Expansion of virtual reality (VR) technology has provoked an interest in cybersickness, a subtype of motion sickness induced by immersion in VR. Finding means for preventing and managing cybersickness requires good understanding of its nature, including its relationship to "classic" motion sickness. The knowledge about this relationship is controversial, partly because there were no studies where the same cohort was exposed to the two provocations. With this approach, we demonstrate that symptoms and physiological manifestations of the two conditions are identical.
Keywords: cybersickness; motion sickness; nausea; skin conductance; virtual reality.