Researchers at the University of Maryland have identified measurable changes in brain wave activity that accompany cybersickness, the dizziness, nausea and disorientation that many people feel during immersive experiences. In a study published on September 25, 2026, in the journal Virtual Reality, the team used electroencephalography, or EEG, to record brain activity while participants viewed immersive content designed to induce symptoms associated with the vergence-accommodation conflict, a mismatch inherent to many virtual and augmented reality displays. The findings offer real-time signals that could help designers detect and reduce cybersickness symptoms as they occur. The work was led by University of Maryland computer science professor and dean Amitabh Varshney and conducted in collaboration with the Food and Drug Administration and Sony Group Corporation, with Mattie Johnson, a computer science Ph.D. student, serving as first author. The paper is titled Quantifying and characterizing vergence-accommodation-conflict-induced cybersickness in immersive environments.

Cybersickness is a type of motion sickness triggered by moving digital content, and for years developers of virtual and augmented reality technologies have worked to address this unwanted side effect. Its symptoms can include nausea, dizziness, sweating, blurred vision and disorientation. Previous studies cited by the Maryland team found that 65.2 percent of virtual reality users reported experiencing cybersickness, with 23.9 percent reporting severe symptoms. The problem reaches beyond entertainment. VR and AR technologies are now used in healthcare, teaching, job training, building design and even to plan surgeries, and their effectiveness is compromised by cybersickness, as Johnson emphasized. VR and AR technologies are not just for gaming anymore, she said, and the new results show that EEG could complement traditional symptom questionnaires and support VR and AR systems that respond to cybersickness in real time. Those statements frame the practical motivation for the study without overstating what the experiment itself demonstrated.

The Maryland study focused on one specific cause of discomfort: the vergence-accommodation conflict, often abbreviated as VAC. This is a mismatch between where the eyes converge to view an object and the distance at which they focus. In the real world, these two distances generally correspond, because the object a person converges on is the same object they focus on. In many VR and AR displays, however, the eyes may converge on a virtual object that appears near or far while focusing on a display set at a fixed focal plane. According to the researchers, this mismatch is an inherent challenge for many immersive displays and is believed to contribute to visual discomfort and cybersickness. Because the conflict is built into the optics of common headsets, it served as the targeted trigger in the experimental environment that participants experienced during the study.

Measuring cybersickness has traditionally depended on subjective reporting. The standard instrument is the Simulator Sickness Questionnaire, a 16-question survey developed in 1993 to evaluate the experiences of U.S. military fighter pilots using flight simulators. While the questionnaire remains useful, it relies on participants’ reports after an immersive experience and does not provide continuous measurements during exposure. Sujal Bista, director of the Immersive Visualization Center at the University of Maryland Institute for Health Computing and a co-author of the paper, said that many people use the questionnaire in VR studies but that it is a subjective way to measure, and that it does not allow for continuous data collection from the user. The team needed a better way to measure in real time, he said. EEG recordings offered a route to physiological data gathered while a participant is inside the environment rather than afterward, when symptoms are reported from memory.

The experimental design recruited 40 participants whose brain activity was recorded using a 64-electrode EEG system while they wore a Meta Quest 2 headset and experienced an immersive environment that induced the vergence-accommodation conflict. After the exposure, participants completed the Simulator Sickness Questionnaire so that the researchers could compare self-reported symptoms with the EEG data collected during immersion. This pairing of continuous physiological recording with a retrospective symptom measure gave the team a way to examine whether the brain signals corresponded to the discomfort participants reported experiencing, rather than documenting brain activity in isolation. The study’s methodology is described in the journal listing as a randomized controlled or clinical trial with people as the subject of research, and the reported results concern this specific population, this specific trigger and this specific headset configuration rather than cybersickness in general.

The EEG recordings showed changes in activity across several brain wave frequency bands during cybersickness, and the pattern differed by brain region. In the frontal lobe, the team found a statistically significant decrease in high brain wave frequencies during cybersickness, while in the occipital lobe they observed a statistically significant decrease in low brain wave frequencies. Johnson explained that these changes in what the researchers call EEG clusters could be useful predictors of a cybersickness experience. The combination of region-specific and frequency-specific changes gives researchers candidate markers that could in principle be monitored while a user is immersed in virtual or augmented content, and the statistical significance reported for both regions indicates that these shifts were unlikely to have arisen by chance in the study sample.

The study builds directly on the group’s earlier work on a different trigger of the same condition. Varshney noted that the team showed in an earlier study that EEG can be a reliable indicator of vection-induced cybersickness, which occurs when a virtual environment creates an illusion of self-motion while the user’s physical body remains completely still. The new study expands those findings to a second type of cybersickness, the kind induced by the vergence-accommodation conflict, and Varshney described the result as an important foundation for making immersive technologies more comfortable and accessible. Taken together, the two studies indicate that EEG-based measurement has now been applied to two distinct categories of cybersickness by the same research group, one driven by illusory self-motion and the other by the optical mismatch between convergence and focus in headset displays.

Detecting cybersickness is only a first step, and the researchers describe how such signals might eventually be used. One possible approach would involve communication between an EEG-monitoring device and a VR headset: if the EEG system detected a pattern associated with emerging cybersickness, the headset could adjust the virtual scene, for example by bringing the displayed content closer to the headset’s focal plane and thereby reducing the vergence-accommodation conflict. Some headset technologies already aim to reduce cybersickness by providing multiple focal planes or otherwise addressing the vergence-accommodation mismatch, and consistent real-time physiological signals could help researchers evaluate and improve those approaches. Johnson said that ultimately the team wants to inform technology that mitigates symptoms in real time, improving user comfort and productivity over extended periods of immersion. These remain proposed directions rather than demonstrated capabilities of the current study, which established the brain signal associations but did not test any mitigation system.

The researchers also outlined next steps for refining their measurements. Johnson and her co-authors plan to investigate eye-tracking data, which could provide another objective measure while helping distinguish brain activity from eye-related artifacts in EEG recordings. The longer-term ambition, described by Bista, is a cybersickness index that combines data from different physiological measures rather than relying on any single signal. The Simulator Sickness Questionnaire still has its uses, Bista said, but now the field has the tools to go from asking participants how they are feeling to asking the brain and body what is really going on. UM-IHC researchers Barbara Brawn, Jonathan Heagerty and Sida Li also co-authored the paper. The research was supported by the Center for Medical Innovations in Extended Reality through U.S. National Science Foundation Award No. 2137229, and the release notes that the article does not necessarily reflect the views of the supporting organizations.

Subject of Research: EEG identification of brain wave signals associated with vergence-accommodation-conflict-induced cybersickness in immersive virtual reality environments

Article Title: UMD researchers identify brain signals linked to cybersickness in immersive environments

Article References: UMD researchers identify brain signals linked to cybersickness in immersive environments. Original publication (Bibliographic details unavailable.)

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Keywords: cybersickness, virtual reality, augmented reality, EEG, brain waves, vergence-accommodation conflict, University of Maryland, immersive technology, Simulator Sickness Questionnaire, motion sickness, Meta Quest 2, real-time detection