This article introduces the Least Increase aversion (LIA) protocol to investigate the relative impact of factors that may trigger cybersickness. The protocol is inspired by the Subjective Matching methodology (SMT) from which it borrows the incremental construction of a richer VR experience, except that the full-blown target experience may cause undesired discomfort. In the first session, the participant briefly encounter all factors at the maximum level. Then in the second session they start with the minimum level of all factors as a Baseline. Subsequently, we expect the participant to minimize their exposure to the most adverse factors. This a pproach ranks the factors from mildest to worst and helps detect individual susceptibility to cybersickness triggers. To validate the applicability of LIA protocol, we further evaluate it with an experiment to identify individual susceptibility to three rotational axes (Yaw, Pitch, and Roll). The findings not only confirm the protocol's capability to accurately discern individual rankings of various factors to cybersickness but also indicate that individual susceptibility is more intricate and multifaceted than initially anticipated.

In this research paper, we conducted a study to investigate the connection between three objective measures: Electrocardio-gram(EGG), Electrogastrogram (EGG), and Electroencephalogram (EEG), and individuals' susceptibility to cybersickness. Our primary objective was to identify which of these factors plays a central role in causing discomfort when experiencing rotations along three different axes: Roll, Pitch, and Yaw. This study involved 35 participants who were tasked with destroying asteroids using their eye gaze while undergoing passive rotations in four separate sessions. The results, when combined with subjective measurements (specifically, Fast motion sickness questionnaire (FMS) and Simulator sickness questionnaire (SSQ) score), demonstrated that EGG measurements were superior in detecting symptoms associated with nausea. As for ECG measurements, our observations did reveal significant changes in Heart Rate Variability (HRV) parameters. However, we caution against relying solely on ECG as a dependable indicator for assessing the extent of cybersickness. Most notably, EEG signals emerged as a crucial resource for discerning individual differences related to these rotational axes. Our findings were significant not only in the context of periodic activities but also underscored the potential of aperiodic activities in detecting the severity of cybersickness and an individual's susceptibility to rotational triggers.

Cybersickness is still an inevitable adverse effect when using VR systems, resulting in different levels of discomfort, and potentially breaking the immersive experience. To date, few studies have focused on exploring VR experience in the supine posture. Recent research indicated that simple adoption of VR game initially designed for a seated posture (by rotating 90 degrees) could lead to more severe cybersickness, even to experienced users. Following the insights from previous literature and the widely-accepted sensory conflict theory, we proposed an assumption that might explain such a phenomenon. The hypothesis is that when the perceived virtual coordinate system contradicts the received real-world coordinate through our vestibular system, the conflict appears, which can lead to a sense of discomfort. Hence, the primary goal of the study is to evaluate whether such conflict has an impact on cybersickness. Furthermore, we explored methods of mitigating this conflict through different game designs so as to improve the experience for the supine posture. The final results show that the design that aligned with the real vertical axis is effective in mitigating cybersickness, especially for games that present an acceleration sensation.

Cybersickness induced through Virtual Reality (VR) applications is still one of its main barriers as it can induce unwanted side-effects in players, significantly hindering the overall experience. Despite the wealth of research available on this topic, it is still an unsolved problem. Although previous studies have explored methods of cybersickness mitigation in addition to correlating physiological factors, there has been little research on the potential correlation of eye behavior and cybersickness. Thanks to advances in eye-tracking technology within HMDs, detecting eye behavior has become a much easier process. This paper explores the differences of pupil position and blink rate in relation to cybersickness intensity. The latter is measured through the standard and a customized version of the Simulator Sickness Questionnaire (SSQ). A total of 34 participant data was collected from two separate playing sessions of a VR maze game, where each session presented a unique control scheme.