Biology subjects

Weech, S.

Publications and source records attributed to Weech, S..

5 recordsLinked to original sources

bioRxiv2023

Multimodal Mitigations for Cybersickness in Motion Base Simulators

1.BackgroundVirtual reality (VR) technologies that integrate with motion-base simulators (MBS) have the potential to accelerate personnel training and enhance workplace safety. Motion sickness on an MBS is a widespread problem with vast individual differences that are likely related to idiosyncrasies in estimates of head, body, and vehicle motions. When combined with head-mounted VR, we term the emergent symptoms cybersickness. MethodsWe conducted two experiments that evaluated cybersickness mitigations in an MBS. In Experiment 1 (N = 8), we tested the effectiveness of a light-touch body harness attached to a mobile-elevated work platform (MEWP) simulator during two nauseogenic VR tasks. In Experiment 2 (N = 14, 7 of whom completed Experiment 1), we tested the effectiveness of a dynamic field-of-view (dFOV) modifier that adaptively restricted the FOV for vehicle rotations in the same VR tasks. We gathered subjective sickness data and qualitative evaluations of the mitigations after the fact. ResultsWe observed a reduced level of sickness in both Experiment 1 and 2 when mitigations were applied. In Experiment 1, the use of a harness led to a mild decrease in total cybersickness of between 3-11%, which was only significant for the nausea dimension. In Experiment 2, the use of dFOV imparted a large benefit to comfort, up to a 45% improvement. Both mitigations primarily improved comfort in a bumpy trench traversal task. ConclusionsCybersickness mitigations can help to deliver VR training for longer, and to more users. The type of content undertaken should be considered when employing new mitigations.

neuroscience↗

bioRxiv2020

Limits of subjective and objective vection for ultra-high frame rate visual displays

Large-field optic flow generates the illusory percept of self-motion, termed vection. Smoother visual motion displays generate a more compelling subjective sense of vection and objective postural responses, as well as a greater sense of immersiveness for the user observing the visual display. Research suggests that the function linking frame rate and vection asymptotes at 60 frames per second (FPS), but previous studies have used only moderate frame rates that do not approach the limits of human perception. Here, we measure vection using subjective and objective (mean frequency and path length of postural centre-of-pressure (COP) excursions) responses following the presentation of high-contrast optic flow stimuli at slow and fast speeds and low and ultra-high frame rates. We achieve this using a novel rendering method implemented with a projector capable of sub-millisecond temporal resolution in order to simulate refresh rates ranging from very low (15 FPS) to ultra-high frame rates (480 FPS). The results suggest that subjective vection was experienced most strongly at 60 FPS. Below and above 60 FPS, subjective vection is generally weaker, shorter, and starts later, although this pattern varied slightly according to the speed of stimuli. For objective measures, while the frequency of postural sway was unaffected by frame rate, COP path length was greatest for 480 FPS stimuli. Together, our results support diminishing returns for vection above 60 FPS and provide insight into the use of high frame rate for enhancing the user experience in visual displays.

neuroscience↗

bioRxiv2019

Reduction of cybersickness during and immediately following noisy galvanic vestibular stimulation

The mechanism underlying cybersickness during virtual reality (VR) exposure is still poorly understood, although research has highlighted a causal role for visual-vestibular sensory conflict. Recently established methods for reducing cybersickness include galvanic vestibular stimulation (GVS) to mimic absent vestibular cues in VR, or vibration of the vestibular organs to add noise to the sensory modality. Here, we examined if applying noise to the vestibular system using noisy-current GVS also affects sickness severity in VR. Participants were exposed to one of two VR games that were classified as either moderate or intense with respect to their nauseogenic effects. The VR content lasted for 50 minutes and was broken down into 3 blocks: 30 minutes of gameplay during exposure to either noisy GVS ({+/-}1750 A) or sham stimulation (0 A), and 10 minutes of gameplay before and after this block. We characterized the effects of noisy GVS in terms of post-minus-pre-exposure cybersickness scores. For the intense VR content, we found a main effect of noisy vestibular stimulation. Participants reported lower cybersickness scores during and directly after exposure to GVS. However, this difference was quickly extinguished ([~]3-6 min) after further exposure to VR, indicating that sensory adaptation did not persist after stimulation was terminated. In contrast, there were no differences between the sham and GVS group for the moderate VR content. The results show the potential for reducing cybersickness with simple non-invasive sensory stimulation. We discuss the prospect that noise-induced sensory re-weighting is responsible for the observed effects, and address other possible mechanisms.

neuroscience↗

bioRxiv2019

Narrative and gaming experience interact to affect presence and cybersickness in virtual reality

Research has established a link between presence and cybersickness in virtual environments, but there is significant disagreement regarding the directionality of the relationship (positive or negative) between the two factors, and if the relationship is modulated by other top-down influences. Several studies have revealed a negative association between the factors, highlighting the prospect that manipulating one factor might affect the other. Here we examined if a top-down factor (narrative context) enhances presence, and whether this effect is associated with a decrease in cybersickness. We analyzed the association between responses to questionnaire measures of cybersickness and presence, as well as the degree to which their relationship was affected by the administration of an enriched or minimal verbal narrative context. The results of the first experiment, conducted in a controlled laboratory environment, revealed that enriched narrative was associated with increased presence, but that the reductive effect of narrative on cybersickness depended on video gaming experience. We also observed the expected negative association between presence and cybersickness, but only in the enriched narrative group. In a second experiment, conducted with a diverse sample at a public museum, we confirmed our previous finding that presence and cybersickness are negatively correlated, specifically when participants experienced an enriched narrative. We also confirmed the interaction between narrative and gaming experience with respect to cybersickness. These results highlight the complexity of the presence-cybersickness relationship, and confirm that both factors can be modulated in a beneficial manner for virtual reality users by means of top-down interventions.

neuroscience↗

bioRxiv2018

Estimating the sensorimotor components of cybersickness

The user base of the virtual reality (VR) medium is growing, and many of these users will experience cybersickness. Accounting for the vast inter-individual variability in cybersickness forms a pivotal step in solving the issue. Most studies of cybersickness focus on a single factor (e.g., balance, sex, vection), while other contributors are overlooked. Here, we characterize the complex relationship between cybersickness and several indices of sensorimotor processing. In a single session, we conducted a battery of tests of balance control, vection responses, and vestibular sensitivity to self-motion. A principal components regression model, primarily composed of balance control measures during vection, significantly predicted 37% of the variability in cybersickness measures. We observed strong, inverse associations between measures of sway and cybersickness. The results reiterate that the relationship between balance control and cybersickness is anything but straightforward. We discuss other factors that may account for the remaining variance in cybersickness.

neuroscience↗