Characteristic changes in the physiological components of cybersickness

Beyond Subjectivity: Continuous Cybersickness Detection Using EEG-based Multitaper Spectrum Estimation

Virtual reality (VR) presents immersive opportunities across many applications, yet the inherent risk of developing cybersickness during interaction can severely reduce enjoyment and platform adoption. Cybersickness is marked by symptoms such as dizziness and nausea, which previous work primarily assessed via subjective post-immersion questionnaires and motion-restricted controlled setups. In this paper, we investigate the dynamic nature of cybersickness while users experience and freely interact in VR. We propose a novel method to continuously identify and quantitatively gauge cybersickness levels from users' passively monitored electroencephalography (EEG) and head motion signals. Our method estimates multitaper spectrums from EEG, integrating specialized EEG processing techniques to counter motion artifacts, and, thus, tracks cybersickness levels in real-time. Unlike previous approaches, our method requires no user-specific calibration or personalization for detecting cybersickness. Our work addresses the considerable challenge of reproducibility and subjectivity in cybersickness research. In addition to our method's implementation, we release our dataset of 16 participants and approximately 2 hours of total recordings to spur future work in this domain. Source code: https://github.com/eth-siplab/EEG_Cybersickness_Estimation_VR-Beyond_Subjectivity.

Impact of cybersickness and presence on treatment satisfaction and clinical outcomes in virtual reality-based biofeedback for depression and anxiety

Virtual Reality-Biofeedback (VR-BF) has emerged as a novel digital intervention for reducing anxiety and depressive symptoms. This study aimed to assess the relationship between cybersickness, presence, treatment satisfaction, and symptom change following VR-BF. In this prospective clinical study, 80 drug-naive adults were enrolled and classified into two groups: those with subclinical depressive and anxiety symptoms (n = 40) and healthy controls (n = 40). All participants completed three sessions of a self-developed VR-BF intervention over four weeks. Clinical outcomes related to depression and anxiety symptoms were assessed using established psychological scales, along with post-intervention evaluations of presence, cybersickness, and treatment satisfaction. Higher presence was associated with greater reductions in anxiety (ΔSTAI: β = -0.24, SE = 0.06, P < 0.001), stress (ΔVAS: β = -0.37, SE = 0.13, P = 0.008), and depressive symptoms (ΔPHQ-9: β = -0.07, SE = 0.02, P = 0.008), and with greater treatment satisfaction (β = 0.07, SE = 0.01, P < 0.001). Cybersickness was inversely correlated with presence (ρ = -0.38, P < 0.001) and satisfaction (β = -0.11, SE = 0.04, P = 0.013) and was associated with smaller improvements in anxiety (ΔSTAI: β = 0.62, SE = 0.30, P = 0.044) and depressive symptoms (ΔPHQ-9: β = 0.28, SE = 0.12, P = 0.019). Female sex and older age were associated with greater clinical improvement and higher satisfaction. These findings underscore the relevance of experiential process factors in VR-BF and support further development of user-centered, tolerable, and clinically effective VR-based interventions.

Acceptability, Usability, and Insights Into Cybersickness Levels of a Novel Virtual Reality Environment for the Evaluation of Depressive Symptoms: Exploratory Observational Study

BACKGROUND

There is a clear need for enhanced mental health assessment, depressive symptom (DS) evaluation being no exception. A promising approach to this aim is using virtual reality (VR), which entails the potential of adding a wider set of assessment domains with enhanced ecological validity. However, whilst several studies have used VR for both diagnostic and treatment purposes, its acceptance, in particular how exposure to virtual environments affects populations with psychiatric conditions remains unknown.

OBJECTIVE

This study aims to report on the acceptability, usability, and cybersickness levels of a pilot VR environment designed for the purpose of differentiating between individuals with DSs.

METHODS

The exploratory study, conducted in Italy, included 50 healthy controls and 50 young adults with mild-to-moderate DSs (without the need for a formal diagnosis). The study used an observational design with approximately 30 minutes of VR exposure followed by a self-report questionnaire battery. The battery included a questionnaire based on the Theoretical Framework of Acceptability, the System Usability Scale as well as the Simulator Sickness Questionnaire.

RESULTS

Results indicate that the majority found VR acceptable for the purposes of mental health screening and treatment. However, for diagnostics, there was a clear preference for VR to be used by mental health professionals as a supplementary tool, as opposed to a stand-alone solution. In practice, following exposure to the pilot VR environment, generally, good levels of acceptability and usability were reported, but areas in need of improvement were identified (such as self-efficacy). Self-reported cybersickness levels were comparable to literature averages but were considerably higher among those with DSs.

CONCLUSIONS

These findings raise questions about the potential interplay between underlying somatic symptoms of depression and VR-induced cybersickness and call for more attention from the scientific community both in terms of methodology as well as potential clinical and theoretical implications. Conclusively, user support indicates a potential for VR to aid mental health assessment, but further research is needed to understand how exposure to virtual environments might affect populations with varying severity and other forms of psychiatric symptoms.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1186/ISRCTN16396369.

Electroencephalography Changes During Cybersickness: Focusing on Delta and Alpha Waves

Virtual reality (VR) is an immersive technology capable of simulating alternate realities, however, it often leads to cybersickness, causing discomfort for users. We conducted an experiment using a group of 30 participants (aged 25 ± 2.1 years) to see the alpha and delta wave changes for three conditions: Blank, Video, and Video Pause, with electroencephalography (EEG) recordings. The experiments were repeated three times (Trial 1, Trial 2, and Trial 3). The results showed a significant increase in delta wave power for Video compared with the Blank (p < 0.05). Video Pause showed a significant decrease compared to Video. Alpha waves significantly decreased during the Video compared with Blank (p < 0.05). Alpha waves during Video Pause showed a significant increase compared to Video (p < 0.05). Our study showed consistent alterations in alpha and delta waves across various visual stimuli for inducing cybersickness, and we observed that the decrease in alpha waves may be significantly associated with cybersickness rather than visual stimuli. These findings have implications for advancing cybersickness research.

Is it all in your head? Reducing virtual reality induced cybersickness by pleasant odor imagery

Although immersive technologies such as virtual reality are constantly growing for personal and professional purposes, their use can often induce a transient state of discomfort known as cybersickness, resulting in numerous symptoms and perceptive-motor vulnerability. In an attempt to develop leads to mitigate cybersickness, encouraging findings have reported decreased symptoms during the presentation of pleasant smells. However, the diffusion of smells in ecological settings is very challenging. An interesting alternative could reside in odor imagery (OI), known for its neurophysiological, behavioral and psychological similarities with odor perception. The aim of this study was therefore to determine the effects of pleasant OI on virtual reality induced cybersickness. Thirty participants performed two 14-minute virtual reality sessions simulating a first-person view from a boat. During the second session we added a picture at the center of the visual field, allowing for pleasant and intense OI based on individualized psychometrical measures. Participants were instructed to focus on the smell evoked by this picture. For both immersions, cybersickness was characterized by the evolution of scores on the Simulator Sickness Questionnaire, and duration of immersion. Our results show that both measures were positively affected by pleasant OI, indicating a decreased intensity of cybersickness symptoms associated with a longer tolerance of the virtual environment. We suggest the observed effects could be mediated by emotional regulation mechanisms driven by pleasant OI, alleviating cybersickness in a similar way to pleasant odor perception. These findings could open the door to new applications of pleasant sensory imagery as strategies to alleviate transient states of discomfort in immersive technologies or perhaps motion-induced sickness.

The Impact of Virtual Reality Content Characteristics on Cybersickness and Head Movement Patterns

Virtual reality (VR) technology has gained popularity across various fields; however, its use often induces cybersickness, characterized by symptoms such as dizziness, nausea, and eye strain. This study investigated the differences in cybersickness levels and head movement patterns under three distinct VR viewing conditions: dynamic VR (DVR), static VR (SVR), and a control condition (CON) using a simulator. Thirty healthy adults participated, and their head movements were recorded using the Meta Quest 2 VR headset and analyzed using Python. The Virtual Reality Sickness Questionnaire (VRSQ) assessed subjective cybersickness levels. The results revealed that the SVR condition induced the highest VRSQ scores (M = 58.057), indicating the most severe cybersickness symptoms, while the DVR condition elicited significantly higher values in head movement variables, particularly in the coefficient of variation (CV) and integral values of head position along the vertical axis, and mean velocity (p < 0.05). These findings suggest that VR content characteristics directly influence users' head movement patterns, closely related to cybersickness occurrence and severity. This study highlights the importance of analyzing head movement patterns in cybersickness research and provides insights for VR content design.

Identifying Behavioral Correlates to Visual Discomfort

Outside of self-report surveys, there are no proven, reliable methods to quantify visual discomfort or visually induced motion sickness symptoms when using head-mounted displays. While valuable tools, self-report surveys suffer from potential biases and low sensitivity due to variability in how respondents may assess and report their experience. Consequently, extreme visual-vestibular conflicts are generally used to induce discomfort symptoms large enough to measure reliably with surveys (e.g., stationary participants riding virtual roller coasters). An emerging area of research is the prediction of discomfort survey results from physiological and behavioral markers. However, the signals derived from experimental paradigms that are explicitly designed to be uncomfortable may not generalize to more naturalistic experiences where comfort is prioritized. In this work we introduce a custom VR headset designed to introduce significant near-eye optical distortion (i.e., pupil swim) to induce visual discomfort during more typical VR experiences. We evaluate visual comfort in our headset while users play the popular VR title Job Simulator and show that eye-tracked dynamic distortion correction improves visual comfort in a multi-session, within-subjects user study. We additionally use representational similarity analysis to highlight changes in head and gaze behavior that are potentially more sensitive to visual discomfort than surveys.

Abnormal brain-heart electrophysiology in mild and severe orthostatic hypotension

INTRODUCTION

This study investigated the changes in cardiocerebral electrophysiology in patients with mild orthostatic hypotension (MOH) and severe orthostatic hypotension (SOH) and their relationship with the severity of orthostatic hypotension, psychiatric symptoms, and cognitive dysfunction.

METHODS

This study included 72 nonorthostatic hypotension (NOH), 17 with MOH, and 11 with SOH. Seated resting-state heart rate variability (HRV) and quantitative electroencephalogram parameters were synchronized and recorded. HRV measures in the time and frequency domains were analyzed, along with the peak frequency and power of the brain waves.

RESULTS

Abnormal neuronal activity was found in FP1 in patients with MOH, whereas it was more widespread in FP1, FP2, and O2 in patients with SOH ( P  < 0.05). Cardiac and cerebral electrophysiological abnormalities were significantly associated with orthostatic hypotension severity, psychiatric symptoms, and cognitive dysfunction.

CONCLUSION

Abnormal EEG activity in patients are mainly manifested in the prefrontal and occipital lobes, especially in patients with SOH. These results may help patients to better understand the mechanisms underlying orthostatic hypotension severity and psychiatric and cognitive impairment in orthostatic hypotension.

Controlling Virtual Reality With Brain Signals: State of the Art of Using VR-Based Feedback in Neurofeedback Applications

The rapid progress of commercial virtual reality (VR) technology, open access to VR development software as well as open-source instructions for creating brain-VR interfaces have increased the number of VR-based neurofeedback (NF) training studies. Controlling a VR environment with brain signals has potential advantages for NF applications. More entertaining, multimodal and adaptive virtual feedback modalities might positively affect subjective user experience and could consequently enhance NF training performance and outcome. Nevertheless, there are certain pitfalls and contraindications that make VR-based NF not suitable for everyone. In the present review, we summarize applications of VR-based NF and discuss positive effects of VR-based NF training as well as contraindications such as cybersickness in VR or age- and sex-related differences. The existing literature implies that VR-based feedback is a promising tool for the improvement of NF training performance. Users generally rate VR-based feedback more positively than traditional 2D feedback, albeit to draw meaningful conclusions and to rule out adverse effects of VR, more research on this topic is necessary. The pace in the development of brain-VR synchronization furthermore necessitates ethical considerations on these technologies.

SmoothRide: A Versatile Solution to Combat Cybersickness in Elevation-Altering Environments

Cybersickness continues to bar many individuals from taking full advantage of virtual reality (VR) technology. Previous work has established that navigating virtual terrain with elevation changes poses a significant risk in this regard. In this paper, we investigate the effectiveness of three cybersickness reduction strategies on users performing a navigation task across virtual elevation-altering terrain. These strategies include static field of view (FOV) reduction, a flat surface approach that disables terrain collision and maintains constant elevation for users, and SmoothRide, a novel technique designed to dampen a user's perception of vertical motion as they travel. To assess the impact of these strategies, we conducted a within-subjects study involving 61 participants. Each strategy was compared against a control condition, where users navigated across terrain without any cybersickness reduction measures in place. Cybersickness data were collected using the Fast Motion Sickness Scale (FMS) and Simulator Sickness Questionnaire (SSQ), along with galvanic skin response (GSR) data. We measured user presence using the IGroup Presence questionnaire (IPQ) and a Single-Item Presence Scale (SIP). Our findings reveal that users experienced significantly lower levels of cybersickness using SmoothRide or FOV reduction. Presence scores reported on the IPQ were statistically similar between SmoothRide and the control condition. Conversely, terrain flattening had adverse effects on user presence scores, and we could not identify a significant effect on cybersickness compared to the control. We demonstrate that SmoothRide is an effective, lightweight, configurable, and easy-to-integrate tool for reducing cybersickness in simulations featuring elevation-altering terrain.

Combined Method Comprising Low Burden Physiological Measurements with Dry Electrodes and Machine Learning for Classification of Visually Induced Motion Sickness in Remote-Controlled Excavator

The construction industry is actively developing remote-controlled excavators to address labor shortages and improve work safety. However, visually induced motion sickness (VIMS) remains a concern in the remote operation of construction machinery. To predict the occurrence and severity of VIMS, we developed a prototype system that acquires multiple physiological signals with different mechanisms under a low burden and detects VIMS from the collected data. Signals during VIMS were recorded from nine healthy adult males operating excavator simulators equipped with multiple displays and a head-mounted display. Light gradient-boosting machine-based VIMS detection binary classification models were constructed using approximately 30,000 s of time-series data, comprising 23 features derived from the physiological signals. These models were validated using leave-one-out cross-validation on seven participants who experienced severe VIMS and evaluated through area under the curve (AUC) scores. The mean receiver operating characteristic curve AUC score was 0.84, and the mean precision-recall curve AUC score was 0.71. All features were incorporated into the models, with saccade frequency and skin conductance response identified as particularly important. These trends aligned with subjective assessments of VIMS severity. This study contributes to advancing the use of remote-controlled machinery by addressing a critical challenge to operator performance and safety.

Effects of dynamic visual feedback system on seasickness

Motion sickness (MS) poses challenges for individuals affected, hindering their activities and travel. This study investigates the effect of a visual dynamic device, forming an artificial horizon plane, on symptoms and physiological changes induced by MS. This device consists of vertical light-emitting diodes whose illumination varies according to the boat's movements. Fifteen subjects with moderate-to-severe MS susceptibility were exposed to a seasickness simulator with and without the device. Symptoms were assessed immediately after exposure. Time spent in the simulator, heart rate, and temperature were also recorded. Symptom intensity at the end of the experience did not differ, but the time spent in the simulator was significantly longer with the device (+46%). Variations in heart rate were also observed. The device delays symptom onset and can be used as a tool against MS. Further research is needed to evaluate its effects, for example, during more prolonged exposure to MS-inducing stimuli.

The Effects of Auditory, Visual, and Cognitive Distractions on Cybersickness in Virtual Reality

Cybersickness (CS) is one of the challenges that has hindered the widespread adoption of Virtual Reality (VR). Consequently, researchers continue to explore novel means to mitigate the undesirable effects associated with this affliction, one that may require a combination of remedies as opposed to a solitary stratagem. Inspired by research probing into the use of distractions as a means to control pain, we investigated the efficacy of this countermeasure against CS, studying how the introduction of temporally time-gated distractions affects this malady during a virtual experience featuring active exploration. Downstream of this, we studied how other aspects of the VR experience are affected by this intervention. We discuss the results of a between-subjects study manipulating the presence, sensory modality, and nature of periodic and short-lived (5-12 seconds) distractor stimuli across four experimental conditions: 1) no-distractors (ND); 2) auditory distractors (AD); 3) visual distractors (VD); 4) cognitive distractors (CD). Two of these conditions (VD and AD) formed a yoked control design wherein every matched pair of 'seers' and 'hearers' was periodically exposed to distractors that were identical in terms of content, temporality, duration, and sequence. In the CD condition, each participant had to periodically perform a 2-back working memory task, the duration and temporality of which was matched to distractors presented in each matched pair of the yoked conditions. These three conditions were compared to a baseline control group featuring no distractions. Results indicated that the reported sickness levels were lower in all three distraction groups in comparison to the control group. The intervention also increased the amount of time users were able to endure the VR simulation and avoided causing detriments to spatial memory and virtual travel efficiency. Overall, it appears that it may be possible to make users less consciously aware and bothered by the symptoms of CS, thereby reducing its perceived severity.

Sustainable Integration of Autonomous Vehicles into Road Networks: Ecological and Passenger Comfort Considerations

Autonomous vehicle (AV) technology is rapidly advancing, leading to a sustainable evolution in transportation. AVs offer the promise of enhanced safety, reduced emissions, improved traffic flow, and increased mobility for passengers. However, the integration of AVs into existing traffic networks presents complex challenges related to ecological sustainability and passenger comfort. This review aims to bridge the gap in the literature by providing a comprehensive evaluation of the influence of AVs on both ecology and passenger comfort within traffic networks. The study synthesizes existing knowledge on AV technology, ecological impacts, and passenger comfort to offer a comprehensive understanding of the challenges and opportunities associated with AVs’ integration. The main objectives of this research are to review the current literature on the environmental impact of AVs, analyze studies on passenger comfort in AVs, identify key challenges and opportunities, and propose future research directions. The results highlight the need for a holistic, sustainable approach that considers both ecological and passenger-centric factors in the design and deployment of AVs. Future research directions are proposed to further our understanding of the complex interplay between AVs, the environment, and passenger well-being, and inform policy decisions and technological advancements that promote sustainable and comfortable transportation solutions.

Feature extraction method of EEG based on wavelet packet reconstruction and deep learning model of VR motion sickness feature classification and prediction

The surging popularity of virtual reality (VR) technology raises concerns about VR-induced motion sickness, linked to discomfort and nausea in simulated environments. Our method involves in-depth analysis of EEG data and user feedback to train a sophisticated deep learning model, utilizing an enhanced GRU network for identifying motion sickness patterns. Following comprehensive data pre-processing and feature engineering to ensure input accuracy, a deep learning model is trained using supervised and unsupervised techniques for classifying and predicting motion sickness severity. Rigorous training and validation procedures confirm the model's robustness across diverse scenarios. Research results affirm our deep learning model's 84.9% accuracy in classifying and predicting VR-induced motion sickness, surpassing existing models. This information is vital for improving the VR experience and advancing VR technology.

The Effects of Secondary Task Demands on Cybersickness in Active Exploration Virtual Reality Experiences

Active exploration in virtual reality (VR) involves users navigating immersive virtual environments, going from one place to another. While navigating, users often engage in secondary tasks that require attentional resources, as in the case of distracted driving. Inspired by research generally studying the effects of task demands on cybersickness (CS), we investigated how the attentional demands specifically associated with secondary tasks performed during exploration affect CS. Downstream of this, we studied how increased attentional demands from secondary tasks affect spatial memory and navigational performance. We discuss the results of a multi-factorial between-subjects study, manipulating a secondary task's demand across two levels and studying its effects on CS in two different sickness-inducing levels of an exploration experience. The secondary task's demand was manipulated by parametrically varying $n$ in an aural $n$-back working memory task and the provocativeness of the experience was manipulated by varying how frequently users experienced a yaw-rotational reorientation effect during the exploration. Results revealed that increases in the secondary task's demand increased sickness levels, also resulting in a higher temporal onset rate, especially when the experience was not already highly sickening. Increased attentional demand from the secondary task also vitiated navigational performance and spatial memory. Overall, increased demands from secondary tasks performed during navigation produce deleterious effects on the VR experience.

Who says you are so sick? An investigation on individual susceptibility to cybersickness triggers using EEG, EGG and ECG

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.

Investigating Personalization Techniques for Improved Cybersickness Prediction in Virtual Reality Environments

In recent cybersickness research, there has been a growing interest in predicting cybersickness using real-time physiological data such as heart rate, galvanic skin response, eye tracking, postural sway, and electroencephalogram. However, the impact of individual factors such as age and gender, which are pivotal in determining cybersickness susceptibility, remains unknown in predictive models. Our research seeks to address this gap, underscoring the necessity for a more personalized approach to cybersickness prediction to ensure a better, more inclusive virtual reality experience. We hypothesize that a personalized cybersickness prediction model would outperform non-personalized models in predicting cybersickness. Evaluating this, we explored four personalization techniques: 1) data grouping, 2) transfer learning, 3) early shaping, and 4) sample weighing using an open-source cybersickness dataset. Our empirical results indicate that personalized models significantly improve prediction accuracy. For instance, with early shaping, the Deep Temporal Convolutional Neural Network (DeepTCN) model achieved a 69.7% reduction in RMSE compared to its non-personalized version. Our study provides evidence of personalization techniques' benefits in improving cybersickness prediction. These findings have implications for developing personalized cybersickness prediction models tailored to individual differences, which can be used to develop personalized cybersickness reduction techniques in the future.

Immersive Virtual Reality-Based Methods for Assessing Executive Functioning: Systematic Review

BACKGROUND

Neuropsychological assessments traditionally include tests of executive functioning (EF) because of its critical role in daily activities and link to mental disorders. Established traditional EF assessments, although robust, lack ecological validity and are limited to single cognitive processes. These methods, which are suitable for clinical populations, are less informative regarding EF in healthy individuals. With these limitations in mind, immersive virtual reality (VR)-based assessments of EF have garnered interest because of their potential to increase test sensitivity, ecological validity, and neuropsychological assessment accessibility.

OBJECTIVE

This systematic review aims to explore the literature on immersive VR assessments of EF focusing on (1) EF components being assessed, (2) how these assessments are validated, and (3) strategies for monitoring potential adverse (cybersickness) and beneficial (immersion) effects.

METHODS

EBSCOhost, Scopus, and Web of Science were searched in July 2022 using keywords that reflected the main themes of VR, neuropsychological tests, and EF. Articles had to be peer-reviewed manuscripts written in English and published after 2013 that detailed empirical, clinical, or proof-of-concept studies in which a virtual environment using a head-mounted display was used to assess EF in an adult population. A tabular synthesis method was used in which validation details from each study, including comparative assessments and scores, were systematically organized in a table. The results were summed and qualitatively analyzed to provide a comprehensive overview of the findings.

RESULTS

The search retrieved 555 unique articles, of which 19 (3.4%) met the inclusion criteria. The reviewed studies encompassed EF and associated higher-order cognitive functions such as inhibitory control, cognitive flexibility, working memory, planning, and attention. VR assessments commonly underwent validation against gold-standard traditional tasks. However, discrepancies were observed, with some studies lacking reported a priori planned correlations, omitting detailed descriptions of the EF constructs evaluated using the VR paradigms, and frequently reporting incomplete results. Notably, only 4 of the 19 (21%) studies evaluated cybersickness, and 5 of the 19 (26%) studies included user experience assessments.

CONCLUSIONS

Although it acknowledges the potential of VR paradigms for assessing EF, the evidence has limitations. The methodological and psychometric properties of the included studies were inconsistently addressed, raising concerns about their validity and reliability. Infrequent monitoring of adverse effects such as cybersickness and considerable variability in sample sizes may limit interpretation and hinder psychometric evaluation. Several recommendations are proposed to improve the theory and practice of immersive VR assessments of EF. Future studies should explore the integration of biosensors with VR systems and the capabilities of VR in the context of spatial navigation assessments. Despite considerable promise, the systematic and validated implementation of VR assessments is essential for ensuring their practical utility in real-world applications.

Biophilic classroom environments on stress and cognitive performance: A randomized crossover study in virtual reality (VR)

The emerging Metaverse will likely increase time expenditure in indoor virtual environments, which could impact human health and well-being. The biophilia hypothesis suggests that humans have an innate tendency to seek connections with the natural world and there is increasing evidence that biophilic design such as the incorporation of green plants can yield health benefits. Recently, virtual reality (VR) has been used to regulate stress and improve overall wellness, particularly by incorporating natural settings. In this randomized crossover study, we designed five virtual classroom scenes with different biophilic elements and turbidity in VR and investigated whether the visual stimulations can affect the stress levels and cognitive functions of 30 young adults from a university in China. We measured their physiological indicators of stress reaction by wearable biomonitoring sensors (blood pressure (BP), heart rate (HR), heart rate variability (HRV), and skin conductance level (SCL)), conducted verbal cognitive tests on attention and creativity, and evaluated subjective/perceived (self-reported) stress levels and connection with nature. Albeit our results suggested no significant change in physiological stress reactions or cognitive functions induced by the biophilic and turbid interventions in VR, the addition of biophilic elements in the Metaverse could benefit students' health due to significantly decreased perceived stress levels and increased connections with nature.

Exploring neurophysiological correlates of visually induced motion sickness using electroencephalography (EEG)

Visually induced motion sickness (VIMS) is a common phenomenon when using visual devices such as smartphones and virtual reality applications, with symptoms including nausea, fatigue, and headache. To date, the neuro-cognitive processes underlying VIMS are not fully understood. Previous studies using electroencephalography (EEG) delivered mixed findings, with some reporting an increase in delta and theta power, and others reporting increases in alpha and beta frequencies. The goal of the study was to gain further insight into EEG correlates for VIMS. Participants viewed a VIMS-inducing visual stimulus, composed of moving black-and-white vertical bars presented on an array of three adjacent monitors. The EEG was recorded during visual stimulation and VIMS ratings were recorded after each trial using the Fast Motion Sickness Scale. Time-frequency analyses were conducted comparing neural activity of participants reporting minimal VIMS (n = 21) and mild-moderate VIMS (n = 12). Results suggested a potential increase in delta power in the centro-parietal regions (CP2) and a decrease in alpha power in the central regions (Cz) for participants experiencing mild-moderate VIMS compared to those with minimal VIMS. Event-related spectral perturbations (ERSPs) suggested that group differences in EEG activity developed with increasing duration of a trial. These results support the hypothesis that the EEG might be sensitive to differences in information processing in VIMS and minimal VIMS contexts, and indicate that it may be possible to identify neurophysiological correlate of VIMS. Differences in EEG activity related to VIMS may reflect differential processing of conflicting visual and vestibular sensory information.

Subjective Visual Vertical test with the 3D virtual reality system: effective factors and cybersickness

BACKGROUND

3D Virtual Reality (VR) offers new opportunities in vestibular science. It also presents new challenges and problems.

AIMS/OBJECTIVES

The study aimed to evaluate the effective factors in the 3D VR Subjective Visual Vertical (SVV) test and the impact of cybersickness on the test results.

MATERIAL AND METHODS

The effect of the foam surface, head position in the yaw axis, moving background, and arm position holding the controller was tested. Cybersickness was evaluated using the Simulator Sickness Questionnaire (SSQ).

RESULTS

The head position and controller holding style significantly affected the results. The foam surface and the moving background did not have a significant effect. Although 61.4% of the patients fell into the bad category according to the symptoms of the SSQ score, cybersickness did not significantly affect the SVV results.

CONCLUSIONS AND SIGNIFICANCE

In 3D VR SVV, additional factors should be considered: the headset's weight, head position, and how we hold the controller. The A-effect emerged when the head was 45 degrees turned on the yaw axis. A significant shift was detected in the test, with the arm holding the controller at 90 degrees. Most subjects felt cybersickness at a considerable level. Cybersickness should always be taken into account in VR when planning new applications.

Brain activity during cybersickness: a scoping review

Virtual reality (VR) experiences can cause a range of negative symptoms such as nausea, disorientation, and oculomotor discomfort, which is collectively called cybersickness. Previous studies have attempted to develop a reliable measure for detecting cybersickness instead of using questionnaires, and electroencephalogram (EEG) has been regarded as one of the possible alternatives. However, despite the increasing interest, little is known about which brain activities are consistently associated with cybersickness and what types of methods should be adopted for measuring discomfort through brain activity. We conducted a scoping review of 33 experimental studies in cybersickness and EEG found through database searches and screening. To understand these studies, we organized the pipeline of EEG analysis into four steps (preprocessing, feature extraction, feature selection, classification) and surveyed the characteristics of each step. The results showed that most studies performed frequency or time-frequency analysis for EEG feature extraction. A part of the studies applied a classification model to predict cybersickness indicating an accuracy between 79 and 100%. These studies tended to use HMD-based VR with a portable EEG headset for measuring brain activity. Most VR content shown was scenic views such as driving or navigating a road, and the age of participants was limited to people in their 20 s. This scoping review contributes to presenting an overview of cybersickness-related EEG research and establishing directions for future work.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10055-023-00795-y.

Using 360-degree immersive videos to assess multiple transdiagnostic symptoms: A study focusing on fear of negative evaluation, paranoid thoughts, negative automatic thoughts, and craving

Over the last 20 years, virtual reality (VR) has gained a great interest for both assessment and treatment of various psychopathologies. However, due to high costs and material specificity, VR remains disadvantageous for clinicians. Adopting a multiple transdiagnostic approach, this study aims at testing the validity of a 360-degree immersive video (360IV) for the assessment of five common psychological symptoms (fear of negative evaluation, paranoid thoughts, negative automatic thoughts, craving for alcohol and for nicotine). A 360IV was constructed in the Darius Café and included actors behaving naturally. One hundred and fifty-eight adults from the general population were assessed in terms of their proneness towards the five symptoms, were then exposed to the 360IV and completed measures for the five state symptoms, four dimensions of presence (place, plausibility, copresence and social presence illusions) and cybersickness. Results revealed that the five symptoms occurred during the immersion and were predicted by the participants' proneness towards these symptoms. The 360IV was also able to elicit various levels of the four dimensions of presence while producing few cybersickness. The present study provides evidence supporting the use of the 360IV as a new accessible, ecological, and standardized tool to assess multiple transdiagnostic symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10055-023-00779-y.

Virtual reality consumer product injuries: An analysis of national emergency department data

INTRODUCTION

The growing popularity of virtual reality devices and increasingly widespread distribution of VR products into the home exposes users to risk of bodily harm. Safety features are integrated into the devices themselves, but the burden of cautious use rests upon the end user. The purpose of this study is to quantify and describe the array of injuries and demographics effected by the burgeoning VR industry to inform and encourage mitigation strategies.

MATERIALS AND METHODS

The National Electronic Injury Surveillance System (NEISS) data was used to examine a nationwide sample of emergency department records from 2013 - 2021. Inverse probability sample weights for cases were applied to arrive at national estimates. NEISS data included consumer product injuries, patient age, sex, race and ethnicity, drug and alcohol involvement, diagnoses, injury descriptions, and emergency department disposition.

RESULTS

The first VR-related injury was reported in the NEISS data in 2017, and injuries were estimated to number 125. Incidents of VR-related injuries amplified as increased VR units sold, and by 2021, there was a 352% increase in VR injuries totaling a weighted estimate of 1,336 ED visits. The most common VR-related injury diagnosis is fracture (30.3%), followed by laceration (18.6%), contusion (13.9%), other (11.8%), and strain / sprain (10.0%). VR-related injuries involve the hand (12.1%), face (11.5%), finger (10.6%), and knee (9.0%), head (7.0%) and upper trunk (7.0%). Patients age 0-5 most commonly experienced injuries to the face (62.3%). Injuries in patients 6-18 were mostly to the hand (22.3%) and face (12.8%). Patients 19-54 experienced primarily injuries to the knee (15.3%), finger (13.5%), and wrist (13.3%). Patients aged 55 and older disproportionately experienced injuries in the upper trunk (49.1%) and upper arm (25.2%).

CONCLUSIONS

This is the first study to describe the incidence, demographics and characteristics of injuries from VR device use. Sales of home VR units continue to increase annually and the rapid increase in VR consumer injuries is being managed by emergency departments across the country. An understanding of these injuries will inform VR manufacturers, application developers, and users to promote safe product development and operation.

A Survey on Affective and Cognitive VR

In Virtual Reality (VR), users can be immersed in emotionally intense and cognitively engaging experiences. Yet, despite strong interest from scholars and a large amount of work associating VR and Affective and Cognitive States (ACS), there is a clear lack of structured and systematic form in which this research can be classified. We define "Affective and Cognitive VR" to relate to works which (1) induce ACS, (2) recognize ACS, or (3) exploit ACS by adapting virtual environments based on ACS measures. This survey clarifies the different models of ACS, presents the methods for measuring them with their respective advantages and drawbacks in VR, and showcases Affective and Cognitive VR studies done in an Immersive Virtual Environment (IVE) in a non-clinical context. Our article covers the main research lines in Affective and Cognitive VR. We provide a comprehensive list of references with the analysis of 63 research articles and summarize future works directions.

Emotions are associated with the genesis of visually induced motion sickness in virtual reality

Visually induced motion sickness (VIMS) is a well-known side effect of virtual reality (VR) immersion, with symptoms including nausea, disorientation, and oculomotor discomfort. Previous studies have shown that pleasant music, odor, and taste can mitigate VIMS symptomatology, but the mechanism by which this occurs remains unclear. We predicted that positive emotions influence the VIMS-reducing effects. To investigate this, we conducted an experimental study with 68 subjects divided into two groups. The groups were exposed to either positive or neutral emotions before and during the VIMS-provoking stimulus. Otherwise, they performed exactly the same task of estimating the time-to-contact while confronted with a VIMS-provoking moving starfield stimulation. Emotions were induced by means of pre-tested videos and with International Affective Picture System (IAPS) images embedded in the starfield simulation. We monitored emotion induction before, during, and after the simulation, using the Self-Assessment Manikin (SAM) valence and arousal scales. VIMS was assessed before and after exposure using the Simulator Sickness Questionnaire (SSQ) and during simulation using the Fast Motion Sickness Scale (FMS) and FMS-D for dizziness symptoms. VIMS symptomatology did not differ between groups, but valence and arousal were correlated with perceived VIMS symptoms. For instance, reported positive valence prior to VR exposure was found to be related to milder VIMS symptoms and, conversely, experienced symptoms during simulation were negatively related to subjects’ valence. This study sheds light on the complex and potentially bidirectional relationship of VIMS and emotions and provides starting points for further research on the use of positive emotions to prevent VIMS.

Electroencephalogram microstates and functional connectivity of cybersickness

Virtual reality (VR) is a rapidly developing technology that simulates the real world. However, for some cybersickness-susceptible people, VR still has an unanswered problem-cybersickness-which becomes the main obstacle for users and content makers. Sensory conflict theory is a widely accepted theory for cybersickness. It proposes that conflict between afferent signals and internal models can cause cybersickness. This study analyzes the brain states that determine cybersickness occurrence and related uncomfortable feelings. Furthermore, we use the electroencephalogram (EEG) microstates and functional connectivity approach based on the sensory conflict theory. The microstate approach is a time-space analysis method that allows signals to be divided into several temporarily stable states, simultaneously allowing for the exploration of short- and long-range signals. These temporal dynamics can show the disturbances in mental processes associated with neurological and psychiatric conditions of cybersickness. Furthermore, the functional connectivity approach gives us in-depth insight and relationships between the sources related to cybersickness. We recruited 40 males (24.1 ± 2.3 years), and they watched a VR video on a curved computer monitor for 10 min to experience cybersickness. We recorded the 5-min resting state EEG (baseline condition) and 10-min EEG while watching the VR video (task condition). Then, we performed a microstate analysis, focusing on two temporal parameters: mean duration and global explained variance (GEV). Finally, we obtained the functional connectivity data using eLoreta and lagged phase synchronization (LPS). We discovered five sets of microstates (A-E), including four widely reported canonical microstates (A-D), during baseline and task conditions. The average duration increased in microstates A and B, which is related to the visual and auditory networks. The GEV and duration decreased in microstate C, whereas those in microstate D increased. Microstate C is related to the default mode network (DMN) and D to the attention network. The temporal dynamics of the microstate parameters are from cybersickness disturbing the sensory, DMN, and attention networks. In the functional connectivity part, the LPS between the left and right parietal operculum (OP) significantly decreased (p < 0.05) compared with the baseline condition. Furthermore, the connectivity between the right OP and V5 significantly decreased (p < 0.05). These results also support the disturbance of the sensory network because a conflict between the visual (V5) and vestibular system (OP) causes cybersickness. Changes in the microstates and functional connectivity support the sensory conflict theory. These results may provide additional information in understanding brain dynamics during cybersickness.

EEG-based evaluation of motion sickness and reducing sensory conflict in a simulated autonomous driving environment

Autonomous driving offers significant potential for changes in the automotive industry. However, sensory conflict during autonomous driving can lead to motion sickness. Quantitative evaluation and effective preventions to predict and reduce motion sickness are needed. The goal of this study is to verify the objective indicator of motion sickness level based on encephalography (EEG) that we proposed before and investigate the influence of attenuating sensory conflict on motion sickness. A 6-degree of freedom (DOF) driving simulator platform was used to provide an autonomous driving environment to the subjects, and the subjective motion sickness level (MSL), as well as the EEG signals of 15 healthy subjects, were collected simultaneously during 3 conditions, i) autonomous driving, ii) autonomous driving with eyes blindfolded and iii) active driving. The MSLs were reported by the subjects every two minutes, providing a reference to the recorded EEG signals. The EEG signals were analyzed and compared among different conditions. Average MSLs were higher in autonomous driving than in autonomous driving with eyes blindfolded and active driving, together with the increase of the mean EEG frequency of theta band in the central, parietal and occipital areas (FC5, Cz, CP5, P3, and POz). These findings validated that EEG mean frequency of theta band could be an indicator of motion sickness, besides an attenuated visual input or active control of the vehicle can effectively reduce the generation of motion sickness.

Vibro-motor Reprocessing Therapy towards Managing Motion Sickness Reduction: Evidence from EEG

This study examines the neural activities of participants undergoing vibro-motor reprocessing therapy (VRT) while experiencing motion sickness. We evaluated the efficacy of vibro-motor reprocessing therapy, a novel therapeutic technique based on eye movement desensitization and reprocessing (EMDR), in reducing motion sickness. Based on visually induced motion sickness in two sets of performed sessions, eight participants were exposed to VRT stimulation in a VRT/non-VRT setting. Simultaneously, brain activity changes were recorded using electroencephalography (EEG) at baseline and during stimulus exposure, and comparisons made across the VRT/non-VRT conditions. A significant reduction in the alpha (8-12 Hz) spectral power was observed in the frontal and occipital locations, consistent across all participants. Furthermore, significant reductions were also found in the frontal and occipital delta (0.5-4 Hz) and theta (4-8 Hz) spectral power frequency bands between non-VRT and VRT conditions (p < 0.05). Our results offer novel insights for a potential nonpharmacological treatment and attenuation of motion sickness. Furthermore, symptoms can be observed, and alleviated, in real-time using the reported techniques. Clinical relevance - Instead of using drugs to treat motion sickness, patients could safely use this VRT technique.

Temporal Development of Sense of Presence and Cybersickness during an Immersive VR Experience

Following the advances in modern head-mounted displays, research exploring the human experience of virtual environments has seen a surge in interest. Researchers have examined how to promote individuals’ sense of presence, i.e., their experience of “being” in the VE, as well as to diminish the negative side effects of cybersickness. Studies investigating the relationship between sense of presence and cybersickness have reported heterogeneous results. Authors that found a positive relation have argued that the phenomena have shared cognitive underpinnings. However, recent literature has reported that positive associations can be explained by the confounding factor of immersion. The current study aims to investigate how cybersickness and sense of presence are associated and develop over time. During the experiment, participants were exposed to a virtual roller coaster and presented orally with questions aimed to quantify their perceived sense of presence and cybersickness. The results of the experiment indicate that cybersickness and sense of presence are both modulated by the time spent in the virtual setting. The utilized short measures for sense of presence and cybersickness were found to be reliable alternatives to multi-item questionnaires.

Cybersickness and Its Severity Arising from Virtual Reality Content: A Comprehensive Study

Virtual reality (VR) experiences often elicit a negative effect, cybersickness, which results in nausea, disorientation, and visual discomfort. To quantitatively analyze the degree of cybersickness depending on various attributes of VR content (i.e., camera movement, field of view, path length, frame reference, and controllability), we generated cybersickness reference (CYRE) content with 52 VR scenes that represent different content attributes. A protocol for cybersickness evaluation was designed to collect subjective opinions from 154 participants as reliably as possible in conjunction with objective data such as rendered VR scenes and biological signals. By investigating the data obtained through the experiment, the statistically significant relationships—the degree that the cybersickness varies with each isolated content factor—are separately identified. We showed that the cybersickness severity was highly correlated with six biological features reflecting brain activities (i.e., relative power spectral densities of Fp1 delta, Fp 1 beta, Fp2 delta, Fp2 gamma, T4 delta, and T4 beta waves) with a coefficient of determination greater than 0.9. Moreover, our experimental results show that individual characteristics (age and susceptibility) are also quantitatively associated with cybersickness level. Notably, the constructed dataset contains a number of labels (i.e., subjective cybersickness scores) that correspond to each VR scene. We used these labels to build cybersickness prediction models and obtain a reliable predictive performance. Hence, the proposed dataset is supposed to be widely applicable in general-purpose scenarios regarding cybersickness quantification.

Changes in Electroencephalography Activity of Sensory Areas Linked to Car Sickness in Real Driving Conditions

Car sickness is a major concern for car passengers, and with the development of autonomous vehicles, increasing numbers of car occupants are likely to be affected. Previous laboratory studies have used EEG measurements to better understand the cerebral changes linked to symptoms. However, the dynamics of motion in labs/simulators differ from those of a real car. This study sought to identify specific cerebral changes associated with the level of car sickness experienced in real driving conditions. Nine healthy volunteers participated as front passengers in a slalom session inducing lateral movements at very low frequency (0.2 Hz). They were continuously monitored via EEG recordings and subjectively rated their level of symptoms after each slalom, using a 5-point likert scale. Car-sickness symptoms evolved concomitantly with changes in theta and alpha power in the occipital and parietal areas. These changes may reflect altered sensory integration, as well as a possible influence of sleepiness mitigating symptoms.

Mismatch of Visual-Vestibular Information in Virtual Reality: Is Motion Sickness Part of the Brains Attempt to Reduce the Prediction Error?

Visually induced motion sickness (VIMS) is a relevant limiting factor in the use of virtual reality (VR) devices. Understanding the origin of this problem might help to develop strategies to circumvent this limitation. Previous studies have attributed VIMS to a mismatch between visual, and vestibular information, causing ambiguity of the position of the body in relation to its surrounding. Studies using EEG have shown a shift of the power spectrum to lower frequencies while VIMS is experienced. However, little is known about the relationship between the intensity of the VIMS and the changes in these power spectra. Moreover, the effect of different varieties of VIMS on the causal relationship between brain areas is largely unknown. Here, we used EEG to study 14 healthy subjects in a VR environment who were exposed to increasing levels of mismatch between vestibular and visual information. The frequency power and the bivariate transfer entropy as a measure for the information transfer were calculated. We found a direct association between increasing mismatch levels and subjective VIMS. With increasing VIMS, the proportion of slow EEG waves (especially 1–10 Hz) increases, especially in temporo-occipital regions. Furthermore, we found a general decrease in the information flow in most brain areas but especially in brain areas involved in the processing of vestibular signals and the detection of self-motion. We hypothesize that the general shift of frequency power and the decrease in information flow while experiencing high intensity VIMS represent a brain state of a reduced ability to receive, transmit and process information. We further hypothesize that the mechanism of reduced information flow is a general reaction of the brain to an unresolvable mismatch of information. This reaction aims on transforming a currently unstable model with a high prediction error into a stable model in an environment of minimal contradictory information.

Using Positive Attribute Framing to Attenuate Nocebo Side Effects: A Cybersickness Study

BACKGROUND

Side effect warnings can contribute directly to their occurrence via the nocebo effect. This creates a challenge for clinicians and researchers, because warnings are necessary for informed consent, but can cause harm. Positive framing has been proposed as a method for reducing nocebo side effects whilst maintaining the principles of informed consent, but the limited available empirical data are mixed.

PURPOSE

To test whether positive attribute framing reduces nocebo side effects relative to negative framing, general warning, and no warning.

METHODS

Ninety-nine healthy volunteers were recruited under the guise of a study on virtual reality (VR) and spatial awareness. Participants were randomized to receive positively framed ("7 out of 10 people will not experience nausea"), negatively framed ("3 out of 10 people will experience nausea"), general ("a proportion of people will experience nausea"), or no side effect warnings prior to VR exposure.

RESULTS

Receiving a side effect warning increased VR cybersickness relative to no warning overall, confirming that warnings can induce nocebo side effects. Importantly, however, positive framing reduced cybersickness relative to both negative framing and the general warning, with no difference between the latter two. Further, there was no difference in side effects between positive framing and no warning.

CONCLUSIONS

These findings suggest that positive framing not only reduces nocebo side effects relative to negative framing and general warnings, but actually prevents nocebo side effects from occurring at all. As such, positive attribute framing may be a cheap and ethical way to reduce nocebo side effects.

Comparing the Differences in Brain Activities and Neural Comodulations Associated With Motion Sickness Between Drivers and Passengers

It is common to believe that passengers are more adversely affected by motion sickness than drivers. However, no study has compared passengers and drivers' neural activities and drivers experiencing motion sickness (MS). Therefore, this study attempts to explore brain dynamics in motion sickness among passengers and drivers. Eighteen volunteers participated in simulating the driving winding road experiment while their subjective motion sickness levels and electroencephalogram (EEG) signals were simultaneously recorded. Independent Component Analysis (ICA) was employed to isolate MS-related independent components (ICs) from EEG. Furthermore, comodulation analysis was applied to decompose spectra of interest ICs, related to MS, to find the specific spectra-related temporally independent modulators (IMs). The results showed that passengers' alpha band (8-12 Hz) power increased in correlation with the MS level in the parietal, occipital midline and left and right motor areas, and drivers' alpha band (8-12 Hz) power showed relatively smaller increases than those in the passenger. Further, the results also indicate that the enhanced activation of alpha IMs in the passenger than the driver is due to a higher degree of motion sickness. In conclusion, compared to the driver, the passenger experience more conflicts among multimodal sensory systems and demand neuro-physiological regulation.

Non-Contact Measurement of Motion Sickness Using Pupillary Rhythms from an Infrared Camera

Both physiological and neurological mechanisms are reflected in pupillary rhythms via neural pathways between the brain and pupil nerves. This study aims to interpret the phenomenon of motion sickness such as fatigue, anxiety, nausea and disorientation using these mechanisms and to develop an advanced non-contact measurement method from an infrared webcam. Twenty-four volunteers (12 females) experienced virtual reality content through both two-dimensional and head-mounted device interpretations. An irregular pattern of the pupillary rhythms, demonstrated by an increasing mean and standard deviation of pupil diameter and decreasing pupillary rhythm coherence ratio, was revealed after the participants experienced motion sickness. The motion sickness was induced while watching the head-mounted device as compared to the two-dimensional virtual reality, with the motion sickness strongly related to the visual information processing load. In addition, the proposed method was verified using a new experimental dataset for 23 participants (11 females), with a classification performance of 89.6% (n = 48) and 80.4% (n = 46) for training and test sets using a support vector machine with a radial basis function kernel, respectively. The proposed method was proven to be capable of quantitatively measuring and monitoring motion sickness in real-time in a simple, economical and contactless manner using an infrared camera.

The role of binocular disparity and active motion parallax in cybersickness

Cybersickness is an enduring problem for users of virtual environments. While it is generally assumed that cybersickness is caused by discrepancies in perceived self-motion between the visual and vestibular systems, little is known about the relative contribution of active motion parallax and binocular disparity to the occurrence of cybersickness. We investigated the role of these two depth cues in cybersickness by simulating a roller-coaster ride using a head-mounted display. Participants could see the tracks via a virtual frame placed at the front of the roller-coaster cart. We manipulated the state of the frame, so it behaved like: (1) a window into the virtual scene, (2) a 2D screen, (3) and (4) a window for one of the two depth cues, and a 2D screen for the other. Participants completed the Simulator Sickness Questionnaire before and after the experiment, and verbally reported their level of discomfort at repeated intervals during the ride. Additionally, participants' electrodermal activity (EDA) was recorded. The results of the questionnaire and the continuous ratings revealed the largest increase in cybersickness when the frame behaved like a window, and least increase when the frame behaved like a 2D screen. Cybersickness scores were at an intermediate level for the conditions where the frame simulated only one depth cue. This suggests that neither active motion parallax nor binocular disparity had a more prominent effect on the severity of cybersickness. The EDA responses increased at about the same rate in all conditions, suggesting that EDA is not necessarily coupled with subjectively experienced cybersickness.

Clinical predictors of cybersickness in virtual reality (VR) among highly stressed people

The use of virtual reality (VR) in the treatment of psychiatric disorders is increasing, and cybersickness has emerged as an important obstacle to overcome. However, the clinical factors affecting cybersickness are still not well understood. In this study, we investigated clinical predictors and adaptation effect of cybersickness during VR application in highly stressed people. Eighty-three healthy adult participants with high stress level were recruited. At baseline, we conducted psychiatric, ophthalmologic, and otologic evaluations and extracted physiological parameters. We divided the participants into two groups according to the order of exposure to VR videos with different degrees of shaking and repetitively administered the Simulator Sickness Questionnaire (SSQ) and the Fast Motion sickness Scale (FMS). There was no significant difference in changes in the SSQ or the FMS between groups. The 40–59 years age group showed a greater increase in FMS compared to the 19–39 years age group. Smoking was negatively associated with cybersickness, and a high Positive Affect and Negative Affect Schedule score was positively associated with cybersickness. In conclusion, changing the intensity of shaking in VR did not affect cybersickness. While smoking was a protective factor, more expression of affect was a risk factor for cybersickness.

Virtual Reality Tailored to the Needs of Post-ICU Patients: A Safety and Immersiveness Study in Healthy Volunteers

Supplemental Digital Content is available in the text.

Objectives:

ICU treatments frequently result in long-term psychologic impairments, negatively affecting quality of life. An effective treatment strategy is still lacking. The aim of this study was to describe and evaluate the safety and immersiveness of a newly designed ICU-specific virtual reality module.

Design:

A randomized controlled healthy volunteer trial.

Setting:

ICU of the Franciscus Gasthuis & Vlietland Hospital (Rotterdam, the Netherlands), a large teaching hospital.

Participants:

Forty-five virtual reality–naive healthy volunteers.

Interventions:

Volunteers were randomized to three arms: the head-mounted display virtual reality group (n = 15), the 2D group (n = 15), and the crossover group (n = 15). Safety was assessed by changes in vital signs and the occurrence of simulator sickness (Simulator Sickness Questionnaire). Immersiveness was assessed using the Igroup Presence Questionnaire.

Measurements and Main Results:

Volunteers in the head-mounted display virtual reality group experienced more mild symptoms of simulator sickness, expressed as symptoms of dizziness (p = 0.04) and stomach awareness (p = 0.04), than the 2D group. Nevertheless, none of the individual Simulator Sickness Questionnaire items were scored as being severe, no changes in vital signs were observed, and no sessions were prematurely stopped. Volunteers in the crossover group experienced a higher total presence (p < 0.001) when using head-mounted display virtual reality, expressed as a higher sense of presence (p < 0.001), more involvement (p < 0.01), and more experienced realism (p < 0.001).

Conclusions:

ICU-specific virtual reality appears safe and more immersive than 2D, implicating that ICU-specific virtual reality is feasible for clinical use. One should however be aware of simulator sickness-related symptoms. Future research is needed to confirm these findings in survivors of critical illness.

Floor-vibration VR: Mitigating Cybersickness Using Whole-body Tactile Stimuli in Highly Realistic Vehicle Driving Experiences

This work addresses cybersickness, a major barrier to successful long-exposure immersive virtual reality (VR) experiences since user discomfort frequently leads to prematurely ending such experiences. Starting from sensory conflict theory, we posit that if a vibrating floor delivers vestibular stimuli that minimally match the vibration characteristics of a scenario, the size of the conflict between the visual and vestibular senses will be reduced and, thus, the incidence and/or severity of cybersickness will also be reduced. We integrated a custom-built, computer-controlled vibrating floor in our VR system. To evaluate the system, we implemented a realistic off-road vehicle driving simulator in which participants rode multiple laps as passengers on an off-road course. We programmed the floor to generate vertical vibrations similar to those experienced in real off-road vehicle travel. The scenario and driving conditions were designed to be cybersickness-inducing for users in both the Vibration and No-vibration conditions. We collected subjective and objective data for variables previously shown to be related to levels of cybersickness or presence. These included presence and simulator sickness questionnaires (SSQ), self-rated discomfort levels, and the physiological signals of heart rate, galvanic skin response (GSR), and pupil size. Comparing data between participants in the Vibration group (N=11) to the No-Vibration group (N=11), we found that Delta-SSQ Oculomotor response and the GSR physiological signal, both known to be positively correlated with cybersickness, were significantly lower (with large effect sizes) for the Vibration group. Other variables differed between groups in the same direction, but with trivial or small effect sizes. The results indicate that the floor vibration significantly reduced some measures of cybersickness.

Toward Predicting Motion Sickness Using Virtual Reality and a Moving Platform Assessing Brain, Muscles, and Heart Signals

Motion sickness (MS) and postural control (PC) conditions are common complaints among those who passively travel. Many theories explaining a probable cause for MS have been proposed but the most prominent is the sensory conflict theory, stating that a mismatch between vestibular and visual signals causes MS. Few measurements have been made to understand and quantify the interplay between muscle activation, brain activity, and heart behavior during this condition. We introduce here a novel multimetric system called BioVRSea based on virtual reality (VR), a mechanical platform and several biomedical sensors to study the physiology associated with MS and seasickness. This study reports the results from 28 individuals: the subjects stand on the platform wearing VR goggles, a 64-channel EEG dry-electrode cap, two EMG sensors on the gastrocnemius muscles, and a sensor on the chest that captures the heart rate (HR). The virtual environment shows a boat surrounded by waves whose frequency and amplitude are synchronized with the platform movement. Three measurement protocols are performed by each subject, after each of which they answer the Motion Sickness Susceptibility Questionnaire. Nineteen parameters are extracted from the biomedical sensors (5 from EEG, 12 from EMG and, 2 from HR) and 13 from the questionnaire. Eight binary indexes are computed to quantify the symptoms combining all of them in the Motion Sickness Index (I _MS ). These parameters create the MS database composed of 83 measurements. All indexes undergo univariate statistical analysis, with EMG parameters being most significant, in contrast to EEG parameters. Machine learning (ML) gives good results in the classification of the binary indexes, finding random forest to be the best algorithm (accuracy of 74.7 for I _MS ). The feature importance analysis showed that muscle parameters are the most relevant, and for EEG analysis, beta wave results were the most important. The present work serves as the first step in identifying the key physiological factors that differentiate those who suffer from MS from those who do not using the novel BioVRSea system. Coupled with ML, BioVRSea is of value in the evaluation of PC disruptions, which are among the most disturbing and costly health conditions affecting humans.

Immersive Virtual Reality and Ocular Tracking for Brain Mapping During Awake Surgery: Prospective Evaluation Study

Background

Language mapping during awake brain surgery is currently a standard procedure. However, mapping is rarely performed for other cognitive functions that are important for social interaction, such as visuospatial cognition and nonverbal language, including facial expressions and eye gaze. The main reason for this omission is the lack of tasks that are fully compatible with the restrictive environment of an operating room and awake brain surgery procedures.

Objective

This study aims to evaluate the feasibility and safety of a virtual reality headset equipped with an eye-tracking device that is able to promote an immersive visuospatial and social virtual reality (VR) experience for patients undergoing awake craniotomy.

Methods

We recruited 15 patients with brain tumors near language and/or motor areas. Language mapping was performed with a naming task, DO 80, presented on a computer tablet and then in 2D and 3D via the VRH. Patients were also immersed in a visuospatial and social VR experience.

Results

None of the patients experienced VR sickness, whereas 2 patients had an intraoperative focal seizure without consequence; there was no reason to attribute these seizures to virtual reality headset use. The patients were able to perform the VR tasks. Eye tracking was functional, enabling the medical team to analyze the patients’ attention and exploration of the visual field of the virtual reality headset directly.

Conclusions

We found that it is possible and safe to immerse the patient in an interactive virtual environment during awake brain surgery, paving the way for new VR-based brain mapping procedures.

Trial Registration

ClinicalTrials.gov NCT03010943; https://clinicaltrials.gov/ct2/show/NCT03010943.

Ethical Challenges of Using Virtual Environments in the Assessment and Treatment of Psychopathological Disorders

Clinicians are increasingly interested in the potential of virtual environments for research and praxes. Virtual environments include both immersive and non-immersive simulations of everyday activities. Moreover, algorithmic devices and adaptive virtual environments allow clinicians a medium for personalizing technologies to their patients. There is also increasing recognition of social virtual environments that connect virtual environments to social networks. Although there has been a great deal of deliberation on these novel technologies for assessment and treatment, less discourse has occurred around the ethical challenges that may ensue when these technologies are applied clinically. In this paper, some of the ethical issues involved in the clinical use of novel technologies are discussed.

VR Sickness Versus VR Presence: A Statistical Prediction Model

Although it is well-known that the negative effects of VR sickness, and the desirable sense of presence are important determinants of a user's immersive VR experience, there remains a lack of definitive research outcomes to enable the creation of methods to predict and/or optimize the trade-offs between them. Most VR sickness assessment (VRSA) and VR presence assessment (VRPA) studies reported to date have utilized simple image patterns as probes, hence their results are difficult to apply to the highly diverse contents encountered in general, real-world VR environments. To help fill this void, we have constructed a large, dedicated VR sickness/presence (VR-SP) database, which contains 100 VR videos with associated human subjective ratings. Using this new resource, we developed a statistical model of spatio-temporal and rotational frame difference maps to predict VR sickness. We also designed an exceptional motion feature, which is expressed as the correlation between an instantaneous change feature and averaged temporal features. By adding additional features (visual activity, content features) to capture the sense of presence, we use the new data resource to explore the relationship between VRSA and VRPA. We also show the aggregate VR-SP model is able to predict VR sickness with an accuracy of 90% and VR presence with an accuracy of 75% using the new VR-SP dataset.

Evaluating the Factors Affecting QoE of 360-Degree Videos and Cybersickness Levels Predictions in Virtual Reality

360-degree Virtual Reality (VR) videos have already taken up viewers’ attention by storm. Despite the immense attractiveness and hype, VR conveys a loathsome side effect called “cybersickness” that often creates significant discomfort to the viewers. It is of great importance to evaluate the factors that induce cybersickness symptoms and its deterioration on the end user’s Quality-of-Experience (QoE) when visualizing 360-degree videos in VR. This manuscript’s intent is to subjectively investigate factors of high priority that affect a user’s QoE in terms of perceptual quality, presence, and cybersickness. The content type (fast, medium, and slow), the effect of camera motion (fixed, horizontal, and vertical), and the number of moving targets (none, single, and multiple) in a video can be the factors that may affect the QoE. The significant effect of such factors on end-user QoE under various stalling events (none, single, and multiple) is evaluated in a subjective experiment. The results from subjective experiments show a notable impact of these factors on end-user QoE. Finally, to label the viewing safety concern in VR, we propose a neural network-based QoE prediction method that can predict the degree of cybersickness influenced by 360-degree videos under various stalling events in VR. The performance accuracy of the proposed method is then compared against well-known Machine Learning (ML) algorithms and existing QoE prediction models. The proposed method achieved a 90% prediction accuracy rate and performed well against existing models and other ML methods.

Research on the Comfort of Vehicle Passengers Considering the Vehicle Motion State and Passenger Physiological Characteristics: Improving the Passenger Comfort of Autonomous Vehicles

Comfort is a significant factor that affects passengers’ choice of autonomous vehicles. The comfort of an autonomous vehicle is largely determined by its control algorithm. Therefore, if the comfort of passengers can be predicted based on factors that affect comfort and the control algorithm can be adjusted, it can be beneficial to improve the comfort of autonomous vehicles. In view of this, in the present study, a human-driven experiment was carried out to simulate the typical driving state of a future autonomous vehicle. In the experiment, vehicle motion parameters and the comfort evaluation results of passengers with different physiological characteristics were collected. A single-factor analysis method and binary logistic regression analysis model were used to determine the factors that affect the evaluation results of passenger comfort. A passenger comfort prediction model was established based on the bidirectional long short-term memory network model. The results demonstrate that the accuracy of the passenger comfort prediction model reached 84%, which can provide a theoretical basis for the adjustment of the control algorithm and path trajectory of autonomous vehicles.

Uncertainty promotes information-seeking actions, but what information?

Navigating an unfamiliar city almost certainly brings out uncertainty about getting from place to place. This uncertainty, in turn, triggers information gathering. While navigational uncertainty is common, little is known about what type of information people seek when they are uncertain. The primary choices for information types with environments include landmarks (distal or local), landmark configurations (relation between two or more landmarks), and a distinct geometry, at least for some environments. Uncertainty could lead individuals to more likely seek one of these information types. Extant research informs both predictions about and empirical work exploring this question. This review covers relevant cognitive literature and then suggests empirical approaches to better understand information-seeking actions triggered by uncertainty. Notably, we propose that examining continuous navigation data can provide important insights into information seeking. Benefits of continuous data will be elaborated through one paradigm, spatial reorientation, which intentionally induces uncertainty through disorientation and cue conflict. While this and other methods have been used previously, data have primarily reflected only the final choice. Continuous behavior during a task can better reveal the cognition-action loop contributing to spatial learning and decision making.

Methodological Considerations Concerning Motion Sickness Investigations during Automated Driving

Automated driving vehicles will allow all occupants to spend their time with various non-driving related tasks like relaxing, working, or reading during the journey. However, a significant percentage of people is susceptible to motion sickness, which limits the comfort of engaging in those tasks during automated driving. Therefore, it is necessary to investigate the phenomenon of motion sickness during automated driving and to develop countermeasures. As most existing studies concerning motion sickness are fundamental research studies, a methodology for driving studies is yet missing. This paper discusses methodological aspects for investigating motion sickness in the context of driving including measurement tools, test environments, sample, and ethical restrictions. Additionally, methodological considerations guided by different underlying research questions and hypotheses are provided. Selected results from own studies concerning motion sickness during automated driving which were conducted in a motion-based driving simulation and a real vehicle are used to support the discussion.

Factors Associated With Virtual Reality Sickness in Head-Mounted Displays: A Systematic Review and Meta-Analysis

The use of head-mounted displays (HMD) for virtual reality (VR) application-based purposes including therapy, rehabilitation, and training is increasing. Despite advancements in VR technologies, many users still experience sickness symptoms. VR sickness may be influenced by technological differences within HMDs such as resolution and refresh rate, however, VR content also plays a significant role. The primary objective of this systematic review and meta-analysis was to examine the literature on HMDs that report Simulator Sickness Questionnaire (SSQ) scores to determine the impact of content. User factors associated with VR sickness were also examined. A systematic search was conducted according to PRISMA guidelines. Fifty-five articles met inclusion criteria, representing 3,016 participants (mean age range 19.5–80; 41% female). Findings show gaming content recorded the highest total SSQ mean 34.26 (95%CI 29.57–38.95). VR sickness profiles were also influenced by visual stimulation, locomotion and exposure times. Older samples (mean age ≥35 years) scored significantly lower total SSQ means than younger samples, however, these findings are based on a small evidence base as a limited number of studies included older users. No sex differences were found. Across all types of content, the pooled total SSQ mean was relatively high 28.00 (95%CI 24.66–31.35) compared with recommended SSQ cut-off scores. These findings are of relevance for informing future research and the application of VR in different contexts.