Cybersickness: a Multisensory Integration Perspective

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 Effectiveness of Virtual Reality-Based Training on Cognitive, Social, and Physical Functioning in High-Functioning Older Adults (CoSoPhy FX): 2-Arm, Parallel-Group Randomized Controlled Trial

BACKGROUND

Virtual reality (VR) has emerged as a promising technology for enhancing the health care of older individuals, particularly in the domains of cognition, physical activity, and social engagement. However, existing VR products and services have limited availability and affordability; hence, there is a need for a scientifically validated and personalized VR service to be used by older adults in their homes, which can improve their overall physical, cognitive, and social well-being.

OBJECTIVE

The main purpose of the CoSoPhy FX (Cognitive, Social, and Physical Effects) study was to analyze the effects of a VR-based digital therapeutics app on the cognitive, social, and physical performance abilities of healthy (high-functioning) older adults. This paper presents the study protocol and the results from the recruitment phase.

METHODS

A group of 188 healthy older adults aged 65-85 years, recruited at the Medical University of Lodz, Poland, were randomly allocated to the experimental group (VR dual-task training program) or to the control group (using a VR headset app showing nature videos). A total of 3 cognitive exercises were performed in various 360° nature environments delivered via a VR head-mounted display; the participants listened to their preferred music genre. Each patient received 3 sessions of 12 minutes per week for 12 weeks, totaling a minimum of 36 sessions per participant. Attention and working memory (Central Nervous System Vital Signs computerized cognitive battery) were used as primary outcomes, while other cognitive domains in the Central Nervous System Vital Signs battery, quality of life (World Health Organization-5 Well-Being Index), health-related quality of life (EQ-5D-5L), and anxiety (General Anxiety Disorder 7-item questionnaire) were the secondary outcomes. The group-by-time interaction was determined using linear mixed models with participants' individual slopes.

RESULTS

In total, 122 (39%) of the initial 310 participants failed to meet the inclusion criteria, resulting in a recruitment rate of 61% (188/310). Among the participants, 68 successfully completed the intervention and 62 completed the control treatment. The data are currently being analyzed, and we plan to publish the results by the end of September 2024.

CONCLUSIONS

VR interventions have significant potential among healthy older individuals. VR can address various aspects of well-being by stimulating cognitive functions, promoting physical activity, and facilitating social interaction. However, challenges such as physical discomfort, technology acceptance, safety concerns, and cost must be considered when implementing them for older adults. Further research is needed to determine the long-term effects of VR-based interventions, optimal intervention designs, and the specific populations that would benefit most.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05369897; https://clinicaltrials.gov/study/NCT05369897.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53261.

Enhancing Physical Activity with Immersive Virtual Reality: A Systematic Review

The aim of this article is to review how immersive virtual reality-enhanced physical activity (IVR-PA) can be used to improve psychological, physiological, and performance outcomes linked to exercising and to compare it with non-immersive virtual reality-enhanced physical activity (nIVR-PA) and with traditional physical activity (TR-PA). We also aimed to explore the effectiveness of IVR-PA in promoting psychological well-being and engagement in physical activity. A systematic literature review (Prospero CRD42022330572) was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. OVID (including Medline, Embase, GlobalHealth, and APA PsychInfo), Web of Science, and Sport Discuss were searched. The quality of the studies was assessed using the Effective Public Health Practice Project Quality Assessment. The search identified 26,548 titles. After screening, 20 studies (the total number of participants was 798) published between 2009 and 2023 were included in this systematic review. The quality of the studies was rated as weak (n = 9), moderate (n = 10), or strong (n = 1). Overall, the reviewed studies indicated that, compared with TR-PA and nIVR-PA, IVR-PA was associated with an increase in enjoyment of physical activity, a reduction in perceived exertion, and increased rates of self-efficacy, intrinsic motivation, and exercise intention. Furthermore, some studies showed higher muscular strength and aerobic increase after an IVR-PA intervention compared with TR-PA. The findings suggest that IVR-PA can improve psychological, physiological, and performance outcomes linked to exercising, as well as improving psychological well-being and engagement in physical activity. However, owing to the methodological limitations of the reviewed studies, further research is encouraged.

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.

Investigating cortical activity during cybersickness by fNIRS

This study investigated brain responses during cybersickness in healthy adults using functional near-infrared spectroscopy (fNIRS). Thirty participants wore a head-mounted display and observed a virtual roller coaster scene that induced cybersickness. Cortical activation during the virtual roller coaster task was measured using fNIRS. Cybersickness symptoms were evaluated using a Simulator Sickness Questionnaire (SSQ) administered after the virtual rollercoaster. Pearson correlations were performed for cybersickness symptoms and the beta coefficients of hemodynamic responses. The group analysis of oxyhemoglobin (HbO) and total hemoglobin (HbT) levels revealed deactivation in the bilateral angular gyrus during cybersickness. In the Pearson correlation analyses, the HbO and HbT beta coefficients in the bilateral angular gyrus had a significant positive correlation with the total SSQ and disorientation. These results indicated that the angular gyrus was associated with cybersickness. These findings suggest that the hemodynamic response in the angular gyrus could be a biomarker for evaluating cybersickness symptoms.

Gait patterns during overground and virtual omnidirectional treadmill walking

BACKGROUND

Omnidirectional treadmills (ODTs) offer a promising solution to the virtual reality (VR) locomotion problem, which describes the mismatch between visual and somatosensory information and contributes to VR sickness. However, little is known about how walking on ODTs impacts the biomechanics of gait. This project aimed to compare overground and ODT walking and turning in healthy young adults.

METHODS

Fifteen young adults completed forward walk, 180° turn, and 360° turn tasks under three conditions: (1) overground, (2) on the Infinadeck ODT in a virtual environment without a handrail, and (3) on the ODT with a handrail. Kinematic data for all walking trials were gathered using 3D optical motion capture.

RESULTS

Overall, gait speed was slower during ODT walking than overground. When controlling for gait speed, ODT walking resulted in shorter steps and greater variability in step length. There were no significant differences in other spatiotemporal metrics between ODT and overground walking. Turning on the ODT required more steps and slower rotational speeds than overground turns. The addition of the stability handrail to the ODT resulted in decreased gait variability relative to the ODT gait without the handrail.

CONCLUSION

Walking on an ODT resembles natural gait patterns apart from slower gait speed and shorter step length. Slower walking and shorter step length are likely due to the novelty of physically navigating a virtual environment which may result in a more conservative approach to gait. Future work will evaluate how older adults and those with neurological disease respond to ODT walking.

An old approach to a novel problem: effect of combined balance therapy on virtual reality induced motion sickness: a randomized, placebo controlled, double-blinded study

BACKGROUND

The objective of this study was to investigate the impact of a rehabilitation program aimed at addressing vestibular and proprioceptive deficits, which are believed to underlie the pathophysiology of motion sickness.

METHODS

A total of 121 medical students with motion sickness participated in this study and were randomly divided into intervention (n = 60) and placebo control (n = 61) groups. The intervention group underwent combined balance, proprioception, and vestibular training three times a week for 4 weeks, while the control group received placebo training. The study assessed various measurements, including the Virtual reality sickness questionnaire (VRSQ), tolerance duration, enjoyment level measured by VAS, stability levels using Biodex, and balance with the Flamingo balance test (FBT). All measurements were conducted both at baseline and 4 weeks later.

RESULTS

There was no significant difference in pre-test scores between the intervention and control groups, suggesting a similar baseline in both groups (p > 0.05). The results showed a significant improvement in VRSQ, tolerance duration, VAS, Biodex, and FBT scores in the intervention group (p < 0.05). While, the control group showed a significant increase only in VAS scores after 4 weeks of training (p < 0.05). A statistically significant improvement was found between the groups for VRSQ (p < 0.001), tolerance duration (p < 0.001), VAS (p < 0.001), Biodex (p = 0.015), and FBT scores (p < 0.05), in favor of the intervention group.

CONCLUSIONS

A combined balance training program for motion sickness proves to be effective in reducing motion sickness symptoms, enhancing user enjoyment, and extending the usage duration of virtual reality devices while improving balance and stability. In contrast, placebo training did not alter motion sickness levels. These findings offer valuable insights for expanding the usage of virtual reality, making it accessible to a broader population.

Design guidelines for limiting and eliminating virtual reality-induced symptoms and effects at work: a comprehensive, factor-oriented review

Virtual reality (VR) can induce side effects known as virtual reality-induced symptoms and effects (VRISE). To address this concern, we identify a literature-based listing of these factors thought to influence VRISE with a focus on office work use. Using those, we recommend guidelines for VRISE amelioration intended for virtual environment creators and users. We identify five VRISE risks, focusing on short-term symptoms with their short-term effects. Three overall factor categories are considered: individual, hardware, and software. Over 90 factors may influence VRISE frequency and severity. We identify guidelines for each factor to help reduce VR side effects. To better reflect our confidence in those guidelines, we graded each with a level of evidence rating. Common factors occasionally influence different forms of VRISE. This can lead to confusion in the literature. General guidelines for using VR at work involve worker adaptation, such as limiting immersion times to between 20 and 30 min. These regimens involve taking regular breaks. Extra care is required for workers with special needs, neurodiversity, and gerontechnological concerns. In addition to following our guidelines, stakeholders should be aware that current head-mounted displays and virtual environments can continue to induce VRISE. While no single existing method fully alleviates VRISE, workers' health and safety must be monitored and safeguarded when VR is used at work.

Fully Immersive Virtual Reality Using 360° Videos to Manage Well-Being in Older Adults: A Scoping Review

OBJECTIVE

The development of negative behavioral and psychosocial factors (depression, anxiety, apathy, etc) is associated with poor well-being, which can contribute to health issues in ageing, especially in the context of COVID-19. Despite its relative novelty, fully immersive virtual reality (VR) interventions through 360° immersive videos are becoming more accessible and flexible and constitute an emerging method to potentially enhance well-being. The aim of this scoping review is to assess the effectiveness of 360° interventions on well-being in older adults with or without cognitive impairment, as well as cybersickness and attitudes toward this technology.

DESIGN

Scoping review.

SETTING AND PARTICIPANTS

Older adults with or without cognitive impairment.

METHODS

The PRISMA-SR guideline was followed. Four databases were used, and we selected articles published until April 2022. We have analyzed the effect of 360° videos on the well-being of older adults with respect to the study design, the population, the contents, the duration of intervention, and the outcomes.

RESULTS

A total of 2262 articles were screened, of which 10 articles were finally included in this review. Most of them are pilot studies and used mixed methods including scales and interviews. The material and content of VR are diversified. Many behavioral and psychological outcomes were assessed, including anxiety, apathy, loneliness, depression, social engagement, quality of life, and emotions. The results were positive or mixed, according to the outcomes. We recorded few adverse events, and the interviews show contrasting results concerning the participants' feelings (ie, degree of immersion, familiarity with technology, and VR content).

CONCLUSIONS AND IMPLICATIONS

The use of VR 360° videos seems feasible in community-dwelling older adults or residential aged care facilities, as they are safe and provide enjoyment. It constitutes an emerging and promising therapeutic tool to manage psychosocial disorders. This review provides key considerations for the design and implementation of interventions using VR 360° video in clinical practice.

Experiences of Depersonalization/Derealization Among Users of Virtual Reality Applications: A Cross-Sectional Survey

Previous research shows that virtual reality (VR) users may experience symptoms of depersonalization/derealization (DPDR) immediately after use. However, the impact of long-term VR use on these symptoms has not been analyzed so far. In a preregistered study, we conducted an online survey among a bigger sample of VR users (N = 754) to investigate the relationship between time of use during the past 6 months and the presence of DPDR symptoms. The results support the absence of a linear association between time of VR use and the presence of symptoms, when controlling for other factors. DPDR symptoms are more frequent among younger female users and in those who experience higher levels of embodiment during use. Secondary analyses show that symptoms are more common among newer users and among those who engage in longer sessions. These findings suggest that current common VR experiences are not a cause of long-term DPDR symptoms for the majority of users, yet also encourage further research about specific cases where VR use might trigger DPDR experiences in the long term.

Visuo-vestibular conflicts within the roll plane modulate multisensory verticality perception

The integration of visuo-vestibular information is crucial when interacting with the external environment. Under normal circumstances, vision and vestibular signals provide corroborating information, for example regarding the direction and speed of self-motion. However, conflicts in visuo-vestibular signalling, such as optic flow presented to a stationary observer, can change subsequent processing in either modality. While previous studies have demonstrated the impact of sensory conflict on unisensory visual or vestibular percepts, here we investigated whether visuo-vestibular conflicts impact sensitivity to multisensory percepts, specifically verticality. Participants were exposed to a visuo-vestibular conflicting or non-conflicting motion adaptor before completing a Vertical Detection Task. Sensitivity to vertical stimuli was reduced following visuo-vestibular conflict. No significant differences in criterion were found. Our findings suggest that visuo-vestibular conflicts not only modulate processing in unimodal channels, but also broader multisensory percepts, which may have implications for higher-level processing dependent on the integration of visual and vestibular signals.

Motion sickness and cybersickness - Sensory mismatch

The use of virtual reality (VR) with head-mounted displays (HMD) may cause side effects called cybersickness with symptoms comparable to those of motion sickness. In this study, we explored whether individual balance characteristics and self-reported tendency to motion sickness could be related to cybersickness vulnerability. Healthy young people (N = 45) were exposed to a VR application with HMD for four minutes, standing with no support. Balance characteristics were measured before (Sensory orientation test) and during (balance platform) the VR exposure. Symptoms of cybersickness were recorded by the Simulator sickness questionnaire (SSQ). Data were analyzed for subgroups with and without a tendency to motion sickness. The participants were negatively affected by the VR exposure: SSQ-before: 21.3 (19.5); SSQ-after: 31.8 (25.2); p<0.01, and 73% experienced increased discomfort. The SSQ sub-scores Nausea and Disorientation were affected, but not the sub-score for Oculomotor disturbance. Surprisingly, the participants described discomfort already after the initial balance assessment (Sensory orientation test). Participants with a self-reported tendency to motion sickness were relatively more affected by this challenge to their sensory integration. Increased postural instability was evident during the VR exposure, but there was a sizeable individual variance in the postural response. The study identified no individual balance characteristics which could be associated with the cybersickness vulnerability. The adverse effect of the Sensory orientation test is a novel finding and it became a bias that diminished subgroup differences in cybersickness vulnerability.

Immersive Virtual Reality during Robot-Assisted Gait Training: Validation of a New Device in Stroke Rehabilitation

Background and objective: Duration of rehabilitation and active participation are crucial for gait rehabilitation in the early stage after stroke onset. Virtual reality (VR) is an innovative tool providing engaging and playful environments that could promote intrinsic motivation and higher active participation for non-ambulatory stroke patients when combined with robot-assisted gait training (RAGT). We have developed a new, fully immersive VR application for RAGT, which can be used with a head-mounted display and wearable sensors providing real-time gait motion in the virtual environment. The aim of this study was to validate the use of this new device and assess the onset of cybersickness in healthy participants before testing the device in stroke patients. Materials and Methods: Thirty-seven healthy participants were included and performed two sessions of RAGT using a fully immersive VR device. They physically walked with the Gait Trainer for 20 min in a virtual forest environment. The occurrence of cybersickness, sense of presence, and usability of the device were assessed with three questionnaires: the Simulator Sickness Questionnaire (SSQ), the Presence Questionnaire (PQ), and the System Usability Scale (SUS). Results: All of the participants completed both sessions. Most of the participants (78.4%) had no significant adverse effects (SSQ < 5). The sense of presence in the virtual environment was particularly high (106.42 ± 9.46). Participants reported good usability of the device (86.08 ± 7.54). Conclusions: This study demonstrated the usability of our fully immersive VR device for gait rehabilitation and did not lead to cybersickness. Future studies should evaluate the same parameters and the effectiveness of this device with non-ambulatory stroke patients.

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.

Stroboscopic lighting with intensity synchronized to rotation velocity alleviates motion sickness gastrointestinal symptoms and motor disorders in rats

Motion sickness (MS) is caused by mismatch between conflicted motion perception produced by motion challenges and expected “internal model” of integrated motion sensory pattern formed under normal condition in the brain. Stroboscopic light could reduce MS nausea symptom via increasing fixation ability for gaze stabilization to reduce visuo-vestibular confliction triggered by distorted vision during locomotion. This study tried to clarify whether MS induced by passive motion could be alleviated by stroboscopic light with emitting rate and intensity synchronized to acceleration–deceleration phase of motion. We observed synchronized and unsynchronized stroboscopic light (SSL: 6 cycle/min; uSSL: 2, 4, and 8 cycle/min) on MS-related gastrointestinal symptoms (conditioned gaping and defecation responses), motor disorders (hypoactivity and balance disturbance), and central Fos protein expression in rats receiving Ferris wheel-like rotation (6 cycle/min). The effects of color temperature and peak light intensity were also examined. We found that SSL (6 cycle/min) significantly reduced rotation-induced conditioned gaping and defecation responses and alleviated rotation-induced decline in spontaneous locomotion activity and disruption in balance beam performance. The efficacy of SSL against MS behavioral responses was affected by peak light intensity but not color temperature. The uSSL (4 and 8 cycle/min) only released defecation but less efficiently than SSL, while uSSL (2 cycle/min) showed no beneficial effect in MS animals. SSL but not uSSL inhibited Fos protein expression in the caudal vestibular nucleus, the nucleus of solitary tract, the parabrachial nucleus, the central nucleus of amygdala, and the paraventricular nucleus of hypothalamus, while uSSL (4 and 8 cycle/min) only decreased Fos expression in the paraventricular nucleus of hypothalamus. These results suggested that stroboscopic light synchronized to motion pattern might alleviate MS gastrointestinal symptoms and motor disorders and inhibit vestibular-autonomic pathways. Our study supports the utilization of motion-synchronous stroboscopic light as a potential countermeasure against MS under abnormal motion condition in future.

Estimating objective (EEG) and subjective (SSQ) cybersickness in people with susceptibility to motion sickness

Cybersickness refers to the uncomfortable side effects, such as headaches, dizziness, and nausea, felt while experiencing virtual reality (VR). This study investigated cybersickness in people with sensitivity to motion sickness using electroencephalography (EEG), the Simulator Sickness Questionnaire (SSQ), and simple VR content. Based on the scores from the Motion Sickness Susceptibility Questionnaire (MSSQ), 40 males in their twenties were selected as the sensitive group (n = 20) and non-sensitive group (n = 20). The experiment contained two conditions: a baseline condition representing a resting state and a cybersickness condition in which watching VR content induced cybersickness. The SSQ score increased significantly after watching the VR content in both groups. The sensitive group showed significantly lower absolute power in the beta and gamma bands than the non-sensitive group. The cybersickness condition showed significantly increased delta and decreased alpha compared to the baseline condition. We evaluated EEG and SSQ to identify subjective symptoms and objective physiological changes associated with cybersickness.

Immersive media experience: a survey of existing methods and tools for human influential factors assessment

Virtual reality (VR) applications, especially those where the user is untethered to a computer, are becoming more prevalent as new hardware is developed, computational power and artificial intelligence algorithms are available, and wireless communication networks are becoming more reliable, fast, and providing higher reliability. In fact, recent projections show that by 2022 the number of VR users will double, suggesting the sector was not negatively affected by the worldwide COVID-19 pandemic. The success of any immersive communication system is heavily dependent on the user experience it delivers, thus now more than ever has it become crucial to develop reliable models of immersive media experience (IMEx). In this paper, we survey the literature for existing methods and tools to assess human influential factors (HIFs) related to IMEx. In particular, subjective, behavioural, and psycho-physiological methods are covered. We describe tools available to monitor these HIFs, including the user's sense of presence and immersion, cybersickness, and mental/affective states, as well as their role in overall experience. Special focus is placed on psycho-physiological methods, as it was found that such in-depth evaluation was lacking from the existing literature. We conclude by touching on emerging applications involving multiple-sensorial immersive media and provide suggestions for future research directions to fill existing gaps. It is hoped that this survey will be useful for researchers interested in building new immersive (adaptive) applications that maximize user experience.

Influence of Sensory Conflict on Perceived Timing of Passive Rotation in Virtual Reality

Integration of incoming sensory signals from multiple modalities is central in the determination of self-motion perception. With the emergence of consumer virtual reality (VR), it is becoming increasingly common to experience a mismatch in sensory feedback regarding motion when using immersive displays. In this study, we explored whether introducing various discrepancies between the vestibular and visual motion would influence the perceived timing of self-motion. Participants performed a series of temporal-order judgements between an auditory tone and a passive whole-body rotation on a motion platform accompanied by visual feedback using a virtual environment generated through a head-mounted display. Sensory conflict was induced by altering the speed and direction by which the movement of the visual scene updated relative to the observer's physical rotation. There were no differences in perceived timing of the rotation without vision, with congruent visual feedback and when the speed of the updating of the visual motion was slower. However, the perceived timing was significantly further from zero when the direction of the visual motion was incongruent with the rotation. These findings demonstrate the potential interaction between visual and vestibular signals in the temporal perception of self-motion. Additionally, we recorded cybersickness ratings and found that sickness severity was significantly greater when visual motion was present and incongruent with the physical motion. This supports previous research regarding cybersickness and the sensory conflict theory, where a mismatch between the visual and vestibular signals may lead to a greater likelihood for the occurrence of sickness symptoms.

Alter Game: A Study Protocol on a Virtual "Serious Game" for Relapse Prevention in Patients With Gambling Disorder

Cognitive behavioral therapy (CBT) is the most successful protocol in gambling disorder (GD) treatment. However, it presents some weaknesses, especially concerning relapse prevention (RP). RP is one of the most important therapeutic steps, aiming at managing cravings and to avoid future relapse increasing perceived self-efficacy. Encouraging results come from the blending of psychotherapy and virtual reality (VR), containing gambling cues. The goal of Alter Game (approved by the Ethical Commission, Prot. No. 69346) is verifying the efficacy of an innovative psychological treatment for GD based on the integration of traditional CBT therapy and an immersive VR cue exposure therapy using a serious virtual game, which is a game designed for purposes other than entertainment. RP in virtual cue-exposure therapy allows pathological gamblers to manage the urge to gamble and to avoid relapse by becoming aware of which internal and external triggers are related to craving. We hypothesize that the integrated intervention will be more effective than simple CBT with regard to self-efficacy, craving, and gambling-related distortions. Four virtual ecological environments were developed, and a virtual app, Exludo, interfaced with a computerized multiparametric acquisition system for biofeedback, was created. A sample of about 60 patients aged between 18 and 65 with GD referring to the Addiction Medicine Unit of Verona (Rossi Hospital) will be recruited. Patients will be randomly assigned to the CBT group (16 CBT sessions) or the CBT + VR group (8 CBT sessions + 8 VR cue-exposure therapy sessions). The MCMI-III, the BIS-11, and the SOGS will be used to evaluate inclusion and exclusion criteria, while the Gambling Related Cognitions Scale and the Multidimensional Gambling Self-Efficacy Scale will be used to verify changes as a function of the treatment. Craving will be evaluated through VAS, and psychophysiological variables will be assessed through biofeedback. A pre-test/post-test experimental design with a 1-month follow-up will be conducted. This study will examine an innovative psychotherapeutic protocol for GD treatment, and it will help in identifying new virtual tools to increase the efficacy of traditional therapeutic approaches that could also be applied to treat other addictions.

A Deep Motion Sickness Predictor Induced by Visual Stimuli in Virtual Reality

In a virtual reality (VR) environment, where visual stimuli predominate over other stimuli, the user experiences cybersickness because the balance of the body collapses due to self-motion. Accordingly, the VR experience is accompanied by unavoidable sickness referred to as visually induced motion sickness (VIMS). In this article, our primary purpose is to simultaneously estimate the VIMS score by referring to the content and calculate the temporally induced VIMS sensitivity. To seek our goals, we propose a novel architecture composed of two consecutive networks: 1) neurological representation and 2) spatiotemporal representation. In the first stage, the network imitates and learns the neurological mechanism of motion sickness. In the second stage, the significant feature of the spatial and temporal domains is expressed over the generated frames. After the training procedure, our model can calculate VIMS sensitivity for each frame of the VR content by using the weakly supervised approach for unannotated temporal VIMS scores. Furthermore, we release a massive VR content database. In the experiments, the proposed framework demonstrates excellent performance for VIMS score prediction compared with existing methods, including feature engineering and deep learning-based approaches. Furthermore, we propose a way to visualize the cognitive response to visual stimuli and demonstrate that the induced sickness tends to be activated in a similar tendency, as done in clinical studies.

Virtual Reality for Health Care Professionals During a Pandemic: A Pilot Program

Objective:

The purpose of this pilot study was to evaluate the safety and use of a nature-based virtual reality (VR) experience among health care providers (HCP) during a pandemic.

Methods:

Twenty-four frontline HCP participated in this crossover pilot where the viewing order of the experiences were randomized. All participants attended in-person consent, baseline, and end-of-study visits. The intervention consisted of viewing 2 nature-based scenes (“walk in the woods” and “forest of focus”) through 3-D VR and with computer 4K graphic imagery. Randomization took place with regards to the viewing order (VR vs 4K computer video, scene 1 and 2). Outcomes measured were safety, acceptability and changes in intensity of anxiety feelings, resilience, emotional distress, cognitive function, and self-efficacy.

Results:

Among the 26 HCP expressing interest in the study, 24 enrolled in this study. The majority were male (58.3%), white (66.7%) and of an average age of 46.3 ± 10.5 years (standard deviation (SD)). End of the study survey showed that almost all participants (96%) would participate in the study again and recommend it to others. Twenty-three of the 24 participants also felt relaxed after seeing the imagery. With respect to anxiety (as measured by the STAI Y1), the VR “walk in the woods” had the greatest reduction from pre to post (6.4 points, SD = 5.98) followed by VR “forest of focus” (5.8 points, SD = 9.29), computer screen “forest of focus” (5.0 points, SD = 8.89), and computer screen “walk in the woods” (4.1 points, SD = 6.22). All 4 sessions had a significant decrease in score from pre to post (P-values ≤.005), but there was no significant difference in the change from pre- to post-session between the 4 groups (P-value = .5835).

Conclusion:

The use of the VR among HCP has promise for reducing stress among health care providers during a high stress period, such as a pandemic but much larger studies are needed.

Reducing Cybersickness in 360-Degree Virtual Reality

Despite the technological advancements in Virtual Reality (VR), users are constantly combating feelings of nausea and disorientation, the so-called cybersickness. Cybersickness symptoms cause severe discomfort and hinder the immersive VR experience. Here we investigated cybersickness in 360-degree head-mounted display VR. In traditional 360-degree VR experiences, translational movement in the real world is not reflected in the virtual world, and therefore self-motion information is not corroborated by matching visual and vestibular cues, which may trigger symptoms of cybersickness. We evaluated whether a new Artificial Intelligence (AI) software designed to supplement the 360-degree VR experience with artificial six-degrees-of-freedom motion may reduce cybersickness. Explicit (simulator sickness questionnaire and Fast Motion Sickness (FMS) rating) and implicit (heart rate) measurements were used to evaluate cybersickness symptoms during and after 360-degree VR exposure. Simulator sickness scores showed a significant reduction in feelings of nausea during the AI-supplemented six-degrees-of-freedom motion VR compared to traditional 360-degree VR. However, six-degrees-of-freedom motion VR did not reduce oculomotor or disorientation measures of sickness. No changes were observed in FMS and heart rate measures. Improving the congruency between visual and vestibular cues in 360-degree VR, as provided by the AI-supplemented six-degrees-of-freedom motion system considered, is essential for a more engaging, immersive and safe VR experience, which is critical for educational, cultural and entertainment applications.

Multimodal Biosensing for Vestibular Network-Based Cybersickness Detection

Virtual reality (VR) has the potential to induce cybersickness (CS), which impedes CS-susceptible VR users from the benefit of emerging VR applications. To better detect CS, the current study investigated whether/how the newly proposed human vestibular network (HVN) is involved in flagship consumer VR-induced CS by simultaneously recording autonomic physiological signals as well as neural signals generated in sensorimotor and cognitive domains. The VR stimuli were made up of one or two moderate CS-inducing entertaining task(s) as well as a mild CS-inducing cognitive task implemented before and after the moderate CS task(s). Results not only showed that CS impaired cognitive control ability, represented by the degree of attentional engagement, but also revealed that combined indicators from all three HVN domains could together establish the best regression relationship with CS ratings. More importantly, we found that every HVN domain had its unique advantage with the dynamic changes in CS severity and time. These results provide evidence for involvement of the HVN in CS and indicate the necessity of HVN-based CS detection.

New and Emerging Hazards for Health and Safety within Digitalized Manufacturing Systems

The Fourth Industrial Revolution is radically reshaping the procedures and the manufacturing environments through the digitalization process. The digitalization process can change according to the context and to specific solutions, and it is able to modify manufacturing systems and production areas. All the employees are directly affected by the transformation of the working environment, manufacturing tools, and working conditions and by the increasing need for new competencies. In this context, it is crucial to identify new and emerging hazards concerning the health and safety of the employees to ensure a conscious and safe digital transformation for everyone involved. In this regard, the paper presents the state of the research and defines seven areas of interest for a safe and harmless digital transformation for the employees, drawing attention to the hazards in the different technological areas. The state of the research unveils the absence of detailed analysis to identify specific hazards of 4.0 technologies. Therefore, every specific 4.0 technologies is analyzed by an extensive review to provide a comprehensive matrix of new and emerging hazards for health and safety within digitalized manufacturing systems. The results can help manufacturing organizations to perform robust risk assessments for worker when introducing specific 4.0 technologies.

Virtual Reality to Improve Sequelae of the Postintensive Care Syndrome: A Multicenter, Randomized Controlled Feasibility Study

Supplemental Digital Content is available in the text.

Psychologic sequelae after critical illness, part of the postintensive care syndrome, significantly decrease quality of life. A robustly effective treatment intervention is currently lacking. Virtual reality has beneficial effects on several non-ICU–related psychologic disorders. The aim of this study was to explore patient-related determinants of ICU-specific virtual reality, such as the timing of patients’ self-reported readiness to initiate virtual reality and the number of desired sessions and safety, and to explore the effects of ICU-specific virtual reality on mental health.

Physiological and Metabolic Requirements, and User-Perceived Exertion of Immersive Virtual Reality Exergaming Incorporating an Adaptive Cable Resistance System: An Exploratory Study

Objective: To measure metabolic and physiological demand, subjective fatigue, and enjoyment during a signature 30-minute immersive virtual reality (IVR) adaptive cable resistance exergaming session. Methods: Fourteen healthy college-aged individuals (seven females) were initially acquainted with the IVR equipment and gameplay dynamics. Participants then underwent a 30-minute IVR exergaming session performing six different cable resistance exercises. A portable metabolic gas exchange analyzer concurrently assessed energy expenditure (EE) through indirect calorimetry while a chest-worn monitor captured heart rate (HR). Participants subsequently completed questionnaires, including the Borg scale for rating of perceived exertion (RPE), Physical Activity Enjoyment Scale (PACES), and Simulator Sickness Questionnaire (SSQ). Results: The mean EE, mean metabolic equivalent, and average total calories expended during the 30-minute session were 14.7 (standard deviation [SD] 2.8) kcal/minute, 12.9 (SD 0.5), and 440 (SD 84) kcals respectively. The mean HR was 176 (SD 3.1) beats per minute (bpm) with a mean max HR of 188 SD (SD 2.9) bpm. The combined training volume among all participants was 16,102 kg (SD 4137). Participants classified the IVR training session to be "somewhat hard-to-hard" with a RPE score of 14 (SD 1) while indicating the session to be "enjoyable" with a PACES score of 4.31 (SD 0.36). The participants did not report any cybersickness symptoms, demonstrating an average total SSQ score of 24.04 (SD 24.13). Conclusions: IVR exergaming incorporating cable resistance training elicits high EE and physiological demand with high enjoyment scores while attenuating perceived fatigue. The potential for IVR to elicit these acute training effects over long-term training periods warrants further investigation into its contribution to fitness and health.

Machine-Deep-Ensemble Learning Model for Classifying Cybersickness Caused by Virtual Reality Immersion

This study aims to classify cybersickness (CS) caused by virtual reality (VR) immersion through a machine-deep-ensemble learning model. The heart rate variability and respiratory signal parameters of 20 subjects were measured, while watching a VR video for ∼5 minutes. After the experiment, the subjects were examined for CS and questioned to determine their CS states. Based on the results, we constructed a machine-deep-ensemble learning model that could identify and classify VR immersion CS among subjects. The ensemble model comprised four stacked machine learning models (support vector machine [SVM], k-nearest neighbor [KNN], random forest, and AdaBoost), which were used to derive prediction data, and then, classified the prediction data using a convolution neural network. This model was a multiclass classification model, allowing us to classify subjects' CS into three states (neutral, non-CS, and CS). The accuracy of SVM, KNN, random forest, and AdaBoost was 94.23 percent, 92.44 percent, 93.20 percent, and 90.33 percent, respectively, and the ensemble model could classify the three states with an accuracy of 96.48 percent. This implied that the ensemble model has a higher classification performance than when each model is used individually. Our results confirm that CS caused by VR immersion can be detected as physiological signal data with high accuracy. Moreover, our proposed model can determine the presence or absence of CS as well as the neutral state. Clinical Trial Registration Number: 20-2021-1.

Multisensory Integration as per Technological Advances: A Review

Multisensory integration research has allowed us to better understand how humans integrate sensory information to produce a unitary experience of the external world. However, this field is often challenged by the limited ability to deliver and control sensory stimuli, especially when going beyond audio-visual events and outside laboratory settings. In this review, we examine the scope and challenges of new technology in the study of multisensory integration in a world that is increasingly characterized as a fusion of physical and digital/virtual events. We discuss multisensory integration research through the lens of novel multisensory technologies and, thus, bring research in human-computer interaction, experimental psychology, and neuroscience closer together. Today, for instance, displays have become volumetric so that visual content is no longer limited to 2D screens, new haptic devices enable tactile stimulation without physical contact, olfactory interfaces provide users with smells precisely synchronized with events in virtual environments, and novel gustatory interfaces enable taste perception through levitating stimuli. These technological advances offer new ways to control and deliver sensory stimulation for multisensory integration research beyond traditional laboratory settings and open up new experimentations in naturally occurring events in everyday life experiences. Our review then summarizes these multisensory technologies and discusses initial insights to introduce a bridge between the disciplines in order to advance the study of multisensory integration.

Virtual reality for pediatric periprocedural care

PURPOSE OF REVIEW

Commercial availability of virtual reality headsets and software has exponentially grown over the last decade as it has become more sophisticated, less expensive, and portable. Although primarily used by the general public for entertainment, virtual reality has been adopted by periprocedural clinicians to improve patient experiences and treatments. The purpose of this review is to explore recently reported evidence for virtual reality effectiveness for pediatric periprocedural care and discuss considerations for clinical implementation.

RECENT FINDINGS

In the preprocedure setting, practitioners use virtual reality to introduce children to periprocedural environments, distract attention from preprocedural vascular access, and increase cooperation with anesthesia induction. Intraprocedure, virtual reality decreases sedation requirements, and in some instances, eliminates anesthesia for minor procedures. Virtual reality also augments pain reduction therapies in the acute and extended rehabilitation periods, resulting in faster recovery and improved outcomes. Virtual reality seems to be well treated for pediatric use, given close clinical care and carefully curated content.

SUMMARY

Given the multiple clinical applications of virtual reality to supplement pediatric periprocedural care, practitioners should consider developing clinical programs that reliably provide access to virtual reality. Future research should focus on identification of patient characteristics and types of software that yield optimal patient outcomes.

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.

Profiling of cybersickness and balance disturbance induced by virtual ship motion immersion combined with galvanic vestibular stimulation

Profile of cybersickness and balance disturbance induced by virtual ship motion alone and in combination with galvanic vestibular stimulation (GVS) remained unclear. Subjects were exposed to a ship deck vision scene under simulated Degree 5 or 3 sea condition using a head-mounted virtual reality display with or without GVS. Virtual ship motion at Degree 5 induced significant cybersickness with symptom profile: nausea syndrome > central (headache and dizziness) > peripheral (cold sweating) > increased salivation. During a single session of virtual ship motion exposure, GVS aggravated balance disturbance but did not affect most cybersickness symptoms except cold sweating. Repeated exposure induced cybersickness habituation which was delayed by GVS, while the temporal change of balance disturbance was unaffected. These results suggested that vestibular inputs play different roles in cybersickness and balance disturbance during virtual reality exposure. GVS might not serve as a potential countermeasure against cybersickness induced by virtual ship motion.

Suitability and Comparison of Questionnaires Assessing Virtual Reality-Induced Symptoms and Effects and User Experience in Virtual Environments

Although virtual reality (VR) has already achieved technological maturity, there are still some significant drawbacks for technology acceptance and broader user adoption, presenting research challenges. Thus, there is a need for standard, reliable, and quick assessment tools for Virtual Reality-Induced Symptoms and Effects (VRISE) and user experience in VR Assessing VRISE and user experience could be time consuming, especially when using objective physiological measures. In this study, we have reviewed, compared, and performed a suitability assessment of existing standard measures for evaluating VRISE and user experience in VR We have developed a first-person VR game with different scenes and different conditions. For assessing VRISE symptoms, we have used the Simulator Sickness Questionnaire (SSQ) and Fast Motion Sickness Score (FMS). For assessing user experience, we have used the short version of the User Experience Questionnaire (UEQ-S). We have also used a novel Virtual Reality Neuroscience Questionnaire (VRNQ) for assessing VRISE and user experience aspects. The result has shown that FMS and VRNQ (VRISE section) are suitable for quick assessment of VRISE and that VRNQ (User experience section) is suitable for assessing user experience. The advantage of FMS and VRNQ questionnaires is that they are shorter to fulfill and easier to understand. FMS also enables to record the VRISE levels during the virtual experience and thus capturing its trend over time. Another advantage of the VRNQ is that it also provides the minimum and parsimonious cut-offs to appraise the suitability of VR software, which we have confirmed in our study to be adequate.

Arguing in Favor of Revising the Simulator Sickness Questionnaire Factor Structure When Assessing Side Effects Induced by Immersions in Virtual Reality

Two issues are increasingly of interest in the scientific literature regarding unwanted virtual reality (VR) induced side effects: (1) whether the latent structure of the Simulator Sickness Questionnaire (SSQ) is comprised of two or three factors, and (2) if the SSQ measures symptoms of anxiety that can be misattributed to unwanted negative side effects induced by immersions in VR. Study 1 was conducted with a sample of 876 participants. A confirmatory factor analysis clearly supported a two-factor model composed of nausea and oculomotor symptoms instead of the 3-factor structure observed in simulators. To tease-out symptoms of anxiety from unwanted negative side effects induced by immersions in VR, Study 2 was conducted with 88 participants who were administered the Trier Stress Social Test in groups without being immersed in VR. A Spearman correlation showed that 11 out of 16 side effects correlated significantly with anxiety. A factor analysis revealed that items measuring general discomfort, difficulty concentrating, sweating, nausea, and vertigo loaded significantly on the anxiety factor comprised of items from the State-Trait Anxiety Inventory. Finally, a multiple regression indicated that the items measuring general discomfort and difficulty concentrating significantly predicted increases in anxiety. The overall results support the notion that side effects associated with immersions in VR consist mostly of a nausea and an oculomotor latent structure and that a few items are confounding anxiety and cybersickness. The data support the suggestion to revise the scoring procedures of the Simulator Sickness Questionnaire when using this instrument with immersions in VR.

Test-retest reliability of the virtual reality sickness evaluation using electroencephalography (EEG)

No reliable quantitative and objective measurement method for virtual reality (VR) sickness has been firmly established to date. Electroencephalography (EEG) may be a strong candidate to evaluate VR sickness objectively. However, no test-retest evaluation has been made for VR sickness using EEG. To recruit VR sickness-sensitive participants, we tested 858 participants (age = 20's-50's) using the Motion Sickness Susceptibility Questionnaire (MSSQ). Among them, we recruited 21 males (average age = 25.0) who obtained the 75th percentile of scores on the MSSQ (32.9 ± 5.7). VR sickness was evaluated twice (one week apart) using EEG with VR video content designed to cause VR sickness. A Simulation Sickness Questionnaire (SSQ) was also used to evaluate VR sickness. In terms of the reliability of EEG, ICC and Cronbach's alpha analyses showed that three waves (delta, theta, and alpha) were consistent in two areas (frontal and central). A significant difference in EEG was also found repeatedly between the baseline and VR sickness (delta, theta, and alpha) in two areas (frontal and central). We evaluated EEG for its reliability and found specific waves and areas that showed good consistency and significant changes associated with VR sickness. These findings may support further research of VR sickness evaluation.

Adaptive Rehabilitation Bots in Serious Games

In recent years, we have witnessed a growing adoption of serious games in telerehabilitation by taking advantage of advanced multimedia technologies such as motion capture and virtual reality devices. Current serious game solutions for telerehabilitation suffer form lack of personalization and adaptiveness to patients' needs and performance. This paper introduces "RehaBot", a framework for adaptive generation of personalized serious games in the context of remote rehabilitation, using 3D motion tracking and virtual reality environments. A personalized and versatile gaming platform with embedded virtual assistants, called "Rehab bots", is created. Utilizing these rehab bots, all workout session scenes will include a guide with various sets of motions to direct patients towards performing the prescribed exercises correctly. Furthermore, the rehab bots employ a robust technique to adjust the workout difficulty level in real-time to match the patients' performance. This technique correlates and matches the patterns of the precalculated motions with patients' motions to produce a highly engaging gamified workout experience. Moreover, multimodal insights are passed to the users pointing out the joints that did not perform as anticipated along with suggestions to improve the current performance. A clinical study was conducted on patients dealing with chronic neck pain to prove the usability and effectiveness of our adjunctive online physiotherapy solution. Ten participants used the serious gaming platform, while four participants performed the traditional procedure with an active program for neck pain relief, for two weeks (10 min, 10 sessions/2 weeks). Feasibility and user experience measures were collected, and the results of experiments show that patients found our game-based adaptive solution engaging and effective, and most of them could achieve high accuracy in performing the personalized prescribed therapies.

Exergaming With Beat Saber: An Investigation of Virtual Reality Aftereffects

BACKGROUND

Virtual reality (VR) exergaming has the potential to target sedentary behavior. Immersive environments can distract users from the physical exertion of exercise and can motivate them to continue exergaming. Despite the recent surge in VR popularity, numerous users still experience VR sickness from using head-mounted displays (HMDs). Apart from the commonly assessed self-reported symptoms, depth perception and cognition may also be affected. Considering the potential benefits of VR exergaming, it is crucial to identify the adverse effects limiting its potential and continued uptake.

OBJECTIVE

This study aims to investigate the consequences of playing one of the most popular VR exergames for 10 and 50 min on aspects of vision, cognition, and self-reported VR sickness.

METHODS

A total of 36 participants played an exergame, called Beat Saber, using an HMD. A repeated measures within-subject design was conducted to assess changes in vision, cognition, and well-being after short (10 min) and long (50 min) durations of VR exposure. We measured accommodation, convergence, decision speed, movement speed, and self-reported sickness at 3 test periods-before VR, immediately after VR, and 40 min after VR (late).

RESULTS

Beat Saber was well tolerated, as there were no dropouts due to sickness. For most participants, any immediate aftereffects were short-lived and returned to baseline levels after 40 min of exiting VR. For both short and long exposures, there were changes in accommodation (F1,35=8.424; P=.006) and convergence (F1,35=7.826; P=.008); however, in the late test period, participants returned to baseline levels. Measures on cognition revealed no concern. The total simulator sickness questionnaire (SSQ) scores increased immediately after VR (F1,35=26.515; P<.001) and were significantly higher for long compared with short exposures (t35=2.807; P=.03), but there were no differences in exposure duration in the late test period, with scores returning to baseline levels. Although at a group level, participants' sickness levels returned to baseline 40 min after VR exposure, approximately 14% of the participants still reported high levels of sickness in the late test period after playing 50 min of Beat Saber. We also showed that the participants who experienced a high level of sickness after a short exposure were almost certain to experience a high level of symptoms after a longer exposure.

CONCLUSIONS

Irrespective of the duration of exposure, this study found no strong evidence for adverse symptoms 40 min after exiting VR; however, some individuals still reported high levels of VR sickness at this stage. We recommend that users commit to a waiting period after exiting VR to ensure that any aftereffects have deteriorated. Exergames in HMDs have the potential to encourage people to exercise but are understudied, and the aftereffects of exergaming need to be closely monitored to ensure that VR exergames can reach their full potential.

Multisensory Interactions in Virtual Reality: Optic Flow Reduces Vestibular Sensitivity, but Only for Congruent Planes of Motion

During exposure to Virtual Reality (VR) a sensory conflict may be present, whereby the visual system signals that the user is moving in a certain direction with a certain acceleration, while the vestibular system signals that the user is stationary. In order to reduce this conflict, the brain may down-weight vestibular signals, which may in turn affect vestibular contributions to self-motion perception. Here we investigated whether vestibular perceptual sensitivity is affected by VR exposure. Participants' ability to detect artificial vestibular inputs was measured during optic flow or random motion stimuli on a VR head-mounted display. Sensitivity to vestibular signals was significantly reduced when optic flow stimuli were presented, but importantly this was only the case when both visual and vestibular cues conveyed information on the same plane of self-motion. Our results suggest that the brain dynamically adjusts the weight given to incoming sensory cues for self-motion in VR; however this is dependent on the congruency of visual and vestibular cues.

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.

Virtual Reality (VR) in Assessment and Treatment of Addictive Disorders: A Systematic Review

Background: Substance Use Disorder (SUD) and behavioral addictions are common and require a multidisciplinary approach. New technologies like Virtual Reality could have the potential to improve assessment and treatment of these disorders.

Objective: In the present paper, we therefore present an overview of Virtual Reality (Head Mounted Devices) in the field of addiction medicine for craving assessment and treatment.

Method: We conducted a systematic review by querying PubMed database for the titles of articles published up to March 2019 with the terms [virtual] AND [addictive] OR [addiction] OR [substance] OR [alcohol] OR [cocaine] OR [cannabis] OR [opioid] OR [tobacco] OR [nicotine] OR [methamphetamine] OR [gaming] OR [gambling].

Results: We screened 319 abstracts and analyzed 37 articles, dividing them into two categories, the first for assessment of cue reactivity (craving, psychophysiological response and attention to cue) and the second for intervention, each drug (nicotine, cocaine, alcohol, cannabis, gambling) being detailed within each category.

Conclusions: This overview suggest that VR provide benefits in the assessment and treatment of substance use disorders and behavior addictions and achieve high levels of ecological validity. While, craving provocation in VR is effective across addiction disorders, treatments based exclusively on virtual exposure to drug related cues as shown heterogenous results.

Effects of Full Body Exergaming in Virtual Reality on Cardiovascular and Muscular Parameters: Cross-Sectional Experiment

BACKGROUND

In recent years, many studies have associated sedentary behavior in front of screens with health problems in infants, children, and adolescents. Yet options for exergaming-playing video games that require rigorous physical exercise-seem to fall short of the physical activity levels recommended by the World Health Organization.

OBJECTIVE

The purpose of this study was to investigate the effect of a fully immersive virtual reality (VR)-based training system on cardiovascular and muscular parameters of young adults.

METHODS

A cross-sectional experiment design was used to analyze muscle activity (surface electromyography), heart rate, perceived exertion (RPE), cybersickness symptoms, perceived workload, and physical activity enjoyment (PACES) in 33 participants performing two 5-minute flights on a new training device.

RESULTS

Participants' performance of the planking position required to play the game resulted in moderate aerobic intensity (108 [SD 18.69] bpm). Due to the mainly isometric contraction of the dorsal muscle chain (with a mean activation between 20.6% [SD 10.57] and 26.7% [SD 17.39] maximum voluntary isometric contraction), participants described the exercise as a moderate to vigorous activity (RPE 14.6 [SD 1.82]). The majority reported that they enjoyed the exercise (PACES 3.74 [SD 0.16]). However, six participants had to drop out because of cybersickness symptoms and two because of muscle pain due to prior injuries.

CONCLUSIONS

Our findings suggest that fully immersive VR training systems can contribute to muscle-strengthening activities for healthy users. However, the dropout rate highlights the need for technological improvements in both software and hardware. In prevention and therapy, movement quality is a fundamental part of providing effective resistance training that benefits health. Exergaming on a regular basis has the potential to develop strong muscles and a healthy back. It is essential that future VR-based training systems take into account the recommendations of sport and exercise science.

Vection in virtual reality modulates vestibular-evoked myogenic potentials

The popularity of virtual reality (VR) has increased rapidly in recent years. While significant technological advancements are apparent, a troublesome problem with VR is that between 20% and 80% of users will experience unpleasant side effects such as nausea, disorientation, blurred vision and headaches-a malady known as Cybersickness. Cybersickness may be caused by a conflict between sensory signals for self-motion: while vision signals that the user is moving in a certain direction with certain acceleration, the vestibular organs provide no corroborating information. To resolve the sensory conflict, vestibular cues may be down-weighted leading to an alteration of how the brain interprets actual vestibular information. This may account for the frequently reported after-effects of VR exposure. Here, we investigated whether exposure to vection in VR modulates vestibular processing. We measured vestibular-evoked myogenic potentials (VEMPs) during brief immersion in a vection-inducing VR environment presented via head-mounted display. We found changes in VEMP asymmetry ratio, with a substantial increase in VEMP amplitude recorded on the left sternocleidomastoid muscle following just one minute of exposure to vection in VR. Our results suggest that exposure to vection in VR modulates vestibular processing, which may explain common after-effects of VR.

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 interindividual variability in cybersickness forms a pivotal step in solving the issue. Most studies of cybersickness focus on a single factor (e.g., balance, sex, or vection), while other contributors are overlooked. Here, we characterize the complex relationship between cybersickness and several measures of sensorimotor processing. In a single session, we conducted a battery of tests of balance control, vection responses, and vestibular sensitivity to self-motion. Following this, we measured cybersickness after VR exposure. We constructed a principal components regression model using the measures of sensorimotor processing. The model significantly predicted 37% of the variability in cybersickness measures, with 16% of this variance being accounted for by a principal component that represented balance control measures. The strongest predictor was participants' sway path length during vection, which was inversely related to cybersickness [ r(28) = -0.53, P = 0.002] and uniquely accounted for 7.5% of the variance in cybersickness scores across participants. Vection strength reports and measures of vestibular sensitivity were not significant predictors of cybersickness. We discuss the possible role of sensory reweighting in cybersickness that is suggested by these results, and we identify other factors that may account for the remaining variance in cybersickness. The results reiterate that the relationship between balance control and cybersickness is anything but straightforward. NEW & NOTEWORTHY The advent of consumer virtual reality provides a pressing need for interventions that combat sickness in simulated environments (cybersickness). This research builds on multiple theories of cybersickness etiology to develop a predictive model that distinguishes between individuals who are/are not likely to experience cybersickness. In the future this approach can be adapted to provide virtual reality users with curated content recommendations based on more efficient measurements of sensorimotor processing.