Simulator Sickness Questionnaire Scores Research Articles

The use of transdermal scopolamine to solve methodological issues raised by gender differences in susceptibility to simulator sickness

While car driving simulators are an essential research tool for assessing drivers’ behavior under safe and controlled conditions, gender differences in susceptibility to simulator sickness is a major drawback for the interpretation of the outcomes. The present study assessed the efficacy of a technological (Experiment 1; the use of motion-based driving simulator) and a pharmacological (Experiment 2; the use of transdermal scopolamine) solution to solve the methodological issues raised by gender differences in susceptibility to simulator sickness. In experiment 1, twenty-four women and twenty-four men performed two driving sessions lasting 16min within a high-fidelity motion-based driving simulator. In experiment 2, eight women and eight men were tested in the same simulator but received, in a counterbalanced between subjects design, either a placebo or a scopolamine patch 12h before the experimentation. In both experiments, simulator sickness questionnaire scores were computed before the first driving session and after the first and the second driving sessions. The results showed that only the pharmacological solution was efficient for solving these methodological issues. Indeed, whereas women experienced greater simulator sickness than men under placebo influence (p<0.01) there was no gender difference in susceptibility to simulator sickness following the transdermal scopolamine administration (p>0.05). As a whole, this demonstration paves the way toward better-controlled experiments. Moreover, beyond their implications in many research fields, the results from car driving simulator studies are of use to road safety policy makers. Thus, this approach allowing cancellation of gender differences in susceptibility to simulator sickness is of critical importance at a society level.

Simulator sickness incidence and susceptibility during neck motion-controlled virtual reality tasks

To determine the incidence, severity, and predisposing factors to simulator sickness (SS) when using the neck virtual reality (VR) device in asymptomatic individuals to understand the risk of provoking SS in the development of neck VR as a rehabilitation tool. Thirty-two participants used the VR system. Postural stability was measured before and after each VR module [range of motion (ROM), velocity, and accuracy]. The duration of each module was recorded, and participants reported their SS using a visual analogue scale (SS---VAS)/100 mm. Following the VR assessment, participants completed the Motion Sickness Susceptibility Questionnaire (MSSQ) (child and adult subsections) and Simulator Sickness Questionnaire (SSQ). The incidence of motion sickness during the VR immersion was 28 %, and the mean severity was 17.2 mm on VAS. There was a significant difference in ROM time, total time, MSSQ score, and SSQ score (p < 0.05) between those who reported any level of SS---VAS and those with no SS---VAS. The SS---VAS score displayed significant positive correlations with SSQ score, change in postural stability time pre to post, ROM time, and total time. Results indicate a relatively high incidence but low severity of SS which was associated with the MSSQ child subsection score and exposure time.

Visual blur and motion sickness in an optokinetic drum.

The most commonly cited hypotheses for motion sickness (MS) focus on inconsistent sensory inputs. Visual/vestibular conflicts may lead to MS, but visual input from retinal regions/neural pathways that are sensitive to motion might bear more weight in MS etiology. We hypothesized that inducing blurred vision in an optokinetic drum would attenuate the influence of foveal (parvocellular) input, but not peripheral (magnocellular) input that is sensitive to motion. Increased relative influence of peripheral visual input was predicted to subsequently lead to more visual/vestibular conflict and subsequently more severe MS symptoms. Through goggles that were either clear or frosted, 15 subjects (5 men, 10 women, mean age = 24.9 yr, range = 18-49) viewed the interior of a rotating (60° · s(-1)) optokinetic drum for 10 min. Subjects completed the Simulator Sickness Questionnaire (SSQ) before and after viewing. Overall subjective sickness ratings (0-10) and visually induced self-motion perception (vection) ratings (0-10) were also recorded. Postexposure SSQ scores obtained in the blur condition (total - 52.9, oculomotor - 38.9, disorientation - 69.6) were significantly higher than those obtained in the control condition (total - 30.4, oculomotor - 21.7, disorientation - 37.8). Overall sickness ratings and vection ratings were also significantly higher in the blur condition. These results suggest that visual blur can exacerbate MS, perhaps because of differential influences of visual pathways. Although these results were obtained with an optokinetic drum, possible effects of visual blurring in motion provocative environments such aircraft, watercraft, spacecraft, and land vehicles should be considered.

The impact of 3D and 2D TV watching on neurophysiological responses and cognitive functioning in adults.

Watching three-dimensional television (3D TV) may strain the eyes. However, other potential harmful effects of 3D TV watching have been rarely investigated. The current study examined the impact of 3D TV watching on neurophysiological responses and cognitive functioning as compared with two-dimensional TV (2D TV) watching. A total of 72 individuals were randomly assigned to either a 3D TV watching group or a 2D TV watching group. Electroencephalography (EEG) was used to measure neurophysiological responses, and computerized neurocognitive tests were conducted immediately before and after TV watching. The Simulator Sickness Questionnaire (SSQ) was used to assess visual discomfort. There was a significant change in visual discomfort between the two groups (SSQ score at baseline: 2.28 ± 3.05 for the 3D TV group and 3.69 ± 3.49 for the 2D TV group; SSQ score after watching TV: 4.6 ± 3.35 for the 3D TV group and 4.03 ± 3.47 for the 2D TV group), and this change was greater for the 3D TV watching group (P = 0.025). However, 3D TV watching did not have a differential impact on EEG responses. Furthermore, there were no significant differences between the groups in terms of changes in cognitive performance, except for a subtle difference in backward digit span performance. Our findings suggest that 3D TV watching is as safe as 2D TV watching in terms of neurophysiological responses and cognitive functioning. Potential harmful effects of TV viewing might be similar regardless of whether 3D or 2D TV is viewed.

The effect of visual display on performance in mixed reality simulation

The United States Army continues to develop new and effective ways to use simulation for training. One example is the Non-Rated Crew Member Manned Module (NCM3), a simulator designed to train helicopter crewmembers in critical, high-risk tasks such as aerial door gunnery. The goal of this study was to evaluate visual display’s effect on performance in mixed reality aerial door gunnery. Two discrete groups of subjects, expert and novice, were employed in this study. Participants were randomly assigned to one of the two visual display treatments and executed three training scenarios in the NCM3. Independent variables were visual display, immersive tendency and Simulator Sickness Questionnaire scores. Dependent variables included performance, presence and simulator sickness change scores. The results of the study indicated no main effect of visual display on performance for the expert population while a main effect of visual display on performance was discovered for the novice population. Both visual treatment groups experienced the same degree of presence and simulator sickness. No relationship between an individual’s immersive tendency and their performance nor level of presence was found. Results of this study both support and challenge the commonly held notion that higher immersive simulation leads to better performance.

시각적 동요 기반 선박운항 시뮬레이터에서 SSQ와 COP를 이용한 시뮬레이터 멀미 계측에 관한 연구

본 연구에서는 시각적 동요를 기반으로 하는 선박운항 시뮬레이터(ship handling simulator)에서 시뮬레이터 멀미 설문(SSQ, simulator sickness questionnaire)과 압력 중심(COP, Center Of Pressure)을 이용하여 시뮬레이터 멀미(simulator sickness)를 계측할 수 있는 기법을 제안한다. 실험을 위하여 선박운항시뮬레이터에서 피실험자가 시각적 동요에 노출되도록 하였고 해상상태(sea state)를 3단계로 바꾸어 가며 실험을 수행하였다. 시각적 동요 노출의 직후에 피실험자는 SSQ를 통하여 실험동안의 자각증상에 대한 설문을 작성하였고, 시각적 노출중에는 지면반발력계를 이용하여 피실험자의 COP를 측정하였다. 시각적 동요, SSQ, 그리고 COP의 데이터 분석을 통하여 시뮬레이터 멀미와 피실험자의 COP 사이의 연관성을 고찰하였다. 실험 및 분석을 통하여 해상상태에 따른 SSQ 점수와 피실험자 COP에 대한 각각 관계식을 제시하였고, 피실험자의 종방향 COP가 시뮬레이터 멀미 계측을 위한 지수로 활용될 수 있음을 보였다. In this paper, it is proposed that the effects of simulator sickness due to scene movement in ship handling simulator can be measured by using center of pressure (COP) and a simulator sickness questionnaire (SSQ). For experiments of simulator sickness, twelve participants are exposed to scenes movement from ship handling simulator according to three steps of sea states. During experiments, COPs for subjects are measured by force plate. After exposure to scenes movement, subjects describe their sickness symptoms by answering the SSQ. Throughput analysing the results of scene movement, SSQ, and COP, the relation between the simulator sickness and COP is investigated. It is suggested that formulations for SSQ score and COP with respect to sea state are obtained by the curve fitting technique, and the longitudinal COP can be used for measuring the simulator sickness.

Manipulations to reduce simulator-related transient adverse health effects during simulated driving.

User comfort during simulated driving is of key importance, since reduced comfort can confound the experiment and increase dropout rates. A common comfort-affecting factor is simulator-related transient adverse health effect (SHE). In this study, we propose and evaluate methods to adapt a virtual driving scene to reduce SHEs. In contrast to the manufacturer-provided high-sensory conflict scene (high-SCS), we developed a low-sensory conflict scene (low-SCS). Twenty young, healthy participants drove in both the high-SCS and the low-SCS scene for 10 min on two different days (same time of day, randomized order). Before and after driving, participants rated SHEs by completing the Simulator Sickness Questionnaire (SSQ). During driving, several physiological parameters were recorded. After driving in the high-SCS, the SSQ score increased in average by 129.4 (122.9 %, p = 0.002) compared to an increase of 5.0 (3.4 %, p = 0.878) after driving in the low-SCS. In the low-SCS, skin conductance decreased by 13.8 % (p < 0.01) and saccade amplitudes increased by 16.1 % (p < 0.01). Results show that the investigated methods reduce SHEs in a younger population, and the low-SCS is well accepted by the users. We expect that these measures will improve user comfort.

Simultaneous transcutaneous electrical nerve stimulation mitigates simulator sickness symptoms in healthy adults: a crossover study

BackgroundFlight simulators have been used to train pilots to experience and recognize spatial disorientation, a condition in which pilots incorrectly perceive the position, location, and movement of their aircrafts. However, during or after simulator training, simulator sickness (SS) may develop. Spatial disorientation and SS share common symptoms and signs and may involve a similar mechanism of dys-synchronization of neural inputs from the vestibular, visual, and proprioceptive systems. Transcutaneous electrical nerve stimulation (TENS), a maneuver used for pain control, was found to influence autonomic cardiovascular responses and enhance visuospatial abilities, postural control, and cognitive function. The purpose of present study was to investigate the protective effects of TENS on SS.MethodsFifteen healthy young men (age: 28.6 ± 0.9 years, height: 172.5 ± 1.4 cm, body weight: 69.3 ± 1.3 kg, body mass index: 23.4 ± 1.8 kg/m2) participated in this within-subject crossover study. SS was induced by a flight simulator. TENS treatment involved 30 minutes simultaneous electrical stimulation of the posterior neck and the right Zusanli acupoint. Each subject completed 4 sessions (control, SS, TENS, and TENS + SS) in a randomized order. Outcome indicators included SS symptom severity and cognitive function, evaluated with the Simulator Sickness Questionnaire (SSQ) and d2 test of attention, respectively. Sleepiness was rated using the Visual Analogue Scales for Sleepiness Symptoms (VAS-SS). Autonomic and stress responses were evaluated by heart rate, heart rate variability (HRV) and salivary stress biomarkers (salivary alpha-amylase activity and salivary cortisol concentration).ResultsSimulator exposure increased SS symptoms (SSQ and VAS-SS scores) and decreased the task response speed and concentration. The heart rate, salivary stress biomarker levels, and the sympathetic parameter of HRV increased with simulator exposure, but parasympathetic parameters decreased (p < 0.05). After TENS treatment, SS symptom severity significantly decreased and the subjects were more able to concentrate and made fewer cognitive test errors (p < 0.05).ConclusionsSympathetic activity increased and parasympathetic activity decreased after simulator exposure. TENS was effective in reducing SS symptoms and alleviating cognitive impairment.Trial registration numberAustralia and New Zealand Clinical Trials Register: http://ACTRN12612001172897

Motion Sickness Adaptation to Coriolis-Inducing Head Movements in a Sustained G Flight Simulator

Technological advances have allowed centrifuges to become more than physiological testing and training devices; sustained G, fully interactive flight simulation is now possible. However, head movements under G can result in vestibular stimulation that can lead to motion sickness (MS) symptoms that are potentially distracting, nauseogenic, and unpleasant. In the current study an MS adaptation protocol was tested for head movements under +Gz. Experienced pilots made 14 predetermined head movements in a sustained G flight simulator (at 3 +Gz) on 5 consecutive days and 17 d after training. Symptoms were measured after each head turn using a subjective 0-10 MS scale. The Simulator Sickness Questionnaire (SSQ) was also administered before and after each daily training session. After five daily training sessions, normalized mean MS scores were 58% lower than on Day 1. Mean total, nausea, and disorientation SSQ scores were 55%, 52%, and 78% lower, respectively. During retesting 17 d after training, nearly all scores indicated 90-100% retention of training benefits. The reduction of unpleasant effects associated with sustained G flight simulation using an adaptation training protocol may enhance the effectiveness of simulation. Practical use of sustained G simulators is also likely to be interspersed with other types of ground and in-flight training. Hence, it would be undesirable and unpleasant for trainees to lose adaptation benefits after a short gap in centrifuge use. However, current results suggest that training gaps in excess of 2 wk may be permissible with almost no loss of adaptation training benefits.

The use of adaptation to reduce simulator sickness in driving assessment and research

The technical advancement of driving simulators has decreased their cost and increased both their accuracy and fidelity. This makes them a useful tool for examining driving behavior in risky or unique situations. With the approaching increase of older licensed drivers due to aging of the baby boomers, driving simulators will be important for conducting driving research and evaluations for older adults. With these simulator technologies, some people may experience significant effects of a unique form of motion sickness, known as simulator sickness. These effects may be more pronounced in older adults. The present study examined the feasibility of an intervention to attenuate symptoms of simulator sickness in drivers participating in a study of a driving evaluation protocol. Prior to beginning the experiment, the experimental groups did not differ in subjective simulator sickness scores as indicated by Revised Simulator Sickness Questionnaire scores (all p>0.5). Participants who experienced a two-day delay between an initial acclimation to the driving simulator and the driving session experienced fewer simulator sickness symptoms as indicated by RSSQ total severity scores than participants who did not receive a two-day delay (F(1,88)=4.54, p=.036, partial η2=.049). These findings have implications for improving client well-being and potentially increasing acceptance of driving simulation for driving evaluations and for driving safety research.

Further development of a commercial driving simulation for research in occupational medicine

The purpose of this study was to refine a commercial car driving simulation for occupational research. As the effects of ethanol on driving behavior are well established, we choose alcohol as a test compound to investigate the performance of subjects during simulation. We programmed a night driving scenario consisting of monotonous highway and a rural road on a Foerst F10-P driving simulator. Twenty healthy men, 19-30 years, participated in a pilot study. Subjects were screened for simulator sickness, followed by training on the simulator one hour in total. Experiments were performed in the morning on a separate day. Participants were randomized into either an alcoholized or a control group. All subjects drove two courses consisting of highway and rural road and were sober for the first course. During a 1 h break the ethanol group drank an alcoholic beverage to yield 0.06% blood alcohol concentration (BAC). Generalized linear mixed models were used to analyze the influence of alcohol on driving performance. Among others, independent variables were Simulator Sickness Questionnaire scores and subjective sleepiness. Subjects did not experience simulator sickness during the experiments. Mean BAC before the second test drive was 0.065% in the mildly intoxicated group. There was no clear-cut difference in the number of crashes between 2 groups. BAC of 0.1% would deteriorate mean braking reaction time by 237 ms (SE = 112, p < 0.05). Ethanol slightly impaired the tracking in the right-hand curves (p = 0.058). Braking reaction time improved by 86 ms (SE = 36, p < 0.05) for the second test drive, indicating a learning effect. In sum, a clear ethanol effect was observed in the driving simulation. This simulation seems suitable for occupational research and produces little simulator sickness. Controlling for possible learning effects is recommended in driving simulation studies.

Effects of foveal retinal slip on visually induced motion sickness: a pilot study

This experiment isolated and studied the effects of eye motions on visually induced motion sickness (VIMS) from the effects of foveal retinal slip velocity on VIMS. Eye motion has been shown to contribute to motion sickness. However, most previous work manipulated eye motion using eye fixation pointer. In so doing eye motion suppression was co-founded with increase in the relative velocity between the eyes and the visual stimulus (retinal slip velocity). Retinal slip is a necessary condition in perception of visual motion and could affect VIMS. However, due to difficulties in controlling eye motion in isolation of retinal slip, few work examined this topic. Guo et al. (2011) studied the effect of eye motion by controlling retinal slip velocity and showed that eye motion can still have significant effects on VIMS after retinal slip velocity is controlled. In this study, four conditions represent the factorial combinations of high (+) and low (-) levels of eye motions (EM) and foveal retinal slip velocity (FRSV). Peripheral retinal slip velocity was kept the same throughout the four conditions. A real time eye-slaved pointer was used to achieve the design and presentation of the conditions. Eight subjects participated in the experiment and within subject design was used. Results of Wilcoxon signed rank tests on preliminary data indicated that reduction of foveal retinal slip while keeping eye movements and peripheral retinal slip the same can significantly reduce levels of VIMS (post-exposure total simulator sickness questionnaire scores: p &lt; 0.02 and 7-point nausea ratings: p &lt; 0.05). Implications of these preliminary results are discussed in the paper.

SU-E-I-62: Investigation of Dominant Factors Affecting Fatigue in Image Reading of Radiologists.

To investigate dominant factors affecting fatigue in image reading of radiologists. Two kinds of fatigue were assessed in this study. One was fatigue in the central nervous system evaluated by the critical fusion frequency (CFF). The other was eye fatigue evaluated by a score determined from a questionnaire based on the oculomotor strain subscale from the Simulator Sickness Questionnaire (SSQ). When fatigue increases, the CFF and the SSQ score indicate low and high values, respectively. The fatigue of seventeen radiologists was assessed before and after their daily image reading. The reading times and the numbers of images were different among the assessments, and ranged about 1.5 - 5.0 hours and 1,000 - 12,000 images, respectively. The assessments of fatigue were repeated four times for each radiologist on different days. Finally, the measurements of the two kinds of fatigue were analyzed in terms of years of experience, age, sleeping time the previous night, ambient light conditions, reading time, and the numbers of interpreted images, series, and cases. The CFF and SSQ score after image reading were significantly lower and higher than those measured before image reading, respectively. Younger and less experienced radiologists indicated a higher level of fatigue than older and more experienced radiologists in both the CFF and the SSQ score. When radiologists interpreted clinical images for longer hours, the SSQ score tended to be higher. On the other hand, there was little incremental difference in the CFF among different lengths of reading time. No obvious differences were observed in the other items. Less experience with reading images, a younger age, and a longer reading time could be dominant factors affecting fatigue in image reading.

Subjective evaluation of visual fatigue due to misalignment of motion and still images in a stereoscopic display

Abstract— In this paper, the relative influences of misalignment such as cross‐talk, vertical shift, and motion blur on visual fatigue by using a binocular stereoscopic display has been verified. Experiments were conducted for two cases: a still image and a motion image. They were evaluated by using the simulator sickness questionnaire (SSQ). By changing the disparity angle, cross‐talk, and vertical shift in the still‐image experiment, it was found that the SSQ score of each parameter increased as the amount of each factor increased. With a two‐sample t‐test between the presence and absence of each factor, a significant difference was found for the case of a more than 36‐arcmin disparity, more than 20% cross‐talk, and more than 10% vertical shift. In the motion‐image experiment, in which motion speed and the misalignment were varied, it was found that movement of the disparity angle caused much more visual fatigue in comparison with the misalignment factors, which were cross‐talk and vertical shift. In contrast, motion images in addition to the cross‐talk and/or vertical shift had a slight but unnoticeable relationship to an increase in visual fatigue. Therefore, it was concluded that vertical shift dominated the evaluation for still images, and the movement itself dominated the evaluation for motion images. The results suggest that it is necessary to evaluate visual fatigue according to the representing case, still or motion images, of a 3‐D stereoscopic display.

Validating an Efficient Method to Quantify Motion Sickness

Motion sickness (MS) can be a debilitating side effect associated with motion in real or virtual environments. We analyzed the effect of expectancy on MS and propose and validate a fast and simple MS measure. Several questionnaires measure MS before or after stimulus presentation, but no satisfactory tool has been established to quickly capture MS data during exposure. To fill this gap, we introduce the Fast MS Scale (FMS), a verbal rating scale ranging from zero (no sickness at all) to 20 (frank sickness). Also, little is known about the role of expectancy effects in MS studies. We conducted an experiment that addressed this issue. For this study, 126 volunteers participated in two experiments. During stimulus presentation, participants had to verbally rate the severity of MS every minute before filling in the Simulator Sickness Questionnaire (SSQ). To measure expectancy effects, participants were separated into three groups with either positive, negative, or neutral expectations. We compared the verbal ratings with the SSQ scores. Pearson correlations were high for both the SSQ total score (r = .785) and the nausea subscore (r = .828). No expectancy effects were found. The FMS is a fast and valid method to obtain MS data. It offers the possibility to record MS during stimulus presentation and to capture its time course. We found expectancy not to play a crucial role in MS. However, the FMS has some limitations. The FMS offers improved MS measurement. It is fast and efficient and can be performed online in environments such as virtual reality.

The Sickening Rug: A Repeating Static Pattern That Leads to Motion-Sickness-like Symptoms

The nauseogenic properties of a patterned rug that reputedly caused motion-sickness-like symptoms in those who viewed it was the topic of this study. Naive observers viewed a 1:1 scale image of the black-and-white patterned rug and a homogeneous gray region of equivalent luminance in a counterbalanced within-subjects design. After 5 min of viewing, symptoms were assessed with the simulator sickness questionnaire (SSQ), yielding a total SSQ score and sub-scores for nausea, oculomotor symptoms, and disorientation. All four scores were significantly higher in the rug condition. Observers also reported significantly more self-motion perception in the rug condition, even though they were seated during the experiment. Results are consistent with findings that suggest that neurologically normal individuals who view a repeating static pattern can experience unpleasant symptoms, some of which are similar to motion sickness.

Combined Pitch and Roll and Cybersickness in a Virtual Environment

Stationary subjects who perceive visually induced illusions of self-motion, or vection, in virtual reality (VR) often experience cybersickness, the symptoms of which are similar to those experienced during motion sickness. An experiment was conducted to test the effects of single and dual-axis rotation of a virtual environment on cybersickness. It was predicted that VR displays which induced illusory dual-axis (as opposed to single-axis) self-rotations in stationary subjects would generate more sensory conflict and subsequently more cybersickness. There were 19 individuals (5 men, 14 women, mean age = 19.8 yr) who viewed the interior of a virtual cube that steadily rotated (at 60 degrees x s(-1)) about either the pitch axis or both the pitch and roll axes simultaneously. Subjects completed the Simulator Sickness Questionnaire (SSQ) before a trial and after 5 min of stimulus viewing. Post-treatment total SSQ scores and subscores for nausea, oculomotor, and disorientation were significantly higher in the dual-axis condition. These results support the hypothesis that a vection-inducing VR stimulus that rotates about two axes generates more cybersickness compared to aVR stimulus that rotates about only one. In the single-axis condition, sensory conflict and pseudo-Coriolis effects may have led to symptoms. However, in the dual-axis condition, not only was perceived self-motion more complex (two axes compared to one), the inducing stimulus was consistent with twice as much self-motion. Hence, the increased likelihood/magnitude of sensory conflict and pseudo-Coriolis effects may have subsequently resulted in a higher degree of cybersickness in the dual-axis condition.

Simulator Sickness in a Helicopter Flight Training School

Simulator sickness (SS) is a common problem during flight training and can affect both instructor pilots (IP) and student pilots (SP). This study was conducted in response to complaints about a high incidence of SS associated with use of new simulators for rotary-wing aircraft. The problem was evaluated using the Simulator Sickness Questionnaire (SSQ) to collect data on 73 IP and 129 SP who used the new simulators. Based on analysis of these data, operator comments, and a search of the literature, we recommended limiting simulator flights to 2 h, removing unusual or unnatural maneuvers, turning off the sidescreens to reduce the field-of-view, avoiding use of improperly calibrated simulators until repaired, and stressing proper rest and health discipline among the pilots. The success of these measures was evaluated 1 yr later by collecting SSQ data on 25 IP and 50 SP. There was a main effect of time, in that after the recommendations were implemented, there was a significant reduction in nausea, oculomotor, and total SSQ scores from the pre-study to the post-study. There was also a main effect of experience, as IP reported significantly greater SS than SP for the same scores. Implementation of the recommendations reduced SS in the new simulators at the cost of limiting session duration and shutting down some simulator features. Although the optimal solution to the SS problem lies in addressing SS during a simulator's design stage, these recommendations can be used as interim solutions to reduce SS.

A neuro-fuzzy warning system for combating cybersickness in the elderly caused by the virtual environment on a TFT-LCD

Only a few studies in the literature have focused on the effects of age on virtual environment (VE) sickness susceptibility and even less research was carried out focusing on the elderly. In general, the elderly usually browse VEs on a thin film transistor liquid crystal display (TFT-LCD) at home or somewhere, not a head-mounted display (HMD). While the TFT-LCD is used to present VEs, this set-up does not physically enclose the user. Therefore, this study investigated the factors that contribute to cybersickness among the elderly when immersed into a VE on TFT-LCD, including exposure durations, navigation rotating speeds and angle of inclination. Participants were elderly, with an average age of 69.5 years. The results of the first experiment showed that the rate of simulator sickness questionnaire (SSQ) scores increases significantly with navigational rotating speed and duration of exposure. However, the experimental data also showed that the rate of SSQ scores does not increase with the increase in angle of inclination. In applying these findings, the neuro-fuzzy technology was used to develop a neuro-fuzzy cybersickness-warning system integrating fuzzy logic reasoning and neural network learning. The contributing factors were navigational rotating speed and duration of exposure. The results of the second experiment showed that the proposed system can efficiently determine the level of cybersickness based on the associated subjective sickness estimates and combat cybersickness due to long exposure to a VE.

The Application of Biosignal Feedback for Reducing Cybersickness from Exposure to a Virtual Environment

We examined the efficacy of a new method to reduce cybersickness. A real-time cybersickness detection system was constructed with an artificial neural network whose inputs were the electrophysiological signals of subjects in a virtual environment. The system was equipped with a means of feedback; it temporarily provided a narrow field of view and a message about navigation speed deceleration, both of which acted as feedback outputs whenever electrophysiological inputs signaled the occurrence of cybersickness. This system is named cybersickness relief virtual environment (CRVE). Forty-seven subjects experienced the VR for 9.5 min twice in CRVE and non-CRVE conditions. The results indicated that the frequency of cybersickness and simulator sickness questionnaire scores were lower in the CRVE condition than in the non-CRVE condition. Subjects also showed a higher net increase in tachyarrhythmia from the baseline period to the virtual navigation period in the CRVE condition compared to the non-CRVE condition. These results suggest that a CRVE condition may be a countermeasure against cybersickness.