This study investigates and compares brain signals between persons with and without Multiple Sclerosis (MS) when exposed to cybersickness-provoking Virtual Reality (VR). Cybersickness is a set of discomforts and commonly triggered by VR exposure. It has symptoms similar to motion sickness, such as dizziness, nausea, and disorientation etc. Although cybersickness has been studied for decades, populations with neurological disabilities, such as MS, have remained minimally studied. Cybersickness could have negative impact on effectiveness of VR-based rehabilitation systems and limit the accessibility of VR for persons with disabilities. MS can disrupt communication between neurons (signal carrying nerve cells) from different areas of the brain. Cybersickness also can affect brain signals, for example, frequency powers may change due to cybersickness. This study investigates the combination of MS and cybersickness in terms of brain signals. To investigate the effect of cybersickness on participants' brain signals, electroencephalogram (EEG) data were recorded before, during and after exposure to a cybersickness-provoking VR driving simulation. The EEG data suggests that in response to cybersickness-provoking VR exposure, participants with MS have mostly shown similar changes in brain activity with different magnitudes than participants without MS. Also, for at least one scalp location we have found completely opposite brain signals in MS-Group when compared to Non-MS-Group. Difference in magnitude or completely different trend in brain signals can imply that cybersickness affects persons with MS differently than persons without MS and may be different cybersickness reduction techniques are required for different populations.

The objective of this study is to investigate how different visual components of Virtual Reality (VR), such as field of view, frame rate, and display resolution affect postural stability in VR. Although previous studies identified these visual components as some of the primary factors that differ significantly in VR from reality, the effect of each component on postural stability in VR is yet unknown. While most people experience postural instability in VR, it is worse for people with balance impairments (BIs). This is likely because they depend more on their visual cues to maintain postural stability. Therefore, we conducted a within-subject study with ten people with balance impairments due to Multiple Sclerosis (MS). In each condition, we varied one component and kept all other components fixed. Each participant explored the virtual environment (VE) in a controlled fashion to make sure that the effect of the visual components was consistent for all participants. Results from our study suggest that decreased field of view and frame rate have significant effects on postural stability, but the effect of display resolution is inconclusive. Therefore, VR systems targeting people with balance impairments should focus on improving field of view and frame rate rather than display resolution.

The objective of this study is to investigate how different visual components of Virtual Reality (VR), such as field of view, frame rate, and display resolution affect postural stability in VR. Although previous studies identified these visual components as some of the primary factors that differ significantly in VR from reality, the effect of each component on postural stability is yet unknown. While most people experience postural instability in VR, it is worse for people with balance impairments (BIs). This may be because they depend more on their visual cues to maintain postural stability. We conducted a study with ten people with balance impairments due to Multiple Sclerosis (MS) and seven people without balance impairments to investigate the effect of different visual components on postural stability. In each condition, we varied one of the visual components and kept all other components fixed. Each participant explored the virtual environment (VE) in a controlled fashion to make sure that the effect of the visual components was consistent for all participants. Results from our study suggest that for people with BIs, decreased field of view and decreased frame rate have significant negative effects on postural stability, but the effect of display resolution is inconclusive. However, for people without BIs, there were no significant differences for any of the visual components. Therefore, VR systems targeting people with balance impairments should focus on improving field of view and frame rate before improving display resolution.

The objective of this research is to improve the accessibility of Head-Mounted Displays (HMDs) for users with balance impairments while they are in immersive Virtual Environments (VEs). Previous research has shown that most users experience some imbalance in a fully immersive VE. However, this imbalance is significantly worse in users with balance deficits. Thus, this research aims to determine an effective visual feedback technique to improve balance of persons while using VEs to improve the accessibility of HMDs. In order to do that, we conducted a study with seven users without impairment and seven users with balance impairments due to Multiple Sclerosis (MS). We investigated how a static reference frame (SRF) (e.g., a cross-hair always rendered in the same position on the user's display screen) impacts the participants' balances in VR. Results indicate that a SRF significantly improves balance in VR for users with MS. Based on these results, we propose guidelines for designing more accessible VEs for persons with balance impairments.

Cybersickness is commonly experienced by the users in immersive Virtual Environments (VE). It has symptoms similar to Motion Sickness, such as dizziness, nausea etc. Although there have been many cybersickness experiments conducted with persons without disabilities, persons with disabilities, such as Multiple Sclerosis (MS), have been minimally studied. This is an important area of research because cybersickness could have negative effects on virtual rehabilitation effectiveness and the accessibility of VEs. For this experiment, we recruited 16 participants - 8 persons with MS and 8 persons without MS from similar demographics (e.g. age, race). Two participants from population without MS could not complete the experiment due to severe cybersickness. We asked each participant to experience a VE. We collected Galvanic Skin response (GSR) data before and during VR exposure; GSR is commonly used as an objective measure of cybersickness. Also, Simulator Sickness Questionnaire (SSQ) feedback was recorded before and after the experiment. SSQ results show that the VE induced cybersickness in the participants. The GSR data suggests that the cybersickness may have induced similar physiological changes in participants with MS as participants without MS, albeit with greater variability in participants without MS. However, participants with MS had significantly lower GSR during VR exposure. In this paper, we compare the effects of cybersickness between the people with MS and the people without MS with respect to SSQ score and GSR data.