A virtual reality assessment and training system for unilateral neglect.

Patients with unilateral neglect have problems reporting, responding, or orienting to novel or meaningful stimuli that is presented to the side opposite to that of a brain lesion. This creates a serous problem in regards to daily living activities. However, the established methods for assessing and training of unilateral neglect patients have several deficits. Recently, virtual reality (VR) technologies have been used as an assessment and treatment tool for rehabilitation. Hence, this study designed a VR system to assess and train unilateral neglect patients. In addition, the suitability and feasibility of our VR system for unilateral neglect patients was verified.     

A treadmill and motion coupled virtual reality system for gait training post-stroke.

A virtual reality (VR)-based locomotor training system has been developed for gait rehabilitation post-stroke. The system consists of a self-paced treadmill mounted onto a 6-degrees-of-freedom motion platform. Virtual environments (VEs) that are synchronized with the speed of the treadmill and the motions of the platform are rear-projected onto a screen in front of the walking subject. A feasibility study was conducted to test the capability of two stroke patients and one healthy control to be trained with the system. Three VE scenarios (corridor walking, street crossing, and park stroll) were woven into a gait-training program that provided three levels of complexity (walking speed, slopes, collision avoidances), progression criteria (number of successful trials) and knowledge of results. Results show that, with practice, patients can effectively increase their gait speed as demanded by the task and adapt their gait with respect to the change in physical terrain. However, successful completion of tasks requiring adaptation to increasing demands related to speed and physical terrains does not necessarily predict the patient's ability to anticipate and avoid collision with obstacles during walking. This feasibility study demonstrates that persons with stroke are able to adapt to this novel VR system and be immersed in the VEs for gait training.     

Flirting with virtual reality

Psychoanalysis encourages patients to experience a virtual reality of the psychoanalytic relationship, in which both image and wish can be experimented with. Originally, the patient's awareness was supposed to move back and forth between the virtual and the actual, in a flickering and uncertain fashion. That is uncomfortable, and analysts have often preferred the domain of virtuality or of actuality, or have denied the distinction altogether. Recent philosophical developments and doubts about transference neurosis and reconstruction further tempt analysts to relax the flickering uncertainty of virtual and actual. Patient and analyst may gain comfort but lose something in the process.     

Overground gait training using virtual reality aimed at gait symmetry

This study investigated if training in a virtual reality (VR) environment that provides visual and audio biofeedback on foot placement can induce changes to spatial and temporal parameters of gait during overground walking. Eighteen healthy young adults walked for 23 min back and forth on an instrumented walkway in three different conditions: (i) real environment (RE), (ii) virtual environment (VE) with no biofeedback, and (iii) VE with biofeedback. Visual and audio biofeedback while stepping on virtual footprint targets appearing along a straight path encouraged participants to walk with an asymmetrical step length (SL). A repeated-measures, one-way ANOVA, followed by a pairwise comparison post-hoc analysis with Bonferroni's correction, was performed to compare the step length difference (SLD), stance phase percentage difference (SPPD), and double-support percentage difference (DSPD) between early and late phases of all walking conditions. The results demonstrate the efficacy of the VE biofeedback system for training asymmetrical gait patterns. Participants temporarily adapted an asymmetrical gait pattern immediately post-training in the VE. Induced asymmetries persisted significantly while later walking in the RE. Asymmetry was significant in the spatial parameters of gait (SLD) but not in the temporal parameters (SPPD and DSPD). This paper demonstrates a method to induce unilateral changes in spatial parameters of gait using a novel VR tool. This study provides a proof-of-concept validation that VR biofeedback training can be conducted directly overground and could potentially provide a new method for treatment of hemiplegic gait or asymmetrical walking.     

Reaching within video-capture virtual reality: using virtual reality as a motor control paradigm.

We have developed a virtual reality (VR) system that integrates a three-dimensional tracking device with a video-capture VR platform to record upper limb movements. The influence of target velocity on planning and execution of reaching movements was studied in five healthy subjects. Our initial results suggest that a target's velocity is considered when planning an interceptive action and that a hand reaching toward a moving virtual target is controlled in a similar way to how it is in the real visual environment.     

How the eye measures reality and virtual reality

If virtual reality systems are to make good on their name, designers must know how people perceive space in natural environments, in photographs, and in cinema. Perceivers understand the layout of a cluttered natural environment through the use of nine or more sources of information, each based on different assumptions—occlusion, height in the visual field, relative size, relative density, aerial perspective, binocular disparities, accommodation, convergence, and motion perspective. The relative utility of these sources at different distances is compared, using their ordinal depth-threshold functions. From these, three classes of space around a moving observer are postulated: personal space, action space, and vista space. Within each, a smaller number of sources act in consort, with different relative strengths. Given the general ordinality of the sources, these spaces are likely to be affine in character, stretching and collapsing with viewing conditions. One of these conditions is controlled by lens length in photography and cinematography or by field-of-view commands in computer graphics. These have striking effects on many of these sources of information and, consequently, on how the layout of a scene is perceived.     

Functional balance and dual-task reaction times in older adults are improved by virtual reality and biofeedback training.

Virtual reality (VR) training has been used successfully to rehabilitate functional balance and mobility in both traumatic brain injury (TBI) survivors and elderly subjects. Similarly, computer-based biofeedback (BF) training has resulted in decreased sway during quiet stance and decreased reaction times during a dual-task reaction time paradigm in elderly subjects. The objective of this study was to determine the effect of VR and BF training on balance and reaction time in older adults. Two groups of twelve healthy older adults completed 10-week training programs consisting of two 30-min sessions per week. VR training required that participants lean sideways to juggle a virtual ball. Participants in the BF group viewed a red dot representing their center of gravity on a screen and were required to move the dot to the four corners of the monitor. Measures of functional balance and mobility (Community Balance and Mobility Scale [CB&M]), sway during quiet stance, and reaction time during a dual task paradigm were recorded before training, as well as 1 week and 1 month after the end of the program. Both groups showed significant improvements on the CB&M, as well as decreased reaction times with training. Postural sway during quiet stance did not change significantly.     

The neurobiology of virtual reality pain attenuation.

During the past decade, virtual reality (VR) has gained recognition as a means of attenuating pain during medical procedures. However, while investigators have examined the effects of virtual environments on level of distraction, subjective pain intensity, and brain activity, there have been only a handful of investigations into the neurobiological mechanisms associated with VR's efficacy. In an effort to explain how VR may alter pain perception and produce analgesia, as well as to guide the development of novel and improved VR pain treatments, this review aims to link the wealth of empirical data examining the neurobiology of pain to the growing field of VR. This review is separated into three main sections: (a) a brief overview of the current literature on the use of VR for the treatment of pain; (b) a review of the basic neurobiology of how pain is detected, processed, and controlled by the brain; and (c) an exploration into how current VR pain treatments may impact the pain system to produce analgesia. In addition, the future of VR for pain treatment is discussed, including how current treatments might be improved and novel ways to use VR to treat pain might be developed. Speculation on future VR interventions is based on our current understanding of how the brain processes pain and how VR appears to alter this process and produce analgesia.     

Influence of virtual reality training on the roadside crossing judgments of child pedestrians

The roadside crossing judgments of children aged 7, 9, and 11 years were assessed relative to controls before and after training with a computer-simulated traffic environment. Trained children crossed more quickly, and their estimated crossing times became better aligned with actual crossing times. They crossed more promptly, missed fewer safe opportunities to cross, accepted smaller traffic gaps without increasing the number of risky crossings, and showed better conceptual understanding of the factors to be considered when making crossing judgments. All age groups improved to the same extent, and there was no deterioration when children were retested 8 months later. The results are discussed in relation to theoretical arguments concerning the extent to which children's pedestrian judgments are amenable to training.     

A virtual reality scenario for all seasons: the virtual classroom

Treatment and rehabilitation of the cognitive, psychological, and motor sequelae of central nervous system dysfunction often relies on assessment instruments to inform diagnosis and to track changes in clinical status. Typically, these assessments employ paper-and-pencil psychometrics, hands-on analog/computer tests, and rating of behavior within the context of real-world functional environments. Virtual reality offers the option to produce and distribute identical "standard" simulation environments in which performance can be measured and rehabilitated. Within such digital scenarios, normative data can be accumulated for performance comparisons needed for assessment/diagnosis and for treatment/rehabilitation purposes. In this manner, reusable archetypic virtual environments constructed for one purpose can also be applied for applications addressing other clinical targets. This article will provide a review of such a retooling approach using a virtual classroom simulation that was originally developed as a controlled stimulus environment in which attention processes could be systematically assessed in children with attention-deficit/hyperactivity disorder. This system is now being applied to other clinical targets including the development of tests that address other cognitive functions, eye movement under distraction conditions, social anxiety disorder, and the creation of an earthquake safety training application for children with developmental and learning disabilities.     

Immersiveness and physiological arousal within panoramic video-based virtual reality.

In this paper, we discuss findings from a study that used panoramic video-based virtual environments (PVVEs) to induce self-reported anger. The study assessed "immersiveness" and physiological correlates of anger arousal (i.e., heart rate, blood pressure, galvanic skin response [GSR], respiration, and skin temperature). Results indicate that over time, panoramic video-based virtual scenarios can be, at the very least, physiologically arousing. Further, it can be affirmed from the results that hypnotizability, as defined by the applied measures, interacts with group on physiological arousal measures. Hence, physiological arousal appeared to be moderated by participant hypnotizability and absorption levels.     

Cognitive-behavioral treatment and antidepressants combined with virtual reality exposure for patients with chronic agoraphobia

In this study we compared the efficacy of virtual reality exposure combined with cognitive-behavioral therapy (VRET) to that of traditional cognitive-behavioral therapy (CBT) alone in reducing phobic symptoms in a sample of patients with long-term agoraphobia. The study was a between-subject design with three experimental conditions (VRET group, N = 30; CBT group, N = 30; and medication only group, N = 20) and repeated measures (pre-treatment, post-treatment, and six-month follow-up). All patients were receiving antidepressant medication. Results showed that all therapies were statistically effective both at post-treatment and six-month follow-up. The VRET group showed clinical improvement in most variables measured at follow-up. The CBT group showed the highest dropout rates. These results are discussed pointing out that VRET probably serves as an intermediate procedure for an efficient exposure to phobic stimuli. Besides describing the advantages of VRET for the treatment of agoraphobia symptoms in cost-benefit terms, the study also considered issues related to higher treatment adherence and motivation.     

Manipulating body representations with virtual reality: Clinical implications for anorexia nervosa

Anorexia nervosa patients exhibit distorted body-representations. Specifically, they represent their bodies as larger than reality. Given that this distortion likely exacerbates the condition, there is an obligation to further understand and, if possible, rectify it. In pursuit of this, experimental paradigms are needed which manipulate the spatial content of these representations. In this essay, I discuss how virtual reality technology that implements full-body variants of the rubber-hand illusion may prove useful in this regard, and I discuss some issues related to the clinical application of this method.     

Effectiveness of virtual reality for pediatric pain distraction during i.v. placement.

The objective of this study was to test the efficacy and suitability of virtual reality (VR) as a pain distraction for pediatric intravenous (i.v.) placement. Twenty children (12 boys, 8 girls) requiring i.v. placement for a magnetic resonance imaging/computed tomography (MRI/CT) scan were randomly assigned to two conditions: (1) VR distraction using Street Luge (5DT), presented via a head-mounted display, or (2) standard of care (topical anesthetic) with no distraction. Children, their parents, and nurses completed self-report questionnaires that assessed numerous health-related outcomes. Responses from the Faces Pain Scale-Revised indicated a fourfold increase in affective pain within the control condition; by contrast, no significant differences were detected within the VR condition. Significant associations between multiple measures of anticipatory anxiety, affective pain, i.v. pain intensity, and measures of past procedural pain provided support for the complex interplay of a multimodal assessment of pain perception. There was also a sufficient amount of evidence supporting the efficacy of Street Luge as a pediatric pain distraction tool during i.v. placement: an adequate level of presence, no simulator sickness, and significantly more child-, parent-, and nurse-reported satisfaction with pain management. VR pain distraction was positively endorsed by all reporters and is a promising tool for decreasing pain, and anxiety in children undergoing acute medical interventions. However, further research with larger sample sizes and other routine medical procedures is warranted.     

Impact of tasks and users' characteristics on virtual reality performance.

A better understanding of how users perform virtual reality (VR) tasks may help build better VR interfaces. In this study, we concentrated on the compensatory behavior in VR depending on the tasks and users' characteristics. The tasks characteristics considered were display size (large display vs. desktop monitor) and tasks types (manipulation and travel). The users' characteristics studied were the visual attention abilities and users' satisfaction. Ninety-five subjects participated in the experimentation composed of two parts: the first one consisted in cognitive tests used to evaluate visual attention abilities, and the second one was based on a set of VR tasks. Our result showed that large displays positively affect on performance for some kinds of VR tasks. Moreover, this impact was linked to users' satisfaction and visual attention abilities. Indeed, users with low-level attention abilities and users who preferred the large display took more advantage of large displays. We concluded that large displays can be considered cognitive aids depending on the tasks and users' characteristics.     

Responses to a virtual reality grocery store in persons with and without vestibular dysfunction.

People with vestibular dysfunction often complain of having difficulty walking in visually complex environments. Virtual reality (VR) may serve as a useful therapeutic tool for providing physical therapy to these people. The purpose of this pilot project was to explore the ability of people with and without vestibular dysfunction to use and tolerate virtual environments that can be used in physical therapy. We have chosen grocery store environments, which often elicit complaints from patients. Two patients and three control subjects were asked to stand and navigate in VR grocery stores while finding products. Perceived discomfort, simulator sickness symptoms, distance traveled, and speed of head movement were recorded. Symptoms and discomfort increased in one subject with vestibular dysfunction. The older subjects traveled a shorter distance and had greater speed of head movements compared with young subjects. Environments with a greater number of products resulted in more head movements and a shorter distance traveled.     

Usability of the remote console for virtual reality telerehabilitation: formative evaluation.

The Remote Console (ReCon) is a telerehabilitation application that allows therapists to remotely communicate with patients while monitoring and controlling their virtual rehabilitation exercises. It provides therapists visual feedback of patients' movements, their exercise simulations replicated in real time and with tools to conduct training without a face-to-face session. The Recon underwent a formative evaluation (a type of usability engineering methodology) used to refine its design. Five physical therapists from different practice settings acted as representative users. During the evaluation, these users made errors related to manipulation and finding and understanding controls. Technical issues with the server and audio communication were identified. These findings were used to fine-tune the ReCon system.     

Training cognitive skills in virtual reality: measuring performance.

Across a variety of operational environments, virtual reality (VR) is being increasingly used as a means of simulating hazardous work conditions in order to allow trainees to practice advanced cognitive skills such as problem-solving and decision-making. Replicating dangerous conditions particularly involving heavy machinery in the real world can be dangerous and costly. The use of VR is therefore appealing across many industries such as aviation, mining, and rail. However, while the number of training prototypes increase less focus is being given to appropriate evaluation of the training provided via this technology. Increasing skills acquisition and performance does not depend solely on the appropriate design of simulation training. Of equal importance are strong performance measures which can ultimately feedback on the success or otherwise of training and highlight any deficits to guide ongoing improvements. To ensure cognitive skills acquired in a virtual training environment (VTE) are transferable to the real world, training objectives need to be tied directly to realistic scenario events which in turn are directly linked to measures of specific required behaviors.