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PubMed2005

Neurophysiological age differences during task-performance in a stereoscopic virtual environment.

In today's society, there is an increasing number of workplaces in virtual environments (VE). But, there are only a few reports dealing with occupational health issues or age effects. The question arises how VR generally interferes with cognitive processes. This interference might have relevant implications for workability and work-efficiency in virtual environments. Event-related potentials are known to reflect different stages of stimulus reception, evaluation, and response. We have established an electroencephalographic (EEG) monitoring, focussing on event-related potentials (N100; mismatch negativity, i.e., MMN) to obtain access to attention dependent and pre-attentive processing of sensory stimuli applied in VE. The MMN is known to be correlated with the ability of subjects to react to an unexpected event. The aim of the present study was to investigate cognitive responses to distracting auditory stimuli in two different age groups in a virtual environment (VE) and in a real environment ("real reality"), and to compare characteristic neurophysiological response patterns. Data show that stimulus detection as given by the N100 amplitude and latency does not differ in both age groups and task conditions. In contrast, the pre-attentive processing as given by the MMN is altered in the VR such as the non-VR condition in an age-related manner. A relevant finding of the present study was that the age related differences seen in the non-VR condition were not strengthened in VR.

Adult↗

PubMed2003

Anxiety and presence during VR immersion: a comparative study of the reactions of phobic and non-phobic participants in therapeutic virtual environments derived from computer games.

Virtual reality can be used to provide phobic clients with therapeutic exposure to phobogenic stimuli. However, purpose-built therapeutic VR hardware and software can be expensive and difficult to adapt to individual client needs. In this study, inexpensive and readily adaptable PC computer games were used to provide exposure therapy to 13 phobic participants and 13 non-phobic control participants. It was found that anxiety could be induced in phobic participants by exposing them to phobogenic stimuli in therapeutic virtual environments derived from computer games (TVEDG). Assessments were made of the impact of simulator sickness and of sense of presence on the phobogenic effectiveness of TVEDGs. Participants reported low levels of simulator sickness, and the results indicate that simulator sickness had no significant impact on either anxiety or sense of presence. Group differences, correlations, and regression analyses indicate a synergistic relationship between presence and anxiety. These results do not support Slater's contention that presence and emotion are orthogonal.

Adolescent↗

PubMed2005

Do adolescents with autistic spectrum disorders adhere to social conventions in virtual environments?

The potential for using virtual environments (VEs) in educational contexts for people with autistic spectrum disorders (ASDs) has been recognized. However, very little is known about how people with ASDs interpret and understand VEs. This study aimed to investigate this directly with a group of 12 adolescents with ASDs, each individually matched with comparison participants. Participants were presented with VEs to assess whether they adhered to particular social conventions, such as not walking across grass and flowerbeds en route to a café, or not walking between two people (ostensibly involved in conversation) en route to the bar. Whilst a significant minority of the ASD group adhered to the social conventions, others displayed substantial 'off-task' behaviour and a limited understanding of the VE. It is suggested that some individuals with an ASD, low verbal IQ and weak executive ability require the most support to complete tasks successfully in the VE.

Adolescent↗

PubMed2000

Development and application of a virtual environment for reconstructive surgery.

OBJECTIVE: This paper details the development and application of a Virtual Environment for Reconstructive Surgery (VERS). It addresses the technical and user-interface challenges in developing such a system, and the lessons learned during application of the system in the case of a 17-year-old boy with a severe facial defect arising from the removal of a soft-tissue sarcoma. MATERIALS AND METHODS: Computed tomography (CT) scans were segmented into bone and soft-tissue classifications using traditional and novel algorithms, a surface mesh was generated, and imaging artifacts were removed, yielding a mesh suitable for visualization. This patient-specific mesh was then used in a virtual environment by the surgeons for preoperative visualization of the defect, planning of the surgery, and production of a custom surgical template to aid in repairing the defect. RESULTS: This system was successfully used to plan the surgery of the patient and to produce a custom, patient-specific template that was used to harvest bone from a donor site in order to reconstruct the defect. CONCLUSION: Despite technical challenges, virtual-environment surgical planning is useful as a clinical tool for preoperative visualization, cephalometric analysis, and surgical intervention. It can provide a more precise surgical result than would otherwise be realized using traditional methods.

Adolescent↗

PubMed2002

Emotion and auditory virtual environments: affect-based judgments of music reproduced with virtual reverberation times.

Emotions are experienced both in real and virtual environments (VEs). Most research to date have focused on the content that causes emotional reactions, but noncontent features of a VE (such as the realism and quality of object rendering) may also influence emotional reactions to the mediated object. The present research studied how noncontent features (different reverberation times) of an auditory VE influenced 76 participants' ratings of emotional reactions and expressed emotional qualities of the sounds. The results showed that the two emotion dimensions of pleasantness and arousal were systematically affected if the same musical piece was rendered with different reverberation times. Overall, it was found that high reverberation time was perceived as most unpleasant. Taken together, the results suggested that noncontent features of a VE influence emotional reactions to mediated objects. Moreover, the study suggests that emotional reactions may be a important aspect of the VE experience that can help complementing standard presence questionnaires and quality evaluations.

Adult↗

PubMed2004

Nicotine craving and cue exposure therapy by using virtual environments.

Smokers who are exposed to cues associated with smoking show cardiovascular reactivity and an increase in smoking urges as compared to when they are presented with neutral cues. Cue exposure therapy (CET), which refers to the repeated exposure to drug-related cues in order to extinguish this learned association, has increasingly been proposed as a potential treatment of addictive behaviors, including tobacco smoking. The result of our pilot study suggests that a cue elicited using a virtual environment (VE) is more effective than other cue exposure devices. The VE was composed of craving environments (virtual bar) and objects (an alcoholic drink, a packet of cigarettes, a lighter, an ashtray, a glass of beer, and advertising posters) that are likely to trigger craving, a smoking avatar, and an audio environment that included the noisy sound and music of a restaurant. Sixteen late-adolescent males who smoked at least 10 cigarettes a day were recruited to participate in the VE-CET study. The CET virtual bar program consisted of six sessions, and the participants were exposed repeatedly to each session using different questions and procedures. Although the effects of CET did not yield significant reductions in all of the dependent variables, the craving for cigarettes was gradually decreased during the course of the sessions. This tendency was closely related to the reduction in the smoking count between the morning before the experiment and the start of the experiment. Based on these preliminary results, it appears that VE-CET maybe a useful tool to use in treatment programs to help reduce craving in those who are nicotine dependent.

Adolescent↗

PubMedDate not supplied

How tutors assist adults with learning disabilities to use virtual environments.

PURPOSE: To describe strategies used by tutors teaching adults with learning disabilities to use desktop virtual environments and to investigate their effectiveness by examining changes over time in tutor and learner behaviour. METHOD: Twenty adults with learning disabilities spent 12 sessions with one of four non-disabled tutors learning to use desktop virtual environments designed to teach independent living skills. Sessions were recorded on videotape, categories of behaviour were described and tapes analysed for frequency of tutor behaviours and goals achieved by learners. RESULTS: Tutor strategies were described in terms of whether they aimed to help the learner master the interaction devices or to navigate and achieve goals in the virtual environments and how directive they were. There were some differences between tutors but this did not relate to whether tutors were experienced users themselves of the environments or were initially unfamiliar with them. Goal achievement was maintained at a constant level while help with the interaction devices and specific information about the environment decreased over repeated sessions. Rates of non-specific information did not change. CONCLUSIONS: Pretraining with the interaction devices would free both tutor and learner to concentrate on achieving goals in the environments. Much of the specific help given by the tutor could be incorporated into the software.

Adult↗

PubMed2004

Clinically significant virtual environments for the treatment of panic disorder and agoraphobia.

The aim of this work is the description of virtual environments designed to apply exposure therapy in the treatment of panic disorder and agoraphobia. The program allows the simultaneous exposure to two different kinds of stimuli usually avoided by panic disorder and agoraphobia sufferers (external and interoceptive). The characteristics of the virtual environments are described, as well as the target behaviors that can be simulated with these virtual environments.

Agoraphobia↗

PubMed2006

Assessment of emotional reactivity produced by exposure to virtual environments in patients with eating disorders.

The aim of this study was to assess the usefulness of virtual environments representing situations that are emotionally significant to subjects with eating disorders (ED). These environments may be applied with both evaluative and therapeutic aims and in simulation procedures to carry out a range of experimental studies. This paper is part of a wider research project analyzing the influence of the situation to which subjects are exposed on their performance on body image estimation tasks. Thirty female patients with eating disorders were exposed to six virtual environments: a living-room (neutral situation), a kitchen with high-calorie food, a kitchen with low-calorie food, a restaurant with high-calorie food, a restaurant with low-calorie food, and a swimming-pool. After exposure to each environment the STAI-S (a measurement of state anxiety) and the CDB (a measurement of depression) were administered to all subjects. The results show that virtual reality instruments are particularly useful for simulating everyday situations that may provoke emotional reactions such as anxiety and depression, in patients with ED. Virtual environments in which subjects are obliged to ingest high-calorie food provoke the highest levels of state anxiety and depression.

Adolescent↗

PubMed1999

Measurement of postural stability before and after immersion in a virtual environment.

Research into the effects of simulators has led to suggestions that postural instability occurring after immersion in a virtual reality virtual environment (VR/VE) may have direct implications for the safety of post-immersion activities such as driving or operating machinery. However, experimental studies have highlighted a lack of standardisation in the postural stability measurement techniques applied and subsequent inconsistencies in the results obtained. An experiment was conducted to evaluate the use of static, dynamic and posturographic postural stability measures in determining the effect of participation in an interactive virtual environment (VE) for 20 min. The results demonstrate differences in the sensitivity of postural stability measurement techniques and variations in inter- and intra-individual responses to measures. The VE immersion was found to produce postural instability only when measured using a posturographic technique under normal stance static posture, and then only mildly and not long-lasting. No associations were found between reported symptoms of simulator sickness and postural stability with postural stability measures. This paper discusses issues relating to postural stability measurement and the implications for evaluation of virtual environment effects.

Adult↗

PubMed2004

[Experimental study on human reaction of determination and performance in virtual environment].

OBJECTIVE: To study factuality of ergonomic experimental data from subjects performing virtual environment wearing head mounted display (HMD) and data gloves, so as to improve the reliability of the application of virtual reality in manned spaceflight (e.g. human-machine interface design scheme ergonomic evaluation, and virtual training). METHOD: Experiment in a virtual module is designed and implemented on the virtual reality ergonomic experimental system. First, pre-experiments are done to determine the different levels of objects to be operated and the height of a virtual table which is in the virtual module. On the basis of the pre-experiments, the formal experiments are completed. In addition, a virtual reality questionnaire (VRQ) is developed and employed in order to assess subjective impressions of the virtual environment. RESULT: Normal distribution of performing time is shown when a virtual sphere is put into a drawer of standard cabinet of virtual module on a front table by subjects wearing HMD, its mean value being 36.72 s and variance being 13.798 s. By VRQ analysis, about 70.2% of the subjects thought that HMD has a good stereo quality, they can be immersed in the virtual module. CONCLUSION: When virtual reality is applied in ergonomic evaluation or virtual training, the HMD and data glove of the system would satisfy the requirements of human-computer interaction, so that human performance can be analogized and corresponding truth of experimental result can be achieved.

Data Display↗

PubMed1997

A distributed virtual environment prototype for emergency medical procedures training.

Because of the increasing complexity of emergency medical care, medical staffs require increasingly sophisticated training systems. Virtual environments offer a low cost means to achieve a widely usable yet sophisticated training capability. We describe the Virtual Emergency Room (VER) project, a simulation system designed to enable emergency department personnel within level I and II emergency rooms to practice emergency medical procedures and protocols. Because emergency rooms are manned by a wide variety of medical professionals, we are developing a simulation facility that uses a distributed virtual environment architecture to enable real-time, multi-participant simulations. The potential advantages of this system include the ability to evaluate and refine treatment skills, and the ability to provide scenario-specific training for mobile military field hospital teams. These advantages will ultimately improve the readiness of emergency department staffs for a wide variety of trauma situations. This paper describes the VER and the major components of its distributed virtual environment. The current capabilities of our system are described followed by a discussion of recommended follow-on work.

Computer Simulation↗

PubMedDate not supplied

Comparison of path visualizations and cognitive measures relative to travel technique in a virtual environment.

We describe a between-subjects experiment that compared four different methods of travel and their effect on cognition and paths taken in an immersive virtual environment (IVE). Participants answered a set of questions based on Crook's condensation of Bloom's taxonomy that assessed their cognition of the IVE with respect to knowledge, understanding and application, and higher mental processes. Participants also drew a sketch map of the IVE and the objects within it. The users' sense of presence was measured using the Steed-Usoh-Slater Presence Questionnaire. The participants' position and head orientation were automatically logged during their exposure to the virtual environment. These logs were later used to create visualizations of the paths taken. Path analysis, such as exploring the overlaid path visualizations and dwell data information, revealed further differences among the travel techniques. Our results suggest that, for applications where problem solving and evaluation of information is important or where opportunity to train is minimal, then having a large tracked space so that the participant can walk around the virtual environment provides benefits over common virtual travel techniques.

Cognition↗

PubMed2006

Reification of abstract concepts to improve comprehension using interactive virtual environments and a knowledge-based design: a renal physiology model.

Several abstract concepts in medical education are difficult to teach and comprehend. In order to address this challenge, we have been applying the approach of reification of abstract concepts using interactive virtual environments and a knowledge-based design. Reification is the process of making abstract concepts and events, beyond the realm of direct human experience, concrete and accessible to teachers and learners. Entering virtual worlds and simulations not otherwise easily accessible provides an opportunity to create, study, and evaluate the emergence of knowledge and comprehension from the direct interaction of learners with otherwise complex abstract ideas and principles by bringing them to life. Using a knowledge-based design process and appropriate subject matter experts, knowledge structure methods are applied in order to prioritize, characterize important relationships, and create a concept map that can be integrated into the reified models that are subsequently developed. Applying these principles, our interdisciplinary team has been developing a reified model of the nephron into which important physiologic functions can be integrated and rendered into a three dimensional virtual environment called Flatland, a virtual environments development software tool, within which a learners can interact using off-the-shelf hardware. The nephron model can be driven dynamically by a rules-based artificial intelligence engine, applying the rules and concepts developed in conjunction with the subject matter experts. In the future, the nephron model can be used to interactively demonstrate a number of physiologic principles or a variety of pathological processes that may be difficult to teach and understand. In addition, this approach to reification can be applied to a host of other physiologic and pathological concepts in other systems. These methods will require further evaluation to determine their impact and role in learning.

Comprehension↗

PubMedDate not supplied

Age differences in spatial memory in a virtual environment navigation task.

The use of virtual environment (VE) technology to assess spatial navigation in humans has become increasingly common and provides an opportunity to quantify age-related deficits in human spatial navigation and promote a comparative approach to the neuroscience of cognitive aging. The purpose of the present study was to assess age differences in navigational behavior in a VE and to examine the relationship between this navigational measure and other more traditional measures of cognitive aging. Following pre-training, participants were confronted with a VE spatial learning task and completed a battery of cognitive tests. The VE consisted of a richly textured series of interconnected hallways, some leading to dead ends and others leading to a designated goal location in the environment. Compared to younger participants, older volunteers took longer to solve each trial, traversed a longer distance, and made significantly more spatial memory errors. After 5 learning trials, 86% of young and 24% of elderly volunteers were able to locate the goal without error. Performance on the VE navigation task was positively correlated with measures of mental rotation and verbal and visual memory.

Adult↗

PubMed2003

Capturing behaviour for the use of avatars in virtual environments.

Avatars, representations of people in virtual environments, are subject to human control. However, for most applications, it is impractical for a person to directly control each joint in a complex avatar. Rather, people must be allowed to specify complex behaviours with simple instructions and the avatar permitted to select the correct movements in sequence to execute the instruction. This requires a variety of technologies that are currently available. Human behaviour must be captured and stored it so that it can be retrieved at a later time for use by the avatar. This has been done successfully with a variety of haptic interfaces, with visual observation of human head movements, and with verbal behaviour in natural language applications. The behaviour must be broken into atomic actions that can be sequenced with a regular grammar, and an appropriate grammar developed. Finally, a user interface must be developed so that a person can deliver instructions to the avatar.

Behavior↗

PubMed2005

The effects of direction and movement of attractors on users' behavior in virtual environments.

Despite fast technological developments in virtual reality (VR), methodologies and guidelines for evaluating the design of virtual environments (VEs) are lacking. The theory of perceptual opportunities (POs) has previously been proposed as a basis of such a design methodology. This paper presents an empirical study investigating the effect of representation of POs on users' behavior in VEs. The effects of both direction and movement of attractor on choice of objects in a simple VE were studied. Results showed that vertical static attractors were chosen least frequently. Furthermore, there was an effect of direction for static attractors in favor of the take-off direction. Implications for VE design in the framework of POs are discussed.

Adolescent↗

PubMed2003

Design and testing of a virtual environment to train stroke patients with unilateral spatial neglect to cross a street safely.

Virtual reality (VR) entails the use of advanced technologies, including computers and various multimedia peripherals, to produce a simulated (that is, virtual) environment that users perceive as comparable to real world objects and events. In recent years, virtual reality technologies have begun to be used as an assessment and treatment tool in occupational therapy, in part because of the ability to create environments that provide patients with opportunities to engage in meaningful, purposeful tasks that are related to real-life interests and activities. The objective of this study was to determine the suitability and feasibility of using a PC-based, non-immersive, VR system (that is, a system in which the user has a reduced sense of actual presence in and control over the simulated environment) for training individuals with unilateral spatial neglect to cross streets in a safe and vigilant manner. A virtual environment, consisting of a typical city street, was programmed using Superscape's 3D-Webmaster, a 3D web-authoring tool. Twelve subjects, aged 55 to 75 years, participated in the initial feasibility study and, to date, a further eight subjects have participated in the intervention study. Six of the initial subjects and all eight of the intervention subjects had sustained a right hemispheric stroke at least 6 weeks prior to the study. The remaining subjects were healthy age-matched adults who were independently mobile and had no difficulty in crossing streets. The results show that this virtual environment was suitable in both its cognitive and motor demands for the targeted population and indicate that the virtual reality training is likely to prove beneficial to people who have difficulty with crossing streets. The generalizability of these results, and recommendations regarding the use of virtual reality as an occupational therapy intervention, must be substantiated by further studies using a range of VR platforms with people with different cognitive and motor disabilities.

Accidents, Traffic↗