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At least 667 records · Page 37Linked to original sources

PubMed1998

Current limitations into the application of virtual reality to mental health research.

Virtual Reality (VR) environments have significant potential as a tool in mental health research, but are limited by technical factors and by mental health research factors. Technical difficulties include cost and complexity of virtual environment creation. Mental health research difficulties include current inadequacy of standards to specify needed details for virtual environment design. Technical difficulties are disappearing with technological advances, but the mental health research difficulties will take a concerted effort to overcome. Some of this effort will need to be directed at the formation of collaborative projects and standards for how such collaborations should proceed.

Computer Simulation↗

PubMed2001

Experience-dependent visual cue integration based on consistencies between visual and haptic percepts.

We study the hypothesis that observers can use haptic percepts as a standard against which the relative reliabilities of visual cues can be judged, and that these reliabilities determine how observers combine depth information provided by these cues. Using a novel visuo-haptic virtual reality environment, subjects viewed and grasped virtual objects. In Experiment 1, subjects were trained under motion relevant conditions, during which haptic and visual motion cues were consistent whereas haptic and visual texture cues were uncorrelated, and texture relevant conditions, during which haptic and texture cues were consistent whereas haptic and motion cues were uncorrelated. Subjects relied more on the motion cue after motion relevant training than after texture relevant training, and more on the texture cue after texture relevant training than after motion relevant training. Experiment 2 studied whether or not subjects could adapt their visual cue combination strategies in a context-dependent manner based on context-dependent consistencies between haptic and visual cues. Subjects successfully learned two cue combination strategies in parallel, and correctly applied each strategy in its appropriate context. Experiment 3, which was similar to Experiment 1 except that it used a more naturalistic experimental task, yielded the same pattern of results as Experiment 1 indicating that the findings do not depend on the precise nature of the experimental task. Overall, the results suggest that observers can involuntarily compare visual and haptic percepts in order to evaluate the relative reliabilities of visual cues, and that these reliabilities determine how cues are combined during three-dimensional visual perception.

Cues↗

PubMed2000

The use of virtual reality in the assessment of driving performance in persons with brain injury.

In this article, we present the results of a pilot study that examined the driving performance of persons with brain injury using a virtual reality environment, known as the DriVR. Virtual driving performance was examined and compared to on-road, cognitive, visual-perceptual, and driving video test results. The DriVR appeared to be a useful adjunctive screening tool for assessing driving performance. However as with any new assessment tool, will need to undergo further empirical validation.

Automobile Driver Examination↗

PubMed1998

Comparing virtual and real worlds for acrophobia treatment.

Traditional treatment of phobias involves a process of gradual exposure to the feared object. Virtual Reality (VR) environments have been used to effectively treat phobias by simulating feared situations, yet these initial studies have been performed by comparing the effect to no-treatment conditions. We are in the process of comparing VR exposure treatment to "gold-standard" in-vivo exposure treatment by replicating an actual in-vivo exposure area in a VR model. The process of controlling for differences between the two environments highlights a general procedure of selecting elements in virtual environment design, targeted towards producing particular emotional effects. It also raises questions about the necessity for highly realistic simulation in VR phobia treatment.

Behavior Therapy↗

PubMed2001

The Virtual Cell: a software environment for computational cell biology.

The newly emerging field of computational cell biology requires software tools that address the needs of a broad community of scientists. Cell biological processes are controlled by an interacting set of biochemical and electrophysiological events that are distributed within complex cellular structures. Computational modeling is familiar to researchers in fields such as molecular structure, neurobiology and metabolic pathway engineering, and is rapidly emerging in the area of gene expression. Although some of these established modeling approaches can be adapted to address problems of interest to cell biologists, relatively few software development efforts have been directed at the field as a whole. The Virtual Cell is a computational environment designed for cell biologists as well as for mathematical biologists and bioengineers. It serves to aid the construction of cell biological models and the generation of simulations from them. The system enables the formulation of both compartmental and spatial models, the latter with either idealized or experimentally derived geometries of one, two or three dimensions.

Biology↗

PubMed2000

A study of orientation in a zero gravity environment by means of virtual reality simulation.

When the International Space Station (ISS) is completed and starts its operation, crew members will be stationed for three months or more in orbit aboard the ISS. As they stay longer in the space environment, "habitability" for them will become most important in the design of the interior space. One of the problems about habitability in a zero gravity (0 G) environment is disorientation. Crew members have difficulty in discriminating between "up" and "down" and more serious disorientations may cause space motion sickness. Crew members rely on visual perception to orient themselves because they can't use their sense of equilibrium in a 0 G environment. Although color and the direction of equipment of Space Shuttles or modules has been considered, no systematic study has been conducted on interior space. This study intended to clarify how people acquire visual information and recognize their orientation in a 0 G environment by an experiment in which a subject wears a head-mounted display (HMD) and enters a virtual weightless state represented by computer graphics (CG). Visual information of a room and the degree-of-freedom of motion were varied to examine the influence of the conditions on such a simple task as movement through several connected modules, and the performance and the behavior of each subject were investigated.

Humans↗

PubMed1994

An operator interface for teleprogramming employing synthetic fixtures.

In the teleprogramming system an operator is presented with a virtual reality representation of a remote environment. The operator's interaction within that virtual environment is observed and translated into a sequence of robot program instructions for transmission to, and execution by, a robot at the remote site. In this paper we focus on operator interaction with the master station of the teleprogramming system. The use of synthetic fixtures to provide force and visual clues to assist the operator in performing tasks with speed and precision is discussed. It is suggested that, at least in some situations, it is both necessary and desirable to trade off realism for improved task performance. The difficulty of coping with exceptional conditions and, in particular, uncertainty in the world model used to generate the virtual environment is described and the operator interface for diagnosing and resolving errors is presented. An overview is also given of both the hardware and software used to implement master station for the teleprogramming system.

Computers↗

PubMed2002

Dimensions of distance: a comparison of classroom education and distance education.

Distance is obviously a core issue in distance education. But distance is a factor in classroom-based education as well. Classroom-based teachers and distance educators have a common interest in the dynamics of distance. The focus of much discussion in distance education is on geographical distance and how it may be bridged. However, this focus obscures the more fundamental issue of educational distance. Educational distance includes cognitive distance, role distance and access distance. This form of distance is as potent in the classroom environment as it is in a virtual learning environment. The writer explores this theme by his analysis of the communication patterns between teacher and students in one module in a BSc Health Studies degree programme. The writer has taught this module in both distance education format and in traditional classroom-based format. His finding is that the communication time between the teacher and students in the distance education form of the module is 29% greater than the communication time in the classroom-based form. The most significant feature of the communication pattern is the greater quantity of individual communication between student and teacher in the distance education format. Both the quantity and type of the communication in each of these modes suggest that the more communication-rich distance education format has greater potential for overcoming the problems of educational distance within this module.

Communication↗

PubMed2000

Computer-assisted three-dimensional surgical planning and simulation: 3D virtual osteotomy.

A computer-assisted three-dimensional virtual osteotomy system for orthognathic surgery (CAVOS) is presented. The virtual reality workbench is used for surgical planning. The surgeon immerses in a virtual reality environment with stereo eyewear, holds a virtual "scalpel" (3D Mouse) and operates on a "real" patient (3D visualization) to obtain pre-surgical prediction (3D bony segment movements). Virtual surgery on a computer-generated 3D head model is simulated and can be visualized from any arbitrary viewing point in a personal computer system.

Algorithms↗

PubMed2002

Virtual reality and the person-environment experience.

This paper discusses how a projected virtual reality system that uses video gesture recognition technology can influence the person-environment process. The psychosocial concepts of embodiment, environmental centralization, and environmental personalization are illustrated with examples of virtual reality applications with children with disabilities. Through these, the advantages of using virtual reality to influence the person-environment relationship are discussed. Disadvantages of implementing this virtual reality approach are also presented as well as recommendations for future work in this area.

Attitude↗

PubMed1999

CAREN--Computer Assisted Rehabilitation Environment.

The CAREN project concerns the development of a virtual reality environment in which the agility of healthy subjects and patients can be tested in a variety of reproducible conditions. CAREN is made by customizing hardware and developing software to enable measurements of motion of a subject in detail as a response to a perturbation from the computer driven motion platform. After feeding the data in a human body model simulation, joint moments of force and muscle activation can be calculated. From the time patterns of these responses, inferences can be made concerning the motor programs the subjects launch. Any primary problem in a motor program, resulting in functional failure or inadequacy, can be identified down to the joint and muscle group. Secondary adaptations of patients to a limitation in the periphery (such as lack of muscle force) can be separated from the primary ones. Inadequacy of complete motor programs in children with movement disorders can be classified, recorded and related to progress that may occur. Especially the understanding of compensation strategies in patients may lead to a better therapeutic attitude. CAREN offers not only a test environment with means of almost unlimited exploratory behaviors for patients, but constitutes also a strong tool for motor control research.

Computer Graphics↗

PubMed2000

Virtual reality for relearning daily living skills.

The explosive increase in the power of computers has enabled the creation of fast, interactive 3D environments, sometimes called virtual reality (VR). This technology, often associated with arcade games, is increasingly being used for more serious applications. This paper describes research showing transfer of skills from a virtual environment to the real world. We then describe our VR authoring tool and an application to help cognitively impaired individuals relearn important daily living skills. Additionally we describe the development of a prototype networked system to enable a doctor to monitor remotely the rehabilitation of a group of patients.

Activities of Daily Living↗

PubMed2004

CT virtual reality in the preoperative workup of malunited distal radius fractures: preliminary results.

Our objective was to evaluate the usefulness of CT virtual preoperative planning in the surgical repositioning of malunited distal radius fracture. Eleven patients with malunited distal radius fracture underwent multislice CT of both wrists. A preoperative workup was performed in a virtual reality environment created from the CT data sets. Virtual planning comprised three main procedures, carrying out the virtual osteotomy of the radius, prediction of the final position of the distal radius after osteotomy and computer-assisted manufacturing of a repositioning device, which was later placed at the surgical osteotomy site to reposition objectively the distal radius fragment before fixation with the osteosynthesis. All patients tolerated the surgical procedure well. During surgery, the orthopedic surgeons were not required in any of the cases to alter the position of the distal radius that was determined by the repositioning device. At postoperative follow-up, the anatomic relationship of the distal radius was restored (radial inclination, 21.4 degrees ; volar tilt, 10.3 degrees ; ulnar variance, 0.5 mm). Clinically, a significant improvement of pronation (P=0.012), supination (P=0.01), flexion (P=0.001) and extension (P=0.006) was achieved. Pain decreased from 54 to 7 points. CT virtual reality is a valuable adjunct for the preoperative workup and surgical reposition of malunited distal radius fractures.

Adult↗

PubMed1999

A virtual surgical simulator for the lower limbs.

As the body of knowledge concerning human anatomy and physiology continues to grow, new techniques must emerge to convey it more efficiently to future health care professionals. Computer simulation, interaction and visualization technologies are now being used in the development of virtual training environments. This paper presents a real-time virtual surgical simulator that integrates scientific visualization tools into a surround-screen projection-based (SSPB) immersive environment. This environment focuses on procedures for the lower limbs; however, the techniques described can be applied to other portions of the body. The research consists of three phases: environment modeling, volume visualization and immersive surgical simulation. Environment modeling involved modeling an operating room with all of the relevant elements. The volume visualization phase required the application of marching cubes and decimation techniques to the Visible Human Project (VHP) dataset to generate models of the lower limbs. The simulator integrated modeling and volume visualization to facilitate the rehearsal of medical procedures and interaction with medical information. Interactive cutting, suturing and X-Ray CT placement over the virtual patient's legs were used to probe underlying structures. The simulator is intended to aid medical students in learning anatomy, physiology and radiological analysis without jeopardizing patient care.

Computer Simulation↗

PubMed2003

Differential contributions of vision and proprioception to movement accuracy.

We examined the relative roles of visual and proprioceptive information about initial hand position on movement accuracy. A virtual reality environment was employed to dissociate visual information about hand position from the actual hand position. Previous studies examining the effects of such dissociations on perception of hand location have indicated a bias toward the visually displayed position. However, an earlier study, which employed optical prisms to dissociate visual and proprioceptive information prior to targeted movements, suggested a bias in movement direction toward that defined by the actual hand position. This implies that visual and proprioceptive information about hand position may be differentially employed for perceptual judgments and movement planning, respectively. We now employ a virtual reality environment to systematically manipulate the visual display of the hand start position from the actual hand position during movements made to a variety of directions. We asked whether subjects would adjust their movements in accord with the virtual or the actual hand location. Subjects performed a series of baseline movements toward one of three targets in each of three blocks of trials. Interspersed among these trials were "probe" trials in which the cursor location, but not the hand location, was displaced relative to the baseline start position. In all cases, cursor feedback was blanked at movement onset. Our findings indicated that subjects systematically adjusted the direction of movement in accord with the virtual, not the actual, start location of the hand. These findings support the hypothesis that visual information about hand position predominates in specifying movement direction.

Adolescent↗

PubMed2006

Frequency of stuttering during challenging and supportive virtual reality job interviews.

UNLABELLED: This paper seeks to demonstrate the possibility of manipulating the frequency of stuttering using virtual reality environments (VREs). If stuttering manifests itself in VREs similarly to the way it manifests itself in real world interactions, then VREs can provide a controlled, safe, and confidential method for treatment practice and generalization. Though many researchers and clinicians recognize the need for generalization activities in the treatment of stuttering, achieving generalization in a clinical setting poses challenges to client confidentiality, safety, and the efficient use of a professionals' time. Virtual reality (VR) technology may allow professionals the opportunity to enhance and assess treatment generalization while protecting the safety and confidentiality of their clients. In this study, we developed a VR job interview environment which allowed experimental control over communication style and gender of interviewers. In this first trial, persons who stutter (PWS) experienced both challenging and supportive VR job interview conditions. The percentage of stuttered syllables was calculated for both interviews for each participant. Self-reported ratings of communication apprehension and confidence were also obtained, and were not significantly correlated with stuttering severity. Results indicated that interviewer communication style affected the amount of stuttering produced by participants, with more stuttering observed during challenging virtual interviews. Additionally, the amount of stuttering observed during the VR job interviews was significantly, positively correlated with the amount of stuttering observed during an interview with the investigator prior to VR exposure. Participants' subjective reports of the VR experience indicate reactions similar to those they report experiencing in the real world. Possible implications for the use of VR in the assessment and treatment of stuttering are discussed. EDUCATIONAL OBJECTIVES: After reading this article, the reader will be able to-(1) list some of the challenges to treatment generalization; (2) describe how virtual reality technology can assist in alleviating some of these challenges; (3) describe how the frequency of stuttering varies across two different virtual environments.

Adult↗

PubMed1996

Transfer of spatial information from a virtual to a real environment in physically disabled children.

A group 10 severely physically disabled children explored a to-scale computer simulation of a real multi-storey building. Following exploration, their knowledge of the spatial properties of the real environment was assessed by asking them to point to fire apparatus that was not visible from the test site. Subjects in a control group were asked to complete the same assessment tasks, but without the opportunity to explore either the real building or the computer simulation. The estimates of the disabled children were superior to the control group indicating good transfer of spatial knowledge. Route finding and recognition reports provided support for the pointing data in indicating good transfer of spatial information.

Child↗

PubMed2005

The psychology of persecutory ideation II: a virtual reality experimental study.

A cognitive model of persecutory delusions is used to predict the occurrence of nonclinical paranoid thoughts in a virtual reality environment. Scorers across the range of paranoia entered a virtual reality scene populated by five computer characters programmed to behave neutrally (N = 30). Many appraisals of the computer characters were positive or neutral. However, there were also persecutory thoughts about the characters. Providing evidence of the validity of the experimental method, persecutory ideation was predicted by higher trait paranoia and a greater sense of presence in the environment. The psychological variables from the cognitive model that predicted persecutory ideation were anxiety, timidity, and hallucinatory predisposition. Further, hallucinatory predisposition distinguished the prediction of paranoid thoughts from social anxiety in virtual reality. It is concluded that nonclinical paranoid thoughts are most closely associated with emotional disturbances and anomalous experiences. Extreme reasoning bias may particularly contribute to the development of clinical phenomena.

Adult↗