User In Virtual Environment Research Articles

Interaction With an Immersive Virtual Environment Corrects Users' Distance Estimates

Two experiments examined whether prior interaction within an immersive virtual environment (VE) enabled people to improve the accuracy of their distance judgments and whether an improved ability to estimate distance generalized to other means of estimating distances. Prior literature has consistently found that users of immersive VEs underestimate distances by approximately 50%. In each of the two experiments, 16 participants viewed objects in an immersive VE and estimated their distance to them by means of blindfolded walking tasks before and after interacting with the VE. The interaction task significantly corrected users' underestimation bias to nearly veridical. Differences between pre- and post-interaction mean distance estimation accuracy were large (d = 4.63), and significant (p < .001), and they generalized across response task. This finding limits the generality of the underestimation effect in VEs and suggests that distance underestimation in VEs may not be a road block to the development of VE applications. Potential or actual applications of this research include the improvement of VE systems requiring accurate spatial awareness.

Realising voice dialogue management in a collaborative virtual environment

The applications of 3D-virtual environments and Voice User Interface (VUI) on personal computers have received significant attention in recent years. Since speech is the most natural way of communication, incorporating VUI into virtual environments can greatly enhance user interaction and immersiveness. Although there have been many researches addressing the issue of integrating VUI and 3D-virtual environment, most of the proposed solutions do not provide an effective mechanism for multiuser dialogue management. The objective of this research is on providing a solution for integrated dialogue management and realising such a mechanism in a collaborative Multi User Virtual Environment (MUVE). We have designed a dialogue scripting language called eXtensible Animation Markup Language Voice Extension (XAML-V), based on the VoiceXML standard, to address the issues of synchronisation with animation and dialogue management for multiuser interaction. We have also realised such a language on a MUVE to evaluate the effectiveness of this design.

Multimodal Virtual Environments: Response Times, Attention, and Presence

Multimodal virtual environments (VE) succeed better than single-sensory technologies in creating a sense of presence. We hypothesize that the underlying cognitive mechanism is related to a faster mental processing of multimodal events. Comparing simple detection times of unimodal (auditory, visual, and haptic) events, with bimodal and trimodal combinations, we show that mental processing times are in the following order: unimodal &gt; bimodal &gt; trimodal. Given this processing-speed advantage, multimodal VE users start their cognitive process faster, thus, in a similar exposure time they can pay attention to more informative cues and subtle details in the environment and integrate them creatively. This richer, more complete and coherent experience may contribute to an enhanced sense of presence.

Suppressed Perception of Head-Referenced Image Motion during Head Movement

A previous investigation in our laboratory showed that virtual environment users rely on image velocity errors rather than image displacement errors to sense head-tracking latency. In that study, the effect of image displacement error may have been suppressed because its peak amplitudes were associated with higher head velocity, which is thought to suppress visual motion sensitivity. To determine whether diminished motion sensitivity could play a role in user discrimination of latency, we investigated whether subjective perception of image motion comparable to that caused by latency is impaired by concurrent horizontal or vertical head movement. Eight participants monocularly viewed a checkerboard pattern in a head-mounted display that was oscillated from side-to-side with half peak-to-peak amplitudes from 0° to 5.64°. Perceptual sensitivity to image motion amplitude was reduced by almost half, during 30° repetitive horizontal head movements at 0.4 Hz. Accordingly, the reduced sensitivity to motion during head movement appears to be a phenomenon that modulates users' tolerance of erroneous image motion caused by virtual environment latency.

Wearable vibrotactile systems for virtual contact and information display

This paper presents a development history of a wearable, scalable vibrotactile stimulus delivery system. This history has followed a path from desktop-based, fully wired systems, through hybrid approaches consisting of a wireless connection from the host computer to a body-worn control box and wires to each tactor, to a completely wireless system employing Bluetooth technology to connect directly from the host to each individual tactor unit. Applications for such a system include delivering vibrotactile contact cues to users of virtual environments, providing directional cues in order to increase situational awareness in both real and virtual environments, and for general information display in wearable contexts. Through empirical study, we show that even a simple configuration, such as eight tactors arrayed around the torso, can be effective in increasing situational awareness in a building-clearing task, compared to users who perform the same task without the added cues.

The frequent wayfinding-sequence (FWS) methodology: Finding preferred routes in complex virtual environments

Advances in computing techniques, as well as the reduction in the cost of technology, have made possible the viability and spread of complex virtual environments (VEs). However, efficient navigation within these environments remains problematic for the user. Several research projects have shown that users of VEs are often disoriented and have extreme difficulty completing navigational tasks. Furthermore, there is often more than one route to get to a specified destination. Novice users often lack the spatial knowledge needed to pick an appropriate route due to the deficiency of experience with the system. A number of navigation tools such as maps, 3-D thumbnails, trails, and personal agents have been proposed. The introduction of these tools have met with some degree of success, but most researchers agree that new techniques need to be developed to aid users efficiently navigate within complex VEs. In this paper, we propose the frequent wayfinding-sequence (FWS) methodology that uses a modified sequence mining technique to discover a model of routes taken by experienced users of a VE. The model is used to build an interface that provides navigation assistance to novice users by recommending routes. We conducted both real world and simulation experiments using our methodology. Results from the real world experiment suggest that the FWS approach has the potential to improve the user's navigation performance and the quality of the human-computer interaction. Our simulation studies showed that our approach is scalable, efficient, and able to find useful route models for complex VEs.

Virtual prints: Augmenting virtual environments with interactive personal marks

This paper introduces the concept of Virtual Prints (ViPs) as an intuitive metaphor for supporting interaction and navigation, as well as a number of additional tasks in virtual environments (VEs). Three types of ViPs are described: Virtual Footprints, which are used for tracking user navigation (position, orientation and movement), Virtual Handprints, which are used for tracing user interaction with the VE, and Virtual Markers, which are ‘special’ marks (usually coupled with information) that can be created upon user request. In a VE, the ViPs concept is instantiated and supported through a software mechanism (the ViPs mechanism) that allows users to create, manage and interact with their personal ViPs, as well as other users’ ViPs. The paper presents the background and related work upon which the suggested concept builds, as well as the distinctive properties that differentiate ViPs from other related efforts. An account of how users can interact with ViPs is provided and related issues and challenges are discussed along with techniques and methods for addressing them. The paper also describes the process followed towards defining and experimenting with the concept of ViPs by means of iterative design and evaluation of an interactive prototype. This process involved exploratory studies, as well as several inspections and formal tests with both experts and potential end-users, in order to assess the usefulness of the concept and identify possible shortcomings, and also to evaluate and improve the usability of the proposed designs and software prototypes. In general, the findings of the studies reinforce the initial hypothesis that ViPs are an intuitive and powerful concept, and show that the related software is easy to learn and use. Overall, the results of the studies support strong evidence that an appropriately designed and implemented, fully functional ViPs mechanism can significantly increase the usability of VEs.

Embodiment and Spatial Behavior in Virtual Environments: Comments on Durlach et al. (2000)

Durlach et al. (2000) outlined a research program for the use of virtual environments (VEs) to train spatial abilities, and have invited comments. Our perspective is that some of the problems facing researchers in VE navigation, and also perceptual-motor skills, stem from the possibility that psychological processes that underlie navigation and motor skills in real and in virtual environments may be somewhat different. VE users may then have to make use of different strategies and abilities to those that they would normally use to manually manipulate and to navigate around the world. We suggest that such differences may arise because, when performing VE motor skills and navigation, the subject is effectively disembodied.

Applied virtual environments to support learning of social interaction skills in users with Asperger's Syndrome

Asperger's Syndrome (AS) is an autistic spectrum disorder characterised by normal to high IQ but with marked impairment in social skills. Successful social skills training appears to be best achieved either in situ or in role-play situations where users can explore different outcomes resulting from their social behaviour. Single user virtual environments (SVEs) provide an opportunity for users with AS to learn social interaction skills in a safe environment which they can visit as many times as they like.The use of game-like tasks can provide an incentive and can also be used to guide the user through progressive learning stages. Collaborative virtual environments (CVEs) allow several users to interact simultaneously within the virtual environment, each taking different perspectives or role-play characters. Within the AS interactive project a series of SVEs and CVEs have been developed in collaboration with users and professional groups with an overall aim of supporting social skills learning. Initial evaluation studies have been carried out which have been used to both inform and refine the design of these virtual environments (VEs) as well as giving an insight into the understanding and interpretation of these technologies by users with AS.

Rotational Dynamic Illusion Related to Physiological Influence in Virtual Environments

As virtual environment (VE) technology has become more disseminated, harmful physiological influences on users of VE have been reported such as simulator sickness and motion sickness – collectively called VE sickness. For VE safety and comfort, we note a new dynamic visual illusion, called ""rotational dynamic illusion"". Several psychophysical experiments measuring head movement in illusion observation suggest that perceptive features of rotational dynamic illusion are closely related to balance, which causes VE sickness. These features will be effective in realizing VE safety and comfort and trigger advances in VE technology development.

Mobile agent middleware for mobile computing

Mobile computing requires an advanced infrastructure that integrates suitable support protocols, mechanisms, and tools. This mobility middleware should dynamically reallocate and trace mobile users and terminals and permit communication and coordination of mobile entities. In addition, open and untrusted environments must overcome system heterogeneity and grant the appropriate security level. Solutions to these issues require compliance with standards to interoperate with different systems and legacy components and a reliable security infrastructure based on standard cryptographic mechanisms and tools. Many proposals suggest using mobile agent technology middleware to address these issues. A mobile agent moves entities in execution together with code and achieved state, making it possible to upgrade distributed computing environments without suspending service. We propose three mobile computing services: user virtual environment (UVE), mobile virtual terminal (MVT), and virtual resource management (VRM). UVE provides users with a uniform view of their working environments independent of current locations and specific terminals. MVT extends traditional terminal mobility by preserving the terminal execution state for restoration at new locations, including active processes and subscribed services. VRM permits mobile users and terminals to maintain access to resources and services by automatically requalifying the bindings and moving specific resources or services to permit load balancing and replication.

Descriptive Study of Student's Attitudes Toward Communicating Computers in an Elementary Science Methods Course

This research study was conducted in Indiana University in the fall semester of 1998-99 academic-year. The aim of the study was to analyze the affect of using telecommunication technologies on pre-service teachers’ attitudes toward computers and their attitudes toward communicating on computers. The telecommunication technologies integrated were Alta Vista Forum and Tapped In. Alta Vista Forum is an electronic conferencing program and Tapped In is a Multi User Virtual Environment. A survey was applied as pretest and posttest to observe attitudinal change of students.

Simulator Sickness in a Virtual Environments Driving Simulator

Some users of virtual environments experience adverse effects known as simulator sickness. Common symptoms are generally grouped into nausea, oculomotor discomfort, and disorientation. This research examined whether the severity and type of simulator sickness differs due to the type of driving environment or the gender of the driver. Three environments with variations in driver workload were developed: Highway, Rural, and City. Tests were conducted using Northeastern University's Virtual Driving Simulator. The Simulator Sickness Questionnaire (SSQ) and postural stability tests, were used to gather data before and after participants drove the virtual environments based driving simulator. In comparison with past research, a different SSQ profile was found in that most of the symptoms reported were in the oculomotor discomfort category. This included eye strain, headaches, difficulty focusing, and blurred vision. Subjects who drove the Highway or Rural Road environments had more symptoms than those who drove the City environment. This indicates that vehicle velocity may be a factor in driving simulator sickness since subjects drove 60 mph in the Highway and Rural Road environments, but only 25 mph in the City environment. In both the before and after tests, females had less postural stability than males. Females also had a greater increase in oculomotor discomfort symptoms than males. Additional research is needed to determine why females experience more simulator sickness than males.

Virtual environments applications and applied ergonomics

The usability of virtual environments has attracted considerable efforts from ergonomists. Work has included studies of the side or after effects of participation in a virtual environment (VE) as well as the appropriateness of the Virtual Reality hardware and software interfaces and the understanding of factors which determine participant performance. Equally important for applied ergonomics is to understand how best to specify, build, implement and evaluate virtual environment solutions to everyday industrial, commercial, educational and medical problems. The potential value of ergonomics applied to virtual environments, and vice versa, are discussed. Two particular instances of VE development relevant to applied ergonomics are described – structured development and evaluation of industrial training and participatory redesign of workplaces. This paper is one of a number of contributions to a special issue on ergonomics in the study and use of virtual environments.

Using Psychophysics to Measure Negative Side Effects in Immersive Virtual Environments

A study was done to determine the effectiveness of using free modulus magnitude estimation, a psychophysical measurement technique, to assess the experience of negative side effects in users of immersive virtual environments (VEs). Two different task environments, a maze and an office, were factorially combined with head-tracking on or off to provide multiple levels of side effect inducing conditions. Sixteen subjects participated in a four day experiment. Both head-tracking and task environment showed significant main effects. The experiment showed that magnitude estimation is a sensitive, efficient, and effective measure of negative side effects experienced in users of immersive VEs.

Simulator Sickness and Related Findings in a Virtual Environment

Research indicates that users of Virtual Environments (VEs) can experience a variety of effects known as “simulator sickness.” A PC-based VE system was used to investigate sickness occurring in conjunction with a 20-minute exposure to the game Ascent. Forty undergraduates served as participants. Sickness was measured with the Simulator Sickness Questionnaire (SSQ). Data on gender, possible lingering/delayed effects, inter-pupillary distance (IPD), and final level reached in Ascent were also collected. Statistical comparison of the pre- and post-exposure SSQ data established sickness occurrence. The results indicated that sickness could be severe and may involve lingering and/or delayed effects. Gender differences in mean sickness scores were not statistically significant. A significant negative correlation was found between IPD and the SSQ Eyestrain symptom. Significant negative correlations were also found between sickness scores and final level reached in Ascent. These findings provide some insight into possible effects of VE exposure and suggest some areas for research.

Navigational Training in Virtual and Real Buildings

Three experiments explored aspects of virtual reality (VR) that may influence its utility for training in navigating architectural spaces. Taken together, these experiments suggest that the utility of virtual reality depends on characteristics of the user-virtual environment interface. In experiments testing the importance of movement control, full participant control of rotational and forward movement in VR led to nearly optimal training on a medium-sized building, but limited control in VR was worse than no control. Transparent walls, a VR possibility that goes beyond real-world options, were beneficial during training and on a direct measure of learning spatial layouts. Finally, in an experiment examining both training and transfer, VR training was similar to real-world training, and was quicker and transferred better to navigating a real-world building than floor-plan training. However, this held only when the testing route was traveled in the trained direction.

Cybersickness is Not Simulator Sickness

Factor analysis of a large number of motion sickness self-reports from exposure to military flight simulators revealed three separate clusters of symptoms. Based on this analysis a symptom profile emerged for simulators where Oculomotor symptoms predominated, followed by Nausea and least by Disorientation-like symptoms. Current users of virtual environment (VE) systems have also begun to report varying degrees of what they are calling cybersickness, which initially appeared to be similar to simulator sickness. We have found, after examination of eight experiments using different VE systems, that the profile of cybersickness is sufficiently different from simulator sickness — with Disorientation being the predominant symptom and Oculomotor the least. The total severity of cybersickness was also found to be approximately three times greater than that of simulator sickness. Perhaps these different strains of motion sickness may provide insight into the different causes of the two maladies.

The Effects of Optic Flow, Proprioception, and Texture on Novice Locomotion in Virtual Environments

The ability of a user to move to different locations within a virtual environment (VE) is a fundamental action that subserves the activities of exploration and manipulation. By empirical analogy, the perceptual information used to locomote to a target within a virtual environment is compared to the perceptual information used to walk to a location in the real world. An experiment is reported that had participants move to a location as accurately as possible within a VE where a target object was presented. The amount of visual feedback available to participants was manipulated. Three conditions were compared: static viewing of the target and virtual environment before locomotion, the disappearance of the target object as movement to the object was initiated, and locomotion to the target while both object and environment were present. In addition, the composition of virtual environments was either textured or polygonal. Error measures indicated that users locomote within VE's with less accuracy than those that walk blindfolded in the real world. Texture had its largest effect on the accuracy of movement when optic flow was not available, that is, static estimates of distance. Discussions center on the relative contribution of visual, cognitive, and proprioceptive information to VE user movement accuracy.

An Integrated Virtual Environment System

Virtual environment research involves a number of related problems from a variety of domains. A joint research at the George Washington University and the Naval Research Laboratory is bringing together issues from these domains to study the factors that contribute to an integrated virtual environment. The research can be divided into three general categories: human factors, motion control, and sound synchronization. Human factors issues involve the development of new paradigms for movement and navigation, essential for performance of general tasks in virtual spaces. Novel approaches to motion control are being explored to help users of virtual environments interact and control virtual objects. This involves both interactive control as well as automation through evolutionary approaches. The sounds being generated as a result of these motions are modeled with compositional techniques to parameterize and synchronize them to the events in the environment. The research is being approached from both a fundamental point of view typical of an academic environment as well as from an application oriented point of view of interest to the Navy. The cooperative relationship has benefited both the George Washington University and the Naval Research Laboratory.