Media Presence and Inner Presence: The Sense of Presence in Virtual Reality Technologies

Abstract. Presence is widely accepted as the key concept to be considered in any research involving human interaction with Virtual Reality (VR). Since its original description, the concept of presence has developed over the past decade to be considered by many researchers as the essence of any experience in a virtual environment. The VR generating systems comprise two main parts: a technological component and a psychological experience. The different relevance given to them produced two different but coexisting visions of presence: the rationalist and the psychological/ecological points of view. The rationalist point of view considers a VR system as a collection of specific machines with the necessity of the inclusion \ud of the concept of presence. The researchers agreeing with this approach describe the sense of presence as a function of the experience of a given medium (Media Presence). The main result of this approach is the definition of presence as the perceptual illusion of non-mediation produced by means of the disappearance of the medium from the conscious attention of the subject. At the other extreme, there \ud is the psychological or ecological perspective (Inner Presence). Specifically, this perspective considers presence as a neuropsychological phenomenon, evolved from the interplay of our biological and cultural inheritance, whose goal is the control of the human activity. \ud Given its key role and the rate at which new approaches to understanding and examining presence are appearing, this chapter draws together current research on presence to provide an up to date overview of the most widely accepted approaches to its understanding and measurement

Three Dimensional Tracking in Augmented Environments: User Performance Trade-Offs Between System Latency and Update Rate

Three-dimensional tracking performance was measured as a function of system latency (35-335 msec) and update rate (10-30 Hz). Twelve subjects used a custom, see-through head mounted stereo display to control the position of a virtual response cursor with hand and body movements. User performance trade-offs between latency and update rate were measured with objective and subjective measures and a possible performance model was evaluated. The results indicate that earlier findings suggesting that latency influenced tracking performance more than did update rate, could be due to previous studies having tested latency over a larger dynamic range. Iso-performance contours are used to compare objective performance with subjective perception and performance judgments

Simulation of High-Visual Quality Scenes in Low-Cost Virtual Reality

With the increasing popularity of virtual reality, many video games and virtual experiences with high-visual quality have been developed recently. Virtual reality with a high-quality representation of scenes is still an experience linked to high-cost devices. There are currently low-cost virtual reality solutions by using mobile devices, but in those cases, the visual quality of the presented virtual environments must be simplified for running on mobile devices with limited hardware characteristics. In this work, we present a novel Image-Based Rendering technique for low-cost virtual reality. We have conducted a performance evaluation of three mobile devices with different hardware characteristics. Results show that our technique represents high-visual quality virtual environments with considerably better performance compared to traditional rendering solutions.Workshop: WCGIV – Computación Gráfica, Imágenes y VisualizaciónRed de Universidades con Carreras en Informátic

Realidad virtual: Un medio de comunicación de contenidos. Aplicación como herramienta educativa y factores de diseño e implantación en museos y espacios públicos

En el presente artículo se hará una reflexión sobre las amplias posibilidades ofrecidas por la Realidad Virtual (RV) en general, y los sistemas de visualización inmersiva e interactiva en particular, como vehículo de comunicación de contenidos, bajo una aproximación pedagógica orientada hacia la museística y los espacios públicos. Se analizaran las características principales de este medio de cara a la transmisión de información, así como aquellos factores de diseño e implantación más relevantes en su aplicación al ámbito de los museos y exposiciones. Se utilizaran dos casos de estudio de particular relevancia para exponer alguna de las técnicas de diseño, desarrollo e implementación más usuales a la hora de abordar un proyecto de estas características, y los procedimientos seguidos para dotarlos de un contenido relevante, coherente y didáctico. El primer trabajo presentado, denominado “Botafumeiro Virtual”, si bien tiene un alcance limitado en la proporción de contenido presentado, encierra y ejemplifica, en su concepción, los conceptos básicos de inmersión, interacción, realimentación y presencia, inherentes a los entornos virtuales, además de ser un original propuesta para la puesta en valor conceptos relativos al patrimonio-histórico-artístico-cultural, como lo demuestran los diferentes premios y menciones obtenidas. El segundo proyecto presentado, corresponde al “género” clásico de la Realidad Virtual denominado “Virtual Walktrhough”, o “Paseo Virtual” en donde se presentan una serie de contenidos, orientados hacia el patrimonio natural en este caso particular, de una forma “mixta”, utilizando las técnicas narrativas audiovisuales tradicionales, en conjunción con elementos heredados de los entornos virtuales

The Utility of Measures of Attention and Situation Awareness for Quantifying Telepresence

Telepresence is defined as the sensation of being present at a remote robot task site while physically present at a local control station. This concept has received substantial attention in the recent past as a result of hypothesized benefits of presence experiences on human task performance with teleoperation systems. Human factors research, however, has made little progress in establishing a relationship between the concept of telepresence and teleoperator performance. This has been attributed to the multidimensional nature of telepresence, the lack of appropriate studies to elucidate this relationship, and the lack of a valid and reliable, objective measure of telepresence. Subjective measures (e.g., questionnaires, rating scales) are most commonly used to measure telepresence. Objective measures have been proposed, including behavioral responses to stimuli presented in virtual worlds (e.g. ducking virtual objects). Other research has suggested use of physiological measures, such as cardiovascular responses to indicate the extent of telepresence experiences in teleoperation tasks. The objective of the present study was to assess the utility of using measures of attention allocation and situation awareness (SA) to objectively describe telepresence. Attention and SA have been identified as cognitive constructs potentially underlying telepresence experiences. Participants in this study performed a virtual mine neutralization task involving remote control of a simulated robotic rover and integrated tools to locate, uncover, and dispose of mines. Subjects simultaneously completed two secondary tasks that required them to monitor for low battery signals associated with operation of the vehicle and controls. Subjects were divided into three groups of eight according to task difficulty, which was manipulated by varying the number, and spacing, of mines in the task environment. Performance was measured as average time to neutralize four mines. Telepresence was assessed using a Presence questionnaire. Situation awareness was measured using the Situation Awareness Global Assessment Technique. Attention was measured as a ratio of the number of ?low battery signal detections to the total number of signals presented through the secondary task displays. Analysis of variance results revealed level of difficulty to significantly affect performance time and telepresence. Regression analysis revealed level of difficulty, immersive tendencies, and attention to explain significant portions of the variance in telepresence

The development of a hybrid virtual reality/video view-morphing display system for teleoperation and teleconferencing

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2000.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 84-89).The goal of this study is to extend the desktop panoramic static image viewer concept (e.g., Apple QuickTime VR; IPIX) to support immersive real time viewing, so that an observer wearing a head-mounted display can make free head movements while viewing dynamic scenes rendered in real time stereo using video data obtained from a set of fixed cameras. Computational experiments by Seitz and others have demonstrated the feasibility of morphing image pairs to render stereo scenes from novel, virtual viewpoints. The user can interact both with morphed real world video images, and supplementary artificial virtual objects (“Augmented Reality”). The inherent congruence of the real and artificial coordinate frames of this system reduces registration errors commonly found in Augmented Reality applications. In addition, the user’s eyepoint is computed locally so that any scene lag resulting from head movement will be less than those from alternative technologies using remotely controlled ground cameras. For space applications, this can significantly reduce the apparent lag due to satellite communication delay. This hybrid VR/view-morphing display (“Virtual Video”) has many important NASA applications including remote teleoperation, crew onboard training, private family and medical teleconferencing, and telemedicine. The technical objective of this study developed a proof-of-concept system using a 3D graphics PC workstation of one of the component technologies, Immersive Omnidirectional Video, of Virtual Video. The management goal identified a system process for planning, managing, and tracking the integration, test and validation of this phased, 3-year multi-university research and development program.by William E. Hutchison.S.M

Simulation-based Cognitive Workload Modeling And Evaluation Of Adaptive Automation Invoking And Revoking Strategies

In human-computer systems, such as supervisory control systems, large volumes of incoming and complex information can degrade overall system performance. Strategically integrating automation to offload tasks from the operator has been shown to increase not only human performance but also operator efficiency and safety. However, increased automation allows for increased task complexity, which can lead to high cognitive workload and degradation of situational awareness. Adaptive automation is one potential solution to resolve these issues, while maintaining the benefits of traditional automation. Adaptive automation occurs dynamically, with the quantity of automated tasks changing in real-time to meet performance or workload goals. While numerous studies evaluate the relative performance of manual and adaptive systems, little attention has focused on the implications of selecting particular invoking or revoking strategies for adaptive automation. Thus, evaluations of adaptive systems tend to focus on the relative performance among multiple systems rather than the relative performance within a system. This study takes an intra-system approach specifically evaluating the relationship between cognitive workload and situational awareness that occurs when selecting a particular invoking-revoking strategy for an adaptive system. The case scenario is a human supervisory control situation that involves a system operator who receives and interprets intelligence outputs from multiple unmanned assets, and then identifies and reports potential threats and changes in the environment. In order to investigate this relationship between workload and situational awareness, discrete event simulation (DES) is used. DES is a standard technique in the analysis iv of systems, and the advantage of using DES to explore this relationship is that it can represent a human-computer system as the state of the system evolves over time. Furthermore, and most importantly, a well-designed DES model can represent the human operators, the tasks to be performed, and the cognitive demands placed on the operators. In addition to evaluating the cognitive workload to situational awareness tradeoff, this research demonstrates that DES can quite effectively model and predict human cognitive workload, specifically for system evaluation. This research finds that the predicted workload of the DES models highly correlates with well-established subjective measures and is more predictive of cognitive workload than numerous physiological measures. This research then uses the validated DES models to explore and predict the cognitive workload impacts of adaptive automation through various invoking and revoking strategies. The study provides insights into the workload-situational awareness tradeoffs that occur when selecting particular invoking and revoking strategies. First, in order to establish an appropriate target workload range, it is necessary to account for both performance goals and the portion of the workload-performance curve for the task in question. Second, establishing an invoking threshold may require a tradeoff between workload and situational awareness, which is influenced by the task’s location on the workload-situational awareness continuum. Finally, this study finds that revoking strategies differ in their ability to achieve workload and situational awareness goals. For the case scenario examined, revoking strategies based on duration are best suited to improve workload, while revoking strategies based on revoking thresholds are better for maintaining situational awareness

Plausibility Illusion in Virtual Environments

Historically, research into subjective user experience in virtual environments has focused on presence, the feeling of "being there" in the virtual environment. Recently, Professor Mel Slater proposed that in addition to this feeling of being in the virtual space, researchers also need to consider the subjective feeling that the events depicted in the virtual environment appear real. He coined the terms Place Illusion (PI) and Plausibility Illusion (Psi), respectively, to refer to these subjective feelings. There exists a substantial amount of previous research applicable to PI, but very little regarding Psi. This dissertation fleshes out the concept of Plausibility Illusion by introducing new terminology, and reports on several experiments investigating the factors and effects of Psi. I demonstrate that Psi can be detected using existing presence measures, including questionnaires and physiological metrics. Of particular interest in these results is that factors contributing to Plausibility Illusion affected heart rate, with inconsistent behavior of the virtual environment leading to increased heart rate. I also demonstrate that study participants' individual differences affected how they interacted with a virtual environment, leading to different levels of Plausibility Illusion and, therefore, presence. I further demonstrate that, among the factors tested, the virtual body is the most important factor contributing to users' feelings of Plausibility Illusion, and that the coherence of the virtual scenario is the second most important factor. This shows it is feasible to determine a rank ordering of factors that affect users' sense of Plausibility Illusion in virtual environments, offering guidance to creators and developers.Doctor of Philosoph

Factors for the sense of presence within virtual architecture

Die Dissertation adressiert das Gebiet der Entwicklung von (räumlicher) Präsenz in computer-generierten virtuellen Umgebungen im speziellen und virtueller Architektur im besonderen. Der erste Teil motiviert die Arbeit, führt in die Terminologie ein und beschreibt die grundlegenden Prinzipien der virtuellen Realität (VR) und von VR-basierter Architektur. Der Schwerpunkt liegt auf sogenannten immersiven VR-Systemen. Der folgende Teil erarbeitet den theoretischen Hintergrund der Entwickling von Präsenz unter besonderer Beachtung philosophischer und kognitiver Ansätze. Ein eigenes Kapitel widmet sich der Klassifikation von Präsenz-Faktoren unter dem Gesichtspunkt der praktischen Gestaltung virtueller Architektur. Letztendlich werden verschiedene empirische Untersuchungen vorgestellt, die die entwickelten Ansaetze evaluieren und beschreiben. Die Ergebnisse werden im Kontext des architektonischen Gestaltens diskutiert.The dissertation addresses the domain of the development of the sense of presense within computer-generated virtual environments in general and within virtual architecture in particular. The first part provides motivation and terminology as well as the description of the basic principles of the generation of virtual worlds and virtual reality based architecture. The focus is set on so called immersive virtual reality systems. The following part offers a theoretical background on the sense of presence with special respect to philosophical and cognitive approaches. Considering practical aspects in developing virtual environments and architecture a classification framework for contributing factors is given in a seperate chapter. Finally several empirical investigations serve as a proof of the approaches developed and will be discussed in the context of architectural design

Life Sciences Program Tasks and Bibliography for FY 1997

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1997. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive internet web page