Skip Nav Destination
Close Modal
Update search
NARROW
Format
Journal
TocHeadingTitle
Date
Availability
1-20 of 41
Mel Slater
Close
Follow your search
Access your saved searches in your account
Would you like to receive an alert when new items match your search?
1
Sort by
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2019) 28: 5–27.
Published: 01 January 2019
Abstract
View article
PDF
There is an alarming level of violence by police in the US toward African Americans. Although this may be rooted in explicit racial bias, the more intractable problem is overcoming implicit bias, bias that is non-conscious but demonstrated in actual behavior. If bias is implicit, it is difficult to change through explicit methods that attempt to change attitudes. We carried out a study using virtual reality (VR) with 38 officers in a US police department, who took part in an interrogation of an African American suspect alongside an officer who was racially abusive toward the suspect. Seventeen of the participants witnessed the interview again from a third person perspective (Observer) and 21 from the embodied perspective of the suspect, now a victim of the interrogation (Victim condition), having been assigned randomly to these two groups. Some weeks later, all witnessed aggression by an officer toward an African American man in a virtual cafe scenario. The results show that the actions of those who had been in the Victim condition were coded as being more helpful toward the victim than those in the Observer condition. We argue that such VR exposures operate at the experiential and implicit level rather than the explicit, and hence are more likely to be effective in combating aggression rooted in implicit bias.
Includes: Supplementary data
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2016) 25 (3): 287.
Published: 01 December 2016
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2014) 23 (3): 242–252.
Published: 01 October 2014
Abstract
View article
PDF
Recent advances in humanoid robot technologies have made it possible to inhabit a humanlike form located at a remote place. This allows the participant to interact with others in that space and experience the illusion that the participant is actually present in the remote space. Moreover, with these humanlike forms, it may be possible to induce a full-body ownership illusion, where the robot body is perceived to be one's own. We show that it is possible to induce the full-body ownership illusion over a remote robotic body with a highly robotic appearance. Additionally, our results indicate that even with nonmanual control of a remote robotic body, it is possible to induce feelings of agency and illusions of body ownership. Two established control methods, an SSVEP-based BCI and eye tracking, were tested as a means of controlling the robot's gesturing. Our experience and the results indicate that both methods are tractable for immersive control of a humanoid robot in a social telepresence setting.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2014) 23 (3): 287–299.
Published: 01 October 2014
Abstract
View article
PDF
An experiment was carried out to examine the extent to which an avatar can be perceived by people as similar to themselves, including their face and body. The avatar was judged by the participants themselves rather than by third parties. The experiment was organized in two phases. The initial phase consisted of a forced-choice, paired comparison method used to create a ranking of 10 virtual faces in order of preference. This set of faces included a facial mesh, created by a custom software pipeline to rapidly generate avatars that resembled the experimental participants. Six more faces, derived from the participants' own face, were also shown in order to gain insight into the acceptance of a variety of facial similarities. In the second phase, full-body avatars with the most and least preferred faces were presented along with the direct pipeline output. Participants rated their level of satisfaction with those avatars as virtual self-representations and provided the level of perceived resemblance to themselves. The results show that our avatars are perceived to be similar to the self, rated at 7.5/10. Those avatars with faces derived from the participants' face mixed with an ethnically similar face were also rated with high scores. These results differ significantly from how arbitrary avatars are perceived. Therefore, reasonably physically similar avatars can also be expected to be perceived as similar by participants.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2012) 21 (4): 373–387.
Published: 01 November 2012
Abstract
View article
PDF
What does it feel like to own, to control, and to be inside a body? The multidimensional nature of this experience together with the continuous presence of one's biological body, render both theoretical and experimental approaches problematic. Nevertheless, exploitation of immersive virtual reality has allowed a reframing of this question to whether it is possible to experience the same sensations towards a virtual body inside an immersive virtual environment as toward the biological body, and if so, to what extent. The current paper addresses these issues by referring to the Sense of Embodiment (SoE). Due to the conceptual confusion around this sense, we provide a working definition which states that SoE consists of three subcomponents: the sense of self-location, the sense of agency, and the sense of body ownership. Under this proposed structure, measures and experimental manipulations reported in the literature are reviewed and related challenges are outlined. Finally, future experimental studies are proposed to overcome those challenges, toward deepening the concept of SoE and enhancing it in virtual applications.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2012) 21 (4): 406–422.
Published: 01 November 2012
Abstract
View article
PDF
This paper presents the use of our multimodal mixed reality telecommunication system to support remote acting rehearsal. The rehearsals involved two actors, located in London and Barcelona, and a director in another location in London. This triadic audiovisual telecommunication was performed in a spatial and multimodal collaborative mixed reality environment based on the “destination-visitor” paradigm, which we define and put into use. We detail our heterogeneous system architecture, which spans the three distributed and technologically asymmetric sites, and features a range of capture, display, and transmission technologies. The actors' and director's experience of rehearsing a scene via the system are then discussed, exploring successes and failures of this heterogeneous form of telecollaboration. Overall, the common spatial frame of reference presented by the system to all parties was highly conducive to theatrical acting and directing, allowing blocking, gross gesture, and unambiguous instruction to be issued. The relative inexpressivity of the actors' embodiments was identified as the central limitation of the telecommunication, meaning that moments relying on performing and reacting to consequential facial expression and subtle gesture were less successful.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2012) 21 (2): 229–243.
Published: 01 April 2012
Abstract
View article
PDF
In order to rehearse for a play or a scene from a movie, it is generally required that the actors are physically present at the same time in the same place. In this paper we present an example and experience of a full body motion shared virtual environment (SVE) for rehearsal. The system allows actors and directors to meet in an SVE in order to rehearse scenes for a play or a movie, that is, to perform some dialogue and blocking (positions, movements, and displacements of actors in the scene) rehearsal through a full body interactive virtual reality (VR) system. The system combines immersive VR rendering techniques as well as network capabilities together with full body tracking. Two actors and a director rehearsed from separate locations. One actor and the director were in London (located in separate rooms) while the second actor was in Barcelona. The Barcelona actor used a wide field-of-view head-tracked head-mounted display, and wore a body suit for real-time motion capture and display. The London actor was in a Cave system, with head and partial body tracking. Each actor was presented to the other as an avatar in the shared virtual environment, and the director could see the whole scenario on a desktop display, and intervene by voice commands. A video stream in a window displayed in the virtual environment also represented the director. The London participant was a professional actor, who afterward commented on the utility of the system for acting rehearsal. It was concluded that full body tracking and corresponding real-time display of all the actors' movements would be a critical requirement, and that blocking was possible down to the level of detail of gestures. Details of the implementation, actors, and director experiences are provided.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2011) 20 (4): 371–392.
Published: 01 August 2011
Abstract
View article
PDF
This paper focuses on the development and evaluation of a haptic enhanced virtual reality system which allows a human user to make physical handshakes with a virtual partner through a haptic interface. Multimodal feedback signals are designed to generate the illusion that a handshake with a robotic arm is a handshake with another human. Advanced controllers of the haptic interface are developed to respond to user behaviors online. Techniques to achieve online behavior generation are presented, such as a hidden-Markov-model approach to human interaction strategy estimation. Human-robot handshake experiments were carried out to evaluate the performance of the system. Two different approaches to haptic rendering were compared in experiments: a controller in basic mode with an embedded curve in the robot that disregards the human partner, and an interactive robot controller for online behavior generation. The two approaches were compared with the ground truth of another human driving the robot via teleoperation instead of the controller implementing a virtual partner. In the evaluation results, the human approach is rated to be most human-like, with the interactive controller following closely behind, followed by the controller in basic mode. This paper mainly concentrates on discussing the development of the haptic rendering algorithm for the handshaking system, its integration with visual and haptic cues, and reports about the results of subjective evaluation experiments that were carried out.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2010) 19 (4): 291–301.
Published: 01 August 2010
Abstract
View article
PDF
This paper introduces the concept and discusses the implications of immersive journalism, which is the production of news in a form in which people can gain first-person experiences of the events or situation described in news stories. The fundamental idea of immersive journalism is to allow the participant, typically represented as a digital avatar, to actually enter a virtually recreated scenario representing the news story. The sense of presence obtained through an immersive system (whether a Cave or head-tracked head-mounted displays [HMD] and online virtual worlds, such as video games and online virtual worlds) affords the participant unprecedented access to the sights and sounds, and possibly feelings and emotions, that accompany the news. This paper surveys current approaches to immersive journalism and the theoretical background supporting claims regarding avatar experience in immersive systems. We also provide a specific demonstration: giving participants the experience of being in an interrogation room in an offshore prison. By both describing current approaches and demonstrating an immersive journalism experience, we open a new avenue for research into how presence can be utilized in the field of news and nonfiction.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2010) 19 (4): iii.
Published: 01 August 2010
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2010) 19 (1): 1–11.
Published: 01 February 2010
Abstract
View article
PDF
Brain–computer interfaces (BCIs) are becoming more and more popular as an input device for virtual worlds and computer games. Depending on their function, a major drawback is the mental workload associated with their use and there is significant effort and training required to effectively control them. In this paper, we present two studies assessing how mental workload of a P300-based BCI affects participants' reported sense of presence in a virtual environment (VE). In the first study, we employ a BCI exploiting the P300 event-related potential (ERP) that allows control of over 200 items in a virtual apartment. In the second study, the BCI is replaced by a gaze-based selection method coupled with wand navigation. In both studies, overall performance is measured and individual presence scores are assessed by means of a short questionnaire. The results suggest that there is no immediate benefit for visualizing events in the VE triggered by the BCI and that no learning about the layout of the virtual space takes place. In order to alleviate this, we propose that future P300-based BCIs in VR are set up so as require users to make some inference about the virtual space so that they become aware of it, which is likely to lead to higher reported presence.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2009) 18 (3): 185–199.
Published: 01 June 2009
Abstract
View article
PDF
A sign of presence in virtual environments is that people respond to situations and events as if they were real, where response may be considered at many different levels, ranging from unconscious physiological responses through to overt behavior, emotions, and thoughts. In this paper we consider two responses that gave different indications of the onset of presence in a gradually forming environment. Two aspects of the response of people to an immersive virtual environment were recorded: their eye scanpath, and their skin conductance response (SCR). The scenario was formed over a period of 2 min, by introducing an increasing number of its polygons in random order in a head-tracked head-mounted display. For one group of experimental participants ( n = 8) the environment formed into one in which they found themselves standing on top of a 3 m high column. For a second group of participants ( n = 6) the environment was otherwise the same except that the column was only 1 cm high, so that they would be standing at normal ground level. For a third group of participants ( n = 14) the polygons never formed into a meaningful environment. The participants who stood on top of the tall column exhibited a significant decrease in entropy of the eye scanpath and an increase in the number of SCR by 99 s into the scenario, at a time when only 65% of the polygons had been displayed. The ground level participants exhibited a similar decrease in scanpath entropy, but not the increase in SCR. The random scenario grouping did not exhibit this decrease in eye scanpath entropy. A drop in scanpath entropy indicates that the environment had cohered into a meaningful perception. An increase in the rate of SCR indicates the perception of an aversive stimulus. These results suggest that on these two dimensions (scanpath entropy and rate of SCR) participants were responding realistically to the scenario shown in the virtual environment. In addition, the response occurred well before the entire scenario had been displayed, suggesting that once a set of minimal cues exists within a scenario, it is enough to form a meaningful perception. Moreover, at the level of the sympathetic nervous system, the participants who were standing on top of the column exhibited arousal as if their experience might be real. This is an important practical aspect of the concept of presence.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2008) 17 (3): 293–309.
Published: 01 June 2008
Abstract
View article
PDF
This paper presents qualitative findings from an experiment designed to investigate breaks in presence. Participants spent approximately five minutes in an immersive Cave-like system depicting a virtual bar with five virtual characters. On four occasions the projections were made to go white to trigger clearly identifiable anomalies in the audiovisual experience. Participants' physiological responses were measured throughout to investigate possible physiological correlates of these experienced anomalies. Analysis of subsequent interviews with participants suggests that these anomalies were subjectively experienced as breaks in presence. This is significant in the context of our research approach, which considers presence as a multilevel construct ranging from higher-level subjective responses to lower-level behavioral and automatic responses. The fact that these anomalies were also associated with an identifiable physiological signature suggests future avenues for exploring less intrusive ways of studying temporal fluctuations in presence during the course of the mediated experience itself. The findings also reveal that breaks in presence have multiple causes and can range in intensity, resulting in varying recovery times. In addition, presence can vary in intensity within the same space, suggesting that presence in an immersive virtual environment can fluctuate temporally and that spatial behavior is consistent with what would be expected in an equivalent real environment.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2007) 16 (4): 447–456.
Published: 01 August 2007
Abstract
View article
PDF
The problems of valid design of questionnaires and analysis of ordinal response data from questionnaires have had a long history in the psychological and social sciences. Gardner and Martin (2007, this issue) illustrate some of these problems with reference to an earlier paper (Garau, Slater, Pertaub, & Razzaque, 2005) that studied copresence with virtual characters within an immersive virtual environment. Here we review the critique of Gardner and Martin supporting their main arguments. However, we show that their critique could not take into account the historical circumstances of the experiment described in the paper, and moreover that a reanalysis using more appropriate statistical methods does not result in conclusions that are different from those reported in the original paper. We go on to argue that in general such questionnaire data is treated far too seriously, and that a different paradigm is needed for presence research—one where multivariate physiological and behavioral data is used alongside subjective and questionnaire data, with the latter not having any specially privileged role.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2007) 16 (1): 100–110.
Published: 01 February 2007
Abstract
View article
PDF
We have set up a brain-computer interface (BCI) to be used as an input device to a highly immersive virtual reality CAVE-like system. We have carried out two navigation experiments: three subjects were required to rotate in a virtual bar room by imagining left or right hand movement, and to walk along a single axis in a virtual street by imagining foot or hand movement. In this paper we focus on the subjective experience of navigating virtual reality “by thought,” and on the interrelations between BCI and presence.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2007) 16 (1): iii–iv.
Published: 01 February 2007
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2006) 15 (5): 500–514.
Published: 01 October 2006
Abstract
View article
PDF
Healthy participants are able to move forward within a virtual environment (VE) by the imagination of foot movement. This is achieved by using a brain-computer interface (BCI) that transforms thought-modulated electroencephalogram (EEG) recordings into a control signal. A BCI establishes a communication channel between the human brain and the computer. The basic principle of the Graz-BCI is the detection and classification of motor-imagery-related EEG patterns, whereby the dynamics of sensorimotor rhythms are analyzed. A BCI is a closed-loop system and information is visually fed back to the user about the success or failure of an intended movement imagination. Feedback can be realized in different ways, from a simple moving bar graph to navigation in VEs. The goals of this work are twofold: first, to show the influence of different feedback types on the same task, and second, to demonstrate that it is possible to move through a VE (e.g., a virtual street) without any muscular activity, using only the imagination of foot movement. In the presented work, data from BCI feedback displayed on a conventional monitor are compared with data from BCI feedback in VE experiments with a head-mounted display (HMD) and in a high immersive projection environment (Cave). Results of three participants are reported to demonstrate the proof-of-concept. The data indicate that the type of feedback has an influence on the task performance, but not on the BCI classification accuracy. The participants achieved their best performances viewing feedback in the Cave. Furthermore the VE feedback provided motivation for the subjects.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2006) 15 (5): 553–569.
Published: 01 October 2006
Abstract
View article
PDF
An experiment was conducted in a Cave-like environment to explore the relationship between physiological responses and breaks in presence and utterances by virtual characters towards the participants. Twenty people explored a virtual environment (VE) that depicted a virtual bar scenario. The experiment was divided into a training and an experimental phase. During the experimental phase breaks in presence (BIPs) in the form of whiteouts of the VE scenario were induced for 2 s at four equally spaced times during the approximately 5 min in the bar scenario. Additionally, five virtual characters addressed remarks to the subjects. Physiological measures including electrocardiagram (ECG) and galvanic skin response (GSR) were recorded throughout the whole experiment. The heart rate, the heart rate variability, and the event-related heart rate changes were calculated from the acquired ECG data. The frequency response of the GSR signal was calculated with a wavelet analysis. The study shows that the heart rate and heart rate variability parameters vary significantly between the training and experimental phase. GSR parameters and event-related heart rate changes show the occurrence of breaks in presence. Event-related heart rate changes also signified the virtual character utterances. There were also differences in response between participants who report more or less socially anxious.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2006) 15 (5): 599–610.
Published: 01 October 2006
Abstract
View article
PDF
Presence research relies heavily on empirical experiments involving subjects in mediated environments. Since presence is a complex, multidimensional concept, experiments on presence can be extremely resource intensive and produce large amounts of data of different types. As the presence community matures, we would like to suggest that data collected in experiments be made publicly available to the community. This will allow the verification of experimental results, comparison of results of experiments carried out in different laboratories, and evaluation of new data-analysis methods. This will, eventually, lead to consistency in approaches and increased confidence in results. In this paper we present the complete dataset from a large-scale experiment that we have carried out in highly immersive virtual reality. We describe the data we have gathered and give examples of the types of analysis that can be made based on that data.
Journal Articles
Publisher: Journals Gateway
Presence: Teleoperators and Virtual Environments (2006) 15 (5): iii.
Published: 01 October 2006
1