Abstract: BACKGROUND: Altering the normal association between touch and its visual correlate can result in the illusory perception of a fake limb as part of our own body. Thus, when touch is seen to be applied to a rubber hand while felt synchronously on the corresponding hidden real hand, an illusion of ownership of the rubber hand usually occurs. The illusion has also been demonstrated using visuomotor correlation between the movements of the hidden real hand and the seen fake hand. This type of paradigm has been used with respect to the whole body generating out-of-the-body and body substitution illusions. However, such studies have only ever manipulated a single factor and although they used a form of virtual reality have not exploited the power of immersive virtual reality (IVR) to produce radical transformations in body ownership. PRINCIPAL FINDINGS: Here we show that a first person perspective of a life-sized virtual human female body that appears to substitute the male subjects' own bodies was sufficient to generate a body transfer illusion. This was demonstrated subjectively by questionnaire and physiologically through heart-rate deceleration in response to a threat to the virtual body. This finding is in contrast to earlier experimental studies that assume visuotactile synchrony to be the critical contributory factor in ownership illusions. Our finding was possible because IVR allowed us to use a novel experimental design for this type of problem with three independent binary factors: (i) perspective position (first or third), (ii) synchronous or asynchronous mirror reflections and (iii) synchrony or asynchrony between felt and seen touch. CONCLUSIONS: The results support the notion that bottom-up perceptual mechanisms can temporarily override top down knowledge resulting in a radical illusion of transfer of body ownership. The research also illustrates immersive virtual reality as a powerful tool in the study of body representation and experience, since it supports experimental manipulations that would otherwise be infeasible, with the technology being mature enough to represent human bodies and their motion.
Abstract: An experiment was carried out to examine the impact on electrodermal activity of people when approached by
groups of 1 or 4 virtual characters to varying distances. It was premised on the basis of proxemics theory that the closer the approach of the virtual characters to the participant, the greater the level of physiological arousal.
Physiological arousal was measured by the number of skin conductance responses within a short time period
after the approach, and the maximum change in skin conductance level 5s after the approach. The virtual
characters were each either female or a cylinder of human size, and 1 or 4 characters approached each subject a total of 12 times. Twelve male subjects were recruited for the experiment. The results suggest that the number of skin conductance responses after the approach and the change in skin conductance level increased the closer the virtual characters approached towards the participants. Moreover, these response variables were inversely correlated with the number of visits, showing a typical adaptation effect. There was some evidence to suggest that the number of characters who simultaneously approached (1 or 4) was positively associated with the responses. Surprisingly there was no evidence of a difference in response between the humanoid characters and cylinders on the basis of these physiological data. It is suggested the similarity in this quantitative arousal response to virtual characters and virtual objects might mask a profound difference in qualitative response, an interpretation supported by questionnaire and interview results. Overall the experiment supported the premise that people exhibit heightened physiological arousal the closer they are approached by virtual characters.
Abstract: BACKGROUND: Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement) can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation. METHODOLOGY/PRINCIPAL FINDINGS: To achieve this we used a data-glove that uses sensors transmitting the positions of fingers to a virtually projected hand in the synchronous but not in the asynchronous condition. The illusion of ownership was measured by means of questionnaires. Questions related to ownership gave significantly larger values for the synchronous than for the asynchronous condition. Proprioceptive displacement provided an objective measure of the illusion and had a median value of 3.5 cm difference between the synchronous and asynchronous conditions. In addition, the correlation between the feeling of ownership of the virtual arm and the size of the drift was significant. CONCLUSIONS/SIGNIFICANCE: We conclude that synchrony between visual and proprioceptive information along with motor activity is able to induce an illusion of ownership over a virtual arm. This has implications regarding the brain mechanisms underlying body ownership as well as the use of virtual bodies in therapies and rehabilitation.
Abstract: A new definition of immersion with respect to virtual environment (VE) systems has been proposed in earlier work, based on the concept of simulation. One system (A) is said to be more immersive than another (B) if A can be used to simulate an application as if it were running on B. Here we show how this concept can be used as the basis for a psychophysics of presence in VEs, the sensation of being in the place depicted by the virtual environment displays (Place Illusion, PI), and also the illusion that events occurring in the virtual environment are real (Plausibility Illusion, Psi). The new methodology involves matching experiments akin to those in color science. Twenty participants first experienced PI or Psi in the initial highest level immersive system, and then in 5 different trials chose transitions from lower to higher order systems and declared a match whenever they felt the same level of PI or Psi as they had in the initial system. In each transition they could change the type of illumination model used, or the field-of-view, or the display type (powerwall or HMD) or the extent of self-representation by an avatar. The results showed that the 10 participants instructed to choose transitions to attain a level of PI corresponding to that in the initial system tended to first choose a wide field-of-view and head-mounted display, and then ensure that they had a virtual body that moved as they did. The other 10 in the Psi group concentrated far more on achieving a higher level of illumination realism, although having a virtual body representation was important for both groups. This methodology is offered as a way forward in the evaluation of the responses of people to immersive virtual environments, a unified theory and methodology for psychophysical measurement.
Notes: See the accompanying video:
http://www.youtube.com/watch?v=QEKxyhSPiVg
Abstract: This paper reviews experimental methods for the study of the responses of people to violence in digital media, and in particular considers the issues of internal validity and ecological validity or generalisability of results to events in the real world. Experimental methods typically involve a significant level of abstraction from reality, with participants required to carry out tasks that are far removed from violence in real life, and hence their ecological validity is questionable. On the other hand studies based on field data, while having ecological validity, cannot control multiple confounding variables that may have an impact on observed results, so that their internal validity is questionable. It is argued that immersive virtual reality may provide a unification of these two approaches. Since people tend to respond realistically to situations and events that occur in virtual reality, and since virtual reality simulations can be completely controlled for experimental purposes, studies of responses to violence within virtual reality are likely to have both ecological and internal validity. This depends on a property that we call 'plausibility' - including the fidelity of the depicted situation with prior knowledge and expectations. We illustrate this with data from a previously published experiment, a virtual reprise of Stanley Milgram's 1960s obedience experiment, and also with pilot data from a new study being developed that looks at bystander responses to violent incidents.
Abstract: Abstract This work investigates novel alternative means of interaction in a virtual environment (VE). We analyze whether humans can remap established body functions to learn to interact with digital information in an environment that is cross-sensory by nature and uses vocal utterances in order to influence (abstract) virtual objects. We thus establish a correlation among learning, control of the interface, and the perceived sense of presence in the VE. The application enables intuitive interaction by mapping actions (the prosodic aspects of the human voice) to a certain response (i.e., visualization). A series of single-user and multiuser studies shows that users can gain control of the intuitive interface and learn to adapt to new and previously unseen tasks in VEs. Despite the abstract nature of the presented environment, presence scores were generally very high.
Abstract: The apparently stable brain representation of our bodies is easily challenged. We have recently shown that the illusion of ownership of a three-dimensional virtual hand can be evoked through synchronous tactile stimulation of a person's hidden real hand and that of the virtual hand. This reproduces the well-known rubber-hand illusion, but in virtual reality. Here we show that some aspects of the illusion can also occur through motor imagery used to control movements of a virtual hand. When movements of the virtual hand followed motor imagery, the illusion of ownership of the virtual hand was evoked and muscle activity measured through electromyogram correlated with movements of the virtual arm. Using virtual bodies has a great potential in the fields of physical and neural rehabilitation, making the understanding of ownership of a virtual body highly relevant.
Abstract: We discuss three experiments that investigate how virtual limbs and bodies can come to feel like real limbs and bodies. The first experiment shows that an illusion of ownership of a virtual arm appearing to project out of a person's shoulder can be produced by tactile stimulation on a person's hidden real hand and synchronous stimulation on the seen virtual hand. The second shows that the illusion can be produced by synchronous movement of the person's hidden real hand and a virtual hand. The third shows that a weaker form of the illusion can be produced when a brain-computer interface is employed to move the virtual hand by means of motor imagery without any tactile stimulation. We discuss related studies that indicate that the ownership illusion may be generated for an entire body. This has important implications for the scientific understanding of body ownership and several practical applications.
Abstract: In this paper, I address the question as to why participants tend to respond realistically to situations and events portrayed within an immersive virtual reality system. The idea is put forward, based on the experience of a large number of experimental studies, that there are two orthogonal components that contribute to this realistic response. The first is 'being there', often called 'presence', the qualia of having a sensation of being in a real place. We call this place illusion (PI). Second, plausibility illusion (Psi) refers to the illusion that the scenario being depicted is actually occurring. In the case of both PI and Psi the participant knows for sure that they are not 'there' and that the events are not occurring. PI is constrained by the sensorimotor contingencies afforded by the virtual reality system. Psi is determined by the extent to which the system can produce events that directly relate to the participant, the overall credibility of the scenario being depicted in comparison with expectations. We argue that when both PI and Psi occur, participants will respond realistically to the virtual reality.
Abstract: BACKGROUND: Judging whether we can trust other people is central to social interaction, despite being error-prone. A fear of others can be instilled by the contemporary political and social climate. Unfounded mistrust is called paranoia, and in severe forms is a central symptom of schizophrenia. AIMS: To demonstrate that individuals without severe mental illness in the general population experience unfounded paranoid thoughts, and to determine factors predictive of paranoia using the first laboratory method of capturing the experience. METHOD: Two hundred members of the general public were comprehensively assessed, and then entered a virtual reality train ride populated by neutral characters. Ordinal logistic regressions (controlling for age, gender, ethnicity, education, intellectual functioning, socio-economic status, train use, playing of computer games) were used to determine predictors of paranoia. RESULTS: The majority agreed that the characters were neutral, or even thought they were friendly. However, a substantial minority reported paranoid concerns. Paranoia was strongly predicted by anxiety, worry, perceptual anomalies and cognitive inflexibility. CONCLUSIONS: This is the most unambiguous demonstration of paranoid ideation in the general public so far. Paranoia can be understood in terms of cognitive factors. The use of virtual reality should lead to rapid advances in the understanding of paranoia.
Abstract: A tetraplegic patient was able to induce midcentral localized beta oscillations in the electroencephalogram (EEG) after extensive mental practice of foot motor imagery. This beta oscillation was used to simulate a wheel chair movement in a virtual environment (VE). The analysis of electrocardiogram (ECG) data revealed that the induced beta oscillations were accompanied by a characteristic heart rate (HR) change in form of a preparatory HR acceleration followed by a short-lasting deceleration in the order of 10-20 bpm (beats-per-minute). This provides evidence that mental practice of motor performance is accompanied not only by activation of cortical structures but also by central commands into the cardiovascular system with its nuclei in the brain stem.
Abstract: We present a participant study that compares biological exploration tasks using volume renderings of laser confocal microscopy data across three environments which vary in level of immersion. For the tasks, data, and visualization approach used in our study, we found that subjects qualitatively preferred and quantitatively performed better in environments with greater levels of immersion. Subjects performed real-world biological data analysis tasks that emphasized understanding spatial relationships including characterizing the general features in a volume, identifying co-located features, and reporting geometric relationships such as whether clusters of cells were coplanar. After analyzing data in each environment, subjects were asked to choose which environment they wanted to analyze additional data sets in--subjects uniformly selected the Cave environment.
Abstract: This paper presents the quantitative and qualitative findings from an experiment designed to evaluate a developing model of affective postures for full-body virtual characters in immersive virtual environments (IVEs). Forty-nine participants were each requested to explore a virtual environment by asking two virtual characters for instructions. The participants used a CAVE-like system to explore the environment. Participant responses and their impression of the virtual characters were evaluated through a wide variety of both quantitative and qualitative methods. Combining a controlled experimental approach with various data-collection methods provided a number of advantages such as providing a reason to the quantitative results. The quantitative results indicate that posture plays an important role in the communication of affect by virtual characters. The qualitative findings indicated that participants attribute a variety of psychological states to the behavioral cues displayed by virtual characters. In addition, participants tended to interpret the social context portrayed by the virtual characters in a holistic manner. This suggests that one aspect of the virtual scene colors the perception of the whole social context portrayed by the virtual characters. We conclude by discussing the importance of designing holistically congruent virtual characters especially in immersive settings.
Abstract: BACKGROUND: In recent years a close association between anxiety and persecutory ideation has been established, contrary to the traditional division of neurosis and psychosis. Nonetheless, the two experiences are distinct. The aim of this study was to identify factors that distinguish the occurrence of social anxiety and paranoid thoughts in an experimental situation. METHOD: Two hundred non-clinical individuals broadly representative of the UK general population were assessed on a range of psychological factors, experienced a neutral virtual reality social environment, and then completed state measures of paranoia and social anxiety. Clustered bivariate logistic regressions were carried out, testing interactions between potential predictors and the type of reaction in virtual reality. RESULTS: The strongest finding was that the presence of perceptual anomalies increased the risk of paranoid reactions but decreased the risk of social anxiety. Anxiety, depression, worry and interpersonal sensitivity all had similar associations with paranoia and social anxiety. CONCLUSIONS: The study shows that social anxiety and persecutory ideation share many of the same predictive factors. Non-clinical paranoia may be a type of anxious fear. However, perceptual anomalies are a distinct predictor of paranoia. In the context of an individual feeling anxious, the occurrence of odd internal feelings in social situations may lead to delusional ideas through a sense of 'things not seeming right'. The study illustrates the approach of focusing on experiences such as paranoid thinking rather than diagnoses such as schizophrenia.
Abstract: Real-time global illumination in VR systems enhances scene realism by incorporating soft shadows, reflections of objects in the scene, and color bleeding. The Virtual Light Field (VLF) method enables real-time global illumination rendering in VR. The VLF has been integrated with the Extreme VR system for real-time GPU-based rendering in a Cave Automatic Virtual Environment.
Abstract: OBJECTIVE: Virtual reality (VR) has begun to be used to research the key psychotic symptom of paranoia. The initial studies have been with non-clinical individuals and individuals at high risk of psychosis. The next step is to develop the technology for the understanding and treatment of clinical delusions. Therefore the present study investigated the acceptability and safety of using VR with individuals with current persecutory delusions. Further, it set out to determine whether patients feel immersed in a VR social environment and, consequently, experience paranoid thoughts. METHOD: Twenty individuals with persecutory delusions and twenty non-clinical individuals spent 4 min in a VR underground train containing neutral characters. Levels of simulator sickness, distress, sense of presence, and persecutory ideation about the computer characters were measured. A one-week follow-up was conducted to check longer-term side effects. RESULTS: The VR experience did not raise levels of anxiety or symptoms of simulator sickness. No side effects were reported at the follow-up. There was a considerable degree of presence in the VR scenario for all participants. A high proportion of the persecutory delusions group (65%) had persecutory thinking about the computer characters, although this rate was not significantly higher than the non-clinical group. CONCLUSIONS: The study indicates that brief experiences in VR are safe and acceptable to people with psychosis. Further, patients with paranoia can feel engaged in VR scenes and experience persecutory thoughts. Exposure to social situations using VR has the potential to be incorporated into cognitive behavioural interventions for paranoia.
Abstract: The integration of the human brain with computers is an interesting new area of applied neuroscience, where one application is replacement of a person's real body by a virtual representation. Here we demonstrate that a virtual limb can be made to feel part of your body if appropriate multisensory correlations are provided. We report an illusion that is invoked through tactile stimulation on a person's hidden real right hand with synchronous virtual visual stimulation on an aligned 3D stereo virtual arm projecting horizontally out of their shoulder. An experiment with 21 male participants showed displacement of ownership towards the virtual hand, as illustrated by questionnaire responses and proprioceptive drift. A control experiment with asynchronous tapping was carried out with a different set of 20 male participants who did not experience the illusion. After 5 min of stimulation the virtual arm rotated. Evidence suggests that the extent of the illusion was also correlated with the degree of muscle activity onset in the right arm as measured by EMG during this period that the arm was rotating, for the synchronous but not the asynchronous condition. A completely virtual object can therefore be experienced as part of one's self, which opens up the possibility that an entire virtual body could be felt as one's own in future virtual reality applications or online games, and be an invaluable tool for the understanding of the brain mechanisms underlying body ownership.
Abstract: BACKGROUND: Virtual reality provides a means of studying paranoid thinking in controlled laboratory conditions. However, this method has not been used with a clinical group. AIMS: To establish the feasibility and safety of using virtual reality methodology in people with an at-risk mental state and to investigate the applicability of a cognitive model of paranoia to this group. METHOD: Twenty-one participants with an at-risk mental state were assessed before and after entering a virtual reality environment depicting the inside of an underground train. RESULTS: Virtual reality did not raise levels of distress at the time of testing or cause adverse experiences over the subsequent week. Individuals attributed mental states to virtual reality characters including hostile intent. Persecutory ideation in virtual reality was predicted by higher levels of trait paranoia, anxiety, stress, immersion in virtual reality, perseveration and interpersonal sensitivity. CONCLUSIONS: Virtual reality is an acceptable experimental technique for use with individuals with at-risk mental states. Paranoia in virtual reality was understandable in terms of the cognitive model of persecutory delusions.
Abstract: The aim of the present study was to demonstrate for the first time that brain waves can be used by a tetraplegic to control movements of his wheelchair in virtual reality (VR). In this case study, the spinal cord injured (SCI) subject was able to generate bursts of beta oscillations in the electroencephalogram (EEG) by imagination of movements of his paralyzed feet. These beta oscillations were used for a self-paced (asynchronous) brain-computer interface (BCI) control based on a single bipolar EEG recording. The subject was placed inside a virtual street populated with avatars. The task was to "go" from avatar to avatar towards the end of the street, but to stop at each avatar and talk to them. In average, the participant was able to successfully perform this asynchronous experiment with a performance of 90%, single runs up to 100%.
Abstract: We have set up a brain-computer inter-face (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.
Notes: Oct xD;Special issue: 8th Annual International Workshop on Presence II - Guest editor's introduction xD;ISI:000242341800001 xD;http://www.mitpressjournals.org/toc/pres/15/5
Notes: Oct xD;Walking by thinking: The brainwaves are crucial, not the muscles! xD;ISI:000242341800003 xD;http://www.mitpressjournals.org/toc/pres/15/5
Abstract: Cardiac responses induced by motor imagery were investigated in 3 subjects in a series of experiments with a synchronous (cue-based) Brain-Computer Interface (BCI). The cue specified right hand vs. leg/foot motor imagery. After a number of BCI training sessions reaching a classification accuracy of at least 80%, the BCI experiments were carried out in an immersive virtual environment (VE), commonly referred as a "CAVE". In this VE, the subjects were able to move along a virtual street by motor imagery alone. The thought-based control of VE resulted in an acceleration of the heart rate in 2 subjects and a heart rate deceleration in the other subject. In control experiments in front of a PC, all 3 subjects displayed a significant heart rate deceleration of the order of about 3-5%. This heart rate decrease during motor imagery in a normal environment is similar to that observed during preparation for a voluntary movement. The heart rate acceleration in the VE is interpreted as effect of an increased mental effort to walk as far as possible in VE.
Abstract: This paper examines a necessary condition for successful exploitation of a virtual environment (VE) in therapeutic intervention for fear of public speaking. The condition is that clients experience a degree of anxiety in the VE that is similar to what they would have been expected to experience in a similar real world setting. We refer to this as a "presence" response. The experimental study involved 20 people who were confident public speakers and 16 who were phobic, assessed on a standard psychological scale. Half of each group spoke within a VE depicting an empty seminar room, and the other half within the same room but populated by a neutrally behaving virtual audience of five people. Three responses were measured--a questionnaire-based measure of anxiety, a measure of self-focused attention on somatic responses, and actual heart rate. On all responses, the people with phobia showed a significant increase in signs of anxiety when speaking to the virtual audience compared to the empty room, whereas the confident people did not. The result was strong in spite of the relatively low representational and behavioral fidelity of the virtual characters.
Abstract: Online analysis and classification of single electroencephalogram (EEG) trials during motor imagery were used for navigation in the virtual environment (VE). The EEG was recorded bipolarly with electrode placement over the hand and foot representation areas. The aim of the study was to demonstrate for the first time that it is possible to move through a virtual street without muscular activity when the participant only imagines feet movements. This is achieved by exploiting a brain-computer interface (BCI) which transforms thought-modulated EEG signals into an output signal that controls events within the VE. The experiments were carried out in an immersive projection environment, commonly referred to as a "Cave" (Cruz-Neira, C., Sandin, D.J., DeFanti, T.A., Surround-screen projection-based virtual reality: the design and implementation of the CAVE. Proceedings of the 20th annual conference on Computer graphics and interactive techniques, ACM Press, 1993, pp. 135-142) where participants were able to move through a virtual street by foot imagery only. Prior to the final experiments in the Cave, the participants underwent an extensive BCI training.
Abstract: BACKGROUND: Stanley Milgram's 1960s experimental findings that people would administer apparently lethal electric shocks to a stranger at the behest of an authority figure remain critical for understanding obedience. Yet, due to the ethical controversy that his experiments ignited, it is nowadays impossible to carry out direct experimental studies in this area. In the study reported in this paper, we have used a similar paradigm to the one used by Milgram within an immersive virtual environment. Our objective has not been the study of obedience in itself, but of the extent to which participants would respond to such an extreme social situation as if it were real in spite of their knowledge that no real events were taking place. METHODOLOGY: Following the style of the original experiments, the participants were invited to administer a series of word association memory tests to the (female) virtual human representing the stranger. When she gave an incorrect answer, the participants were instructed to administer an 'electric shock' to her, increasing the voltage each time. She responded with increasing discomfort and protests, eventually demanding termination of the experiment. Of the 34 participants, 23 saw and heard the virtual human, and 11 communicated with her only through a text interface. CONCLUSIONS: Our results show that in spite of the fact that all participants knew for sure that neither the stranger nor the shocks were real, the participants who saw and heard her tended to respond to the situation at the subjective, behavioural and physiological levels as if it were real. This result reopens the door to direct empirical studies of obedience and related extreme social situations, an area of research that is otherwise not open to experimental study for ethical reasons, through the employment of virtual environments.
Abstract: 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.
Notes: The responses of people to virtual humans in an immersive virtual environment xD;Y2 - Feb ISI:000228559100008 ISI Document Delivery No.: 918PC xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/garau-slater2005.pdf
Abstract: Immersive virtual environments can break the deep, everyday connection between where our senses tell us we are and where we are actually located and whom we are with. The concept of 'presence' refers to the phenomenon of behaving and feeling as if we are in the virtual world created by computer displays. In this article, we argue that presence is worthy of study by neuroscientists, and that it might aid the study of perception and consciousness.
Abstract: Paranoia is a complex phenomenon that is likely to arise from a number of factors. In a recent cognitive model of persecutory delusions, three key factors are highlighted: anomalous experiences, emotion, and reasoning. In the first of two linked studies, we report a questionnaire survey of nonclinical paranoia designed to assess the theoretical model. A nonclinical population (N = 327) completed measures of paranoia, anomalous experiences (hallucinatory predisposition, perceptual anomalies), emotion (depression, anxiety, self-focus, stress, interpersonal sensitivity), and reasoning (need for closure). Paranoia was best explained by separation anxiety, depression, fragile inner self, hallucinatory experiences, discomfort with ambiguity, stress, self-focus, perceptual anomalies, and anxiety. The findings are consistent with the central predictions within the model of paranoia.
Notes: Transatlantic touch: A study of haptic collaboration over long distance xD;TY - JOUR Y2 - Jun ISI:000222445000007 834XU PRESENCE-TELEOPER VIRTUAL ENV xD;http://www.mitpressjournals.org/doi/abs/10.1162/1054746041422370?journalCode=pres
Notes: An eye gaze model for dyadic interaction in an immersive virtual environment: Practice and experience xD;ISI:000220705200001 xD;http://www.blackwell-synergy.com/links/doi/10.1111/j.1467-8659.2004.00001.x/full/?cookieSet=1
Notes: How colorful was your day? Why questionnaires cannot assess presence in virtual environments xD;TY - JOUR Y2 - Aug ISI:000223975500008 855LT PRESENCE-TELEOPER VIRTUAL ENV xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/colourful.pdf
Abstract: This paper reports on a pilot study of the extent to which social anxiety can be generated within a virtual environment. Ten subjects were exposed to a virtual reality experience depicting a London underground train and also a wine bar. The first provided a social setting with virtual characters (avatars) that had relatively neutral behaviors towards the subject, and the second was more socially demanding--with subjects required to interact with relatively disinterested avatars. The purpose was to assess whether social anxiety would be greater for the wine bar experience than the train journey experience, taking into account prior tendencies to social anxiety, and the order of presentation. The results suggest that social anxiety was higher for the wine bar experience, but lower for the second exposure.
Abstract: The use of virtual reality permits individuals' reactions to standard controlled environments to be studied. It may therefore provide a means for understanding the interpretations of experience relevant to clinical disorders. The use of this technology for understanding persecutory ideation has not been investigated. A pilot study was undertaken to examine whether individuals have persecutory thoughts about virtual reality characters under controlled conditions and if there are factors that predict the occurrence of such thoughts.Twenty-four nonclinical participants entered a neutral virtual environment that contained computer-generated people. The participants completed dimensional assessments of items related to psychiatric symptoms and their thoughts about the virtual characters.Positive views about the virtual characters were common. However, a number of participants had ideas of reference and ideas of persecution about the virtual characters. Individuals who had persecutory thoughts about the virtual characters had significantly higher levels of interpersonal sensitivity and anxiety.The study provides direct evidence that individuals attribute mental states to virtual reality characters. Important for the study of clinical phenomena, some individuals have thoughts of a persecutory nature about virtual characters. Additionally, the findings indicate that feelings of interpersonal vulnerability and anxiety may directly contribute to the development of persecutory ideation in response to essentially neutral contexts. Virtual reality may prove to be a valuable methodology for developing an understanding of persecutory ideation.
Abstract: This note addresses the confounding of the term 'presence' with several different
distinct aspects of experience. Distinctions should be made between immersion,
presence, involvement, emotional response, degree of interest. An analogy with
colour science is pursued, specifically the difference between wavelength
distribution and perception of colour - where the former is like 'immersion' the
latter is like 'presence' (a human response). On top of this colours may be
experienced as interesting, emotion-producing and so on. Just as the emotional
experience engendered by a colour is not the same as the perception of the colour,
which is not a simple function of the wavelength distribution, so involvement,
interest or emotional response in a virtual reality is not the same as presence,
which is not the same as immersion.
Notes: An experiment on public speaking anxiety in response to three different types of virtual audience xD;TY - JOUR Y2 - Feb ISI:000174565200005 534BR PRESENCE-TELEOPER VIRTUAL ENV xD;http://www.cs.ucl.ac.uk/staff/M.Slater/Papers/SocialPhobia/fops_presence.pdf
Notes: Constant time queries on uniformly distributed points on a hemisphere xD;TY - JOUR xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/Sphere/index.htm
Notes: Presence and the sixth sense xD;TY - JOUR Y2 - Aug ISI:000177668300008 587XA PRESENCE-TELEOPER VIRTUAL ENV xD;http://www.mitpressjournals.org/doi/abs/10.1162/105474602760204327
Notes: Special issue: VRST'99 - Introduction xD;TY - JOUR Y2 - Feb ISI:000172143200001 492AL PRESENCE-TELEOPER VIRTUAL ENV xD;<Go to ISI>://000172143200001
Notes: Collaborating in networked immersive spaces: as good as being there together? xD;TY - JOUR Y2 - Oct ISI:000171668700006 484AU COMPUT GRAPH-UK xD;http://www.equator.ac.uk/var/uploads/Schroeder2001.pdf
Abstract: The present investigation, with a virtual reality set-up, aimed to study attentional orienting within a three-dimensional visual world. Near and far stimuli were used. Half of the subjects were provided with a virtual representation of their body, whereas half were not. Results showed a different distribution of attentional resources in the two conditions, suggesting a dissociation between attentional systems controlling the proximal and the distal visual space. In particular, attention was focused close to the subject's body when a virtual representation of it was present, whereas attention was focused away from the body when a virtual representation of the body was not present.
Abstract: Can virtual reality exposure therapy be used to treat people with social phobia? To answer this question it is vital to known if people will respond to virtual humans (avatars) in a virtual social setting in the same way they would to real humans. If someone is extremely anxious with real people, will they also be anxious when faced with simulated people, despite knowing that the avatars are computer generated? In [17] we described a small pilot study that placed 10 people before a virtual audience. The purpose was to assess the extent to which social anxiety, specifically fear of public speaking, was induced by the virtual audience and the extent of influence of degree of immersion (head mounted display or desktop monitor. The current paper describes a follow up study conducted with 40 subjects and the results clearly show that not only is social anxiety induced by the audience, but the degree of anxiety experienced is directly related to the type of virtual audience feedback the speaker receives. In particular, a hostile negative audience scenario was found to generate strong affect in speakers, regardless of whether or not they normally suffered from fear of public speaking.
Notes: Components for distributed virtual environments xD;TY - JOUR Y2 - Feb ISI:000172143200006 492AL PRESENCE-TELEOPER VIRTUAL ENV xD;<Go to ISI>://000172143200006
Notes: Using presence questionnaires in reality xD;TY - JOUR Y2 - Oct ISI:000165086200007 ISI Document Delivery No.: 369UW xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/questionnaire-paper.pdf
Notes: Special issue: The first workshop on presence - Guest editor's introduction xD;TY - JOUR Y2 - Apr ISI:000087106900001 315HG PRESENCE-TELEOPER VIRTUAL ENV xD;<Go to ISI>://000087106900001
Notes: Small-group behavior in a virtual and real environment: A comparative study xD;TY - JOUR Y2 - Feb ISI:000086561400004 305VN PRESENCE-TELEOPER VIRTUAL ENV xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/inhabit-pres-rev.pdf
Notes: Dynamic polygon visibility ordering for head-slaved viewing in virtual environments xD;TY - JOUR Y2 - Jun ISI:000165378200003 375AW COMPUTER GRAPHICS FORUM xD;<Go to ISI>://000165378200003
Notes: The chording glove: A glove-based text input device xD;TY - JOUR Y2 - May ISI:000080105100002 192XM IEEE TRANS SYST MAN CYBERN C xD;<Go to ISI>://000080105100002
Notes: Real people meeting virtually real people - a review of some experiments in shared virtual environments xD;TY - JOUR Y2 - Jan ISI:000080284600013 196AA BT TECHNOL J xD;<Go to ISI>://000080284600013
Notes: Measuring presence: A response to the Witmer and Singer presence questionnaire xD;TY - JOUR Y2 - Oct ISI:000083113800007 245MY PRESENCE-TELEOPER VIRTUAL ENV xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/pq.pdf
Notes: Public speaking in virtual reality: Facing an audience of avatars xD;TY - JOUR Y2 - Mar-Apr ISI:000078734000002 169EF IEEE COMPUT GRAPH APPL xD;<Go to ISI>://000078734000002
Abstract: We describe an experiment to assess the influence of body movements on presence in a virtual environment. In the experiment 20 participants were to walk through a virtual field of trees and count the trees with diseased leaves. A 2 x 2 between subjects design was used to assess the influence of two factors on presence: tree height variation and task complexity. The field with greater variation in tree height required participants to bend down and look up more than in the lower variation tree height field. In the higher complexity task participants were told to remember the distribution of diseased trees in the field as well as to count them. The results showed a significant positive association between reported presence and the amount of body movement in particular, head yaw--and the extent to which participants bent down and stood up. There was also a strong interaction effect between task complexity and gender: Women in the more-complex task reported a much lower sense of presence than in the simpler task. For applications in which presence is an important requirement, the research in this paper suggests that presence will be increased when interaction techniques are employed that permit the user to engage in whole-body movement.
Notes: A framework for immersive virtual environments (FIVE): Speculations on the role of presence in virtual environments xD;TY - JOUR Y2 - Dec ISI:000071173500002 YN487 PRESENCE-TELEOPER VIRTUAL ENV xD;<Go to ISI>://000071173500002
Notes: Introduction to special issue: Framework for Immersive Virtual Environments Conference of the FIVE Working Group, London, December 1995 xD;TY - JOUR Y2 - Dec ISI:000071173500001 YN487 PRESENCE-TELEOPER VIRTUAL ENV xD;<Go to ISI>://000071173500001
Notes: A Distributed Frame Buffer for Rapid Dynamic Changes to 3d Scenes xD;TY - JOUR Y2 - Mar-Apr ISI:A1995RE24100010 RE241 COMPUT GRAPH xD;<Go to ISI>://A1995RE24100010
Notes: An Algorithm to Support 3D Interaction on Relatively Low Performance Graphics Systems xD;TY - JOUR Y2 - Fal ISI:A1992JP71500009 JP715 COMPUT GRAPH xD;<Go to ISI>://A1992JP71500009
Notes: Graphics Workstations - a European Perspective xD;TY - JOUR Y2 - Mar ISI:A1991FA95100012 FA951 IEEE COMPUT GRAPH APPL xD;<Go to ISI>://A1991FA95100012
Notes: Liberation from Rectangles - a Tiling Method for Dynamic Modification of Objects on Raster Displays xD;TY - JOUR ISI:A1989U368700013 U3687 COMPUT GRAPH xD;<Go to ISI>://A1989U368700013
Notes: Times Cited: 0 xD;Schmorrow, DD Estabrooke, IV Grootjen, M xD;5th International Conference on Foundation of Augmented Cognition xD;JUL 19-24, 2009 xD;San Diego, CA
Notes: The 5th Forum of European Neuroscience xD;The “virtual arm†illusion: Displacement of sensation of ownership to a virtual arm in virtual reality xD;http://fens2006.neurosciences.asso.fr/abstracts/R7/A232_21.html
Notes: VRST xD;Presence in Response to Dynamic Visual Realism: A Preliminary Report of an Experiment Study xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/sp051-khanna.pdf
Notes: The 8th Annual International Workshop on Presence: Presence 2005 xD;Non-Verbal Communication for Correlational Characters xD;TY - CONF Y2 - 21-23rd September, 2005 Non-Verbal Communication for Correlational Characters ISBN 0-9551232-0-8 xD;http://www.cs.ucl.ac.uk/research/vr/Projects/Presencia/Presence2005/index.htm
Notes: The 8th Annual International Workshop on Presence: Presence 2005 xD;Sharing and Analysing Presence Experiments Data xD;TY - CONF Y2 - 21-23rd September, 2005 Sharing and Analysing Presence Experiments Data ISBN 0-9551232-0-8 xD;http://www.cs.ucl.ac.uk/research/vr/Projects/Presencia/Presence2005/index.htm
Notes: The 8th Annual International Workshop on Presence: Presence 2005 xD;Integration of a Brain-Computer Interface into Virtual Environments xD;TY - CONF Y2 - 21-23rd September, 2005 Integration of a Brain-Computer Interface into Virtual Environments ISBN 0-9551232-0-8 xD;http://www.cs.ucl.ac.uk/research/vr/Projects/Presencia/Presence2005/index.htm
Notes: The 8th Annual International Workshop on Presence: Presence 2005 xD;Walking From Thoughts: Not the Muscles Are Crucial, But the Brain Waves! xD;TY - CONF Y2 - 21-23rd September, 2005 Walking From Thoughts: Not the Muscles Are Crucial, But the Brain Waves! ISBN 0-9551232-0-8 xD;http://www.cs.ucl.ac.uk/research/vr/Projects/Presencia/Presence2005/index.htm
Notes: PRESENCE 2005: The 8th Annual International Workshop on Presence xD;Analysis of Subject Behavior in a Virtual Reality User Study xD;0-9551232-0-8 xD;http://www.cs.ucl.ac.uk/research/vr/Projects/Presencia/Presence2005/index.htm
Notes: (2004) xD;An Investigation of Presence Response across Variations in Visual Realism xD;An Investigation of Presence Response across Variations in Visual Realism ISBN 84-9705-649-3 xD;http://www.cs.ucl.ac.uk/staff/a.brogni/public/download/2004_Vinayagamoorthy_AIO.pdf
Notes: 8th Annual Conference for the Scientific Study of Consciousness xD;June 25th, 2004 xD;From Presence Towards Consciousness xD;http://143.129.203.3/assc8/wor.html
Notes: Presence 2004 xD;Temporal and Spatial Variations in Presence: A Qualitative Analysis, 7th International Conference on Presence xD;TY - CONF Y2 - October 13-15 Temporal and Spatial Variations in Presence: A Qualitative Analysis, 7th International Conference on Presence ISBN 84-9705-649-3 xD;http://www.cs.ucl.ac.uk/staff/m.garau/papers/garau_time_space_presence.pdf
Notes: 7th International Conference on Presence, Presence 2004 xD;Navigating Virtual Reality by Thought: First Steps xD;TY - CONF Y2 - October 13-15, 2004 Navigating Virtual Reality by Thought: First Steps ISBN 84-9705-649-3 xD;http://www.cs.ucl.ac.uk/staff/d.friedman/nav7.PDF
Notes: 7th International Conference on Presence, Presence 2004 xD;Heart-Rate Variability and Event-Related ECG in Virtual Environments xD;ISBN 84-9705-649-3 xD;http://www.cs.ucl.ac.uk/staff/a.brogni/public/download/2004_Guger_HRV.pdf
Notes: Computer graphics international xD;A Virtual Light Field Approach to Global Illumination xD;TY - CONF Y2 - Jun A Virtual Light Field Approach to Global Illumination 1530-1052 0769521711 CN052786230 3393.982300 21st; Conference Also known as CGI 2004 COMPUTER GRAPHICS INTERNATIONAL- PROCEEDINGS- 2004 c2004 English Selected papers xD;http://www.cs.ucl.ac.uk/research/vr/Projects/VLF/Media/cgi2004/CGI_144.pdf
Notes: The 6th Annual International Workshop on Presence xD;Aalborg, Denmark xD;PDF xD;More Breaks Less Presence xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/bipspres.pdf
Notes: The 6th Annual International Workshop on Presence xD;Aalborg, Denmark xD;Physiological Responses to Breaks in Presence: A Pilot Study xD;http://www.cs.ucl.ac.uk/staff/m.slater/Papers/physbips.pdf
Notes: Information Visualisation xD;The Empathic Visualisation Algorithm (EVA) - An Automatic Mapping from Abstract Data to Naturalistic Visual Structure xD;http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1028852
Notes: Medicine Meets Virtual Reality 2001: Outer Space, Inner Space, Virtual Space An experiment on fear of public speaking in virtual reality xD;TY - CHAP ISI:000169103300070 BS21P xD;<Go to ISI>://000169103300070
Notes: Proceedings of the third international conference on Collaborative virtual environments xD;Acting in Virtual Reality xD;TY - CONF Acting in Virtual Reality 1-58113-303-0 xD;http://www.cs.ucl.ac.uk/staff/m.slater/vr/Projects/Acting/Publications/actingpaper.pdf
Notes: Comparing Immersive Virtual Reality with Other Display Modes for Visualizing Complex 3D Geometry xD;http://www.cs.ucl.ac.uk/research/vr/Projects/Immersion/Experiment2/paper.pdf
Notes: The 8th Annual International Workshop on Presence: Presence 2005 xD;ISBN 0-9551232-0-8 xD;TY - BOOK Presence 2005 xD;http://www.cs.ucl.ac.uk/research/vr/Projects/Presencia/Presence2005/index.htm xD;internal-pdf://index[1]-1846897153/index[1].htm
