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1.
IEEE Comput Graph Appl ; 43(6): 117-125, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37930892

RESUMO

VR United is a virtual reality application that we have developed to support multiple people simultaneously interacting in the same environment. Each person is represented with a virtual body that looks like themselves. Such immersive shared environments have existed and been the subject of research for the past 30 years. Here, we demonstrate how VR United meets criteria for successful interaction, where a journalist from the Financial Times in London interviewed a professor in New York for two hours. The virtual location of the interview was a restaurant, in line with the series of interviews published as "Lunch with the FT." We show how the interview was successful, as a substitute for a physically present one. The article based on the interview was published in the Financial Times as normal for the series. We finally consider the future development of such systems, including some implications for immersive journalism.

2.
J Cogn Neurosci ; 35(9): 1410-1422, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37255451

RESUMO

Out-of-body experiences (OBEs) are subjective experiences of seeing one's own body and the environment from a location outside the physical body. They can arise spontaneously or in specific conditions, such as during the intake of dissociative drug. Given its unpredictable occurrence, one way to empirically study it is to induce subjective experiences resembling an OBE using technology such as virtual reality. We employed a complex multisensory method of virtual embodiment in a virtual reality scenario with seven healthy participants to induce virtual OBE-like experiences. Participants performed two conditions in a randomly determined order. For both conditions, the participant's viewpoint was lifted out of the virtual body toward the ceiling of the virtual room, and real body movements were (visuo-tactile ON condition) or were not (visuo-tactile OFF condition) translated into movements on the virtual body below-the latter aiming to maintain a feeling of connection with the virtual body. A continuous 128-electrode EEG was recorded. Participants reported subjective experiences of floating in the air and of feeling high up in the virtual room at a strong intensity, but a weak to moderate feeling of being "out of their body" in both conditions. The EEG analysis revealed that this subjective experience was associated with a power shift that manifested in an increase of delta and a decrease of alpha relative power. A reduction of theta complexity and an increase of beta-2 connectivity were also found. This supports the growing body of evidence revealing a prominent role of delta activity during particular conscious states.


Assuntos
Eletroencefalografia , Realidade Virtual , Humanos , Emoções , Tato
3.
Virtual Real ; 27(2): 651-675, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36034584

RESUMO

We created a virtual reality version of a 1983 performance by Dire Straits, this being a highly complex scenario consisting of both the virtual band performance and the appearance and behaviour of the virtual audience surrounding the participants. Our goal was to understand the responses of participants, and to learn how this type of scenario might be improved for later reconstructions of other concerts. To understand the responses of participants we carried out two studies which used sentiment analysis of texts written by the participants. Study 1 (n = 25) (Beacco et al. in IEEE Virtual Reality: 538-545, 2021) had the unexpected finding that negative sentiment was caused by the virtual audience, where e.g. some participants were fearful of being harassed by audience members. In Study 2 (n = 26) notwithstanding some changes, the audience again led to negative sentiment-e.g. a feeling of being stared at. For Study 2 we compared sentiment with questionnaire scores, finding that the illusion of being at the concert was associated with positive sentiment for males but negative for females. Overall, we found sentiment was dominated by responses to the audience rather than the band. Participants had been placed in an unusual situation, being alone at a concert, surrounded by strangers, who seemed to pose a social threat for some  of them. We relate our findings to the concept of Plausibility, the illusion that events and situations in the VR are really happening. The results indicate high Plausibility, since the negative sentiment, for example in response to being started at, only makes sense if the events are experienced as actually happening. We conclude with the need for co-design of VR scenarios, and the use of sentiment analysis in this process, rather than sole reliance on concepts proposed by researchers, typically expressed through questionnaires, which may not reflect the experiences of participants. Supplementary Information: The online version contains supplementary material available at 10.1007/s10055-022-00685-9.

4.
Sci Rep ; 11(1): 23923, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34907279

RESUMO

The proportion of the population who experience persecutory thoughts is 10-15%. People then engage in safety-seeking behaviours, typically avoiding social interactions, which prevents disconfirmatory experiences and hence paranoia persists. Here we show that persecutory thoughts can be reduced if prior to engaging in social interaction in VR participants first see their virtual body-double doing so. Thirty non-clinical participants were recruited to take part in a study, where they were embodied in a virtual body that closely resembled themselves, and asked to interact with members of a crowd. In the Random condition (n = 15) they observed their body-double wandering around but not engaging with the crowd. In the Targeted condition the body-double correctly interacted with members of the crowd. The Green Paranoid Thoughts Scale was measured 1 week before and 1 week after the exposure and decreased only for those in the Targeted condition. The results suggest that the observation of the body-double correctly carrying out a social interaction task in VR may lead to anxiety-reducing mental rehearsal for interaction thus overcoming safety behaviours. The results also extend knowledge of the effects of vicarious agency, suggesting that identification with the actions of body-double can influence subsequent psychological state.

5.
R Soc Open Sci ; 8(9): 210537, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34540251

RESUMO

Virtual reality applications depend on multiple factors, for example, quality of rendering, responsiveness, and interfaces. In order to evaluate the relative contributions of different factors to quality of experience, post-exposure questionnaires are typically used. Questionnaires are problematic as the questions can frame how participants think about their experience and cannot easily take account of non-additivity among the various factors. Traditional experimental design can incorporate non-additivity but with a large factorial design table beyond two factors. Here, we extend a previous method by introducing a reinforcement learning (RL) agent that proposes possible changes to factor levels during the exposure and requires the participant to either accept these or not. Eventually, the RL converges on a policy where no further proposed changes are accepted. An experiment was carried out with 20 participants where four binary factors were considered. A consistent configuration of factors emerged where participants preferred to use a teleportation technique for navigation (compared to walking-in-place), a full-body representation (rather than hands only), the responsiveness of virtual human characters (compared to being ignored) and realistic compared to cartoon rendering. We propose this new method to evaluate participant choices and discuss various extensions.

7.
Int J Surg Case Rep ; 77: 104-106, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33160166

RESUMO

INTRODUCTION: Cutaneous spread of solid visceral metastasis is very unusual presentation, usually in breast, lung, colon, ovarian carcinomas, and malignant melanoma. Less than 5% of cases of cutaneous spread are from renal neoplasms. PRESENTATION OF CASE: We present the case of a 48-year-old woman with a large lower lip tumor whose anatomopathological analysis of the lesion led us to identify a Clear Cell Renal Cell Carcinoma (ccRCC). DISCUSSION: The clinical manifestations of the ccRCC can be mild, generating a late diagnosis through metastasis of primary neoplasia. Their presentations can be varied, as described in this report. CONCLUSION: The knowledge of the different types of presentation of CCCR metastases can assist in decision making, but the progression of staging often only allows palliative measures.

8.
Sci Rep ; 10(1): 6207, 2020 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-32277079

RESUMO

Group pressure can often result in people carrying out harmful actions towards others that they would not normally carry out by themselves. However, few studies have manipulated factors that might overcome this. Here male participants (n = 60) were in a virtual reality (VR) scenario of sexual harassment (SH) of a lone woman by a group of males in a bar. Participants were either only embodied as one of the males (Group, n = 20), or also as the woman (Woman, n = 20). A control group (n = 20) only experienced the empty bar, not the SH. One week later they were the Teacher in a VR version of Milgram's Obedience experiment where they were encouraged to give shocks to a female Learner by a group of 3 virtual males. Those who had been in the Woman condition gave about half the number of shocks of those in the Group condition, with the controls between these two. We explain the results through embodiment promoting identification with the woman or the group, and delegitimization of the group for those in the Woman condition. The experiment raised important ethical issues, showing that a VR study with positive ethical intentions can sometimes produce unexpected and non-beneficent results.


Assuntos
Assédio Sexual , Adulto , Dominação-Subordinação , Feminino , Humanos , Masculino , Influência dos Pares , Realidade Virtual , Adulto Jovem
10.
PLoS One ; 13(11): e0203358, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30395568

RESUMO

Mortality is an obvious if uncomfortable part of the human condition, yet it is impossible to study its impact on anyone who experiences it. Reports of phenomena associated with death such as out-of-the-body (OBE) and near death experiences (NDE) can only be studied post-hoc, since it is impossible to design a scientific study where an experimental group experiences death (and returns) and a control group does not. Yet NDEs seem to have a profound influence on the subsequent lives of people and are therefore worthy of study. Terror Management Theory, which argues that death anxiety contributes to in-group solidarity and hostility to out-groups, relies on studies that manipulate opinions and cannot be based on experiential evidence. Here we introduce a potential methodology that uses immersive virtual reality (VR) for the study of mortality and NDEs. Participants are embodied in alternate bodies in a beautiful island along with two companions. They explore the island and carry out tasks together. The mechanism of embodiment produces strong illusions of ownership over their life-sized virtual bodies. Over time each participant witnesses the death of the two companions and then her own death-which includes the reported features of an NDE (OBE, life review, the tunnel leading to white light) followed by a period of observation of the continuing activities in the virtual world on an external screen. Fifteen female participants experienced 6 sessions in the island, each starting as a child and gradually maturing, and eventually ageing and dying. Sixteen control subjects formed a waiting group. We introduce this as a methodology for the study of these issues, and present promising results, suggesting that those who experienced the island report life attitude changes, becoming more concerned with others and more interested in global rather than material issues compared to the control group. The results are based on a small sample size, and should be considered as indicative of the possibilities of this new methodology as a way forward for future studies in this field.


Assuntos
Atitude Frente a Morte , Morte , Modelos Psicológicos , Realidade Virtual , Adulto , Feminino , Humanos
11.
Front Robot AI ; 5: 91, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-33500970

RESUMO

Virtual Reality (VR) has been widely applied to cultural heritage such as the reconstruction of ancient sites and artifacts. It has hardly been applied to the reprise of specific important moments in history. On the other hand immersive journalism does attempt to recreate current events in VR, but such applications typically give the viewer a disembodied non-participatory role in the scene of interest. Here we show how VR was used to reconstruct a specific historical event, where a famous photograph was brought to life, showing Lenin, the leader of the 1917 October Russian Revolution, giving a speech to Red Army recruits in Moscow 1920. We carried out a between groups experimental study with three conditions: Embodied-where the participant was first embodied as Lenin and then later in the audience watching Lenin; Included-where the participant was not embodied as Lenin but was embodied as part of the audience; and Observing-where the participant mainly viewed the scene from a disembodied third person point of view. Twenty participants were assigned to each of the three conditions in a between-groups design. We found that the level of presence was greatest in the Embodied and Included conditions, and that participants were least likely to later follow up information about the Russian Revolution in the Observing condition. Our conclusion is that if the VR setup allows for a period of embodiment as a character in the scenario then this should be employed in order to maximize the chance of participant presence and engagement with the story.

12.
PLoS One ; 12(1): e0169343, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28068368

RESUMO

Immersive virtual reality can be used to visually substitute a person's real body by a life-sized virtual body (VB) that is seen from first person perspective. Using real-time motion capture the VB can be programmed to move synchronously with the real body (visuomotor synchrony), and also virtual objects seen to strike the VB can be felt through corresponding vibrotactile stimulation on the actual body (visuotactile synchrony). This setup typically gives rise to a strong perceptual illusion of ownership over the VB. When the viewpoint is lifted up and out of the VB so that it is seen below this may result in an out-of-body experience (OBE). In a two-factor between-groups experiment with 16 female participants per group we tested how fear of death might be influenced by two different methods for producing an OBE. In an initial embodiment phase where both groups experienced the same multisensory stimuli there was a strong feeling of body ownership. Then the viewpoint was lifted up and behind the VB. In the experimental group once the viewpoint was out of the VB there was no further connection with it (no visuomotor or visuotactile synchrony). In a control condition, although the viewpoint was in the identical place as in the experimental group, visuomotor and visuotactile synchrony continued. While both groups reported high scores on a question about their OBE illusion, the experimental group had a greater feeling of disownership towards the VB below compared to the control group, in line with previous findings. Fear of death in the experimental group was found to be lower than in the control group. This is in line with previous reports that naturally occurring OBEs are often associated with enhanced belief in life after death.


Assuntos
Simulação por Computador , Morte , Medo/psicologia , Interface Usuário-Computador , Percepção Visual , Humanos , Inquéritos e Questionários
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