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Tekgün E, Erdeniz B. Contributions of Body-Orientation to Mental Ball Dropping Task During Out-of-Body Experiences. Front Integr Neurosci 2022; 15:781935. [PMID: 35058754 PMCID: PMC8764241 DOI: 10.3389/fnint.2021.781935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/18/2021] [Indexed: 11/25/2022] Open
Abstract
Out-of-body experiences (OBEs) provide fascinating insights into our understanding of bodily self-consciousness and the workings of the brain. Studies that examined individuals with brain lesions reported that OBEs are generally characterized by participants experiencing themselves outside their physical body (i.e., disembodied feeling) (Blanke and Arzy, 2005). Based on such a characterization, it has been shown that it is possible to create virtual OBEs in immersive virtual environments (Ehrsson, 2007; Ionta et al., 2011b; Bourdin et al., 2017). However, the extent to which body-orientation influences virtual OBEs is not well-understood. Thus, in the present study, 30 participants (within group design) experienced a full-body ownership illusion (synchronous visuo-tactile stimulation only) induced with a gender-matched full-body virtual avatar seen from the first-person perspective (1PP). At the beginning of the experiment, participants performed a mental ball dropping (MBD) task, seen from the location of their virtual avatar, to provide a baseline measurement. After this, a full-body ownership illusion (embodiment phase) was induced in all participants. This was followed by the virtual OBE illusion phase of the experiment (disembodiment phase) in which the first-person viewpoint was switched to a third-person perspective (3PP), and participants' disembodied viewpoint was gradually raised to 14 m above the virtual avatar, from which altitude they repeated the MBD task. During the experiment, this procedure was conducted twice, and the participants were allocated first to the supine or the standing body position at random. Results of the MBD task showed that the participants experienced increased MBD durations during the supine condition compared to the standing condition. Furthermore, although the findings from the subjective reports confirmed the previous findings of virtual OBEs, no significant difference between the two postures was found for body ownership. Taken together, the findings of the current study make further contributions to our understanding of both the vestibular system and time perception during OBEs.
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Tekgün E, Erdeniz B. Influence of vestibular signals on bodily self-consciousness: Different sensory weighting strategies based on visual dependency. Conscious Cogn 2021; 91:103108. [PMID: 33770704 DOI: 10.1016/j.concog.2021.103108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/27/2021] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
Previous studies showed that the vestibular system is crucial for multisensory integration, however, its contribution to bodily self-consciousness more specifically on full-body illusions is not well understood. Thus, the current study examined the role of visuo-vestibular conflict on a full-body illusion (FBI) experiment that was induced during a supine body position. In a mixed design experiment, 56 participants underwent through a full-body illusion protocol. During the experiment, half of the participants received synchronous visuo-tactile stimulation, and the other half received asynchronous visuo-tactile stimulation, while their physical body was lying in a supine position, but the virtual body was standing. Additionally, the contribution of individual sensory weighting strategies was investigated via the Rod and Frame task (RFT), which was applied both before (pre-FBI standing and pre-FBI supine) and after the full-body illusion (post-FBI supine) protocol. Subjective reports of the participants confirmed previous findings suggesting that there was a significant increase in ownership over a virtual body during synchronous visuo-tactile stimulation. Additionally, further categorization of participants based on their visual dependency (by RFT) showed that those participants who rely more on visual information (visual field dependents) perceived the full-body illusion more strongly than non-visual field dependents during the synchronous visuo-tactile stimulation condition. Further analysis provided not only a quantitative demonstration of full-body illusion but also revealed changes in perceived self-orientation based on their field dependency. Altogether, findings of the current study make further contributions to our understanding of the vestibular system and brought new insight for individual sensory weighting strategies during a full-body illusion.
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Affiliation(s)
- Ege Tekgün
- İzmir University of Economics, Department of Psychology, İzmir, Turkey
| | - Burak Erdeniz
- İzmir University of Economics, Department of Psychology, İzmir, Turkey.
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Daniel A, Barker L, Martini M. Pain modulation by illusory body rotation: A new way to disclose the interaction between the vestibular system and pain processing. Eur J Pain 2020; 24:1119-1129. [DOI: 10.1002/ejp.1556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Aster Daniel
- School of Psychology University of East London London UK
| | - Leon Barker
- School of Arts and Digital Industries University of East London London UK
| | - Matteo Martini
- School of Psychology University of East London London UK
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Toet A, Kuling IA, Krom BN, van Erp JBF. Toward Enhanced Teleoperation Through Embodiment. Front Robot AI 2020; 7:14. [PMID: 33501183 PMCID: PMC7805894 DOI: 10.3389/frobt.2020.00014] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 01/21/2020] [Indexed: 12/27/2022] Open
Abstract
Telerobotics aims to transfer human manipulation skills and dexterity over an arbitrary distance and at an arbitrary scale to a remote workplace. A telerobotic system that is transparent enables a natural and intuitive interaction. We postulate that embodiment (with three sub-components: sense of ownership, agency, and self-location) of the robotic system leads to optimal perceptual transparency and increases task performance. However, this has not yet been investigated directly. We reason along four premises and present findings from the literature that substantiate each of them: (1) the brain can embody non-bodily objects (e.g., robotic hands), (2) embodiment can be elicited with mediated sensorimotor interaction, (3) embodiment is robust against inconsistencies between the robotic system and the operator's body, and (4) embodiment positively correlates to dexterous task performance. We use the predictive encoding theory as a framework to interpret and discuss the results reported in the literature. Numerous previous studies have shown that it is possible to induce embodiment over a wide range of virtual and real extracorporeal objects (including artificial limbs, avatars, and android robots) through mediated sensorimotor interaction. Also, embodiment can occur for non-human morphologies including for elongated arms and a tail. In accordance with the predictive encoding theory, none of the sensory modalities is critical in establishing ownership, and discrepancies in multisensory signals do not necessarily lead to loss of embodiment. However, large discrepancies in terms of multisensory synchrony or visual likeness can prohibit embodiment from occurring. The literature provides less extensive support for the link between embodiment and (dexterous) task performance. However, data gathered with prosthetic hands do indicate a positive correlation. We conclude that all four premises are supported by direct or indirect evidence in the literature, suggesting that embodiment of a remote manipulator may improve dexterous performance in telerobotics. This warrants further implementation testing of embodiment in telerobotics. We formulate a first set of guidelines to apply embodiment in telerobotics and identify some important research topics.
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Affiliation(s)
- Alexander Toet
- Perceptual and Cognitive Systems, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
| | - Irene A. Kuling
- Perceptual and Cognitive Systems, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
| | - Bouke N. Krom
- Intelligent Autonomous Systems, Netherlands Organisation for Applied Scientific Research (TNO), The Hague, Netherlands
| | - Jan B. F. van Erp
- Perceptual and Cognitive Systems, Netherlands Organisation for Applied Scientific Research (TNO), Soesterberg, Netherlands
- Human Media Interaction, University of Twente, Enschede, Netherlands
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Buck LE, Rieser JJ, Narasimham G, Bodenheimer B. Interpersonal Affordances and Social Dynamics in Collaborative Immersive Virtual Environments: Passing Together Through Apertures. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2019; 25:2123-2133. [PMID: 30794184 DOI: 10.1109/tvcg.2019.2899232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
An essential question in understanding how to develop and build collaborative immersive virtual environments (IVEs) is recognizing how people perform actions together. Many actions in the real world require that people act without prior planning, and these actions are executed quite successfully. In this paper, we study the common action of two people passing through an aperture together in both the real world (Experiment 1) and in a distributed, collaborative IVE (Experiment 2). The aperture's width is varied from too narrow to be passable to so wide as to be easily passable by both participants together simultaneously. We do this in the real world for all possible gender-based pairings. In virtual reality, however, there is potential for the gender of the participant and the gender of the self-avatar to be different. We also investigate the joint action for all possible gender-based pairings in the distributed IVE. Results indicated that, in the real world, social dynamics between gendered pairings emerged; male-male pairings refused to concede to one another until absolutely necessary while other pairings did not. Male-female pairings were most likely to provide ample space to one another during passage. These behaviors seemed not to appear in the IVE, and avatar gender across all pairings generated no significant behavioral differences. In addition, participants tended to require wider gaps to allow for passage in the IVE. These findings establish base knowledge of social dynamics and affordance behaviors within multi-user IVEs.
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Verhulst A, Normand JM, Lombart C, Sugimoto M, Moreau G. Influence of Being Embodied in an Obese Virtual Body on Shopping Behavior and Products Perception in VR. Front Robot AI 2018; 5:113. [PMID: 33500992 PMCID: PMC7806053 DOI: 10.3389/frobt.2018.00113] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 09/10/2018] [Indexed: 01/12/2023] Open
Abstract
Research in Virtual Reality (VR) showed that embodiment can influence participants' perceptions and behavior when embodied in a different yet plausible virtual body. In this paper, we study the changes an obese virtual body has on products perception (e.g., taste, etc.) and purchase behavior (e.g., number purchased) in an immersive virtual retail store. Participants (of a normal BMI on average) were embodied in a normal (N) or an obese (OB) virtual body and were asked to buy and evaluate food products in the immersive virtual store. Based on stereotypes that are classically associated with obese people, we expected that the group embodied in obese avatars would show a more unhealthy diet, (i.e., buy more food products and also buy more products with high energy intake, or saturated fat) and would rate unhealthy food as being tastier and healthier than participants embodied in “normal weight” avatars. Our participants also rated the perception of their virtual body: the OB group perceived their virtual body as significantly heavier and older. They also rated their sense of embodiment and presence within the immersive virtual store. These measures did not show any significant difference between groups. Finally, we asked them to rate different food products in terms of tastiness, healthiness, sustainability and price. The only difference we noticed is that participants embodied in an obese avatar (OB group) rated the coke as being significantly tastier and the apple as being significantly healthier. Nevertheless, while we hypothesized that participants embodied in a virtual body with obesity would show differences in their shopping patterns (e.g., more “unhealthy” products bought) there were no significant differences between the groups. Stereotype activation failed for our participants embodied in obese avatars, who did not exhibit a shopping behavior following the (negative) stereotypes related to obese people. conversely, while the opposite hypothesis (participants embodied in obese avatars would buy significantly more healthy products in order to “transform” their virtual bodies) could have been made, it was not the case either. We discuss these results and propose hypotheses as to why the behavior of the manipulated group differed from the one we expected. Indeed, unlike previous research, our participants were embodied in virtual avatars which differed greatly from their real bodies. Obese avatars should not only modify users' visual characteristics such as hair or skin color, etc. We hypothesize that an obese virtual body may require some other non-visual stimulus, e.g., the sensation of the extra weight or the change in body size. This main difference could then explain why we did not notice any important modification on participants' behavior and perceptions of food products. We also hypothesize that the absence of stereotype activation and thus of statistical difference between our N and OB groups might be due to higher-level cognitive processes involved while purchasing food products. Indeed our participants might have rejected their virtual bodies when performing the shopping task, while the embodiment and presence ratings did not show significant differences, and purchased products based on their real (non-obese) bodies. This could mean that stereotype activation is more complex that previously thought.
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Affiliation(s)
- Adrien Verhulst
- CRENAU, AAU UMR CNRS 1563, Computer Science and Mathematics Department, École Centrale de Nantes, Nantes, France
| | - Jean-Marie Normand
- CRENAU, AAU UMR CNRS 1563, Computer Science and Mathematics Department, École Centrale de Nantes, Nantes, France.,Hybrid, Inria, Rennes, France
| | - Cindy Lombart
- In Situ Lab, Marketing Department, Audencia Business School, Nantes, France
| | - Maki Sugimoto
- Interactive Media Lab, Department of Information and Computer Science, Faculty of Science and Technology, Keio University, Kanagawa, Japan
| | - Guillaume Moreau
- CRENAU, AAU UMR CNRS 1563, Computer Science and Mathematics Department, École Centrale de Nantes, Nantes, France.,Hybrid, Inria, Rennes, France
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Bergström I, Kilteni K, Slater M. First-Person Perspective Virtual Body Posture Influences Stress: A Virtual Reality Body Ownership Study. PLoS One 2016; 11:e0148060. [PMID: 26828365 PMCID: PMC4734707 DOI: 10.1371/journal.pone.0148060] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/11/2016] [Indexed: 11/18/2022] Open
Abstract
In immersive virtual reality (IVR) it is possible to replace a person’s real body by a life-sized virtual body that is seen from first person perspective to visually substitute their own. Multisensory feedback from the virtual to the real body (such as the correspondence of touch and also movement) can also be present. Under these conditions participants typically experience a subjective body ownership illusion (BOI) over the virtual body, even though they know that it is not their real one. In most studies and applications the posture of the real and virtual bodies are as similar as possible. Here we were interested in whether the BOI is diminished when there are gross discrepancies between the real and virtual body postures. We also explored whether a comfortable or uncomfortable virtual body posture would induce feelings and physiological responses commensurate with the posture. We carried out an experiment with 31 participants in IVR realized with a wide field-of-view head-mounted display. All participants were comfortably seated. Sixteen of them were embodied in a virtual body designed to be in a comfortable posture, and the remainder in an uncomfortable posture. The results suggest that the uncomfortable body posture led to lesser subjective BOI than the comfortable one, but that participants in the uncomfortable posture experienced greater awareness of their autonomic physiological responses. Moreover their heart rate, heart rate variability, and the number of mistakes in a cognitive task were associated with the strength of their BOI in the uncomfortable posture: greater heart rate, lower heart rate variability and more mistakes were associated with higher levels of the BOI. These findings point in a consistent direction—that the BOI over a body that is in an uncomfortable posture can lead to subjective, physiological and cognitive effects consistent with discomfort that do not occur with the BOI over a body in a comfortable posture.
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Affiliation(s)
- Ilias Bergström
- Event Lab, Facultat de Psicologia, Universitat de Barcelona, Barcelona, Spain
| | - Konstantina Kilteni
- Event Lab, Facultat de Psicologia, Universitat de Barcelona, Barcelona, Spain
| | - Mel Slater
- Event Lab, Facultat de Psicologia, Universitat de Barcelona, Barcelona, Spain
- Department of Computer Science, University College London, London, United Kingdom
- Institició Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- * E-mail:
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