An ‘In the Wild’ Experiment on Presence and Embodiment using Consumer Virtual Reality Equipment

Consumer virtual reality systems are now becoming widely available. We report on a study on presence and embodiment within virtual reality that was conducted ‘in the wild’, in that data was collected from devices owned by consumers in uncontrolled settings, not in a traditional laboratory setting. Users of Samsung Gear VR and Google Cardboard devices were invited by web pages and email invitation to download and run an app that presented a scenario where the participant would sit in a bar watching a singer. Each participant saw one of eight variations of the scenario: with or without a self-avatar; singer inviting the participant to tap along or not; singer looking at the participant or not. Despite the uncontrolled situation of the experiment, results from an in-app questionnaire showed tentative evidence that a self-avatar had a positive effect on self-report of presence and embodiment, and that the singer inviting the participant to tap along had a negative effect on self-report of embodiment. We discuss the limitations of the study and the platforms, and the potential for future open virtual reality experiments

The potential of remote XR experimentation: Defining benefits and limitations through expert survey and case study

Experimentation using extended reality (XR) technology is predominantly conducted in-lab with a co-present researcher. Remote XR experiments, without co-present researchers, have been less common, despite the success of remote approaches for non-XR investigations. In order to understand why remote XR experiments are atypical, this article outlines the perceived limitations, as well as potential benefits, of conducting remote XR experiments, through a thematic analysis of responses to a 30-item survey of 46 XR researchers. These are synthesized into five core research questions for the XR community, and concern types of participant, recruitment processes, potential impacts of remote setup and settings, the data-capture affordances of XR hardware and how remote XR experiment development can be optimized to reduce demands on the researcher. It then explores these questions by running two experiments in a fully “encapsulated” remote XR case study, in which the recruitment and experiment processes is distributed and conducted unsupervised. It discusses the design, experiment, and results from this case study in the context of these core questions

Evaluating Grasping Visualizations and Control Modes in a VR Game

A primary goal of the Virtual Reality(VR) community is to build fully immersive and presence-inducing environments with seamless and natural interactions. To reach this goal, researchers are investigating how to best directly use our hands to interact with a virtual environment using hand tracking. Most studies in this field require participants to perform repetitive tasks. In this article, we investigate if results of such studies translate into a real application and game-like experience. We designed a virtual escape room in which participants interact with various objects to gather clues and complete puzzles. In a between-subjects study, we examine the effects of two input modalities (controllers vs. hand tracking) and two grasping visualizations (continuously tracked hands vs. virtual hands that disappear when grasping) on ownership, realism, efficiency, enjoyment, and presence. Our results show that ownership, realism, enjoyment, and presence increased when using hand tracking compared to controllers. Visualizing the tracked hands during grasps leads to higher ratings in one of our ownership questions and one of our enjoyment questions compared to having the virtual hands disappear during grasps as is common in many applications. We also confirm some of the main results of two studies that have a repetitive design in a more realistic gaming scenario that might be closer to a typical user experience

Immersive competence and immersive literacy: Exploring how users learn about immersive experiences

While immersive experiences mediated through near-eye displays are still a relatively immature medium, there are millions of consumer devices in use. The level of awareness of the forms of the interface and media will vary enormously across the potential audience. Users might own personal devices or might encounter immersive systems in various venues. We introduce the term immersive competence to refer to the general practical knowledge and skills that users accumulate about how typical immersive interfaces work—the ways in which buttons are used, main locomotion techniques, etc. We then introduce the term immersive literacy to refer to awareness of how immersive interfaces are unique, when they might be appropriate, typical forms of media, etc. We sketch out how users develop competence and literacy with immersive media, and then highlight various open questions that are raised

Web-Based VR Experiments Powered by the Crowd

We build on the increasing availability of Virtual Reality (VR) devices and Web technologies to conduct behavioral experiments in VR using crowdsourcing techniques. A new recruiting and validation method allows us to create a panel of eligible experiment participants recruited from Amazon Mechanical Turk. Using this panel, we ran three different crowdsourced VR experiments, each reproducing one of three VR illusions: place illusion, embodiment illusion, and plausibility illusion. Our experience and worker feedback on these experiments show that conducting Web-based VR experiments using crowdsourcing is already feasible, though some challenges---including scale---remain. Such crowdsourced VR experiments on the Web have the potential to finally support replicable VR experiments with diverse populations at a low cost.Comment: The Web Conference 2018 (WWW 2018); update citation forma

Embodiment and Presence in Virtual Reality After Stroke. A Comparative Study With Healthy Subjects

[EN] The ability of virtual reality (VR) to recreate controlled, immersive, and interactive environments that provide intensive and customized exercises has motivated its therapeutic use after stroke. Interaction and bodily presence in VR-based interventions is usually mediated through virtual selves, which synchronously represent body movements or responses to events on external input devices. Embodied self-representations in the virtual world not only provide an anchor for visuomotor tasks, but their morphologies can have behavioral implications. While research has focused on the underlying subjective mechanisms of exposure to VR on healthy individuals, the transference of these findings to individuals with stroke is not evident and remains unexplored, which could affect the experience and, ultimately, the clinical effectiveness of neurorehabilitation interventions. This study determined and compared the sense of embodiment and presence elicited by a virtual environment under different perspectives and levels of immersion in healthy subjects and individuals with stroke. Forty-six healthy subjects and 32 individuals with stroke embodied a gender-matched neutral avatar in a virtual environment that was displayed in a first-person perspective with a head-mounted display and in a third-person perspective with a screen, and the participants were asked to interact in a virtual task for 10 min under each condition in counterbalanced order, and to complete two questionnaires about the sense of embodiment and presence experienced during the interaction. The sense of body-ownership, self-location, and presence were more vividly experienced in a first-person than in a third-person perspective by both healthy subjects (p < 0.001, eta(2)(p) = 0.212; p = 0.005, eta(2)(p) = 0.101; p = 0.001, eta(2)(p) = 0.401, respectively) and individuals with stroke (p = 0.019, eta(2)(p) = 0.070; p = 0.001, eta(2)(p) = 0.135; p = 0.014, eta(2)(p) = 0.077, respectively). In contrast, no agency perspective-related differences were found in any group. All measures were consistently higher for healthy controls than for individuals with stroke, but differences between groups only reached statistical significance in presence under the first-person condition (p < 0.010, eta(2)(p) = 0.084). In spite of these differences, the participants experienced a vivid sense of embodiment and presence in almost all conditions. These results provide first evidence that, although less intensively, embodiment and presence are similarly experienced by individuals who have suffered a stroke and by healthy individuals, which could support the vividness of their experience and, consequently, the effectiveness of VR-based interventions.This study was funded by Ministerio de Economía y Competitividad of Spain (Project RTC-2017-6051-7 and Grant BES-2014-068218), Fundació la Marató de la TV3 (Grant 201701-10), and Universitat Politècnica de València (Grant PAID-10-18). We acknowledge the support of NVIDIA Corporation with the donation of the Titan Xp GPU used for this research.Borrego, A.; Latorre, J.; Alcañiz Raya, ML.; Llorens Rodríguez, R. (2019). Embodiment and Presence in Virtual Reality After Stroke. A Comparative Study With Healthy Subjects. Frontiers in Neurology. 10:1-8. https://doi.org/10.3389/fneur.2019.01061S1810Berlucchi, G., & Aglioti, S. (1997). The body in the brain: neural bases of corporeal awareness. Trends in Neurosciences, 20(12), 560-564. doi:10.1016/s0166-2236(97)01136-3Legrand, D. (2006). The Bodily Self: The Sensori-Motor Roots of Pre-Reflective Self-Consciousness. Phenomenology and the Cognitive Sciences, 5(1), 89-118. doi:10.1007/s11097-005-9015-6Arzy, S., Overney, L. S., Landis, T., & Blanke, O. (2006). Neural Mechanisms of Embodiment. Archives of Neurology, 63(7), 1022. doi:10.1001/archneur.63.7.1022De Vignemont, F. (2011). Embodiment, ownership and disownership. Consciousness and Cognition, 20(1), 82-93. doi:10.1016/j.concog.2010.09.004Giummarra, M. J., Gibson, S. J., Georgiou-Karistianis, N., & Bradshaw, J. L. (2008). Mechanisms underlying embodiment, disembodiment and loss of embodiment. Neuroscience & Biobehavioral Reviews, 32(1), 143-160. doi:10.1016/j.neubiorev.2007.07.001Ma, K., & Hommel, B. (2015). The role of agency for perceived ownership in the virtual hand illusion. Consciousness and Cognition, 36, 277-288. doi:10.1016/j.concog.2015.07.008Kilteni, K., Maselli, A., Kording, K. P., & Slater, M. (2015). Over my fake body: body ownership illusions for studying the multisensory basis of own-body perception. Frontiers in Human Neuroscience, 9. doi:10.3389/fnhum.2015.00141Clark, A., Kiverstein, J., & Vierkant, T. (Eds.). (2013). Decomposing the Will. doi:10.1093/acprof:oso/9780199746996.001.0001Frith, C. D., Blakemore, S.-J., & Wolpert, D. M. (2000). Abnormalities in the awareness and control of action. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 355(1404), 1771-1788. doi:10.1098/rstb.2000.0734Bermúdez i Badia, S., Fluet, G. G., Llorens, R., & Deutsch, J. E. (2016). Virtual Reality for Sensorimotor Rehabilitation Post Stroke: Design Principles and Evidence. Neurorehabilitation Technology, 573-603. doi:10.1007/978-3-319-28603-7_28Perez-Marcos, D., Sanchez-Vives, M. V., & Slater, M. (2011). Is my hand connected to my body? The impact of body continuity and arm alignment on the virtual hand illusion. Cognitive Neurodynamics, 6(4), 295-305. doi:10.1007/s11571-011-9178-5IJsselsteijn, W. A., de Kort, Y. A. W., & Haans, A. (2006). Is This My Hand I See Before Me? The Rubber Hand Illusion in Reality, Virtual Reality, and Mixed Reality. Presence: Teleoperators and Virtual Environments, 15(4), 455-464. doi:10.1162/pres.15.4.455Banakou, D., Groten, R., & Slater, M. (2013). Illusory ownership of a virtual child body causes overestimation of object sizes and implicit attitude changes. Proceedings of the National Academy of Sciences, 110(31), 12846-12851. doi:10.1073/pnas.1306779110Yee, N., & Bailenson, J. (2007). The Proteus Effect: The Effect of Transformed Self-Representation on Behavior. Human Communication Research, 33(3), 271-290. doi:10.1111/j.1468-2958.2007.00299.xSteed, A., Frlston, S., Lopez, M. M., Drummond, J., Pan, Y., & Swapp, D. (2016). An ‘In the Wild’ Experiment on Presence and Embodiment using Consumer Virtual Reality Equipment. IEEE Transactions on Visualization and Computer Graphics, 22(4), 1406-1414. doi:10.1109/tvcg.2016.2518135Colomer, C., Llorens, R., Noé, E., & Alcañiz, M. (2016). Effect of a mixed reality-based intervention on arm, hand, and finger function on chronic stroke. Journal of NeuroEngineering and Rehabilitation, 13(1). doi:10.1186/s12984-016-0153-6Laver, K. E., Lange, B., George, S., Deutsch, J. E., Saposnik, G., & Crotty, M. (2017). Virtual reality for stroke rehabilitation. Cochrane Database of Systematic Reviews. doi:10.1002/14651858.cd008349.pub4Llorens, R., Borrego, A., Palomo, P., Cebolla, A., Noé, E., i Badia, S. B., & Baños, R. (2017). Body schema plasticity after stroke: Subjective and neurophysiological correlates of the rubber hand illusion. Neuropsychologia, 96, 61-69. doi:10.1016/j.neuropsychologia.2017.01.007Zeller, D., Gross, C., Bartsch, A., Johansen-Berg, H., & Classen, J. (2011). Ventral Premotor Cortex May Be Required for Dynamic Changes in the Feeling of Limb Ownership: A Lesion Study. Journal of Neuroscience, 31(13), 4852-4857. doi:10.1523/jneurosci.5154-10.2011Folstein, M. F., Folstein, S. E., & McHugh, P. R. (1975). «Mini-mental state». Journal of Psychiatric Research, 12(3), 189-198. doi:10.1016/0022-3956(75)90026-6Romero, M., Sánchez, A., Marín, C., Navarro, M. D., Ferri, J., & Noé, E. (2012). Clinical usefulness of the Spanish version of the Mississippi Aphasia Screening Test (MASTsp): validation in stroke patients. Neurología (English Edition), 27(4), 216-224. doi:10.1016/j.nrleng.2011.06.001Latorre, J., Llorens, R., Colomer, C., & Alcañiz, M. (2018). Reliability and comparison of Kinect-based methods for estimating spatiotemporal gait parameters of healthy and post-stroke individuals. Journal of Biomechanics, 72, 268-273. doi:10.1016/j.jbiomech.2018.03.008Lloréns, R., Noé, E., Naranjo, V., Borrego, A., Latorre, J., & Alcañiz, M. (2015). Tracking Systems for Virtual Rehabilitation: Objective Performance vs. Subjective Experience. A Practical Scenario. Sensors, 15(3), 6586-6606. doi:10.3390/s150306586Slater, M., & Steed, A. (2000). A Virtual Presence Counter. Presence: Teleoperators and Virtual Environments, 9(5), 413-434. doi:10.1162/105474600566925Slater, M., Spanlang, B., Sanchez-Vives, M. V., & Blanke, O. (2010). First Person Experience of Body Transfer in Virtual Reality. PLoS ONE, 5(5), e10564. doi:10.1371/journal.pone.0010564Petkova, V. I., Khoshnevis, M., & Ehrsson, H. H. (2011). The Perspective Matters! Multisensory Integration in Ego-Centric Reference Frames Determines Full-Body Ownership. Frontiers in Psychology, 2. doi:10.3389/fpsyg.2011.00035Maselli, A., & Slater, M. (2013). The building blocks of the full body ownership illusion. Frontiers in Human Neuroscience, 7. doi:10.3389/fnhum.2013.00083Debarba, H. G., Molla, E., Herbelin, B., & Boulic, R. (2015). Characterizing embodied interaction in First and Third Person Perspective viewpoints. 2015 IEEE Symposium on 3D User Interfaces (3DUI). doi:10.1109/3dui.2015.7131728Burin, D., Livelli, A., Garbarini, F., Fossataro, C., Folegatti, A., Gindri, P., & Pia, L. (2015). Are Movements Necessary for the Sense of Body Ownership? Evidence from the Rubber Hand Illusion in Pure Hemiplegic Patients. PLOS ONE, 10(3), e0117155. doi:10.1371/journal.pone.0117155Post-stroke cognitive disorders TeasellR SalterK FaltynekP CotoiA EskesG Evidence-Based Review of Stroke Rehabilitatio

Comparing Mixed Reality Agent Representations: Studies in the Lab and in the Wild

Mixed-reality systems provide a number of different ways of representing users to each other in collaborative scenarios. There is an obvious tension between using media such as video for remote users compared to representations as avatars. This paper includes two experiments (total n = 80) on user trust when exposed to two of three different user representations in an immersive virtual reality environment that also acts as a simulation of typical augmented reality simulations: full body video, head and shoulder video and an animated 3D model. These representations acted as advisors in a trivia quiz. By evaluating trust through advisor selection and self-report, we found only minor differences between representations, but a strong effect of perceived advisor expertise. Unlike prior work, we did not find the 3D model scored poorly on trust, perhaps as a result of greater congruence within an immersive context