Avatar Embodiment Research Articles

Does distance matter? Embodiment and perception of personalized avatars in relation to the self-observation distance in virtual reality

Virtual reality applications employing avatar embodiment typically use virtual mirrors to allow users to perceive their digital selves not only from a first-person but also from a holistic third-person perspective. However, due to distance-related biases such as the distance compression effect or a reduced relative rendering resolution, the self-observation distance (SOD) between the user and the virtual mirror might influence how users perceive their embodied avatar. Our article systematically investigates the effects of a short (1 m), middle (2.5 m), and far (4 m) SOD between users and mirror on the perception of their personalized and self-embodied avatars. The avatars were photorealistic reconstructed using state-of-the-art photogrammetric methods. Thirty participants repeatedly faced their real-time animated self-embodied avatars in each of the three SOD conditions, where they were repeatedly altered in their body weight, and participants rated the 1) sense of embodiment, 2) body weight perception, and 3) affective appraisal towards their avatar. We found that the different SODs are unlikely to influence any of our measures except for the perceived body weight estimation difficulty. Here, the participants perceived the difficulty significantly higher for the farthest SOD. We further found that the participants’ self-esteem significantly impacted their ability to modify their avatar’s body weight to their current body weight and that it positively correlated with the perceived attractiveness of the avatar. Additionally, the participants’ concerns about their body shape affected how eerie they perceived their avatars. The participants’ self-esteem and concerns about their body shape influenced the perceived body weight estimation difficulty. We conclude that the virtual mirror in embodiment scenarios can be freely placed and varied at a distance of one to four meters from the user without expecting major effects on the perception of the avatar.

Challenges in Implementing Low-Latency Holographic-Type Communication Systems.

Holographic-type communication (HTC) permits new levels of engagement between remote users. It is anticipated that it will give a very immersive experience while enhancing the sense of spatial co-presence. In addition to the newly revealed advantages, however, stringent system requirements are imposed, such as multi-sensory and multi-dimensional data capture and reproduction, ultra-lightweight processing, ultra-low-latency transmission, realistic avatar embodiment conveying gestures and facial expressions, support for an arbitrary number of participants, etc. In this paper, we review the current limitations to the HTC system implementation and systemize the main challenges into a few major groups. Furthermore, we propose a conceptual framework for the realization of an HTC system that will guarantee the desired low-latency transmission, lightweight processing, and ease of scalability, all accompanied with a higher level of realism in human body appearance and dynamics.

Avatar embodiment: from cognitive self-representation to digital body ownership

Virtual reality experiences often use avatars to enhance their immersive potential, tapping into cognitive processes by which their bodies are perceived as our own. This in turn supposes that we are able to embody our cognitive self-representation in the avatar and accept the digital representation of this virtual body as an integral part of our identified body. This paper explores how the theory of embodied cognition accounts for the relationship between cognition, body, and environment. It further elaborates on the process of cognitive self-representation through notions of cognitive body, self-identity and goes on to define the avatar as a digitally simulated body, outlining its perceptual differences with the physical body. Finally, the process of digital body ownership is described according to sensorimotor theories of perception, while self-resembling avatars are identified as particularly conducive to embodiment.

Virtual Reality Embodiment in Motor Imagery Brain–Computer Interface Training

This study investigates how the avatar embodiment in virtual reality (VR) influences training for operation of motor imagery brain–computer interfaces (MI-BCIs). In previous studies, we demonstrated the possibility to induce a BCI-based VR avatar embodiment (using mental commands instead of motion tracking) for purposes of training facilitation. This paper examines the relationship between BCI performance and subjective levels of embodiment, as well as differences in BCI performance achieved with training in two different VR environments. MI-BCI training variants with the following forms of feedback were studied: a) with feedback exploiting avatar embodiment in immersive VR (avatar movements indicating the user performance), b) with feedback exploiting avatar embodiment in gamified and progressively paced VR training, and c) with symbolic feedback in the standard training with Graz protocol. On-line performance from the BCI experiments and questionnaires on the sense of ownership and sense of agency toward the virtual avatar were studied. Questionnaire analysis showed that a robust sense of embodiment arose in the VR training environments, with a strong correlation between the reported ownership and agency toward the avatar. Interestingly, the achieved BCI performance was uncorrelated with both the ownership and the agency. Using gamification further increased the performance (but not the reported sense of ownership) in the training session. Embodiment in VR mediated by synchrony between mental commands and visual stimulation in VR arose under different conditions than embodiment based on visuo-motor synchrony. Consistency between the perceived sense of ownership and agency plays a more important role than the ability to issue MI-BCI commands correctly. These findings help to elucidate the positive effect of embodiment to initial steps in BCI training and can be leveraged in future MI-BCI training designs.

A randomized controlled pilot study examining immediate effects of embodying a virtual reality superhero in people with chronic low back pain

Purpose In virtual reality, avatar embodiment can spur perceptions and behaviours related the avatars’ characteristics. We tested whether embodying superhero-like avatars can change self-perceptions in people with chronic low back pain (CLBP). Design A non-blinded pilot randomized controlled trial. Methods Participants were randomly allocated to embody a superhero (VR-SH, n = 20) or a neutral, non-superhero (VR-Play, n = 10) avatar. Primary outcomes related to body image (e.g., self-perceived vulnerability) and pain intensity were assessed at baseline, during exposure, immediately after and at one-week follow-up. Fear of movement, strength and patient impression of change were also recorded. Results The VR-SH group reported gains in body image during (p < .001, η p 2 =0.71) and immediately after (p < .001, η p 2 =0.66) VR, whereas the VR-Play group reported small gains during VR (p = .021, η p 2 =0.46) but not immediately after (p = .076, η p 2 =0.31). Pain, strength and fear of movement did not change and there were no sustained effects at follow-up (all ps > .05). A greater proportion of people in the VR-SH group reported at least minimal improvement at follow-up (7/20 vs. 1/10). Conclusion A VR-SH session produced temporary positive effects on body image. Future research may consider whether larger and sustained effects can be obtained with multisession exposures or explore combined interventions. Implications for rehabilitation Physical confidence and bodily trust can be significantly enhanced in people with chronic back pain using virtual reality. These positive body image effects may have implications for rehabilitation, such as in enhancing confidence with movement Whether a multisession intervention might produce more robust effects and changes in pain is yet to be determined

Impact of an overweight body representation in virtual reality on locomotion in a motor imagery task.

Virtual reality immersion enables a person to embody avatars that strongly deviate from his/her biological body. Interestingly, the person's expectations about the embodied avatar lead to congruous behavior, phenomenon referred to as the Proteus effect. The objective of the present study was to investigate, in virtual reality, the relationship between body-shape representation and expected physical abilities in a locomotor imagery task, in the context of overweight avatar embodiment. Given the negative stereotypes concerning overweight people's physical abilities, we expected overweight avatar embodiment to have a negative impact on performance in the locomotor imagery task. Thirty-five healthy-weight participants, with a body mass index between 16.5 and 30 at the time of the experiment or in the past, embodied both a healthy-weight avatar and an overweight avatar on two different experimental sessions while performing the imagery task (walking four different distances on two different slopes). In accordance with our hypothesis, participants took longer to perform the locomotor imagery task when embodying an overweight avatar than when embodying a healthy-weight one (the "avatar effect")-especially so when the distance to be covered was long. We conclude that, as has already been reported for people with anorexia nervosa, considering one's own body to be fatter than it really is leads to congruent weight-related behavior.

Avatars for Teleconsultation: Effects of Avatar Embodiment Techniques on User Perception in 3D Asymmetric Telepresence.

A 3D Telepresence system allows users to interact with each other in a virtual, mixed, or augmented reality (VR, MR, AR) environment, creating a shared space for collaboration and communication. There are two main methods for representing users within these 3D environments. Users can be represented either as point cloud reconstruction-based avatars that resemble a physical user or as virtual character-based avatars controlled by tracking the users' body motion. This work compares both techniques to identify the differences between user representations and their fit in the reconstructed environments regarding the perceived presence, uncanny valley factors, and behavior impression. Our study uses an asymmetric VR/AR teleconsultation system that allows a remote user to join a local scene using VR. The local user observes the remote user with an AR head-mounted display, leading to facial occlusions in the 3D reconstruction. Participants perform a warm-up interaction task followed by a goal-directed collaborative puzzle task, pursuing a common goal. The local user was represented either as a point cloud reconstruction or as a virtual character-based avatar, in which case the point cloud reconstruction of the local user was masked. Our results show that the point cloud reconstruction-based avatar was superior to the virtual character avatar regarding perceived co-presence, social presence, behavioral impression, and humanness. Further, we found that the task type partly affected the perception. The point cloud reconstruction-based approach led to higher usability ratings, while objective performance measures showed no significant difference. We conclude that despite partly missing facial information, the point cloud-based reconstruction resulted in better conveyance of the user behavior and a more coherent fit into the simulation context.

Exercising With Embodied Young Avatars: How Young vs. Older Avatars in Virtual Reality Affect Perceived Exertion and Physical Activity Among Male and Female Elderly Individuals.

This study demonstrated that implementation of the Proteus effect via manipulation of avatar age in VR is effective among elderly individuals in the context of exercise. One hundred and four elderly adults aged 60 years and older who did not engage in vigorous physical activities participated in this experiment with a 2 (avatar age: young vs. older) × 2 (sex: male vs. female) design. The results showed that the embodiment of younger avatars (age approximately 20 years) in VR leads to greater perceived exercise exertion regardless of sex after controlling for age and emotion. Older adults with young avatars perceived a greater contribution of efforts to exercise. This study also found that among those who did not engage in vigorous exercise, female older adults who embodied young avatars reported greater self-efficacy for future exercise and greater physical activity during the exercise phase than those who embodied older avatars. This study suggests that females are more likely to be motivated to continue exercising through young avatar embodiment. In contrast, female elderly who embodied old avatars reported significant fewer physical activity than male elderly who embodied old avatars. This indicated that the Proteus effect had stronger effects among females than among older males. Although we found the Proteus effect through VR avatar manipulation, the effect was temporary and limited to the experimental phase. This study is the first to examine the Proteus effect among elderly individuals in the context of exercise. It also contributes to the literature by indicating that avatar age manipulation is an effective means of promoting exercise among elderly individuals and helping them achieve exercise outcomes. This study further demonstrates that female elderly individuals respond to young avatars differently than male elderly individuals, with female elderly individuals showing more positive effects of young avatar embodiment than males. Implications and theoretical contributions are discussed.

Virtual Mirror and Beyond: The Psychological Basis for Avatar Embodiment via a Mirror

In virtual reality (VR), a virtual mirror is often used to display the VR avatar to the user for enhancing the embodiment. The reflected image of the synchronization of the virtual body with the user’s movement is expected to be recognized as the user’s own reflection. In addition to the visuo-motor synchrony, there are some mirror reflection factors that are probably involved in avatar embodiment. This paper reviews literature on the psychological studies that involve mirror-specific self-identification and embodied perception to clarify how the reflected image of the virtual body is embodied. Furthermore, subjective misconceptions about mirror reflections reported in naïve optics have also been reviewed to discuss the potential of virtual mirror displays to modulate avatar embodiment.

The Effect of VR Avatar Embodiment on Improving Attitudes and Closeness Toward Immigrants

Past research has discussed how the embodiment of an outgroup avatar in virtual reality (VR) can reduce intergroup bias. However, little is known about the mechanisms and boundary conditions that shape this effect. This study examines how the embodiment of both outgroup and ingroup VR avatars in different orders influences attitudes and perceived closeness toward a co-ethnic immigrant outgroup in Singapore. It also investigates the role of empathy and social identity orientation (SIO) in this relationship. An experiment with four avatar embodiment conditions (ingroup-then-outgroup, outgroup-then-ingroup, ingroup-only, and outgroup-only) was carried out with 171 participants from a public university in Singapore. Results showed that embodying an outgroup avatar alone, compared to embodying an ingroup avatar alone, significantly improves both attitudes and closeness toward an immigrant outgroup. The order of embodiment matters to an extent, suggesting the greater effectiveness of outgroup-first over ingroup-first embodiment in reducing bias. Empathy mediates the effect of all three outgroup embodiment conditions on improved attitudes and closeness toward immigrants. It was also found that the stronger one’s SIO is, the more effective embodiment is in improving perceived closeness with the outgroup via empathy. Theoretical implications of these findings are discussed.

Exercising With a Six Pack in Virtual Reality: Examining the Proteus Effect of Avatar Body Shape and Sex on Self-Efficacy for Core-Muscle Exercise, Self-Concept of Body Shape, and Actual Physical Activity.

This study investigates the Proteus effect from the first-person perspective and during avatar embodiment in actual exercise. In addition to the immediate measurements of the Proteus effect, prolonged effects such as next-day perception and exercise-related outcomes are also explored. We theorized the Proteus effect as altered perceived self-concept and explored the association between virtual reality (VR) avatar manipulation and self-concept in the exercise context. While existing studies have mainly investigated the Proteus effect in a non-VR environment or after VR embodiment, we aim to contribute to the literature by addressing this concern to explore how the Proteus effect works in actual VR exercise. Through a 2 (avatar body shape: with a six pack vs. normal) × 2 (sex: male vs. female) between-subject experiment, the results partially support the Proteus effect. Regarding actual physical activity, embodying an avatar with a six pack during exercise creates fewer body movements. No significant effect was found for perceived exertion. We also explored the role of sex as a potential moderator in the association of the Proteus effect on exercise outcomes. The Proteus effect was supported by immediate and next-day self-efficacy for core-muscle exercise only among female participants. The between-subject design allowed us to probe how avatar manipulation of muscular body shape with a six pack as opposed to normal body shape influences participants’ self-concept and exercise outcomes, as limited VR studies have employed within-subject comparisons. This also contributes to the literature by providing an upward comparison (e.g., muscular with a six pack vs. normal) as opposed to the previous downward comparison regarding body fitness (e.g., normal vs. obese). The overall results supported the Proteus effect in the context of core-muscle exercise when comparing normal and ideal body shape avatars. However, the Proteus effect as an altered self-concept and its effects on self-efficacy for exercise were supported among females but not males. Whereas the female participants who embodied avatars with a six pack associated themselves more with the muscular concept than other people, the male participants who embodied avatars with a six pack perceived themselves as more normal than others. Theoretical and practical implications are discussed.

Avatar-Based Self-Influence in a Traditional CMC Environment

Abstract. Dubbed the Proteus effect, research has shown that avatars influence user behavior in virtual reality and video game environments ( Yee &amp; Bailenson, 2007 , 2009 ); however, does this same effect occur in the less dynamic but more prevalent traditional computer-mediated communication (CMC)? As CMC evolves to allow user avatars, the question of its influence increases in importance. This study examines the Proteus effect in traditional CMC, which tends to be dominated by text-based communication. Embodiment is presented as a moderator for the Proteus effect. Two methods for inducing embodiment (via choice and via familiarizing tasks) were tested along with a proposed model for the Proteus effect in social media environments. A 2 (avatar) × 2 (embodiment by choice) × 2 (embodiment by familiarizing tasks) between-subject design with 406 participants showed a significant main effect of familiarizing tasks on embodiment, an interaction effect of avatar embodiment and avatar condition on aggressive behavior, and an unpredicted main effect of embodiment on aggressive attitude.

The Influence of Avatar Embodiment on Time Perception - Towards VR for Time-Based Therapy

Psycho-pathological conditions, such as depression or schizophrenia, are often accompanied by a distorted perception of time. People suffering from this conditions often report that the passage of time slows down considerably and that they are “stuck in time.” Virtual Reality (VR) could potentially help to diagnose and maybe treat such mental conditions. However, the conditions in which a VR simulation could correctly diagnose a time perception deviation are still unknown. In this paper, we present an experiment investigating the difference in time experience with and without a virtual body in VR, also known as avatar. The process of substituting a person’s body with a virtual body is called avatar embodiment. Numerous studies demonstrated interesting perceptual, emotional, behavioral, and psychological effects caused by avatar embodiment. However, the relations between time perception and avatar embodiment are still unclear. Whether or not the presence or absence of an avatar is already influencing time perception is still open to question. Therefore, we conducted abetween-subjectsdesign with and without avatar embodiment as well as a real condition (avatarvs.no-avatarvs.real). A group of 105 healthy subjects had to wait for seven and a half minutes in a room without any distractors (e.g., no window, magazine, people, decoration) or time indicators (e.g., clocks, sunlight). The virtual environment replicates the real physical environment. Participants were unaware that they will be asked to estimate their waiting time duration as well as describing their experience of the passage of time at a later stage. Our main finding shows that the presence of an avatar is leading to a significantly faster perceived passage of time. It seems to be promising to integrate avatar embodiment in future VR time-based therapy applications as they potentially could modulate a user’s perception of the passage of time. We also found no significant difference in time perception between therealand the VR conditions (avatar,no-avatar), but further research is needed to better understand this outcome.

Second Life comme espace de sociabilité pendant la pandémie de COVID-19

Les mondes virtuels et les jeux en ligne ont connu une remarquable croissance en termes de fréquentation dans les premiers mois de la pandémie COVID-19. Nous discutons ici de l’utilisation de Second Life comme espace de sociabilité dans ce contexte. Partant de notre recherche ethnographique nous présentons quelques hypothèses pour expliquer comment ce type de plateforme en ligne est privilégié au détriment d’autres, notamment dans la situation de distanciation physique vécue dans plusieurs pays. Une analyse centrée sur les caractéristiques sociotechniques de cet environnement numérique, ainsi que sur les expériences vécues par ses utilisateurs, nous permet de proposer l’immersion, la corporéité des avatars, la synchronicité et la persistance de ce monde comme éléments distinctifs de l’attraction exercée aujourd’hui par ce type de plateforme.

Autonomy and nomadic Relativism of Digital Identity

The article examines identity in such digital spaces as video games and virtual reality. These digital spaces are defined as interactive artificial environment, autonomous from reality, with its own ontology, scenario, narrative and mythological context. Video games have an immersive experience that is enhanced in virtual reality due to the ability to integrate into the embodiment of the game&amp;apos;s model. The type of digital identity that is defined by the video game designer in accordance with narrative and artistic goals is what we call a character. The opposite type is an avatar, it reflects strategies of self-presentation of an individual (user). Digital identity interests us primarily because of the ability to be independent (autonomous) from human physiology and from social categories that are attributed to the user in the real world. Digital identity can be constructed by the individuals in accordance with their preferences, which makes it possible to solve many gender, racial, and age problems. The possibility to integrate into an avatar embodiment and interact with in-game items it reinforces the distance from real embodiment. Moreover, in multiplayer games with the civil roleplay, it can exist in an artificial society and have introspective meaning for another members of the society. Another significant feature of digital identity is the relativism. Digital identity can be relativistic due to the which allow one to have different identities in different games or change the appearance of an avatar in one game during a play time. Autonomy and relativism can be the strategy for the implementation of projects of nomadic identity by Rosi Braidotti and Donna Haraway, in which subject is not sticked to any constants, but constantly defines and redefines oneself through performative acts.

A Self-Guiding Tool to Conduct Research With Embodiment Technologies Responsibly.

The extension of the sense of self to the avatar during experiences of avatar embodiment requires thorough ethical and legal consideration, especially in light of potential scenarios involving physical or psychological harm caused to, or by, embodied avatars. We provide researchers and developers working in the field of virtual and robot embodiment technologies with a self-guidance tool based on the principles of Responsible Research and Innovation (RRI). This tool will help them engage in ethical and responsible research and innovation in the area of embodiment technologies in a way that guarantees all the rights of the embodied users and their interactors, including safety, privacy, autonomy, and dignity.

Using Facial Animation to Increase the Enfacement Illusion and Avatar Self-Identification.

Through avatar embodiment in Virtual Reality (VR) we can achieve the illusion that an avatar is substituting our body: the avatar moves as we move and we see it from a first person perspective. However, self-identification, the process of identifying a representation as being oneself, poses new challenges because a key determinant is that we see and have agency in our own face. Providing control over the face is hard with current HMD technologies because face tracking is either cumbersome or error prone. However, limited animation is easily achieved based on speaking. We investigate the level of avatar enfacement, that is believing that a picture of a face is one's own face, with three levels of facial animation: (i) one in which the facial expressions of the avatars are static, (ii) one in which we implement lip-sync motion and (iii) one in which the avatar presents lip-sync plus additional facial animations, with blinks, designed by a professional animator. We measure self-identification using a face morphing tool that morphs from the face of the participant to the face of a gender matched avatar. We find that self-identification on avatars can be increased through pre-baked animations even when these are not photorealistic nor look like the participant.

Whose pain is it, anyway? On avatar embodiment, slapstick performances, and virtual pain

This article investigates the relationship of the player and her avatar in humorous single-player video games. Referring to slapstick performance characteristics and their perception as described by Louise Peacock (2014), it discusses the concepts of empathic and goal-oriented engagement by Petri Lankoski (2010), and proxy embodiment by Rune Klevjer (2012) along Manual Samuel (Perfectly Paranormal 2016), and Octodad: Dadliest Catch (Young Horses 2014). Considering mastery in ludic performance, and punishment for lack thereof, it focuses the tension between pain represented in avatar corporeality, and pain experienced by the player due to failing. Thus, this article provides a perspective that constructs the avatar-player-relationship in single-player video games as a central double act typical to slapstick performances.

Avatar Embodiment Enhances Haptic Confidence on the Out-of-Body Touch Illusion.

In the real world, our bodies influence how we perceive ourselves and how others perceive us. Our body can also affect estimations of object sizes and distances. But how does our body affect our haptic experience? Here, we examined the modulation of a visuo-haptic illusion of touch on a virtual stick in virtual reality, when participants were embodied in an avatar and when they were not. During the experiments participants (n = 49) received successions of three taps delivered from two independent controllers while they saw visual stimuli presented sequentially along the virtual stick. The stimulation pattern resulted in a robust illusion of tapping directly on the virtual stick. After each trial, participants were asked to report where they perceived the taps. We found that participants in both the body and no-body conditions displaced the second tap toward the center of the stick, and reported similar levels of certainty about their reported location. However, the illusion of touch on the stick, as measured by the reported location of the tap, was significantly stronger for those who had a virtual body than those who did not. Therefore, our study shows that avatar embodiment can change haptic perception.

When Your Robot Avatar Misbehaves You Are Likely to Apologize: An Exploration of Guilt During Robot Embodiment

Would people feel guilty if their robot avatar acted autonomously to harm someone? We examined the experience of guilt during robot avatar embodiment, a form of embodiment where the participants experience the body of a humanoid robot as if it were their own. In particular, we analyzed what happens when a robot avatar spontaneously verbally abuses someone during a conversation using the participant’s voice, without this being the intention of the participant. In a 2 × 2 between-subjects experimental design, participants embodied a humanoid robot that added either offensive or neutral words during a conversation with a confederate, and had control over the robot’s movements or not (synch. vs. asynch.). We found that guilt and shame were positively associated with offensive words and that apologizing and verbal repair were positively related to guilt. Also, body ownership was moderately associated to apologizing and verbal repair. The results suggest that people may feel guilty for the actions of their robot avatars even if they are not the real agents of these actions. The work highlights the importance of examining the moral and legal aspects related to robot embodiment technologies.