The Impact of Embodying Photorealistic Avatars with Ideal Body Weight on Self-Esteem in Virtual Reality

Assigned Human-Computer Interaction Master Thesis Embodiment Lab

Motivation

Weight and eating disorders are among the most common mental illnesses in adults (World Health Organization, 2022). Low self-esteem (Kästner et al., 2019), a negative body image (Nakamura et al., 1999) and a lower quality of life (Jenkins et al., 2011) are common accompanying symptoms. A widely used therapeutic approach for treating eating disorders and disturbed body images is the cognitive behavioral therapy (CBT) (Farrell et al., 2006; Murphy et al., 2010). One part of the CBT is a mirror exposure that is used to correct a distorted view of one’s own body (Legenbauer & Vocks, 2014). New approaches are often supported by virtual reality (VR) and even include virtual mirror exposures (Portingale et al., 2024). In a recent review, Perez et al. (2023) found that in the improvement of body image disturbances in eating disorders (Anorexia nervosa, Bulimia nervosa), extended reality technologies were in 80% of the studies useful. These studies often use avatars, which can have a big impact on the human perception and behavior (Yee & Bailenson, 2007). Several studies recommend using photorealistically customized avatars when focusing on body perception in VR (Döllinger et al., 2022; Mölbert et al., 2018; Turbyne et al., 2021). Wolf et al. (2021) showed that the embodiment of avatars has an impact on the perception of the avatar’s body weight. Furthermore, findings by Wolf et al. (2022a) indicate a positive correlation between self-esteem and the perceived attractiveness of a participant’s avatar. Given that avatar embodiment in VR can influence self-esteem (Koek & Chen, 2023), and that many individuals are dissatisfied with their body weight (Ipsos, 2018), which in turn affects their self-esteem (O’Dea, 2012), this leads to the following research questions.

RQ1: How does the embodiment of a personalized photorealistic avatar with self-defined ideal body weight affect the user’s perceived attractiveness of that avatar, the user’s implicit and explicit self-esteem, body weight perception, and body image?

RQ2: How does the changed attractiveness of a personalized photorealistic avatar affect the user’s implicit and explicit self-esteem, body weight perception, and body image?

Concept

In this project, we implement a VR study, to investigate the effect of the embodiment of a personalized photorealistic avatar with self-defined ideal body weight on attractiveness, as well as implicit and explicit self-esteem. This is based on a previous pilot study (Holderrieth, 2024).

The project employs a between-subject design with two groups. The between factor of these two groups is the body weight of the participant’s avatar (self-defined ideal or actual).

We measure as dependent variables avatar and real body attractiveness, self-esteem, body-esteem, body weight perception and body image. As controls, we assess body mass index, body shape concerns, Sense of Embodiment, self-identification, simulator sickness and affective appraisal.

To assess implicit self-esteem, the participants will perform an Implicit Association Test (IAT) for self-esteem in VR. As described by Nosek et al. (2007), the IAT is a sorting task with two pre-defined response options. These response options contain two items from two different dimensions. Participants are required to assign stimulus items to one of two pre-defined response options. The IAT states, that the task is easier, when the items of the two dimensions are strongly associated to the same group. The procedure of the IAT consists of five different blocks, including five practice blocks and two critical blocks. The critical blocks are compared regarding latencies. The IAT will be assessed on a white canvas in the virtual environment. On this canvas, the stimulus items will appear in the middle. The categories are indicated in the left/right corner. To assign an item to left/right, the participants need to press a button on the left/right controller. If their assignment was wrong, this will be indicated by a red cross on the canvas and the participants have to assign again.

The procedure of the study is divided in three phases. In the opening phase, the participants get information about the study and consent to it. In the body scan phase, we generate the photorealistic avatars of the participants by using the avatar scanner from our lab. The experiment phase starts with the attractiveness measurement of the body, pre-questionnaires (demographics, BSQ, SSES, BESAA, BISS, VRSQ) and the interpupillary distance measurement. When the photorealistic avatar is ready for use, the participants get an instruction to the head-mounted display and controllers. In the VR exposure phase, the participants perform an eye test. Subsequently, they perform the IAT, the attractiveness measurement of the avatar and BWP tasks. Then, they step into their avatar, which has either their self-defined ideal or their current body weight. The embodiment starts and they perform body movement and confrontation tasks. Then, VEQ and VEQ+ are assessed. Afterwards, they step out of their avatar (embodiment stops) and they perform the IAT, as well as the attractiveness measurement and BWP tasks. After the VR exposure, the participants answer SSES, BESAA, BISS, UVI and VRSQ. After the last attractiveness measurement, they answer qualitative questions.

Time Schedule

| Due Date | Task | |————–|————————————-| | 11.11.2024 | Ethics proposal | | 19.11.2024 | Set up hypotheses | | 19.11.2024 | Study procedure | | 26.11.2024 | Create study in SONA | | 26.11.2024 | Create questionnaires in LimeSurvey | | 10.12.2024 | Implementation | | 07.01.2024 | Prepare data collection | | 21.02.2025 | Data collection | | 11.04.2025 | Data evaluation | | 30.05.2025 | Write thesis |

References

Döllinger, N., Wolf, E., Mal, D., Wenninger, S., Botsch, M., Latoschik, M. E., & Wienrich, C. (2022). Resize Me! Exploring the user experience of embodied realistic modulatable avatars for body image intervention in virtual reality. Frontiers in Virtual Reality, 3.

Farrell, C., Shafran, R., & Lee, M. (2006). Empirically evaluated treatments for body image disturbance: A review. European Eating Disorders Review, 14 (5), 289–300.

Holderrieth, L. (2024). Do you feel better? The impact of embodying photorealistic avatars with ideal body weight on self-esteem and body perception in virtual reality.

Ipsos. (2018). Global Views On Food – 2018 What are the world’s food habits? IPSOS GLOBAL ADVISOR.

Jenkins, P. E., Hoste, R. R., Meyer, C., & Blissett, J. M. (2011). Eating disorders and quality of life: A review of the literature. Clinical Psychology Review, 31 (1), 113–121.

Kästner, D., Löwe, B., & Gumz, A. (2019). The role of self-esteem in the Treatment of patients with anorexia nervosa – A systematic review and meta-analysis. International Journal of Eating Disorders, 52 (2), 101–116.

Koek, D. W. J., & Chen, H.-H. (2023). My avatar makes me feel good? The effects of avatar personalization and virtual human interactions on self-esteem.

Legenbauer, T., & Vocks, S. (2014). Interventionen zur Veränderung des Körperbildes. In T. Legenbauer & S. Vocks (Eds.), Manual der kognitiven Verhaltenstherapie bei Anorexie und Bulimie (pp. 231–252). Springer.

Mölbert, S. C., Thaler, A., Mohler, B. J., Streuber, S., Romero, J., Black, M. J., Zipfel, S., Karnath, H.-O., & Giel, K. E. (2018). Assessing body image in anorexia nervosa using biometric self-avatars in virtual reality: Attitudinal components rather than visual body size estimation are distorted. Psychological Medicine, 48 (4), 642–653.

Murphy, R., Straebler, S., Cooper, Z., & Fairburn, C. G. (2010). Cognitive Behavioral Therapy for Eating Disorders. Psychiatric Clinics, 33 (3), 611–627.

Nakamura, K., Hoshino, Y., Watanabe, A., Honda, K., Niwa, S., Tominaga, K., Shimai, S., & Yamamoto, M. (1999). Eating problems in female Japanese high school students: A prevalence study. International Journal of Eating Disorders, 26 (1), 91–95.

Nosek, B. A., Greenwald, A. G., & Banaji, M. R. (2007). The implicit association test at age 7: A methodological and conceptual review. In J. A. Bargh (Ed.), Automatic processes in social thinking and behavior (pp. 265–292). Psychology Press.

O’Dea, J. (2012). Body image and self-esteem. In T. Cash (Ed.), Encyclopedia of body image and human appearance (pp. 141–147). Academic Press.

Perez, M., Pineda-Rafols, A., Egea-Romero, M. P., Gonzalez-Moreno, M., & Rincon, E. (2023). Addressing Body Image Disturbance through Metaverse-Related Technologies: A Systematic Review. Electronics, 12 (22), 4580.

Portingale, J., Krug, I., Liu, H., Kiropoulos, L., & Butler, D. (2024). Your body, my experience: A systematic review of embodiment illusions as a function of and method to improve body image disturbance. Clinical Psychology: Science and Practice, No Pagination Specified–No Pagination Specified.

Turbyne, C., Goedhart, A., de Koning, P., Schirmbeck, F., & Denys, D. (2021). Systematic Review and Meta-Analysis of Virtual Reality in Mental Healthcare: Effects of Full Body Illusions on Body Image Disturbance. Frontiers in Virtual Reality, 2.

Wolf, E., Döllinger, N., Mal, D., Wenninger, S., Bartl, A., Botsch, M., Latoschik, M. E., & Wienrich, C. (2022a). Does distance matter? Embodiment and perception of personalized avatars in relation to the self-observation distance in virtual reality. Frontiers in Virtual Reality, 3.

Wolf, E., Merdan, N., Dölinger, N., Mal, D., Wienrich, C., Botsch, M., & Latoschik, M. E. (2021). The Embodiment of Photorealistic Avatars Influences Female Body Weight Perception in Virtual Reality. 2021 IEEE Virtual Reality and 3D User Interfaces (VR), 65–74.

World Health Organization. (2022, June 8). Mental disorders. Retrieved July 24, 2024, from https://www.who.int/news- room/fact- sheets/detail/mentaldisorders

Yee, N., & Bailenson, J. (2007). The Proteus Effect: The Effect of Transformed Self-Representation on Behavior. Human Communication Research, 33 (3), 271–290.

Contact Persons at the University Würzburg