Embodiment in different size virtual bodies produces changes in women's body image distortion and dissatisfaction

Abstract

Introduction: Body image disturbance is considered a pervasive issue among women and is a core feature of eating disorders. Previous research provides evidence of the ability of body ownership illusions in virtual reality to produce changes in one's own body representation, especially in body size estimation. However, less information is available about changes in subjective body attitudes. This study assesses whether owning a female virtual avatar with different body sizes produces changes in body image distortion and body image dissatisfaction in women. Method: Forty female college students were exposed to an immersive virtual environment, in which they were sequentially embodied in three avatars using synchronous visuo-tactile stimulation. The first and third avatar had the same body size as the participant, but the second one had a larger body size. In the larger avatar condition, the group was divided into two: 20 participants owned a virtual body 20% larger and the other twenty a virtual body 40% larger. Body image distortion and body image dissatisfaction were assessed before and after embodiment in each of the three avatars using a silhouette test. Results: Mixed between-within analyses of variance showed a statistically significant effect of the variable Time (four assessment points) on body image distortion (F (3, 38) =2.825, p=.042, η2 = 0.069) and body image dissatisfaction (F (3, 38) =6.933, p<.001, η2 = 0.154). The effect of the variable Group (20% increase versus 40% increase in the larger body size avatar) and the interaction between time and group were not statistically significant. Overall, participants reported a reduction in the body image overestimation after owning the same-size avatar for the second time (M=8.88, SD=12.48) than at the other assessment points (at pre-test: M=13.00, SD=17.09; after owning the first same-size virtual body: M=13.75, SD=11.14; and the larger size avatar: M=14.50, SD=15.18). In regards to body image dissatisfaction, the highest levels were recorded at pre-test (M=16.38, SD=18.54) and after owning the larger size avatar (M=15.50, SD=19.57) and lowest levels after owning the same-size avatar for the second time (M=6.88, SD=13.85). More interestingly, the reduction in body dissatisfaction after owning the same-size avatar for the second time compared with pre-test was statistically significant (F (1, 38) =18.098, p<.001, η2 = 0.323). Conclusion: This study extends the evidence available about the ability of full virtual body ownership illusions to modify the mental representation of one's own body. Owning a virtual body with different body sizes produces changes not only in size overestimation but also in body dissatisfaction; and, most importantly, inducing the ownership illusion of a largersize virtual body reduces body dissatisfaction when subjects return to the samesize avatar, probably due to a comparison effect.