Which Body Would You Like to Have? The Impact of Embodied Perspective on Body Perception and Body Evaluation in Immersive Virtual Reality

Abstract

In this experiment, we aimed to measure the conscious internal representation of one's body appearance and allow the participants to compare this to their ideal body appearance and to their real body appearance. We created a virtual representation of the internal image participants had of their own body shape. We also created a virtual body corresponding to the internal representation they had of their ideal body shape, and we built another virtual body based on their real body measures. Participants saw the three different virtual bodies from an embodied first-person perspective and from a third-person perspective and had to evaluate the appearance of those virtual bodies. We observed that female participants evaluated their real body as more attractive when they saw it from a third-person perspective, and that their level of body dissatisfaction was lower after the experimental procedure. We believe that third-person perspective allowed female participants to perceive their real body shape without applying the negative prior beliefs usually associated to the "self", and that this resulted in a more positive evaluation of their body shape. We speculate that this method could be applied with patients suffering from eating disorders, by making their body perception more realistic and therefore improve their body satisfaction.

Keywords: body evaluation; body image; body perception; body satisfaction; eating disorders; immersive virtual reality; visual perspective.

Figure 1

A participant wearing the Optitrack body suit and the nVision SX111 HMD.

Figure 2

Arduino board (Left) and vibrators (Right).

Figure 3

Model of the laboratory displayed in the virtual environment.

Figure 4

The body structure constructed by the participant (colored cylinders placed behind the orange cylinder) and the schematic picture on the wall (the part that needed to be estimated was highlighted in red on the schematic picture, here “chest width”). The orange cylinder here is the one used for the estimation, the other cylinders are already placed in space corresponding to the other body parts estimated by the participants.

Figure 5

Position of the 32 markers on the body of the participant, 1 marker on the top of the head, 4 markers on each arm, 8 markers on the torso, 5 markers on the hips and buttocks, 4 markers on each leg, 1 marker on each foot.

Figure 6

Avatar seen in first-person perspective, on the left, front view of the avatar reflected in the mirror and yellow balls moving toward the legs to create visuo-tactile feedback. On the right, view of the virtual body when the participant looks down.

Figure 7

Avatar seen in third-person perspective, from the point of view of the participant.

Figure 8

Box plot presenting the level of body ownership depending on the perspective. The horizontal thick lines indicate the value of the medians, the boxes are the interquartile ranges (IQR), the whiskers extend from max (median - 1.5*IQR, smallest value) to min (median + 1.5*IQR, largest value). Outliers are shown individually as separated dots. Mirror and LookDown correspond to the level of body ownership for all the avatars when presented in 1PP. BO 3PP corresponds to the level of body ownership for all the avatars when presented in 3PP.

Figure 9

On the top, average shape of the body image avatars showing the mean (over)estimation females gave of their own body shape. Below, averaged shape of the ideal body avatars generated with the mean estimation females gave of their ideal body measures.

Figure 10

On the top, average shape of the body image avatars showing the mean estimation males gave of their own body shape. Below, average shape of the ideal body avatars showing the mean estimation males gave of their ideal body shape.

Figure 11

On the top Box plot presenting the scores obtained during the body evaluation phase. Answers to the question: How fat do you think this body is?—Below Box plot presenting the scores obtained during the body evaluation phase. Answers to the question: How thin do you think this body is? The horizontal thick lines indicate the value of the medians, the boxes are the interquartile ranges (IQR), the whiskers extend from max (median - 1.5*IQR, smallest value) to min (median + 1.5*IQR, largest value). Outliers are shown individually as separated dots.

Figure 12

On the top, Box plot presenting the scores obtained during the body evaluation phase. Answers to the question: How much would you like your body to resemble this one?—Below, Box plot presenting the scores obtained during the evaluation phase. Answers to the question: How attractive does this body look to you? The horizontal thick lines indicate the value of the medians, the boxes are the interquartile ranges (IQR), the whiskers extend from max (median - 1.5*IQR, smallest value) to min (median + 1.5*IQR, largest value). Outliers are shown individually as separated dots.

Figure 13

On the top, Box plot presenting the scores obtained during the body evaluation phase. Answers to the question: How fat do you think this body is?—Below, Box plot presenting the scores obtained during the body evaluation phase. Answers to the question: How thin do you think this body is? The horizontal thick lines indicate the value of the medians, the boxes are the interquartile ranges (IQR), the whiskers extend from max (median - 1.5*IQR, smallest value) to min (median + 1.5*IQR, largest value). Outliers are shown individually as separated dots.

Figure 14

On the top, Box plot presenting the scores obtained during the body evaluation phase. Answers to the question: How much would you like your body to resemble this one?—Below, Box plot presenting the scores obtained during the body evaluation phase. Answers to the question: How attractive does this body look to you?- The horizontal thick lines indicate the value of the medians, the boxes are the interquartile ranges (IQR), the whiskers extend from max (median - 1.5*IQR, smallest value) to min (median + 1.5*IQR, largest value). Outliers are shown individually as separated dots.

Figure 15

Box plot presenting the scores obtained during the evaluation phase. Answers to the question: How much would you like your body to resemble this one. The horizontal thick lines indicate the value of the medians, the boxes are the interquartile ranges (IQR). Outliers are shown individually as separated dots.