The Effect of a Virtual-Reality Full-Body Illusion on Body Representation in Obesity

Background. The effective illusory ownership over an artificial body in modulating body representations in healthy and eating disorders population has been repeatedly reported in recent literature. In this study, we extended this research in the field of obesity: specifically, we investigated whether ownership over a virtual body with a skinny abdomen might be successfully experienced by participants affected by obesity. Methods. Fifteen participants with obesity and fifteen healthy-weight participants took part at this study in which the VR-Full-Body Illusion was adopted. The strength of illusion was investigated through the traditional Embodiment Questionnaire, while changes in bodily experience were measured through a body size estimation task. Results. Participants with obesity as well as healthy-weight participants reported to experience the illusion. About the body size estimation task, both groups reported changes only in the estimation of the abdomen’s circumference after the experimental condition, in absence of any another difference. Discussion. Participants with obesity reported to experience the illusion over a skinny avatar, but the modulation of the bodily experience seems controversial. Future lines of research exploiting this technique for modulating body representations in obesity, specifically in terms of potential therapeutic use, were discussed.

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Use of a real-life practical context changes the relationship between implicit body representations and real body measurements

Scientific Reports ◽

10.1038/s41598-021-93865-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lize De Coster ◽

Pablo Sánchez-Herrero ◽

Jorge López-Moreno ◽

Ana Tajadura-Jiménez

Keyword(s):

Body Size ◽

Real Life ◽

Well Being ◽

The Body ◽

Body Measurements ◽

Size Estimation ◽

Body Representations ◽

Concrete Body ◽

Body Size Estimation ◽

Abstract Condition

AbstractA mismatch exists between people’s mental representations of their own body and their real body measurements, which may impact general well-being and health. We investigated whether this mismatch is reduced when contextualizing body size estimation in a real-life scenario. Using a reverse correlation paradigm, we constructed unbiased, data-driven visual depictions of participants’ implicit body representations. Across three conditions—own abstract, ideal, and own concrete body—participants selected the body that looked most like their own, like the body they would like to have, or like the body they would use for online shopping. In the own concrete condition only, we found a significant correlation between perceived and real hip width, suggesting that the perceived/real body match only exists when body size estimation takes place in a practical context, although the negative correlation indicated inaccurate estimation. Further, participants who underestimated their body size or who had more negative attitudes towards their body weight showed a positive correlation between perceived and real body size in the own abstract condition. Finally, our results indicated that different body areas were implicated in the different conditions. These findings suggest that implicit body representations depend on situational and individual differences, which has clinical and practical implications.

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The link between anxiety and assessment of body attitudes and body size estimation in anorexia nervosa

Journal of Experimental Psychopathology ◽

10.1177/2043808721997632 ◽

2021 ◽

Vol 12 (1) ◽

pp. 204380872199763

Author(s):

Birgit Hasenack ◽

Lot Sternheim ◽

Jojanneke Bijsterbosch ◽

Anouk Keizer

Keyword(s):

Anorexia Nervosa ◽

Body Size ◽

State Anxiety ◽

Body Representation ◽

Size Estimation ◽

Visual Estimation ◽

Estimation Task ◽

Body Attitude ◽

Before And After ◽

Body Size Estimation

Although body size estimation (BSE) tasks are frequently used to investigate distorted body representation in anorexia nervosa (AN), the link between anxiety and task performance has been overlooked. To investigate this, 30 female healthy controls (HCs) and 29 female AN patients completed two body attitude questionnaires and three BSE tasks (the Visual Estimation Task, the Tactile Estimation Task and the Hoop Task). Participants completed two body attitude questionnaires and three BSE tasks; the Visual Estimation Task, the Tactile Estimation Task, and the Hoop Task. The STAI-6 was administered before and after each body-related task to assess state anxiety. Results showed that state anxiety levels increased significantly more in AN patients than in HC after completing each task. Thus, performance of AN patients on BSE and other body-related tasks might not just indicate the (mis)perception of their body but also co-occur with increased state anxiety. This has implications for the interpretation of these tasks and for furthering our understanding of the mechanisms that underlie distorted body image in AN.

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Body-Size Estimation in Anorexia Nervosa

Perceptual and Motor Skills ◽

10.2466/pms.1995.81.1.23 ◽

1995 ◽

Vol 81 (1) ◽

pp. 23-31 ◽

Cited By ~ 29

Author(s):

Enrico Molinari

Keyword(s):

Body Image ◽

Anorexia Nervosa ◽

Body Size ◽

The Body ◽

Control Group ◽

Size Estimation ◽

Image Perception ◽

Pelvic Area ◽

Body Size Estimation ◽

Different Parts

The aim was to explore the body-image perception of a group of 20 hospitalised anorexic patients, aged 18 to 21 years, undergoing a period of treatment. The instrument used was the Askevold nonverbal perception test as modified by Allamani and colleagues in 1978 to assess perception of the dimensions of different parts of the body by exploiting the capacity to project them into space. The four parts were the head, the thoracic area, the abdominal area, and the pelvic area. Analysis of responses indicated that anorexic patients overestimated the abdominal and the pelvic areas much more than the 20 members of the control group (50% vs 30%). The areas of the head and thorax were perceived almost in their real dimensions by the anorexic patients but were underestimated by the control group.

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The influence of bmi and psychological variables in the body size estimation among adult women

Psico ◽

10.15448/1980-8623.2016.3.22086 ◽

2016 ◽

Vol 47 (3) ◽

pp. 179

Author(s):

Gabriela Salim Xavier ◽

Sebastião Sousa Almeida

Keyword(s):

Body Size ◽

The Body ◽

Adult Women ◽

Size Estimation ◽

Psychological Variables ◽

Body Size Estimation

O objetivo desse estudo foi quantificar a estimação da imagem corporal para avaliar as variáveis que a influenciam – Índice de Massa Corporal (IMC), insatisfação com a imagem corporal e sintomas depressivos em mulheres eutróficas (n = 40) e com excesso de peso (n = 40). A avaliação da imagem corporal e dos sintomas depressivos foi conduzida por meio da Escala de Figuras de Silhuetas (EFS) e pelo Inventário de Depressão de Beck (BDI), em suas versões brasileiras, respectivamente. No grupo eutrófico, a insatisfação e a pontuação do BDI explicaram 55% e 12% da variação da estimação, respectivamente. No grupo com excesso de peso, a insatisfação com a imagem corporal foi responsável por 14% da variação da estimação da imagem corporal, enquanto o IMC, individualmente, por somente 9%. Quando avaliados em conjunto, esse percentual aumenta para 42%, indicando que juntos – IMC e insatisfação – agregam maior valor explicativo para essa variável. A insatisfação foi considerada a variável mais saliente, influenciando em maiores proporções os valores de estimação obtidos, particularmente entre as mulheres eutróficas.

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Anorexia Subjective Body Size Estimation Task

PsycTESTS Dataset ◽

10.1037/t28285-000 ◽

2010 ◽

Author(s):

Dewi Guardia ◽

Gilles Lafargue ◽

Pierre Thomas ◽

Vincent Dodin ◽

Olivier Cottencin ◽

...

Keyword(s):

Body Size ◽

Size Estimation ◽

Estimation Task ◽

Body Size Estimation

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Body Image Distortion in Bulimia Nervosa

The British Journal of Psychiatry ◽

10.1192/bjp.147.4.408 ◽

1985 ◽

Vol 147 (4) ◽

pp. 408-412 ◽

Cited By ~ 41

Author(s):

Sandra A. Birtchnell ◽

J. Hubert Lacey ◽

Anne Harte

Keyword(s):

Body Image ◽

Body Size ◽

Previous History ◽

The Body ◽

Size Estimation ◽

Image Perception ◽

Body Width ◽

Duration Of Illness ◽

Body Size Estimation ◽

Visual Size

Body image perception was measured in 50 women with bulima nervosa and 19 age and weight matched female controls, using a visual size estimation apparatus. Both groups overestimated body widths, but not the width of a neutral object, and whilst there was a trend for bulimics to overestimate more than controls this did not reach significance. The part of the body most overestimated corresponded to the part most disliked in only a third of both groups. The bulimics without a previous history of anorexia nervosa overestimated body width more than those with such a history; this may be related to the fact that the former had a significantly greater weight index. Bulimics who were within 5% of mean-matched population weight overestimated body width less than the others, this difference reaching significance when compared with the heavier groups; a similar, but non-significant, trend was demonstrated in controls. This may be linked to a greater dissatisfaction with body size. Duration of illness, frequency of bingeing and self-induced vomiting were not shown significantly to alter body size estimation. The bulimics who completed a 10-session outpatient treatment programme subsequently demonstrated a significant decrease in overestimation of waist and hip width.

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Body Size Estimation in Anorexia Nervosa

The British Journal of Psychiatry ◽

10.1192/s0007125000298942 ◽

1988 ◽

Vol 153 (S2) ◽

pp. 23-26 ◽

Cited By ~ 32

Author(s):

Andrew M. Whitehouse ◽

Christopher P. L. Freeman ◽

Annette Annandale

Keyword(s):

Anorexia Nervosa ◽

Body Size ◽

Body Part ◽

Normal Weight ◽

The Body ◽

Size Perception ◽

Size Estimation ◽

Significant Difference ◽

Body Size Perception ◽

Body Size Estimation

Clinicians who deal with patients with anorexia nervosa are well acquainted with their patients' inability to recognise their emaciation. The patients' insistence that they are normal weight or even overweight, against clear evidence to the contrary, led Bruch (1962) to state that the misperception reaches “delusional proportions”. Studies of body size perception in anorexia nervosa that have used the ‘body part’ method have invariably found that the patients overestimate their body size (Slade & Russell, 1973; Crisp & Kalucy, 1974; Pierloot & Houben, 1978; Garner et al, 1976; Button et al, 1977; Fries, 1977; Casper et al, 1979) but the majority have not found any significant difference in size estimation between patients and controls (Slade, 1985).

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I am the metre: The representation of one’s body size affects the perception of tactile distances on the body

Quarterly Journal of Experimental Psychology ◽

10.1177/17470218211044488 ◽

2021 ◽

pp. 174702182110444

Author(s):

Giorgia Tosi ◽

Angelo Maravita ◽

Daniele Romano

Keyword(s):

Body Size ◽

Mental Representation ◽

Tactile Stimulation ◽

Body Representation ◽

The Body ◽

Different Levels ◽

Specific Impact ◽

Full Body

Humans must ground the perception of one’s body in a mental representation to move in space and interact with objects. This representation can be temporarily altered artificially. In the full-body illusion (FBI), participants see a virtual (or filmed) body receiving a tactile stimulation. When participants receive touches on their body similarly to the seen one (i.e., homologous location and synchronous timing), they embody the seen alien body. While the subjective embodiment of alien bodies of different sizes has been already manipulated with the FBI, it remains unexplored whether the body-metric perception is impacted too. We first developed a new setup for the FBI using 360° videos to favour the embodiment. The FBI was induced for bodies of three sizes adopting anatomical and non-anatomical viewpoints, and we measured the subjective embodiment. The results suggest that humans can embody normal size or bigger bodies seen from anatomical viewpoints, but not smaller ones. We then investigated if the FBI modulates the body-metric representation. We found that the resized bodies’ vision affects the perception of one’s body-metric representation, but this was independent of the embodiment, suggesting that the FBI alters the body representation at different levels with a specific impact.

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