Influence of Being Embodied in an Obese Virtual Body on Shopping Behavior and Products Perception in VR

Research in Virtual Reality (VR) showed that embodiment can influence participants' perceptions and behavior when embodied in a different yet plausible virtual body. In this paper, we study the changes an obese virtual body has on products perception (e.g., taste, etc.) and purchase behavior (e.g., number purchased) in an immersive virtual retail store. Participants (of a normal BMI on average) were embodied in a normal (N) or an obese (OB) virtual body and were asked to buy and evaluate food products in the immersive virtual store. Based on stereotypes that are classically associated with obese people, we expected that the group embodied in obese avatars would show a more unhealthy diet, (i.e., buy more food products and also buy more products with high energy intake, or saturated fat) and would rate unhealthy food as being tastier and healthier than participants embodied in “normal weight” avatars. Our participants also rated the perception of their virtual body: the OB group perceived their virtual body as significantly heavier and older. They also rated their sense of embodiment and presence within the immersive virtual store. These measures did not show any significant difference between groups. Finally, we asked them to rate different food products in terms of tastiness, healthiness, sustainability and price. The only difference we noticed is that participants embodied in an obese avatar (OB group) rated the coke as being significantly tastier and the apple as being significantly healthier. Nevertheless, while we hypothesized that participants embodied in a virtual body with obesity would show differences in their shopping patterns (e.g., more “unhealthy” products bought) there were no significant differences between the groups. Stereotype activation failed for our participants embodied in obese avatars, who did not exhibit a shopping behavior following the (negative) stereotypes related to obese people. conversely, while the opposite hypothesis (participants embodied in obese avatars would buy significantly more healthy products in order to “transform” their virtual bodies) could have been made, it was not the case either. We discuss these results and propose hypotheses as to why the behavior of the manipulated group differed from the one we expected. Indeed, unlike previous research, our participants were embodied in virtual avatars which differed greatly from their real bodies. Obese avatars should not only modify users' visual characteristics such as hair or skin color, etc. We hypothesize that an obese virtual body may require some other non-visual stimulus, e.g., the sensation of the extra weight or the change in body size. This main difference could then explain why we did not notice any important modification on participants' behavior and perceptions of food products. We also hypothesize that the absence of stereotype activation and thus of statistical difference between our N and OB groups might be due to higher-level cognitive processes involved while purchasing food products. Indeed our participants might have rejected their virtual bodies when performing the shopping task, while the embodiment and presence ratings did not show significant differences, and purchased products based on their real (non-obese) bodies. This could mean that stereotype activation is more complex that previously thought.

[1]  R. Stevenson,et al.  The Body and the Beautiful: Health, Attractiveness and Body Composition in Men’s and Women’s Bodies , 2016, PloS one.

[2]  Mel Slater,et al.  Virtual Embodiment of White People in a Black Virtual Body Leads to a Sustained Reduction in Their Implicit Racial Bias , 2016, Front. Hum. Neurosci..

[3]  H. Ehrsson,et al.  Moving a Rubber Hand that Feels Like Your Own: A Dissociation of Ownership and Agency , 2012, Front. Hum. Neurosci..

[4]  O. Blanke,et al.  Spatial aspects of bodily self-consciousness , 2009, Consciousness and Cognition.

[5]  Mark Woodward,et al.  Indices of abdominal obesity are better discriminators of cardiovascular risk factors than BMI: a meta-analysis. , 2008, Journal of clinical epidemiology.

[6]  M. Livingstone,et al.  Markers of the validity of reported energy intake. , 2003, The Journal of nutrition.

[7]  T. Metzinger,et al.  Full-body illusions and minimal phenomenal selfhood , 2009, Trends in Cognitive Sciences.

[8]  K. Brownell,et al.  Obesity and public policy. , 2012, Annual review of clinical psychology.

[9]  Chelsea A. Heuer,et al.  Obesity stigma: important considerations for public health. , 2010, American journal of public health.

[10]  Mel Slater,et al.  How to Build an Embodiment Lab: Achieving Body Representation Illusions in Virtual Reality , 2014, Front. Robot. AI.

[11]  H. Ehrsson The Experimental Induction of Out-of-Body Experiences , 2007, Science.

[12]  V. Groom,et al.  The influence of racial embodiment on racial bias in immersive virtual environments , 2009 .

[13]  Pengzhou Li,et al.  From genetics and epigenetics to the future of precision treatment for obesity , 2017, Gastroenterology report.

[14]  Hong Yu Wong,et al.  Owning an Overweight or Underweight Body: Distinguishing the Physical, Experienced and Virtual Body , 2014, PloS one.

[15]  Jorge Peña,et al.  The Priming Effects of Avatars in Virtual Settings , 2009, Commun. Res..

[16]  Sun Joo Grace Ahn,et al.  Self-Endorsing Versus Other-Endorsing in Virtual Environments , 2011 .

[17]  Chelsea A. Heuer,et al.  The Stigma of Obesity: A Review and Update , 2009, Obesity.

[18]  Marc Erich Latoschik,et al.  Avatar anthropomorphism and illusion of body ownership in VR , 2015, 2015 IEEE Virtual Reality (VR).

[19]  Olaf Blanke,et al.  Keeping in Touch with One's Self: Multisensory Mechanisms of Self-Consciousness , 2009, PloS one.

[20]  Yannan Jiang,et al.  Using a 3D Virtual Supermarket to Measure Food Purchase Behavior: A Validation Study , 2015, Journal of medical Internet research.

[21]  Leonard M. Lodish,et al.  Comparing Dynamic Consumer Choice in Real and Computer-simulated Environments , 1992 .

[22]  K. J. Blom,et al.  The Effects of Rotating the Self Out of the Body in the Full Virtual Body Ownership Illusion , 2014, Perception.

[23]  Tian Yu,et al.  Can a virtual supermarket bring realism into the lab? Comparing shopping behavior using virtual and pictorial store representations to behavior in a physical store , 2016, Appetite.

[24]  M. Slater,et al.  Multisensory Stimulation Can Induce an Illusion of Larger Belly Size in Immersive Virtual Reality , 2011, PloS one.

[25]  Mel Slater,et al.  First-Person Perspective Virtual Body Posture Influences Stress: A Virtual Reality Body Ownership Study , 2016, PloS one.

[26]  M. Nieuwdorp,et al.  Evaluating Causality of Gut Microbiota in Obesity and Diabetes in Humans , 2018, Endocrine reviews.

[27]  E. Blaak,et al.  Gender differences in fat metabolism , 2001, Current opinion in clinical nutrition and metabolic care.

[28]  A. Engel,et al.  The Sense of Agency Is More Sensitive to Manipulations of Outcome than Movement-Related Feedback Irrespective of Sensory Modality , 2016, PloS one.

[29]  Mel Slater,et al.  Drumming in Immersive Virtual Reality: The Body Shapes the Way We Play , 2013, IEEE Transactions on Visualization and Computer Graphics.

[30]  C. Nishida Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies , 2004, The Lancet.

[31]  N. Schuurman,et al.  Association of supermarket characteristics with the body mass index of their shoppers , 2013, Nutrition Journal.

[32]  Valeria I. Petkova,et al.  The Perspective Matters! Multisensory Integration in Ego-Centric Reference Frames Determines Full-Body Ownership , 2011, Front. Psychology.

[33]  Ye Yuan,et al.  Is the rubber hand illusion induced by immersive virtual reality? , 2010, 2010 IEEE Virtual Reality Conference (VR).

[34]  Mel Slater,et al.  The Sense of Embodiment in Virtual Reality , 2012, PRESENCE: Teleoperators and Virtual Environments.

[35]  Maria V. Sanchez-Vives,et al.  Extending Body Space in Immersive Virtual Reality: A Very Long Arm Illusion , 2012, PloS one.

[36]  M. Slater,et al.  The building blocks of the full body ownership illusion , 2013, Front. Hum. Neurosci..

[37]  M. Siegrist,et al.  What is healthy food? Objective nutrient profile scores and subjective lay evaluations in comparison , 2015, Appetite.

[38]  Tabitha C. Peck,et al.  Putting yourself in the skin of a black avatar reduces implicit racial bias , 2013, Consciousness and Cognition.

[39]  Jill Anderson,et al.  Keeping in touch. , 2003, Mental health today.

[40]  Dapeng Zhao,et al.  Brief communication: Body mass index, body adiposity index, and percent body fat in Asians. , 2013, American journal of physical anthropology.

[41]  R. Gerber,et al.  Evaluating the Power of Food Scale in obese subjects and a general sample of individuals: development and measurement properties , 2009, International Journal of Obesity.

[42]  John A. List,et al.  What Experimental Protocol Influence Disparities Between Actual and Hypothetical Stated Values? , 2001 .

[43]  M. Slater,et al.  Illusory ownership of a virtual child body causes overestimation of object sizes and implicit attitude changes , 2013, Proceedings of the National Academy of Sciences.

[44]  Mel Slater,et al.  Transcending the Self in Immersive Virtual Reality , 2014, Computer.

[45]  O. Santos,et al.  Association between hedonic hunger and body-mass index versus obesity status , 2018, Scientific Reports.

[46]  J. Bailenson,et al.  The Proteus Effect: The Effect of Transformed Self-Representation on Behavior , 2007 .

[47]  A. Lowenfels A REVIEW AND UPDATE , 1979 .

[48]  G. Antonides,et al.  Consumer segmentation based on food-category attribute importance: The relation with healthiness and sustainability perceptions , 2016, Appetite.

[49]  Samuel E. Jones,et al.  Height, body mass index, and socioeconomic status: mendelian randomisation study in UK Biobank , 2016, British Medical Journal.

[50]  Henry Völzke,et al.  The predictive value of different measures of obesity for incident cardiovascular events and mortality. , 2010, The Journal of clinical endocrinology and metabolism.

[51]  O. Blanke,et al.  Body ownership and embodiment: Vestibular and multisensory mechanisms , 2008, Neurophysiologie Clinique/Clinical Neurophysiology.

[52]  S. Subramanian,et al.  Ecological analysis of secular trends in low birth weight births and adult height in Japan , 2017, Journal of Epidemiology & Community Health.

[53]  M. Butryn,et al.  Hedonic hunger: A new dimension of appetite? , 2007, Physiology & Behavior.

[54]  L. Johnston,et al.  Racial/ethnic and socioeconomic status differences in overweight and health-related behaviors among American students: national trends 1986-2003. , 2006, The Journal of adolescent health : official publication of the Society for Adolescent Medicine.

[55]  P. Haggard,et al.  Having a body versus moving your body: How agency structures body-ownership , 2006, Consciousness and Cognition.

[56]  R. Carels,et al.  Individual differences in food perceptions and calorie estimation: An examination of dieting status, weight, and gender , 2007, Appetite.

[57]  Jean-Luc Dugelay,et al.  Weight estimation from visual body appearance , 2010, 2010 Fourth IEEE International Conference on Biometrics: Theory, Applications and Systems (BTAS).

[58]  C. Crandall Prejudice against fat people: ideology and self-interest. , 1994, Journal of personality and social psychology.

[59]  R. Troiano,et al.  Psychosocial predictors of energy underreporting in a large doubly labeled water study. , 2004, The American journal of clinical nutrition.

[60]  M. McGlone,et al.  The Cowl Makes the Monk: How Avatar Appearance and Role Labels Affect Cognition in Virtual Worlds , 2012 .

[61]  Colin R. Martin,et al.  Caloric estimation of healthy and unhealthy foods in normal-weight, overweight and obese participants. , 2016, Eating behaviors.

[62]  Carol T. Miller,et al.  The ironic effects of weight stigma , 2014 .

[63]  Maria V. Sanchez-Vives,et al.  First Person Experience of Body Transfer in Virtual Reality , 2010, PloS one.

[64]  K. Roininen,et al.  Quantification of Consumer Attitudes to Health and Hedonic Characteristics of Foods , 1999, Appetite.

[65]  R. Sturm,et al.  Obesity and economic environments , 2014, CA: a cancer journal for clinicians.

[66]  J. Sobal Obesity and socioeconomic status: a framework for examining relationships between physical and social variables. , 1991, Medical anthropology.

[67]  M. Kamal,et al.  Role of gut microbiota in obesity, type 2 diabetes and Alzheimer's disease. , 2014, CNS & neurological disorders drug targets.

[68]  W. Hall,et al.  Public Views on Food Addiction and Obesity: Implications for Policy and Treatment , 2013, PloS one.

[69]  L. Mayhew,et al.  Waist-to-Height Ratio Is More Predictive of Years of Life Lost than Body Mass Index , 2014, PloS one.

[70]  Mel Slater,et al.  Depth of Presence in Virtual Environments , 1994, Presence: Teleoperators & Virtual Environments.

[71]  Seung-Chul Yoo,et al.  Virtual shopping and unconscious persuasion: The priming effects of avatar age and consumers' age discrimination on purchasing and prosocial behaviors , 2015, Comput. Hum. Behav..

[72]  S. Riedel-Heller,et al.  Weight-based discrimination: an ubiquitary phenomenon? , 2016, International Journal of Obesity.

[73]  R. Carels,et al.  Qualitative perceptions and caloric estimations of healthy and unhealthy foods by behavioral weight loss participants , 2006, Appetite.

[74]  L. Mossberg,et al.  Consumer immersion: a key to extraordinary experiences , 2013 .

[75]  M. Shimizu,et al.  Comparison of body mass index, waist circumference, and waist-to-height ratio for predicting the clustering of cardiometabolic risk factors by age in Japanese workers--Japan Epidemiology Collaboration on Occupational Health study. , 2014, Circulation journal : official journal of the Japanese Circulation Society.

[76]  Jonathan D. Cohen,et al.  Rubber hands ‘feel’ touch that eyes see , 1998, Nature.