Flexing Muscles in Virtual Reality: Effects of Avatars' Muscular Appearance on Physical Performance

Virtual reality (VR) allows users to embody any possible avatar. Previous work found that the appearance of avatars can change our perception and behavior. Such behavioral changes based on stereotypical assessments are known as the Proteus effect. Exergames involve physical activities of players, however, it is currently unknown if behavioral changes caused by an avatar's appearance can affect players' performance in physically engaging tasks. Therefore, we conducted a study with 30 participants to determine the effect of avatars' muscularity on physical performance and perception of effort. We found that participants in muscular avatars had a lower perceived exertion during an isometric force task. Furthermore, male participants embodying a muscular avatar had a higher grip strength. Results suggest that embodying avatars associated with power and strength can decrease the perception of effort and enhance physical performance. We discuss how body ownership, user identification, and gender moderate avatars' effects.

[1]  Andrey Krekhov,et al.  Beyond Human: Animals as an Escape from Stereotype Avatars in Virtual Reality Games , 2019, CHI PLAY.

[2]  R Jouvent,et al.  Body image perception among men in three countries. , 2000, The American journal of psychiatry.

[3]  M. Avraamides,et al.  Is your virtual self as sensational as your real? Virtual Reality: The effect of body consciousness on the experience of exercise sensations , 2019, Psychology of Sport and Exercise.

[4]  B. Hommel,et al.  Body ownership and response to threat , 2015, Psychological research.

[5]  Gender Difference Regarding Body Image: A Comparative Study , 2016 .

[6]  Lars L. Andersen,et al.  Muscle Activation and Perceived Loading During Rehabilitation Exercises: Comparison of Dumbbells and Elastic Resistance , 2010, Physical Therapy.

[7]  J. Bailenson,et al.  Virtual Superheroes: Using Superpowers in Virtual Reality to Encourage Prosocial Behavior , 2013, PloS one.

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

[9]  Justin M. Harris,et al.  If I Were You: Perceptual Illusion of Body Swapping , 2008, PloS one.

[10]  M. Ernst,et al.  Humans integrate visual and haptic information in a statistically optimal fashion , 2002, Nature.

[11]  Natalie L. Myers,et al.  SUSTAINED ISOMETRIC SHOULDER CONTRACTION ON MUSCULAR STRENGTH AND ENDURANCE: A RANDOMIZED CLINICAL TRIAL. , 2015, International journal of sports physical therapy.

[12]  S Sprigle,et al.  Resistance properties of Thera-Band tubing during shoulder abduction exercise. , 1999, The Journal of orthopaedic and sports physical therapy.

[13]  Younbo Jung,et al.  Wii, Myself, and Size: The Influence of Proteus Effect and Stereotype Threat on Overweight Children's Exercise Motivation and Behavior in Exergames. , 2014, Games for health journal.

[14]  Niels Henze,et al.  Utilizing the Proteus Effect to Improve Interactions using Full-Body Avatars in Virtual Reality , 2019, MuC Workshopband.

[15]  Joan Llobera,et al.  The relationship between virtual body ownership and temperature sensitivity , 2013, Journal of The Royal Society Interface.

[16]  Maria V. Sanchez-Vives,et al.  Virtual Hand Illusion Induced by Visuomotor Correlations , 2010, PloS one.

[17]  Perttu Hämäläinen,et al.  Martial arts in artificial reality , 2005, CHI.

[18]  Mary C. Whitton,et al.  Walking > walking-in-place > flying, in virtual environments , 1999, SIGGRAPH.

[19]  Regan L. Mandryk,et al.  Fostering Intrinsic Motivation through Avatar Identification in Digital Games , 2016, CHI.

[20]  D. Bem.  Self-Perception Theory , 1972 .

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

[22]  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.

[23]  Holger Regenbrecht,et al.  The Experience of Presence: Factor Analytic Insights , 2001, Presence: Teleoperators & Virtual Environments.

[24]  Joan López-Moliner,et al.  quickpsy: An R Package to Fit Psychometric Functions for Multiple Groups , 2016, R J..

[25]  Christof Lutteroth,et al.  Virtual Performance Augmentation in an Immersive Jump & Run Exergame , 2019, CHI.

[26]  Jeremy N. Bailenson,et al.  Experiencing Nature: Embodying Animals in Immersive Virtual Environments Increases Inclusion of Nature in Self and Involvement With Nature , 2016, J. Comput. Mediat. Commun..

[27]  J. Levine,et al.  Energy Expenditure of Sedentary Screen Time Compared With Active Screen Time for Children , 2006, Pediatrics.

[28]  S. Vocks,et al.  Gender Differences in Body Evaluation: Do Men Show More Self-Serving Double Standards Than Women? , 2019, Front. Psychol..

[29]  H E Ross,et al.  Charpentier (1891) on the size—weight illusion , 1999, Perception & psychophysics.

[30]  Robert W. Kentridge,et al.  My body until proven otherwise: Exploring the time course of the full body illusion , 2020, Consciousness and Cognition.

[31]  L. Rowell Huesmann,et al.  Effects of Avatar Race in Violent Video Games on Racial Attitudes and Aggression , 2014 .

[32]  Bradley S. Duerstock,et al.  Developing Rehabilitation Practices Using Virtual Reality Exergaming , 2018, 2018 IEEE International Symposium on Signal Processing and Information Technology (ISSPIT).

[33]  Maria V. Sanchez-Vives,et al.  Towards a Digital Body: The Virtual Arm Illusion , 2008, Frontiers in human neuroscience.

[34]  Ryan E Rhodes,et al.  The health benefits of interactive video game exercise. , 2007, Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme.

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

[36]  Jorge Peña,et al.  I Am What I See: How Avatar and Opponent Agent Body Size Affects Physical Activity Among Men Playing Exergames , 2016, J. Comput. Mediat. Commun..

[37]  Josef Wiemeyer,et al.  Evaluation of mobile applications for fitness training and physical activity in healthy low-trained people - A modular interdisciplinary framework , 2019, Int. J. Comput. Sci. Sport.

[38]  Rachel M. Calogero,et al.  Gender and Body Image , 2010 .

[39]  Kou Murayama,et al.  The competition-performance relation: a meta-analytic review and test of the opposing processes model of competition and performance. , 2012, Psychological bulletin.

[40]  R. Riffenburgh,et al.  Bedside method to estimate actual body weight in the Emergency Department. , 2012, The Journal of emergency medicine.

[41]  T. Hartmann.  The Spatial Presence Experience Scale (spes): a Short Self-report Measure for Diverse Media Settings the Spatial Presence Experience Scale (spes): a Short Self-report Measure for Diverse Media Settings Post-print Version , 2022 .

[42]  G. Borg.  Physical performance and perceived exertion , 1962 .

[43]  Elaine Ewing Fess,et al.  Clinical assessment Recommendations , 1981 .

[44]  Perttu Hämäläinen,et al.  Empowering the Exercise: a Body-Controlled Trampoline Training Game , 2014, Int. J. Comput. Sci. Sport.

[45]  Valentin Schwind,et al.  Touch with foreign hands: the effect of virtual hand appearance on visual-haptic integration , 2018, SAP.

[46]  Robert H. Wozniak.  Classics in Psychology, 1855-1914: Historical Essays , 1998 .

[47]  Malissa Martin,et al.  Grip Strength in Relation to Overall Strength and Functional Capacity in Very Old and Oldest Old Females , 2006 .

[48]  José-Fernán Martínez,et al.  Usage of VR Headsets for Rehabilitation Exergames , 2017, IWBBIO.

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

[50]  Sophia Nimphius,et al.  The Importance of Muscular Strength in Athletic Performance , 2016, Sports Medicine.

[51]  Niels Henze,et al.  Using Presence Questionnaires in Virtual Reality , 2019, CHI.

[52]  Mel Slater,et al.  Body ownership increases the interference between observed and executed movements , 2019, PloS one.

[53]  Sandra L. Calvert,et al.  Adolescent Exergame Play for Weight Loss and Psychosocial Improvement: A Controlled Physical Activity Intervention , 2012, Obesity.

[54]  Samuele M. Marcora,et al.  Psychobiology of Perceived Effort During Physical Tasks , 2012 .

[55]  J. Firrell,et al.  Which setting of the dynamometer provides maximal grip strength? , 1996, The Journal of hand surgery.

[56]  Konrad Paul Kording,et al.  Over my fake body: body ownership illusions for studying the multisensory basis of own-body perception , 2015, Front. Hum. Neurosci..

[57]  H. Potts,et al.  Younger Adolescents’ Perceptions of Physical Activity, Exergaming, and Virtual Reality: Qualitative Intervention Development Study , 2019, JMIR serious games.

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

[59]  R. Robertson,et al.  Just noticeable difference in perception of physical exertion during cycle exercise in young adult men and women , 2013, European Journal of Applied Physiology.

[60]  C. Spence,et al.  Neuroscience and Biobehavioral Reviews , 2022 .

[61]  Kristen Harrison,et al.  Television Viewers' Ideal Body Proportions: The Case of the Curvaceously Thin Woman , 2003 .

[62]  B. Fernhall,et al.  Evaluation of the Energy Cost of Playing a Dance Simulation Video Game in Overweight and Non-Overweight Children and Adolescents , 2005, International journal of sports medicine.

[63]  Jeremy N. Bailenson,et al.  The Proteus Effect , 2009, Commun. Res..

[64]  Ju Lu,et al.  Can using exergames improve physical fitness? A 12-week randomized controlled trial , 2017, Comput. Hum. Behav..

[65]  G. Gescheider.  Psychophysics: The Fundamentals , 1997 .

[66]  Kenneth Knoblauch,et al.  Modeling Psychophysical Data in R , 2012 .

[67]  Renée A. Botta,et al.  For Your Health? The Relationship Between Magazine Reading and Adolescents' Body Image and Eating Disturbances , 2003 .

[68]  Marc Erich Latoschik,et al.  The Impact of Avatar Personalization and Immersion on Virtual Body Ownership, Presence, and Emotional Response , 2018, IEEE Transactions on Visualization and Computer Graphics.

[69]  G. Borg.  Psychophysical scaling with applications in physical work and the perception of exertion. , 1990, Scandinavian journal of work, environment & health.

[70]  J. J. Higgins,et al.  The aligned rank transform for nonparametric factorial analyses using only anova procedures , 2011, CHI.

[71]  Christof Lutteroth,et al.  Me vs. Super(wo)man: Effects of Customization and Identification in a VR Exergame , 2020, CHI.

[72]  K. Chua,et al.  Aerobic Demands of the Dance Simulation Game , 2002, International journal of sports medicine.

[73]  G. Borg.  Psychophysical bases of perceived exertion. , 1982, Medicine and science in sports and exercise.

[74]  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..

[75]  Mel Slater,et al.  Conversations between self and self as Sigmund Freud—A virtual body ownership paradigm for self counselling , 2015, Scientific Reports.

[76]  Paul Coulton,et al.  Mobile exergaming , 2008, ACE '08.

[77]  Maria V. Sanchez-Vives,et al.  Inducing Illusory Ownership of a Virtual Body , 2009, Front. Neurosci..

[78]  Christof Lutteroth,et al.  Interactive Feedforward for Improving Performance and Maintaining Intrinsic Motivation in VR Exergaming , 2018, CHI.

[79]  T. Takken,et al.  Is grip strength a predictor for total muscle strength in healthy children, adolescents, and young adults? , 2010, European Journal of Pediatrics.

[80]  B. Pageaux.  The Psychobiological Model of Endurance Performance: An Effort-Based Decision-Making Theory to Explain Self-Paced Endurance Performance , 2014, Sports Medicine.

[81]  Benjamin Pageaux,et al.  Perception of effort in Exercise Science: Definition, measurement and perspectives , 2016, European journal of sport science.

[82]  D. Delignières,et al.  Self-perception of fitness and personality traits. , 1994, Perceptual and motor skills.

[83]  G. R. Leon,et al.  Three to Four Year Prospective Evaluation of Personality and Behavioral Risk Factors for Later Disordered Eating in Adolescent Girls and Boys , 1999 .

[84]  Jorge Peña,et al.  Increasing exergame physical activity through self and opponent avatar appearance , 2014, Comput. Hum. Behav..

[85]  A. L. Baylor.  Promoting motivation with virtual agents and avatars: role of visual presence and appearance , 2009, Philosophical Transactions of the Royal Society B: Biological Sciences.

[86]  René Reinhard,et al.  Acting your avatar’s age: effects of virtual reality avatar embodiment on real life walking speed , 2019, Media Psychology.

[87]  Avan Aihie Sayer,et al.  A review of the measurement of grip strength in clinical and epidemiological studies: towards a standardised approach. , 2011, Age and ageing.

[88]  Benjamin J. Li,et al.  Avatar characteristics induce users’ behavioral conformity with small-to-medium effect sizes: a meta-analysis of the proteus effect , 2019, Media Psychology.

[89]  Christoph Klimmt,et al.  A Process Model of the Formation of Spatial Presence Experiences , 2007 .

[90]  Stephen Yang,et al.  Healthy Video Gaming: Oxymoron or Possibility? , 2008 .

[91]  Yvonne de Kort,et al.  Virtual Fitness: Stimulating Exercise Behavior through Media Technology , 2006, PRESENCE: Teleoperators and Virtual Environments.

[92]  Tabitha C. Peck,et al.  A threat to a virtual hand elicits motor cortex activation , 2014, Experimental Brain Research.

[93]  Kazumichi Matsumiya,et al.  Separate multisensory integration processes for ownership and localization of body parts , 2019, Scientific Reports.

[94]  Philipp Brauner,et al.  Increase Physical Fitness and Create Health Awareness through Exergames and Gamification - The Role of Individual Factors, Motivation and Acceptance , 2013, SouthCHI.

[95]  M. Snyder.  On the Self-Fulfilling Nature of Social Stereotypes. , 1977 .

[96]  Mel Slater,et al.  Virtually Being Einstein Results in an Improvement in Cognitive Task Performance and a Decrease in Age Bias , 2018, Front. Psychol..

[97]  Béatrice S. Hasler,et al.  Virtual race transformation reverses racial in-group bias , 2017, PloS one.

[98]  Samuele M. Marcora.  Can Doping be a Good Thing? Using Psychoactive Drugs to Facilitate Physical Activity Behaviour , 2015, Sports Medicine.

[99]  David I. Anderson,et al.  Weight Discrimination Using an Upper-Extremity Prosthesis , 2002 .

[100]  JungYounbo,et al.  Wii, Myself, and Size: The Influence of Proteus Effect and Stereotype Threat on Overweight Children's Exercise Motivation and Behavior in Exergames. , 2014 .

[101]  M. Slater,et al.  Measuring the Effects through Time of the Influence of Visuomotor and Visuotactile Synchronous Stimulation on a Virtual Body Ownership Illusion , 2014, Perception.