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Myga KA, Azañón E, Ambroziak KB, Ferrè ER, Longo MR. Haptic experience of bodies alters body perception. Perception 2024; 53:716-729. [PMID: 39324272 DOI: 10.1177/03010066241270627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2024]
Abstract
Research on media's effects on body perception has mainly focused on the role of vision of extreme body types. However, haptics is a major part of the way children experience bodies. Playing with unrealistically thin dolls has been linked to the emergence of body image concerns, but the perceptual mechanisms remain unknown. We explore the effects of haptic experience of extreme body types on body perception, using adaptation aftereffects. Blindfolded participants judged whether the doll-like stimuli explored haptically were thinner or fatter than the average body before and after adaptation to an underweight or overweight doll. In a second experiment, participants underwent a traditional visual adaptation paradigm to extreme bodies, using stimuli matched to those in Experiment 1. For both modalities, after adaptation to an underweight body test bodies were judged as fatter. Adaptation to an overweight body produced opposite results. For the first time, we show adiposity aftereffects in haptic modality, analogous to those established in vision, using matched stimuli across visual and haptic paradigms.
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Affiliation(s)
- Kasia A Myga
- Department of Psychological Sciences, Birkbeck, University of London, London, UK; Department of Neurology, Otto-Von-Guericke University, Magdeburg, Germany; Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Elena Azañón
- Department of Neurology, Otto-Von-Guericke University, Magdeburg, Germany; Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; Center for Intervention and Research on Adaptive and Maladaptive Brain Circuits Underlying Mental Health (C-I-R-C), Jena-Magdeburg-Halle, Germany
| | | | | | - Matthew R Longo
- Department of Psychological Sciences, Birkbeck, University of London, London, UK
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2
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House T, Stephen ID, Brooks KR, Bould H, Attwood AS, Penton-Voak IS. The effect of an odd-one-out visual search task on attentional bias, body size adaptation, and body dissatisfaction. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231817. [PMID: 39021772 PMCID: PMC11252673 DOI: 10.1098/rsos.231817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 05/20/2024] [Indexed: 07/20/2024]
Abstract
Body image disturbance is a both a risk factor for, and a symptom of, many eating disorders and refers to the misperception of and dissatisfaction with one's own body. Women with high body dissatisfaction have been shown to direct more attention to low body mass index (BMI) bodies, which results in the overestimation of body size via body size adaptation. Therefore, attention may have a causal role in body image disturbance. We conducted a novel training visual search task with 142 young adult women who we trained to attend to either high or low BMI bodies. We assessed the effects of this training on attention to bodies of different sizes, body size adaptation, and body dissatisfaction. Women trained to attend to low BMI bodies decreased their perceptions of a 'normal' body size via adaptation from pre- to post-training (p < 0.001); however, women trained to attend to high BMI bodies showed no change in their perception of a 'normal' body size. We found no lasting effects of the training on attention to body size or body dissatisfaction; however, our visual search task showed poor internal consistency as a measure of attention. These findings indicate that attention to low BMI bodies may exacerbate body image disturbance in women. However, more reliable measures of attentional are required to confirm this finding.
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Affiliation(s)
- T. House
- School of Psychological Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- School of Psychological Science, University of Bristol, Bristol BS8 1QU, UK
| | - I. D. Stephen
- Department of Psychology, Bournemouth University, Bournemouth, UK
| | - K. R. Brooks
- School of Psychological Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- Perception in Action Research Centre (PARC), Macquarie University, Sydney, New South Wales 2109, Australia
- Lifespan Health & Wellbeing Research Centre, Macquarie University, Sydney, New South Wales 2109, Australia
| | - H. Bould
- Centre for Academic Mental Health, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol BS8 1QU, UK
- Gloucestershire Health and Care NHS Foundation Trust, Centre for Academic Mental Health, University of Bristol, Bristol BS8 1QU, UK
- MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol, Bristol BS8 1QU, UK
| | - A. S. Attwood
- School of Psychological Science, University of Bristol, Bristol BS8 1QU, UK
- MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol, Bristol BS8 1QU, UK
- National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, Bristol, UK
| | - I. S. Penton-Voak
- School of Psychological Science, University of Bristol, Bristol BS8 1QU, UK
- National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, Bristol, UK
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3
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Ip K, Kusyk N, Stephen ID, Brooks KR. Did you skip leg day? The neural mechanisms of muscle perception for body parts. Cortex 2024; 171:75-89. [PMID: 37980724 DOI: 10.1016/j.cortex.2023.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/18/2023] [Accepted: 10/02/2023] [Indexed: 11/21/2023]
Abstract
While the neural mechanisms underpinning the perception of muscularity are poorly understood, recent progress has been made using the psychophysical technique of visual adaptation. Prolonged visual exposure to high (low) muscularity bodies causes subsequently viewed bodies to appear less (more) muscular, revealing a recalibration of the neural populations encoding muscularity. Here, we use visual adaptation to further elucidate the tuning properties of the neural processes underpinning muscle perception for the upper and lower halves of the body. Participants manipulated the apparent muscularity of upper and lower bodies until they appeared 'normal', prior to and following exposure to a series of top/bottom halves of bodies that were either high or low in muscularity. In Experiment 1, participants were adapted to isolated own-gender body halves from one of four conditions; increased (muscularity) upper (body half), increased lower, decreased upper, or decreased lower. Despite the presence of muscle aftereffects when the body halves the participants viewed and manipulated were congruent, there was only weak evidence of muscle aftereffect transfer between the upper and lower halves of the body. Aftereffects were significantly weaker when body halves were incongruent, implying minimal overlap in the neural mechanisms encoding muscularity for body half. Experiment 2 examined the generalisability of Experiment 1's findings in a more ecologically valid context using whole-body stimuli, producing a similar pattern of results as Experiment 1, but with no evidence of cross-adaptation. Taken together, the findings are most consistent with muscle-encoding neural populations that are body-half selective. As visual adaptation has been implicated in cases of body size and shape misperception, the present study furthers our current understanding of how these perceptual inaccuracies, particularly those involving muscularity, are developed, maintained, and may potentially be treated.
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Affiliation(s)
- Keefe Ip
- School of Psychological Sciences, Macquarie University, Sydney, NSW, Australia.
| | - Nicole Kusyk
- School of Psychological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ian D Stephen
- NTU Psychology, Nottingham Trent University, Nottingham, England, UK
| | - Kevin R Brooks
- School of Psychological Sciences, Macquarie University, Sydney, NSW, Australia; Perception and Action Research Centre (PARC), Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia; Lifespan Health & Wellbeing Research Centre, Macquarie University, Sydney, NSW, Australia
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4
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Chazelle T, Guerraz M, Palluel-Germain R. Mirror exposure following visual body-size adaptation does not affect own body image. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221589. [PMID: 37593706 PMCID: PMC10427814 DOI: 10.1098/rsos.221589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 07/24/2023] [Indexed: 08/19/2023]
Abstract
Prolonged visual exposure to large bodies produces a thinning aftereffect on subsequently seen bodies, and vice versa. This visual adaptation effect could contribute to the link between media exposure and body shape misperception. Indeed, people exposed to thin bodies in the media, who experience fattening aftereffects, may internalize the distorted image of their body they see in the mirror. This preregistered study tested this internalization hypothesis by exposing 196 young women to an obese adaptor before showing them their reflection in the mirror, or to a control condition. Then, we used a psychophysical task to measure the effects of this procedure on perceptual judgements about their own body size, relative to another body and to the control mirror exposure condition. We found moderate evidence against the hypothesized self-specific effects of mirror exposure on perceptual judgements. Our work strengthens the idea that body size adaptation affects the perception of test stimuli rather than the participants' own body image. We discuss recent studies which may provide an alternative framework to study media-related distortions of perceptual body image.
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Affiliation(s)
- Thomas Chazelle
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, LPNC, 38000 Grenoble, France
| | - Michel Guerraz
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, LPNC, 38000 Grenoble, France
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5
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Perception of the non-dominant hand as larger after non-judgmental focus on its details. Sci Rep 2022; 12:15670. [PMID: 36123432 PMCID: PMC9485221 DOI: 10.1038/s41598-022-19919-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 09/06/2022] [Indexed: 11/08/2022] Open
Abstract
We investigated whether brief non-judgmental focus on the details of one's non-dominant hand might lead to changes in perception of its size, and if such a change would be related to central coherence, body dissatisfaction, or how much participants liked their hand. After two pilot experiments (N = 28 and N = 30 respectively: Appendix 1), a within-subject experiment (N = 82) was conducted. Subjects were mainly university students. They were asked to rate the size of their non-dominant hand and how much they liked it, and the size of an external object (a X-box controller) on a visual-analog scale before and after focusing on their details for 5 min, as well as the size of another object (a calculator) before and after a 5 min long distraction task. After completing the tasks, they were asked to respond to a brief questionnaire on body dissatisfaction. A s significant interaction between time and factors (non-dominant hand, X-box controller and calculator) emerged (F(2, 78) = 6.41, p = .003). Participants rated their hand as larger after focusing on its details compared to baseline, and this change was significantly larger than those reported for the X-box controller. No significant change in how they liked their hand was observed, and contrary to the pilot experiments, the perceived change in size of the hand was not related to body dissatisfaction. The significant change in reporting of the size of the hand after focusing on its details seems to be an interesting finding, worth further replications.
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6
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Devine S, Germain N, Ehrlich S, Eppinger B. Changes in the Prevalence of Thin Bodies Bias Young Women's Judgments About Body Size. Psychol Sci 2022; 33:1212-1225. [PMID: 35802627 DOI: 10.1177/09567976221082941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Body dissatisfaction is pervasive among young women in Western countries. Among the many forces that contribute to body dissatisfaction, the overrepresentation of thin bodies in visual media has received notable attention. In this study, we proposed that prevalence-induced concept change may be one of the cognitive mechanisms that explain how beauty standards shift. We conducted a preregistered online experiment with young women (N = 419) and found that when the prevalence of thin bodies in the environment increased, the concept of being overweight expanded to include bodies that would otherwise be judged as "normal." Exploratory analyses revealed significant individual differences in sensitivity to this effect, in terms of women's judgments about other bodies as well as their own. These results suggest that women's judgments about other women's bodies are biased by an overrepresentation of thinness and lend initial support to policies designed to increase size-inclusive representation in the media.
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Affiliation(s)
| | - Nathalie Germain
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval
| | - Stefan Ehrlich
- Division of Psychological and Social Medicine and Developmental Neurosciences, Faculty of Medicine, Technische Universität Dresden
| | - Ben Eppinger
- Faculty of Psychology, Technische Universität Dresden.,PERFORM Centre, Concordia University.,Department of Psychology, University of Greifswald.,Department of Psychology, Concordia University
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7
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D'Argenio G, Finisguerra A, Urgesi C. Experience-dependent reshaping of body gender perception. PSYCHOLOGICAL RESEARCH 2022; 86:1184-1202. [PMID: 34387745 PMCID: PMC9090903 DOI: 10.1007/s00426-021-01569-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 07/25/2021] [Indexed: 11/29/2022]
Abstract
Protracted exposure to specific stimuli causes biased visual aftereffects at both low- and high-level dimensions of a stimulus. Recently, it has been proposed that alterations of these aftereffects could play a role in body misperceptions. However, since previous studies have mainly addressed manipulations of body size, the relative contribution of low-level retinotopic and/or high-level object-based mechanisms is yet to be understood. In three experiments, we investigated visual aftereffects for body-gender perception, testing for the tuning of visual aftereffects across different characters and orientation. We found that exposure to a distinctively female (or male) body makes androgynous bodies appear as more masculine (or feminine) and that these aftereffects were not specific for the individual characteristics of the adapting body (Exp.1). Furthermore, exposure to only upright bodies (Exp.2) biased the perception of upright, but not of inverted bodies, while exposure to both upright and inverted bodies (Exp.3) biased perception for both. Finally, participants' sensitivity to body aftereffects was lower in individuals with greater communication deficits and deeper internalization of a male gender role. Overall, our data reveals the orientation-, but not identity-tuning of body-gender aftereffects and points to the association between alterations of the malleability of body gender perception and social deficits.
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Affiliation(s)
- Giulia D'Argenio
- Department of Life Sciences, University of Trieste, Trieste, Italy. giulia.d'
- Laboratory of Cognitive Neuroscience, Department of Languages and Literatures, Communication, Education and Society, University of Udine, via Margreth, 3, 33100, Udine, Italy. giulia.d'
| | | | - Cosimo Urgesi
- Laboratory of Cognitive Neuroscience, Department of Languages and Literatures, Communication, Education and Society, University of Udine, via Margreth, 3, 33100, Udine, Italy.
- Scientific Institute, IRCCS E. Medea, Pasian di Prato, Udine, Italy.
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8
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D'Amour S, Alexe D, Harris LR. Changes in the perceived size of the body following exposure to distorted self-body images. ROYAL SOCIETY OPEN SCIENCE 2022; 9:210722. [PMID: 35462776 PMCID: PMC9019518 DOI: 10.1098/rsos.210722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Inaccurate perceptions, such as under- or over-estimation of body size are often found in clinical eating disorder populations but have recently been shown also in healthy people. However, it is not yet clear how body size perception may be affected when the internal body representation is manipulated. In this study, visual adaptation was used to investigate whether exposure to distorted visual feedback alters the representation of body size and how long any such effects might last. Participants were exposed for five minutes to a distorted life-size image of themselves that was either 20% wider or 20% narrower than their normal size. Accuracy was measured using our novel psychophysical method that taps into the implicit body representation. The accuracy of the representation was assessed at 6, 12 and 18 min following exposure to adaptation. Altered visual feedback caused changes in participants' judgements of their body size: adapting to a wider body resulted in size overestimation whereas underestimations occurred after adapting to a narrower body. These distortions lasted throughout testing and did not fully return back to normal within 18 min. The results are discussed in terms of the emerging literature indicating that the internal representation of the body is dynamic and flexible.
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Affiliation(s)
- Sarah D'Amour
- Centre for Vision Research, York University, Toronto, Canada
| | - Deborah Alexe
- Centre for Vision Research, York University, Toronto, Canada
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9
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House T, Stephen ID, Penton-Voak IS, Brooks KR. The effect of attention on body size adaptation and body dissatisfaction. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211718. [PMID: 35223063 PMCID: PMC8864361 DOI: 10.1098/rsos.211718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/31/2022] [Indexed: 05/03/2023]
Abstract
Attentional bias to low-fat bodies is thought to be associated with body dissatisfaction-a symptom and risk factor of eating disorders. However, the causal nature of this relationship is unclear. In three preregistered experiments, we trained 370 women to attend towards either high- or low-fat body stimuli using an attention training dot probe task. For each experiment, we analysed the effect of the attention training on (i) attention to subsequently presented high- versus low-fat body stimuli, (ii) visual adaptation to body size, and (iii) body dissatisfaction. The attention training had no effect on attention towards high- or low-fat bodies in an online setting (Experiment 1), but did increase attention to high-fat bodies in a laboratory setting (Experiment 2). Neither perceptions of a 'normal' body size nor levels of body dissatisfaction changed as a result of the attention training in either setting. The results in the online setting did not change when we reduced the stimulus onset-asynchrony of the dot probe task from 500 to 100 ms (Experiment 3). Our results provide no evidence that the dot probe training task used here has robust effects on attention to body size, body image disturbance or body dissatisfaction.
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Affiliation(s)
- T. House
- School of Psychological Science, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
- Department of Psychology, University of Bristol, Bristol, UK
| | - I. D. Stephen
- Department of Psychology, Nottingham Trent University, Nottingham, UK
| | - I. S. Penton-Voak
- Department of Psychology, University of Bristol, Bristol, UK
- National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, UK
| | - K. R. Brooks
- School of Psychological Science, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
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10
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Abstract
Many who suffer from eating disorders claim that they see themselves as "fat". Despite decades of research into the phenomenon, behavioural evidence has failed to confirm that eating disorders involve visual misperception of own-body size. I illustrate the importance of this phenomenon for our understanding of perceptual processing, outline the challenges involved in experimentally confirming it, and provide solutions to those challenges.
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Affiliation(s)
- Stephen Gadsby
- Department of Philosophy, 445418University of Antwerp, Antwerp, Belgium
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11
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Brooks KR, Stevenson RJ, Stephen ID. Over or Under? Mental Representations and the Paradox of Body Size Estimation. Front Psychol 2021; 12:706313. [PMID: 34413814 PMCID: PMC8369339 DOI: 10.3389/fpsyg.2021.706313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/30/2021] [Indexed: 12/20/2022] Open
Affiliation(s)
- Kevin R Brooks
- Body Image & Ingestion Group (BIIG), Faculty of Medicine, Health & Human Sciences, School of Psychological Sciences, Macquarie University, Sydney, NSW, Australia.,Perception in Action Research Centre (PARC), Faculty of Medicine, Health & Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Richard J Stevenson
- Body Image & Ingestion Group (BIIG), Faculty of Medicine, Health & Human Sciences, School of Psychological Sciences, Macquarie University, Sydney, NSW, Australia.,Perception in Action Research Centre (PARC), Faculty of Medicine, Health & Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ian D Stephen
- Body Image & Ingestion Group (BIIG), Faculty of Medicine, Health & Human Sciences, School of Psychological Sciences, Macquarie University, Sydney, NSW, Australia.,Perception in Action Research Centre (PARC), Faculty of Medicine, Health & Human Sciences, Macquarie University, Sydney, NSW, Australia
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12
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Meneguzzo P, Collantoni E, Bonello E, Vergine M, Behrens SC, Tenconi E, Favaro A. The role of sexual orientation in the relationships between body perception, body weight dissatisfaction, physical comparison, and eating psychopathology in the cisgender population. Eat Weight Disord 2021; 26:1985-2000. [PMID: 33090374 PMCID: PMC8292238 DOI: 10.1007/s40519-020-01047-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 10/05/2020] [Indexed: 12/30/2022] Open
Abstract
PURPOSE Body weight dissatisfaction (BWD) and visual body perception are specific aspects that can influence the own body image, and that can concur with the development or the maintenance of specific psychopathological dimensions of different psychiatric disorders. The sexual orientation is a fundamental but understudied aspect in this field, and, for this reason, the purpose of this study is to improve knowledge about the relationships among BWD, visual body size-perception, and sexual orientation. METHODS A total of 1033 individuals participated in an online survey. Physical comparison, depression, and self-esteem was evaluated, as well as sexual orientation and the presence of an eating disorder. A Figure Rating Scale was used to assess different valences of body weight, and mediation analyses were performed to investigated specific relationships between psychological aspects. RESULTS Bisexual women and gay men reported significantly higher BWD than other groups (p < 0.001); instead, higher body misperception was present in gay men (p = 0.001). Physical appearance comparison mediated the effect of sexual orientation in both BWD and perceptual distortion. No difference emerged between women with a history of eating disorders and without, as regards the value of body weight attributed to attractiveness, health, and presence on social media. CONCLUSION This study contributes to understanding the relationship between sexual orientations and body image representation and evaluation. Physical appearance comparisons should be considered as critical psychological factors that can improve and affect well-being. The impact on subjects with high levels of eating concerns is also discussed. LEVEL OF EVIDENCE Level III: case-control analytic study.
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Affiliation(s)
- Paolo Meneguzzo
- Department of Neuroscience, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
| | - Enrico Collantoni
- Department of Neuroscience, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
| | - Elisa Bonello
- Department of Neuroscience, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
| | - Mariantonietta Vergine
- Department of Neuroscience, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
| | - Simone C. Behrens
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
- Department of Perceiving Systems, Max Planck Institute for Intelligent Systems, Tübingen, Germany
| | - Elena Tenconi
- Department of Neuroscience, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
- Padova Neuroscience Center, University of Padova, Padova, Italy
| | - Angela Favaro
- Department of Neuroscience, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
- Padova Neuroscience Center, University of Padova, Padova, Italy
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13
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Zopf R, Kosourikhina V, Brooks KR, Polito V, Stephen ID. Visual body-size adaptation and estimation of tactile distance. Br J Psychol 2021; 112:1012-1027. [PMID: 34120340 DOI: 10.1111/bjop.12514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 04/28/2021] [Indexed: 02/06/2023]
Abstract
Estimating the size of bodies is crucial for interactions with physical and social environments. Body-size perception is malleable and can be altered using visual adaptation paradigms. However, it is unclear whether such visual adaptation effects also transfer to other modalities and influence, for example, the perception of tactile distances. In this study, we employed a visual adaptation paradigm. Participants were exposed to images of expanded or contracted versions of self- or other-identity bodies. Before and after this adaptation, they were asked to manipulate the width of body stimuli to appear as 'normal' as possible. We replicated an effect of visual adaptation such that the body-size selected as most 'normal' was larger after exposure to expanded and thinner after exposure to contracted adaptation stimuli. In contrast, we did not find evidence that this adaptation effect transfers to distance estimates for paired tactile stimuli delivered to the abdomen. A Bayesian analysis showed that our data provide moderate evidence that there is no effect of visual body-size adaptation on the estimation of spatial parameters in a tactile task. This suggests that visual body-size adaptation effects do not transfer to somatosensory body-size representations.
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Affiliation(s)
- Regine Zopf
- Department of Cognitive Science, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia.,Perception in Action Research Centre, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia.,Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia
| | - Veronika Kosourikhina
- Department of Psychology, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Kevin R Brooks
- Perception in Action Research Centre, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia.,Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,Department of Psychology, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Vince Polito
- Department of Cognitive Science, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia.,Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia
| | - Ian D Stephen
- Perception in Action Research Centre, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia.,Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,Department of Psychology, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, New South Wales, Australia
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14
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Chan AWY, Noles DL, Utkov N, Akbilgic O, Smith W. Misalignment between perceptual boundaries and weight categories reflects a new normal for body size perception. Sci Rep 2021; 11:10442. [PMID: 34001935 PMCID: PMC8129102 DOI: 10.1038/s41598-021-89533-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/20/2021] [Indexed: 12/14/2022] Open
Abstract
Combatting the current global epidemic of obesity requires that people have a realistic understanding of what a healthy body size looks like. This is a particular issue in different population sub-groups, where there may be increased susceptibility to obesity-related diseases. Prior research has been unable to systematically assess body size judgement due to a lack of attention to gender and race; our study aimed to identify the contribution of these factors. Using a data-driven multi-variate decision tree approach, we varied the gender and race of image stimuli used, and included the same diversity among participants. We adopted a condition-rich categorization visual task and presented participants with 120 unique body images. We show that gender and weight categories of the stimuli affect accuracy of body size perception. The decision pattern reveals biases for male bodies, in which participants showed an increasing number of errors from leaner to bigger bodies, particularly under-estimation errors. Participants consistently mis-categorized overweight male bodies as normal weight, while accurately categorizing normal weight. Overweight male bodies are now perceived as part of an expanded normal: the perceptual boundary of normal weight has become wider than the recognized BMI category. For female bodies, another intriguing pattern emerged, in which participants consistently mis-categorized underweight bodies as normal, whilst still accurately categorizing normal female bodies. Underweight female bodies are now in an expanded normal, in opposite direction to that of males. Furthermore, an impact of race type and gender of participants was also observed. Our results demonstrate that perceptual weight categorization is multi-dimensional, such that categorization decisions can be driven by ultiple factors.
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Affiliation(s)
- Annie W Y Chan
- Division of Psychology, Department of Life Sciences, Centre for Cognitive Neuroscience, Brunel University London, Gaskell Building, Room 219, Uxbridge, UB8 3PH, UK.
| | - Danielle L Noles
- School of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Nathan Utkov
- Department of Bioinformatics, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Oguz Akbilgic
- Department of Health Informatics and Data Science, Parkinson School of Health Informatics and Public Health, Loyola University Chicago, Maywood, IL, USA
| | - Webb Smith
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, USA
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15
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Is a 'culture of plus-size women' the independent effect of neighborhood disadvantage on female BMI? A cross-sectional study in two Chilean Municipalities. Soc Sci Med 2021; 280:114019. [PMID: 34052702 DOI: 10.1016/j.socscimed.2021.114019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 01/03/2021] [Accepted: 05/06/2021] [Indexed: 11/22/2022]
Abstract
Research has shown that neighborhood disadvantage has an effect on BMI that is independent of individual disadvantage, much more pronounced in women than in men. The mechanisms that explain this gender-specific effect are not yet clear. Since women's body size dissatisfaction is closely linked to gender differences in BMI inequalities, the independent effect of neighborhood disadvantage on female BMI may relate to a local culture of acceptance of female large bodies, that could influence women's parameters for body size dissatisfaction. This study explored how the relation between female BMI, neighborhood income, individual income and education is influenced by body size dissatisfaction in a random sample of 882 women aged 20-60 that reside in two Chilean Municipalities. Data have a two level structure (women nested in 17 neighborhoods); it was collected by direct survey, height and weight were measured with portable instruments. Disadvantaged neighborhoods house mainly poor and low educated women, whereas the wealthier ones were inhabited mostly by affluent women with postsecondary education. The proportion of women without a husband/partner and with more than three children in disadvantaged neighborhoods was higher than better off areas. Multilevel linear regression showed that neighborhood disadvantage had an effect on female BMI that was independent of women's income and education, which was explained by body size dissatisfaction. The mean BMI for body size satisfaction among women in disadvantaged neighborhoods was 2 kg/m2 higher than in affluent areas, which suggests that a 'culture of plus-size women' would emerge in urban clusters of poverty. The findings signal that neighborhood effects on BMI would relate to the socioeconomic polarization of urban areas, with marked concentrations of poverty and wealth, and might be explained by the psychosocial pathways associated to social disadvantage that act in addition to the effects of material conditions to influence people's health.
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16
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Smith MP. Self-estimated BMI, but not self-perceived body size, accurately identifies unhealthy weight in US adults. BMC Public Health 2021; 21:253. [PMID: 33516202 PMCID: PMC7847588 DOI: 10.1186/s12889-021-10316-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 01/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Self-perceptions of health and disease can be a major driver of health behaviors. Improving accuracy of self-ascertainment of obesity may prompt uptake of weight-control behaviors in those with obesity. METHODS We assess performance of self-perceived body size ('too small', 'about right' or 'too large'), self-estimated BMI in kg/m2, and sociodemographics in detecting measured BMI category (under-, normal-, overweight and obese; BMI cutpoints 18.5, 25 and 30) in first bivariate and then multivariable models. RESULTS Of 37,281 adults in the US from NHANES, 2, 34, 33 and 32% were under-, normal-, overweight and obese. Respectively 56, 73, 60 and 91% self-perceived as 'too small', 'about right', 'too large' and 'too large.' Of those who self-perceived as 'too small', 22% were underweight and 10% were overweight or obese. 99.7% of obese participants self-estimated a BMI in the overweight/obese range, including many who did not self-perceive as 'too large'. Among obese participants, self-perception as either 'about right' or 'too small' was more likely for those who were younger (OR for perception as 'too large' 1.01 per year, 95% confidence interval 1.00-1.01) male (OR 0.33, (0.28-0.39)) nonwhite (ORs 0.36-0.79 for different ethnicities), low-income (ORs 0.61 and 1.8 for the lowest and highest of six categories, vs. the third) or measured recently (OR 0.98 (0.96-1.0) per year since 1999). Misperception was less common, but still existed, for participants with moderate or severe obesity (ORs 2.9 (2.3-3.5) and 7.9 (5.4-12), vs. 'mild.') (all p < 0.01.) CONCLUSIONS: A tenth of adults in the US with obesity, especially those from overweight peer groups, self-perceive as normal or underweight and thus may not be motivated to control their weight. However, virtually all self-estimate an overweight or obese BMI. If measured BMI is not available, self-estimates are sufficiently accurate that interventions may rely on it to identify obesity.
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Affiliation(s)
- Maia Phillips Smith
- St. George's University School of Medicine, PO Box 7, True Blue, West Indies, Grenada.
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17
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Brooks KR, Keen E, Sturman D, Mond J, Stevenson RJ, Stephen ID. Muscle and fat aftereffects and the role of gender: Implications for body image disturbance. Br J Psychol 2019; 111:742-761. [PMID: 31880827 DOI: 10.1111/bjop.12439] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 11/19/2019] [Indexed: 11/29/2022]
Abstract
Body image disturbance - a cause of distress amongst the general population and those diagnosed with various disorders - is often attributed to the media's unrealistic depiction of ideal bodies. These ideals are strongly gendered, leading to pronounced fat concern amongst females, and a male preoccupation with muscularity. Recent research suggests that visual aftereffects may be fundamental to the misperception of body fat and muscle mass - the perceptual component of body image disturbance. This study sought to establish the influence of gender on these body aftereffects. Male and female observers were randomly assigned to one of four adaptation conditions (low-fat, high-fat, low-muscle, and high-muscle bodies) and were asked to adjust the apparent fat and muscle levels of male and female bodies to make them appear as 'normal' as possible both before adaptation and after adaptation. While neither the gender of observers nor of body stimuli had a direct effect, aftereffect magnitude was significantly larger when observers viewed own-gender (compared with other-gender) stimuli. This effect, which may be due to attentional factors, could have implications for the development of body image disturbance, given the preponderance of idealized own-gender bodies in media marketed to male and female consumers.
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Affiliation(s)
- Kevin R Brooks
- Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,Perception in Action Research Centre (PARC), Macquarie University, Sydney, New South Wales, Australia.,Body Image and Ingestion Group (BIIG), Macquarie University, Sydney, New South Wales, Australia
| | - Edwina Keen
- Department of Psychology, Macquarie University, Sydney, New South Wales, Australia
| | - Daniel Sturman
- Department of Psychology, Macquarie University, Sydney, New South Wales, Australia
| | - Jonathan Mond
- Centre for Rural Health, University of Tasmania, Hobart, Tasmania, Australia.,Translational Health Research Institute, School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
| | - Richard J Stevenson
- Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,Perception in Action Research Centre (PARC), Macquarie University, Sydney, New South Wales, Australia.,Body Image and Ingestion Group (BIIG), Macquarie University, Sydney, New South Wales, Australia
| | - Ian D Stephen
- Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,Perception in Action Research Centre (PARC), Macquarie University, Sydney, New South Wales, Australia.,Body Image and Ingestion Group (BIIG), Macquarie University, Sydney, New South Wales, Australia
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18
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Brooks KR, Baldry E, Mond J, Stevenson RJ, Mitchison D, Stephen ID. Gender and the Body Size Aftereffect: Implications for Neural Processing. Front Neurosci 2019; 13:1100. [PMID: 31680834 PMCID: PMC6813220 DOI: 10.3389/fnins.2019.01100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 09/30/2019] [Indexed: 12/18/2022] Open
Abstract
Prolonged exposure to wide (thin) bodies causes a perceptual aftereffect such that subsequently viewed bodies appear thinner (wider) than they actually are. This phenomenon is known as visual adaptation. We used the adaptation paradigm to examine the gender selectivity of the neural mechanisms encoding body size and shape. Observers adjusted female and male test bodies to appear normal-sized both before and after adaptation to bodies digitally altered to appear heavier or lighter. In Experiment 1, observers adapted simultaneously to bodies of each gender distorted in opposite directions, e.g., thin females and wide males. The direction of resultant aftereffects was contingent on the gender of the test stimulus, such that in this example female test bodies appeared wider while male test bodies appeared thinner. This indicates at least some separation of the neural mechanisms processing body size and shape for the two genders. In Experiment 2, adaptation involved either wide females, thin females, wide males or thin males. Aftereffects were present in all conditions, but were stronger when test and adaptation genders were congruent, suggesting some overlap in the tuning of gender-selective neural mechanisms. Given that visual adaptation has been implicated in real-world examples of body size and shape misperception (e.g., in anorexia nervosa or obesity), these results may have implications for the development of body image therapies based on the adaptation model.
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Affiliation(s)
- Kevin R. Brooks
- Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, NSW, Australia
- Perception in Action Research Centre, Faculty of Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Evelyn Baldry
- Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, NSW, Australia
| | - Jonathan Mond
- Centre for Rural Health, University of Tasmania, Launceston, TAS, Australia
- Translational Health Research Institute, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Richard J. Stevenson
- Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, NSW, Australia
- Perception in Action Research Centre, Faculty of Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Deborah Mitchison
- Translational Health Research Institute, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Ian D. Stephen
- Body Image and Ingestion Group, Department of Psychology, Macquarie University, Sydney, NSW, Australia
- Perception in Action Research Centre, Faculty of Human Sciences, Macquarie University, Sydney, NSW, Australia
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