1
|
Oswald F, Samra SK. A scoping review and index of body stimuli in psychological science. Behav Res Methods 2023:10.3758/s13428-023-02278-z. [PMID: 38030921 DOI: 10.3758/s13428-023-02278-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2023] [Indexed: 12/01/2023]
Abstract
Naturalistic body stimuli are necessary for understanding many aspects of human psychology, yet there are no centralized databases of body stimuli. Furthermore, there are a high number of independently developed stimulus sets lacking in standardization and reproducibility potential, and a general lack of organization, contributing to issues of both replicability and generalizability in body-related research. We conducted a comprehensive scoping review to index and explore existing naturalistic whole-body stimuli. Our research questions were as follows: (1) What sets of naturalistic human whole-body stimuli are present in the literature? And (2) On what factors (e.g., demographics, emotion expression) do these stimuli vary? To be included, stimulus sets had to (1) include human bodies as stimuli; (2) be photographs, videos, or other depictions of real human bodies (not computer generated, drawn, etc.); (3) include the whole body (defined as torso, arms, and legs); and (4) could include edited images, but still had to be recognizable as human bodies. We identified a relatively large number of existing stimulus sets (N = 79) which offered relative variability in terms of main manipulated factors and the degree of visual information included (i.e., inclusion of heads and/or faces). However, stimulus sets were demographically homogenous, skewed towards White, young adult, and female bodies. We identified significant issues in reporting and availability practices, posing a challenge to the generalizability, reliability, and reproducibility of body-related research. Accordingly, we urge researchers to adopt transparent and accessible practices and to take steps to diversify body stimuli.
Collapse
Affiliation(s)
- Flora Oswald
- Department of Psychology, The Pennsylvania State University, University Park, PA, USA.
- Department of Women's, Gender, and Sexuality Studies, The Pennsylvania State University, University Park, PA, USA.
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, USA.
- Department of Psychology, University of Denver, Denver, CO, USA.
| | | |
Collapse
|
2
|
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.
Collapse
|
3
|
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.
Collapse
Affiliation(s)
- Sarah D'Amour
- Centre for Vision Research, York University, Toronto, Canada
| | - Deborah Alexe
- Centre for Vision Research, York University, Toronto, Canada
| | | |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Brooks KR, Bell J, Boothroyd LG, Stephen ID. Editorial: Experimental Approaches to Body Image, Representation and Perception. Front Psychol 2021; 12:809385. [PMID: 34950094 PMCID: PMC8688355 DOI: 10.3389/fpsyg.2021.809385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 11/16/2021] [Indexed: 12/03/2022] Open
Affiliation(s)
- Kevin R Brooks
- Body Image and Ingestion Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychological Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.,Perception in Action Research Centre, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Jason Bell
- School of Psychological Science, University of Western Australia, Perth, WA, Australia
| | | | - Ian D Stephen
- Body Image and Ingestion Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychological Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.,School of Social Sciences, Nottingham Trent University, Nottingham, United Kingdom
| |
Collapse
|
6
|
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
| |
Collapse
|
7
|
Thapliyal P, Mitchison D, Mond J, Hay P. Gender and help-seeking for an eating disorder: findings from a general population sample. Eat Weight Disord 2020; 25:215-220. [PMID: 30066257 DOI: 10.1007/s40519-018-0555-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 07/24/2018] [Indexed: 11/26/2022] Open
Abstract
PURPOSE This study aimed to compare gender differences in eating disorder (ED) features and to examine the role of gender as a predictor of ED help-seeking controlling for other putative determinants, namely weight/shape overvaluation, age, BMI, and impairment in role functioning. METHODS Demographic, ED symptoms, and related data were collected during household interviews of individuals aged ≥ 15 years. One hundred and forty-eight participants (164 after data were weighted) with an ED syndrome were identified. RESULTS Compared to women, men with an ED were younger and had lower levels of purging and overvaluation. However, men and women with an ED had similar levels of functional impairment, binge eating and strict dieting. In univariate analyses, males in general, but not males with an ED, were significantly less likely than females to seek help for an ED. In multivariate analysis of people with an ED, only BMI was significantly associated with treatment-seeking. CONCLUSION Functional health impairment and common ED behaviours were similar for men and women with EDs. Gender may not be a primary reason to be more or less likely to seek help for an ED. Rather, other features, most notably, a higher BMI, appear to be stronger predictors of ED-specific help-seeking. LEVEL OF EVIDENCE Level V, cross-sectional descriptive study.
Collapse
Affiliation(s)
- Priyanka Thapliyal
- Translational Health Research Institute (THRI), School of Medicine, Western Sydney University, Sydney, NSW, Australia.
| | - Deborah Mitchison
- Department of Psychology, Centre for Emotional Health, Macquarie University, Sydney, Australia
- School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Jonathan Mond
- School of Medicine, Western Sydney University, Sydney, NSW, Australia
- Centre for Rural Health, School of Health Sciences, Faculty of Health, University of Tasmania, Hobart, Australia
| | - Phillipa Hay
- Translational Health Research Institute (THRI), School of Medicine, Western Sydney University, Sydney, NSW, Australia
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Brooks KR, Mond J, Mitchison D, Stevenson RJ, Challinor KL, Stephen ID. Looking at the Figures: Visual Adaptation as a Mechanism for Body-Size and -Shape Misperception. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2019; 15:133-149. [PMID: 31725353 DOI: 10.1177/1745691619869331] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Many individuals experience body-size and -shape misperception (BSSM). Body-size overestimation is associated with body dissatisfaction, anxiety, depression, and the development of eating disorders in individuals who desire to be thinner. Similar symptoms have been noted for those who underestimate their muscularity. Conversely, individuals with high body mass indices (BMI) who underestimate their adiposity may not recognize the risks of or seek help for obesity-related medical issues. Although social scientists have examined whether media representations of idealized bodies contribute to the overestimation of fat or underestimation of muscle, other scientists suggest that increases in the prevalence of obesity could explain body-fat underestimation as a form of renormalization. However, these disparate approaches have not advanced our understanding of the perceptual underpinnings of BSSM. Recently, a new unifying account of BSSM has emerged that is based on the long-established phenomenon of visual adaptation, employing psychophysical measurements of perceived size and shape following exposure to "extreme" body stimuli. By inducing BSSM in the laboratory as an aftereffect, this technique is rapidly advancing our understanding of the underlying mental representation of human bodies. This nascent approach provides insight into real-world BSSM and may inform the development of therapeutic and public-health interventions designed to address such perceptual errors.
Collapse
Affiliation(s)
- Kevin R Brooks
- Department of Psychology, Macquarie University.,Perception in Action Research Centre, Macquarie University
| | - Jonathan Mond
- Centre for Rural Health, University of Tasmania.,Translational Health Research Institute, School of Medicine, Western Sydney University
| | - Deborah Mitchison
- Department of Psychology, Macquarie University.,Translational Health Research Institute, School of Medicine, Western Sydney University.,Centre for Emotional Health, Department of Psychology, Macquarie University
| | - Richard J Stevenson
- Department of Psychology, Macquarie University.,Perception in Action Research Centre, Macquarie University
| | | | - Ian D Stephen
- Department of Psychology, Macquarie University.,Perception in Action Research Centre, Macquarie University
| |
Collapse
|
10
|
Stephen ID, Hunter K, Sturman D, Mond J, Stevenson RJ, Brooks KR. Experimental manipulation of visual attention affects body size adaptation but not body dissatisfaction. Int J Eat Disord 2018; 52:79-87. [PMID: 30565277 DOI: 10.1002/eat.22976] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/05/2018] [Accepted: 10/05/2018] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Prolonged exposure to large/small bodies causes aftereffects in perceived body size. Outside the laboratory, individuals repeatedly exposed to small (large) bodies tend to over- (under-) estimate their size and exhibit increased (decreased) body dissatisfaction. Why, among individuals exposed to approximately equivalent distributions of body sizes, only some develop body size and shape misperception and/or body dissatisfaction is not yet fully understood. METHOD We exposed 61 women to high and low adiposity bodies simultaneously, instructing half to attend to high, and half to low adiposity bodies. RESULTS Participants in the high adiposity attention condition's perception of "normal" body size significantly increased in adiposity, and vice versa. DISCUSSION This suggests that visual attention moderates body size aftereffects. Interventions encouraging visual attention to more realistic ranges of bodies may therefore reduce body misperception. No change in body dissatisfaction was found, suggesting that changes in the perceptual component (misperception) may not necessarily affect the attitudinal component (dissatisfaction) of body image distortion.
Collapse
Affiliation(s)
- Ian D Stephen
- Department of Psychology, Macquarie University, Sydney, Australia
- Perception in Action Research Centre, Macquarie University, Sydney, Australia
- ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, Australia
| | - Katie Hunter
- Department of Psychology, Macquarie University, Sydney, Australia
| | - Daniel Sturman
- Department of Psychology, Macquarie University, Sydney, Australia
| | - Jonathan Mond
- Centre for Rural Health, University of Tasmania, Launceston, Australia
- Translational Health Research Institute, Western Sydney University, Sydney, Australia
| | - Richard J Stevenson
- Department of Psychology, Macquarie University, Sydney, Australia
- Perception in Action Research Centre, Macquarie University, Sydney, Australia
| | - Kevin R Brooks
- Department of Psychology, Macquarie University, Sydney, Australia
- Perception in Action Research Centre, Macquarie University, Sydney, Australia
- ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, Australia
| |
Collapse
|
11
|
Brooks KR, Clifford CWG, Stevenson RJ, Mond J, Stephen ID. The high-level basis of body adaptation. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172103. [PMID: 30110427 PMCID: PMC6030264 DOI: 10.1098/rsos.172103] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 05/01/2018] [Indexed: 05/08/2023]
Abstract
Prolonged visual exposure, or 'adaptation', to thin (wide) bodies causes a perceptual aftereffect such that subsequently seen bodies appear wider (thinner) than they actually are. Here, we conducted two experiments investigating the effect of rotating the orientation of the test stimuli by 90° from that of the adaptor. Aftereffects were maximal when adapting and test bodies had the same orientation. When they differed, the axis of the perceived distortion changed with the orientation of the body. Experiment 1 demonstrated a 58% transfer of the aftereffect across orientations. Experiment 2 demonstrated an even greater degree of aftereffect transfer when the influence of low-level mechanisms was reduced further by using adaptation and test stimuli with different sizes. These results indicate that the body aftereffect is mediated primarily by high-level object-based processes, with low-level retinotopic mechanisms playing only a minor role. The influence of these low-level processes is further reduced when test stimuli differ in size from adaptation stimuli.
Collapse
Affiliation(s)
- Kevin R. Brooks
- Department of Psychology, Macquarie University, Sydney, New South Wales, Australia
- Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, New South Wales, Australia
- ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, New South Wales, Australia
- Author for correspondence: Kevin R. Brooks e-mail:
| | | | - Richard J. Stevenson
- Department of Psychology, Macquarie University, Sydney, New South Wales, Australia
- Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Jonathan Mond
- Translational Health Research Institute, University of Tasmania, Launceston, Tasmania, Australia
- Centre for Health Research, School of Medicine, Western Sydney 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), Faculty of Human Sciences, Macquarie University, Sydney, New South Wales, Australia
- ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, New South Wales, Australia
| |
Collapse
|
12
|
Visual attention mediates the relationship between body satisfaction and susceptibility to the body size adaptation effect. PLoS One 2018; 13:e0189855. [PMID: 29385137 PMCID: PMC5791942 DOI: 10.1371/journal.pone.0189855] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 12/04/2017] [Indexed: 12/16/2022] Open
Abstract
Body size misperception–the belief that one is larger or smaller than reality–affects a large and growing segment of the population. Recently, studies have shown that exposure to extreme body stimuli results in a shift in the point of subjective normality, suggesting that visual adaptation may be a mechanism by which body size misperception occurs. Yet, despite being exposed to a similar set of bodies, some individuals within a given geographical area will develop body size misperception and others will not. The reason for these individual difference is currently unknown. One possible explanation stems from the observation that women with lower levels of body satisfaction have been found to pay more attention to images of thin bodies. However, while attention has been shown to enhance visual adaptation effects in low (e.g. rotational and linear motion) and high level stimuli (e.g., facial gender), it is not known whether this effect exists in visual adaptation to body size. Here, we test the hypothesis that there is an indirect effect of body satisfaction on the direction and magnitude of the body fat adaptation effect, mediated via visual attention (i.e., selectively attending to images of thin over fat bodies or vice versa). Significant mediation effects were found in both men and women, suggesting that observers’ level of body satisfaction may influence selective visual attention to thin or fat bodies, which in turn influences the magnitude and direction of visual adaptation to body size. This may provide a potential mechanism by which some individuals develop body size misperception–a risk factor for eating disorders, compulsive exercise behaviour and steroid abuse–while others do not.
Collapse
|
13
|
Challinor KL, Mond J, Stephen ID, Mitchison D, Stevenson RJ, Hay P, Brooks KR. Body size and shape misperception and visual adaptation: An overview of an emerging research paradigm. J Int Med Res 2017; 45:2001-2008. [PMID: 29076380 PMCID: PMC5805224 DOI: 10.1177/0300060517726440] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although body size and shape misperception (BSSM) is a common feature of anorexia nervosa, bulimia nervosa
and muscle dysmorphia, little is known about its underlying
neural mechanisms. Recently, a new approach has emerged, based on the long-established
non-invasive technique of perceptual adaptation, which allows for inferences about the
structure of the neural apparatus responsible for alterations in visual appearance. Here,
we describe several recent experimental examples of BSSM, wherein exposure to “extreme”
body stimuli causes visual aftereffects of biased perception. The implications of these
studies for our understanding of the neural and cognitive representation of human bodies,
along with their implications for clinical practice are discussed.
Collapse
Affiliation(s)
- Kirsten L Challinor
- 1 School of Psychology, Australian Catholic University, Sydney, New South Wales, Australia
| | - Jonathan Mond
- 2 Centre for Health Research, School of Medicine, Western Sydney University, Sydney, New South Wales, Australia.,3 Centre for Rural Health, University of Tasmania, Launceston, Tasmania, Australia
| | - Ian D Stephen
- 4 Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,5 ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, New South Wales, Australia.,6 Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Deborah Mitchison
- 4 Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,7 Centre for Emotional Health, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,8 School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
| | - Richard J Stevenson
- 4 Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,6 Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Phillipa Hay
- 8 School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
| | - Kevin R Brooks
- 4 Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.,5 ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, New South Wales, Australia.,6 Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, New South Wales, Australia
| |
Collapse
|
14
|
Abstract
Perceptual body size distortions have traditionally been studied using subjective, qualitative measures that assess only one type of body representation-the conscious body image. Previous research on perceived body size has typically focused on measuring distortions of the entire body and has tended to overlook the face. Here, we present a novel psychophysical method for determining perceived body size that taps into implicit body representation. Using a two-alternative forced choice (2AFC), participants were sequentially shown two life-size images of their own face, viewed upright, upside down, or tilted 90°. In one interval, the width or length dimension was varied, while the other interval contained an undistorted image. Participants reported which image most closely matched their own face. An adaptive staircase adjusted the distorted image to hone in on the image that was equally likely to be judged as matching their perceived face as the accurate image. When viewed upright or upside down, face width was overestimated and length underestimated, whereas perception was accurate for the on-side views. These results provide the first psychophysically robust measurements of how accurately healthy participants perceive the size of their face, revealing distortions of the implicit body representation independent of the conscious body image.
Collapse
Affiliation(s)
- Sarah D’Amour
- Department of Psychology, Centre for Vision Research, York University, Toronto, ON, Canada
| | - Laurence R. Harris
- Department of Psychology, Centre for Vision Research, York University, Toronto, ON, Canada
| |
Collapse
|