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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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2
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Bratch A, Chen Y, Engel SA, Kersten DJ. Visual adaptation selective for individual limbs reveals hierarchical human body representation. J Vis 2021; 21:18. [PMID: 34007989 PMCID: PMC8142707 DOI: 10.1167/jov.21.5.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/24/2021] [Indexed: 11/24/2022] Open
Abstract
The spatial relationships between body parts are a rich source of information for person perception, with even simple pairs of parts providing highly valuable information. Computation of these relationships would benefit from a hierarchical representation, where body parts are represented individually. We hypothesized that the human visual system makes use of such representations. To test this hypothesis, we used adaptation to determine whether observers were sensitive to changes in the length of one body part relative to another. Observers viewed forearm/upper arm pairs where the forearm had been either lengthened or shortened, judging the perceived length of the forearm. Observers then adapted to a variety of different stimuli (e.g., arms, objects, etc.) in different orientations and visual field locations. We found that following adaptation to distorted limbs, but not non-limb objects, observers experienced a shift in perceived forearm length. Furthermore, this effect partially transferred across different orientations and visual field locations. Taken together, these results suggest the effect arises in high level mechanisms specialized for specific body parts, providing evidence for a representation of bodies based on parts and their relationships.
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Affiliation(s)
- Alexander Bratch
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Yixiong Chen
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Stephen A Engel
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Daniel J Kersten
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
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3
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Verfaillie K, Daems A. Flexible Orientation Tuning of Visual Representations of Human Body Postures: Evidence From Long-Term Priming. Front Psychol 2020; 11:393. [PMID: 32210896 PMCID: PMC7076911 DOI: 10.3389/fpsyg.2020.00393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/20/2020] [Indexed: 11/13/2022] Open
Abstract
The proficiency of human observers to identify body postures is examined in three experiments. We use a posture decision task in which participants are primed with either anatomically possible or impossible postures (in the latter case the upper and lower body face in opposite directions). In a long-term priming paradigm (i.e., in an initial priming block of trials and a subsequent test phase several minutes later), we manipulate the relation between priming and test postures with respect to the identity of the person in the body postures (Experiment 1), the prototypicality of the depth orientations (Experiment 2), and the variability of the priming orientations (Experiment 3). Reaction time to the test postures is the main dependent variable. In Experiment 1 it is found that priming of postures does not depend on the exact visual appearance of the actor (either same priming and test female or male figure or different figures), supporting the hypothesis that posture priming primarily is determined by the spatial relations between the body parts and much less by characteristics of the person involved. Long-term priming in our paradigm apparently is based on the reactivation of high-level posture representations that make abstraction of the identity of the human figure. In Experiment 2 we observe that privileged or prototypical orientations (e.g., 3/4 views) do not affect long-term priming of body postures. In Experiment 3, we find that increasing or decreasing the variability between the priming and test figures influences reaction time performance. Collectively, these results provide a better understanding of the flexibility (e.g., invariant to identity) and limits (e.g., depending on depth orientation) of the processes supporting human posture recognition.
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Affiliation(s)
- Karl Verfaillie
- Laboratory of Experimental Psychology, Brain and Cognition, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
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Integrating faces and bodies: Psychological and neural perspectives on whole person perception. Neurosci Biobehav Rev 2020; 112:472-486. [PMID: 32088346 DOI: 10.1016/j.neubiorev.2020.02.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/19/2019] [Accepted: 02/15/2020] [Indexed: 11/20/2022]
Abstract
The human "person" is a common percept we encounter. Research on person perception has been focused either on face or body perception-with less attention paid to whole person perception. We review psychological and neuroscience studies aimed at understanding how face and body processing operate in concert to support intact person perception. We address this question considering: a.) the task to be accomplished (identification, emotion processing, detection), b.) the neural stage of processing (early/late visual mechanisms), and c.) the relevant brain regions for face/body/person processing. From the psychological perspective, we conclude that the integration of faces and bodies is mediated by the goal of the processing (e.g., emotion analysis, identification, etc.). From the neural perspective, we propose a hierarchical functional neural architecture of face-body integration that retains a degree of separation between the dorsal and ventral visual streams. We argue for two centers of integration: a ventral semantic integration hub that is the result of progressive, posterior-to-anterior, face-body integration; and a social agent integration hub in the dorsal stream STS.
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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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Sturman D, Stephen ID, Mond J, Stevenson RJ, Brooks KR. Independent Aftereffects of Fat and Muscle: Implications for neural encoding, body space representation, and body image disturbance. Sci Rep 2017; 7:40392. [PMID: 28071712 PMCID: PMC5223140 DOI: 10.1038/srep40392] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 12/06/2016] [Indexed: 02/07/2023] Open
Abstract
Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the “ideal” images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown. Further, most studies focus on body size per se even though this depends on both fat and muscle mass – variables that have very different relationships with health. We tested visual adaptation as a mechanism for inducing body fat and muscle mass misperception, and assessed whether these two dimensions of body space are processed independently. Observers manipulated the apparent fat and muscle mass of bodies to make them appear “normal” before and after inspecting images from one of four adaptation conditions (increased fat/decreased fat/increased muscle/decreased muscle). Exposure resulted in a shift in the point of subjective normality in the direction of the adapting images along the relevant (fat or muscle) axis, suggesting that the neural mechanisms involved in body fat and muscle perception are independent. This supports the viability of adaptation as a model of real-world body size misperception, and extends its applicability to clinical manifestations of body image disturbance that entail not only preoccupation with thinness (e.g., anorexia nervosa) but also with muscularity (e.g., muscle dysmorphia).
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Affiliation(s)
- Daniel Sturman
- Department of Psychology, Macquarie University, Sydney, Australia
| | - Ian D Stephen
- Department of Psychology, Macquarie University, Sydney, Australia.,ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, Australia.,Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, Australia
| | - Jonathan Mond
- Centre for Health Research, School of Medicine, Western Sydney University, Sydney Australia.,Centre for Rural Health, University of Tasmania, Launceston Tasmania
| | - Richard J Stevenson
- Department of Psychology, Macquarie University, Sydney, Australia.,Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, Australia
| | - Kevin R Brooks
- Department of Psychology, Macquarie University, Sydney, Australia.,Perception in Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University, Sydney, Australia
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Marinoiu E, Papava D, Sminchisescu C. Pictorial Human Spaces: A Computational Study on the Human Perception of 3D Articulated Poses. Int J Comput Vis 2016. [DOI: 10.1007/s11263-016-0888-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Mohr HM, Rickmeyer C, Hummel D, Ernst M, Grabhorn R. Altered Visual Adaptation to Body Shape in Eating Disorders: Implications for Body Image Distortion. Perception 2016; 45:725-38. [PMID: 26921409 DOI: 10.1177/0301006616633385] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Previous research has shown that after adapting to a thin body, healthy participants (HP) perceive pictures of their own bodies as being fatter and vice versa. This aftereffect might contribute to the development of perceptual body image disturbances in eating disorders (ED).In the present study, HP and ED completed a behavioral experiment to rate manipulated pictures of their own bodies after adaptation to thin or fat body pictures. After adapting to a thin body, HP judged a thinner than actual body picture to be the most realistic and vice versa, resembling a typical aftereffect. ED only showed such an adaptation effect when they adapted to fat body pictures.The reported results indicate a relationship between body image distortion in ED and visual body image adaptation. It can be suspected that due to a pre-existing, long-lasting adaptation to thin body shapes in ED, an additional visual adaption to thin body shapes cannot be induced. Hence this pre-existing adaptation to thin body shapes could induce perceptual body image distortions in ED.
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Affiliation(s)
- Harald M Mohr
- Department of Psychiatry, Psychosomatics and Psychotherapy, Goethe University Hospital, Frankfurt, Germany
| | - Constanze Rickmeyer
- Department of Psychiatry, Psychosomatics and Psychotherapy, Goethe University Hospital, Frankfurt, Germany; Sigmund-Freud-Institut, Frankfurt, Hessen, Germany
| | - Dennis Hummel
- Department of Neurocognitive Psychology, Institute of Psychology, Goethe University of Frankfurt, Frankfurt, Germany
| | | | - Ralph Grabhorn
- Department of Psychiatry, Psychosomatics and Psychotherapy, Goethe University Hospital, Frankfurt, Germany
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