1
|
Multisensory integration of visual cues from first- to third-person perspective avatars in the perception of self-motion. Atten Percept Psychophys 2021; 83:2634-2655. [PMID: 33864205 DOI: 10.3758/s13414-021-02276-3] [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] [Accepted: 02/05/2021] [Indexed: 11/08/2022]
Abstract
In the perception of self-motion, visual cues originating from an embodied humanoid avatar seen from a first-person perspective (1st-PP) are processed in the same way as those originating from a person's own body. Here, we sought to determine whether the user's and avatar's bodies in virtual reality have to be colocalized for this visual integration. In Experiment 1, participants saw a whole-body avatar in a virtual mirror facing them. The mirror perspective could be supplemented with a fully visible 1st-PP avatar or a suggested one (with the arms hidden by a virtual board). In Experiment 2, the avatar was viewed from the mirror perspective or a third-person perspective (3rd-PP) rotated 90° left or right. During an initial embodiment phase in both experiments, the avatar's forearms faithfully reproduced the participant's real movements. Next, kinaesthetic illusions were induced on the static right arm from the vision of passive displacements of the avatar's arms enhanced by passive displacement of the participant's left arm. Results showed that this manipulation elicited kinaesthetic illusions regardless of the avatar's perspective in Experiments 1 and 2. However, illusions were more likely to occur when the mirror perspective was supplemented with the view of the 1st-PP avatar's body than with the mirror perspective only (Experiment 1), just as they are more likely to occur in the latter condition than with the 3rd-PP (Experiment 2). Our results show that colocalization of the user's and avatar's bodies is an important, but not essential, factor in visual integration for self-motion perception.
Collapse
|
2
|
|
3
|
Longo MR, Holmes M. Distorted perceptual face maps. Acta Psychol (Amst) 2020; 208:103128. [PMID: 32585432 DOI: 10.1016/j.actpsy.2020.103128] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 06/17/2020] [Accepted: 06/17/2020] [Indexed: 11/15/2022] Open
Abstract
Recent research has shown that proprioception relies on distorted representations of body size and shape. By asking participants to localise multiple landmarks in space, perceptual body maps can be constructed. Such maps of the hand and forearm is highly distorted, with large overestimation of limb width compared to length. Here, we investigated perceptual maps of the face, a body part central to our sense of self and personal identity. Participants localised 19 facial landmarks by pointing on a board covering their face. By comparing the relative location of judgments, we constructed perceptual face maps and compared them to actual face structure. These maps were massively distorted, with large overestimation of face width, but not length. This shows that distortions in perceptual body maps are not unique to the hand, but widespread on the body, including parts like the face at the core of our personal identity.
Collapse
Affiliation(s)
- Matthew R Longo
- Department of Psychological Sciences, Birkbeck, University of London, United Kingdom.
| | - Marie Holmes
- Department of Psychological Sciences, Birkbeck, University of London, United Kingdom
| |
Collapse
|
4
|
Lou L. Size Inflation in Drawing From Mirror and Proportional Accuracy in Observational Drawing. Perception 2020; 49:749-770. [PMID: 32567503 DOI: 10.1177/0301006620933147] [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]
Abstract
In three experiments, a bias to inflate in drawing the proportion of an image on a mirror over the mirror itself is demonstrated in a sample (N = 146) of undergraduate students taking introductory psychology classes. The inflation is not confined to the image of one's own head but is likely to occur in depictions of any object from a mirror with the mirror frame included. Having to include in the drawing background objects visible in the mirror is found to reduce the inflation. The inflation also diminishes with a smaller mirror and at a longer viewing distance. An account for the inflation in terms of a mechanism of size constancy contingent on selective attention is offered. The size of the inflation suggests a conflation of the perceived mirror image size with the size of the distal object it signals rather than a complete take-over by the latter. The reduction of the size inflation when participants are asked draw both a target and background objects is more likely a result of the selective attention to proportional relationships in the mirror scene, rather than a manifestation of an evenly scaled visual space under distributed visual spatial attention. The implications of the findings to improving proportional accuracy in observational drawing are discussed.
Collapse
Affiliation(s)
- Leon Lou
- Department of Psychology, Grand Valley State University, Michigan, United States
| |
Collapse
|
5
|
Sex differences in perceptual hand maps: A meta-analysis. Acta Psychol (Amst) 2019; 196:1-10. [PMID: 30933684 DOI: 10.1016/j.actpsy.2019.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/08/2019] [Accepted: 03/07/2019] [Indexed: 02/08/2023] Open
Abstract
A large body of research has suggested that localisation of the hand in external space relies on distorted representations of the hand. We developed a paradigm for measuring implicit perceptual maps of the hand (Longo & Haggard, 2010, Proc Natl Acad Sci USA, 107, 11727-11732), which show systematic deviation from actual hand shape, including overestimation of hand width and underestimation of finger length. Recently, Coelho and Gonzalez (in press, Psychol Res) reported sex differences in these perceptual hand maps, with women showing greater overestimation of hand width, but less underestimation of finger length than men. In the current study, I conducted a meta-analysis of 19 experiments using this paradigm by myself and my colleagues. The results replicated the sex differences reported by Coelho and Gonzalez. Importantly, however, these sex differences were not apparent when actual hand size was included as a covariate in analyses, suggesting that they may, at least in part, be due to women having smaller hands on average than men.
Collapse
|
6
|
Tamè L, Azañón E, Longo MR. A Conceptual Model of Tactile Processing across Body Features of Size, Shape, Side, and Spatial Location. Front Psychol 2019; 10:291. [PMID: 30863333 PMCID: PMC6399380 DOI: 10.3389/fpsyg.2019.00291] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/29/2019] [Indexed: 11/30/2022] Open
Abstract
The processing of touch depends of multiple factors, such as the properties of the skin and type of receptors stimulated, as well as features related to the actual configuration and shape of the body itself. A large body of research has focused on the effect that the nature of the stimuli has on tactile processing. Less research, however, has focused on features beyond the nature of the touch. In this review, we focus on some features related to the body that have been investigated for less time and in a more fragmented way. These include the symmetrical quality of the two sides of the body, the postural configuration of the body, as well as the size and shape of different body parts. We will describe what we consider three key aspects: (1) how and at which stages tactile information is integrated between different parts and sides of the body; (2) how tactile signals are integrated with online and stored postural configurations of the body, regarded as priors; (3) and how tactile signals are integrated with representations of body size and shape. Here, we describe how these different body dimensions affect integration of tactile information as well as guide motor behavior by integrating them in a single model of tactile processing. We review a wide range of neuropsychological, neuroimaging, and neurophysiological data and suggest a revised model of tactile integration on the basis of the one proposed previously by Longo et al.
Collapse
Affiliation(s)
- Luigi Tamè
- Department of Psychological Sciences, Birkbeck University of London, London, United Kingdom.,School of Psychology, University of Kent, Canterbury, United Kingdom
| | - Elena Azañón
- Institute of Psychology, Otto von Guericke University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Matthew R Longo
- Department of Psychological Sciences, Birkbeck University of London, London, United Kingdom
| |
Collapse
|
7
|
My true face: Unmasking one's own face representation. Acta Psychol (Amst) 2018; 191:63-68. [PMID: 30219412 DOI: 10.1016/j.actpsy.2018.08.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/14/2018] [Accepted: 08/27/2018] [Indexed: 11/23/2022] Open
Abstract
Face recognition has been the focus of multiple studies, but little is still known on how we represent the structure of one's own face. Most of the studies have focused on the topic of visual and haptic face recognition, but the metric representation of different features of one's own face is relatively unknown. We investigated the metric representation of the face in young adults by developing a proprioceptive pointing task to locate face landmarks in the first-person perspective. Our data revealed a large overestimation of width for all face features which resembles, in part, the size in somatosensory cortical representation. In contrast, face length was compartmentalised in two different regions: upper (underestimated) and bottom (overestimated); indicating size differences possibly due to functionality. We also identified shifts of the location judgments, with all face areas perceived closer to the body than they really were, due to a potential influence of the self-frame of reference. More importantly, the representation of the face appeared asymmetrical, with an overrepresentation of right side of the face, due to the influence of lateralization biases for strong right-handers. We suggest that these effects may be due to functionality influences and experience that affect the construction of face structural representation, going beyond the parallel of the somatosensory homunculus.
Collapse
|
8
|
Thaler A, Geuss MN, Mohler BJ. The Role of Visual Information in Body Size Estimation. Iperception 2018; 9:2041669518796853. [PMID: 30202510 PMCID: PMC6128079 DOI: 10.1177/2041669518796853] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 08/06/2018] [Indexed: 11/16/2022] Open
Abstract
The conscious representation of our physical appearance is important for many aspects of everyday life. Here, we asked whether different visual experiences of our bodies influence body width estimates. In Experiment 1, width estimates of three body parts (foot, hips, and shoulders) without any visual access were compared to estimates with visual feedback available in a mirror or from a first-person perspective. In the no visual access and mirror condition, participants additionally estimated their head width. There was no influence of viewing condition on body part width estimates. Consistent with previous research, all body part widths were overestimated with greater overestimation of hip and head width. In Experiment 2, participants estimated the size of unfamiliar noncorporeal objects to test whether this overestimation was partially due to the metric body size estimation method or our experimental conditions. Object width was overestimated with visual feedback in a mirror available as compared to when directly looking at the object, but only for objects placed at shoulder and head height. We conclude that at least some of the overestimation of body part width seems to be body specific and occurs regardless of the visual information provided about the own body.
Collapse
Affiliation(s)
- Anne Thaler
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Michael N. Geuss
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Betty J. Mohler
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| |
Collapse
|
9
|
O'Sullivan N, de Bezenac C, Piovesan A, Cutler H, Corcoran R, Fenyvesi D, Bertamini M. I Am There … but Not Quite: An Unfaithful Mirror That Reduces Feelings of Ownership and Agency. Perception 2017; 47:197-215. [PMID: 29161965 DOI: 10.1177/0301006617743392] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The experience of seeing one's own face in a mirror is a common experience in daily life. Visual feedback from a mirror is linked to a sense of identity. We developed a procedure that allowed individuals to watch their own face, as in a normal mirror, or with specific distortions (lag) for active movement or passive touch. By distorting visual feedback while the face is being observed on a screen, we document an illusion of reduced embodiment. Participants made mouth movements, while their forehead was touched with a pen. Visual feedback was either synchronous (simultaneous) with reality, as in a mirror, or asynchronous (delayed). Asynchronous feedback was exclusive to touch or movement in different conditions and incorporated both in a third condition. Following stimulation, participants rated their perception of the face in the mirror, and perception of their own face, on questions that tapped into agency and ownership. Results showed that perceptions of both agency and ownership were affected by asynchrony. Effects related to agency, in particular, were moderated by individual differences in depersonalisation and auditory hallucination-proneness, variables with theoretical links to embodiment. The illusion presents a new way of investigating the extent to which body representations are malleable.
Collapse
Affiliation(s)
- Noreen O'Sullivan
- Department of Psychological Sciences, Institute of Psychology Health and Society, University of Liverpool, Liverpool, UK
| | - Christophe de Bezenac
- Department of Psychological Sciences, Institute of Psychology Health and Society, University of Liverpool, Liverpool, UK
| | - Andrea Piovesan
- Department of Psychological Sciences, Institute of Psychology Health and Society, University of Liverpool, Liverpool, UK
| | - Hannah Cutler
- Department of Psychological Sciences, Institute of Psychology Health and Society, University of Liverpool, Liverpool, UK
| | - Rhiannon Corcoran
- Department of Psychological Sciences, Institute of Psychology Health and Society, University of Liverpool, Liverpool, UK
| | - David Fenyvesi
- Department of Psychological Sciences, Institute of Psychology Health and Society, University of Liverpool, Liverpool, UK
| | - Marco Bertamini
- Department of Psychological Sciences, Institute of Psychology Health and Society, University of Liverpool, Liverpool, UK
| |
Collapse
|
10
|
Differences between predictions of how a reflection behaves based on the behaviour of an object, and how an object behaves based on the behaviour of its reflection. Acta Psychol (Amst) 2015; 161:54-63. [PMID: 26322914 DOI: 10.1016/j.actpsy.2015.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 08/17/2015] [Accepted: 08/20/2015] [Indexed: 10/23/2022] Open
Abstract
We studied adults' understanding of the relationship between objects and their reflections. Two studies investigated whether adults performed in a similar way when asked to predict the movement of a reflection in a flat mirror based on the movement of the corresponding object or, vice versa, predict the movement of the material object based on the movement of its reflection. We used simple movements in the experiments: movements in a straight line at various angles with respect to the mirror. Despite the simplicity of the task, some of the participants made incorrect predictions in a percentage of cases ranging from 0% to 54%, depending on the angle. Asymmetries between the two directions of prediction emerged, in particular in terms of types of error. Results confirmed a cognitive difference between deriving the reflected (virtual) world from the "real" (material) world and vice versa. In particular the expectation that something will be opposite in a mirror is more salient when people imagine how a reflection will be with respect to the material world rather than when they imagine how the material world will be with respect to a reflection.
Collapse
|
11
|
Jenkinson PM, Preston C. New reflections on agency and body ownership: The moving rubber hand illusion in the mirror. Conscious Cogn 2015; 33:432-42. [PMID: 25792444 DOI: 10.1016/j.concog.2015.02.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 02/25/2015] [Accepted: 02/28/2015] [Indexed: 10/23/2022]
Abstract
No previous study has simultaneously examined body ownership and agency in healthy subjects during mirror self-observation. We used a moving rubber hand illusion to examine how both body ownership and agency are affected by seeing (i) the body moving in a mirror, compared with (ii) directly viewing the moving hand, and (iii) seeing a visually identical hand rotated by 180°. We elicited ownership of the hand using direct visual feedback, finding this effect was further enhanced when looking at the hand in a mirror, whereas rotating the hand 180° abolished ownership. Agency was similarly elicited using direct visual feedback, and equally so in the mirror, but again reduced for the 180° hand. We conclude that the reflected body in a mirror is treated as 'special' in the mind, and distinct from other external objects. This enables bodies and actions viewed in a mirror to be directly related to the self.
Collapse
Affiliation(s)
- Paul M Jenkinson
- Department of Psychology, University of Hertfordshire, Hatfield, Hertfordshire, UK.
| | | |
Collapse
|
12
|
Does my face FIT?: a face image task reveals structure and distortions of facial feature representation. PLoS One 2013; 8:e76805. [PMID: 24130790 PMCID: PMC3793930 DOI: 10.1371/journal.pone.0076805] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 09/03/2013] [Indexed: 11/19/2022] Open
Abstract
Despite extensive research on face perception, few studies have investigated individuals' knowledge about the physical features of their own face. In this study, 50 participants indicated the location of key features of their own face, relative to an anchor point corresponding to the tip of the nose, and the results were compared to the true location of the same individual's features from a standardised photograph. Horizontal and vertical errors were analysed separately. An overall bias to underestimate vertical distances revealed a distorted face representation, with reduced face height. Factor analyses were used to identify separable subconfigurations of facial features with correlated localisation errors. Independent representations of upper and lower facial features emerged from the data pattern. The major source of variation across individuals was in representation of face shape, with a spectrum from tall/thin to short/wide representation. Visual identification of one's own face is excellent, and facial features are routinely used for establishing personal identity. However, our results show that spatial knowledge of one's own face is remarkably poor, suggesting that face representation may not contribute strongly to self-awareness.
Collapse
|
13
|
My face through the looking-glass: The effect of mirror reversal on reflection size estimation. Conscious Cogn 2011; 20:1452-9. [DOI: 10.1016/j.concog.2011.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 05/31/2011] [Accepted: 06/02/2011] [Indexed: 11/22/2022]
|
14
|
Cordovil R, Barreiros J. Adults' perception of children's height and reaching capability. Acta Psychol (Amst) 2010; 135:24-9. [PMID: 20472225 DOI: 10.1016/j.actpsy.2010.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 04/15/2010] [Accepted: 04/19/2010] [Indexed: 11/29/2022] Open
Abstract
This study investigated the influence of some characteristics of the task, the model, and the observer, in the estimation errors of adults while judging children's affordances. One hundred and eighteen adults, divided in 4 height groups, estimated height and vertical reaching capability of 3 girls (3.55-, 4.74- and 7.06-years old), in the presence and in the absence of the model. Constant errors (CE) (estimation-real value), absolute percent errors (APE) (/1--estimation/real value/ x 100), and error tendency (underestimations, right judgments, or overestimations) were calculated. A model and a condition effect were verified on APE. APE for the younger model were greater than for the other models (p<0.001), and APE in the absence of the model were greater than in her presence (p<0.05). Generally, adults underestimated height (51.8% of underestimations vs. 32.3% of overestimations) and overestimated reachability (51.3% of overestimations vs. 37.7% of underestimations). The overestimation of reachability was more notorious for the younger model, which might reflect adults' difficulty to consider the specificity of younger children's body proportions. Actually, the overestimation bias may suggest that adults perceive young children as on the basis of adult's geometrical proportions.
Collapse
Affiliation(s)
- Rita Cordovil
- Faculty of Human Kinetics, Technical University of Lisbon, Estrada da Costa, 1495-688 Cruz Quebrada, Portugal.
| | | |
Collapse
|
15
|
Savardi U, Bianchi I, Bertamini M. Naïve predictions of motion and orientation in mirrors: From what we see to what we expect reflections to do. Acta Psychol (Amst) 2010; 134:1-15. [PMID: 20015479 DOI: 10.1016/j.actpsy.2009.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 11/15/2009] [Accepted: 11/16/2009] [Indexed: 11/18/2022] Open
Abstract
The study aimed to investigate naïve beliefs regarding the dynamic and static behavior of reflections. In the first three experiments, participants in the study made predictions about the correspondence between real and reflected movements or about the orientation of the reflection of a static object placed in front of a mirror. In Experiments 1 and 2, paper-and-pencil tasks were used and in Experiment 3 participants were asked to make their predictions while imagining that they were facing a mirror. Results revealed that a percentage of undergraduates (ranging from 25% to 35%) were unable to make correct predictions. We classified the errors into types and found that responses either conform to the belief that reflections do the same or that they do the opposite. This suggests an oversimplification of the geometry of mirror reflections in two directions: participants either generalize what they see when movements are parallel to the mirror or what they see when movements are orthogonal to the mirror. Findings from Experiment 4 confirmed that these two expectations fit in with what people perceive in mirrors. Findings from Experiment 5 confirmed that this is also in agreement with the relationship perceived when looking at similar movements and orientations "outside" mirrors.
Collapse
Affiliation(s)
- Ugo Savardi
- Department of Psychology and Cultural Anthropology, University of Verona, Italy.
| | | | | |
Collapse
|
16
|
False beliefs and naive beliefs: They can be good for you. Behav Brain Sci 2010. [DOI: 10.1017/s0140525x09991178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractNaive physics beliefs can be systematically mistaken. They provide a useful test-bed because they are common, and also because their existence must rely on some adaptive advantage, within a given context. In the second part of the commentary we also ask questions about when a whole family of misbeliefs should be considered together as a single phenomenon.
Collapse
|