Feeling of a presence and anomalous body perception

2021 ◽  
pp. 316-327
Author(s):  
Masayuki Hara ◽  
Olaf Blanke ◽  
Noriaki Kanayama

The feeling of a presence (FoP) is an illusory vivid feeling that there is another person nearby who is not seen, heard, or felt. In neuropsychiatry, FoP has traditionally been classified among disorders of the body schema but has also been reported from times immemorial by healthy individuals in various conditions. Here the chapter reviews key neurological and psychiatric data on FoP and the involved neural mechanisms. Particular relevance will be given to the distinction between body schema versus body image in the FoP. This is followed by a description of recent efforts in engineering and cognitive neuroscience to apply robotics technology to experimentally induce and study FoP and its phenomenology. The chapter concludes by describing an exciting new research field that integrates consciousness studies, cognitive neuroscience, and engineering—cognetics.

2019 ◽  
Author(s):  
Stephen Gadsby

The distinction between body image and body schema has been incredibly influential in cognitive neuroscience. Recently, researchers have begun to speculate about the relationship between these representations (Gadsby, 2017; 2018; Pitron & de Vignemont, 2017; Pitron et al., 2018). Within this emerging literature, Pitron and colleagues (2018) proposed that the long-term body image and long-term body schema co-construct one another, through a process of reciprocal interaction. In proposing this model, they make two assumptions: that the long-term body image incorporates the spatial characteristics of tools, and that it is distorted in the case of Alice in wonderland syndrome. Here, I challenge these assumptions, with a closer examination of what the term “long-term body image” refers to. In doing so, I draw out some important taxonomic principles for research into body representation.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Juyeon Park ◽  
Jennifer Paff Ogle

AbstractWe explored how viewing one’s anthropometric virtual avatar would affect the viewer’s self-body perception through the comparative evaluation of self-concepts—self-esteem and self-compassion, within the framework of allocentric lock theory. We recruited 18 female adults, aged 18–21, who identified themselves to have some level of body image concerns, and who had had no clinical treatment for their body image. Participants were randomly assigned either to the experimental or control group. The experimental group participated in both body positivity program and virtual avatar program, whereas the control group attended the body positivity program, only. The results affirmed that the body positivity program served as a psychological buffer prior to the virtual avatar stimulus. After the virtual avatar experience, the participants demonstrated self-acceptance by lowering their expectation on how they should look like. The findings from exit interviews enriched the quantitative results. This study verified the mechanism of the altered processing of the stored bodily memory by the egocentric sensory input of virtual avatars, and offered practical potential of the study outcomes to be applied in various emerging fields where novel applications of virtual 3D technology are sought, such as fashion e-commerce.


Perception ◽  
10.1068/p5853 ◽  
2007 ◽  
Vol 36 (10) ◽  
pp. 1547-1554 ◽  
Author(s):  
Francesco Pavani ◽  
Massimiliano Zampini

When a hand (either real or fake) is stimulated in synchrony with our own hand concealed from view, the felt position of our own hand can be biased toward the location of the seen hand. This intriguing phenomenon relies on the brain's ability to detect statistical correlations in the multisensory inputs (ie visual, tactile, and proprioceptive), but it is also modulated by the pre-existing representation of one's own body. Nonetheless, researchers appear to have accepted the assumption that the size of the seen hand does not matter for this illusion to occur. Here we used a real-time video image of the participant's own hand to elicit the illusion, but we varied the hand size in the video image so that the seen hand was either reduced, veridical, or enlarged in comparison to the participant's own hand. The results showed that visible-hand size modulated the illusion, which was present for veridical and enlarged images of the hand, but absent when the visible hand was reduced. These findings indicate that very specific aspects of our own body image (ie hand size) can constrain the multisensory modulation of the body schema highlighted by the fake-hand illusion paradigm. In addition, they suggest an asymmetric tendency to acknowledge enlarged (but not reduced) images of body parts within our body representation.


Body schema refers to the system of sensory-motor functions that enables control of the position of body parts in space, without conscious awareness of those parts. Body image refers to a conscious representation of the way the body appears—a set of conscious perceptions, affective attitudes, and beliefs pertaining to one’s own bodily image. In 2005, Shaun Gallagher published an influential book entitled ‘How the Body Shapes the Mind’. This book not only defined both body schema (BS) and body image (BI), but also explored the complicated relationship between the two. The book also established the idea that there is a double dissociation, whereby body schema and body image refer to two different, but closely related, systems. Given that many kinds of pathological cases can be described in terms of body schema and body image (phantom limbs, asomatognosia, apraxia, schizophrenia, anorexia, depersonalization, and body dysmorphic disorder, among others), we might expect to find a growing consensus about these concepts and the relevant neural activities connected to these systems. Instead, an examination of the scientific literature reveals continued ambiguity and disagreement. This volume brings together leading experts from the fields of philosophy, neuroscience, psychology, and psychiatry in a lively and productive dialogue. It explores fundamental questions about the relationship between body schema and body image, and addresses ongoing debates about the role of the brain and the role of social and cultural factors in our understanding of embodiment.


2021 ◽  
pp. 229-243
Author(s):  
Jonathan Cole

In neurological illnesses, the body may present itself to perception in ways which allows insights into the concepts of body image and body schema. Three such conditions are explored. From those who live with spinal cord injury, paralysed and insentient from the neck down, aspects of the importance of the body in one’s sense of self are revealed. Some also describe a coming to terms with their altered bodies. When considering the body image, its adaptability and this reconciliation to a new normal should be considered. Studies on acquired severe sensory loss explore how conscious control, at the body image level, may partially replace the deafferented body schema. There is little evidence, however, for these subjects extending access to previously non-conscious motor schema. Lastly, some narratives from those with congenital absence of movement of facial muscles describe reduced emotional experience and felt embodiment as children. These can be developed as young adults, through shared social interactions. The importance of the social in elaboration of the body image is further implicit in a consideration of the stigma associated with facial disfigurement. Others’ responses to one’s body are crucial in developing our body image and sense of self.


Author(s):  
Rosalia Vazquez-Arevalo ◽  
Alberto Rodríguez Nabor ◽  
Xochitl López Aguilar ◽  
Juan Manuel Mancilla-Díaz

Abstract The objective of this research was to determine the body perception (BP) of preschoolers and compare it with the one reported by their parents. A total of 48 preschoolers participated (Mage = 5 years, SD = 0.5), 21 boys, 27 girls, and their parents (47 fathers and 48 mothers). The children were weighed and measured, also they answered the instrument Seven Figures of Collins (SFC) and seven questions about food, beauty and health. The parents answered the Body Image Questionnaire, the Stunkard Figures, as well as the SFCs to identify the real (RF) and ideal figure(IF) of their children. When children described themselves, they mostly referred the normal figure, coinciding with their parents. A very small proportion of preschoolers perceived themselves with obesity (around 29-30%); while any parent identified their children with obesity. 50% of preschoolers chose thinner silhouettes than their body mass index (BMI), but not emaciated. For RF, most parents chose normal weight for boys and light overweight for girls; for IF parents chose, for both sexes, the one with light overweight. In conclusion, the preschool BP disagreed between reality and perception, regardless of their BMI and gender. The parents also did not have an adequate BP for their children. Resumen El objetivo de esta investigación fue conocer la percepción corporal (PC) de preescolares y compararla con la que sus padres tienen de ellos. Participaron 48 preescolares (Medad = 5 años, DE = 0.5), 21 niños y 27 niñas, y sus padres (47 papás y 48 mamás). Los niños fueron pesados y medidos, contestaron el instrumento Siete Figuras de Collins (SFC) y, con relación a éste, siete preguntas sobre alimentación, belleza y salud. A los padres se les aplicó el Cuestionario de Imagen Corporal, las Figuras de Stunkard, además de las SFC para que identificaran la figura real (FR) e ideal (FI) de sus hijos. Para describirse, los preescolares refirieron mayormente la figura normopeso, coincidiendo con sus padres. Fue mínima la proporción de preescolares que se percibieron con obesidad (presente en 29-30%); mientras que ningún padre la identificó en sus hijos. El 50% de los preescolares eligió siluetas más delgadas a su índice de masa corporal (IMC), pero no emaciadas. Como FR, la mayoría de los padres eligió la normopeso para los niños y con sobrepeso ligero para las niñas; como FI eligieron, para ambos sexos, aquélla con sobrepeso ligero. En conclusión, la PC del preescolar discrepó entre la real y la percibida, independientemente de su IMC y sexo. Los padres tampoco tuvieron una adecuada PC de sus hijos.


CNS Spectrums ◽  
2006 ◽  
Vol 11 (6) ◽  
pp. 419-422 ◽  
Author(s):  
Dan J. Stein ◽  
Paul D. Carey ◽  
James Warwick

ABSTRACTBody dysmorphic disorder (BDD) is characterized by preoccupation with a defect in appearance. Concepts of beauty play a particularly crucial role in humans' mental and social life, and may have specific psychobiologic and evolutionary underpinnings. In particular, there is a growing literature on the neurocircuitry underpinning the body schema, body image and facial expression processing, and aesthetic and symmetry judgments. Speculatively, disruptions in cognitive-affective processes relevant to judgments about physical beauty lead to BDD.


2019 ◽  
Author(s):  
Aubrieann Schettler ◽  
Ian Holstead ◽  
John Turri ◽  
Michael Barnett-Cowan

AbstractWe assessed how self-motion affects the visual representation of the self. We constructed a novel virtual reality experiment that systematically varied an avatar’s motion and also biological sex. Participants were presented with pairs of avatars that visually represented the participant (“self avatar”), or another person (“opposite avatar”). Avatar motion either corresponded with the participant’s motion, or was decoupled from the participant’s motion. The results show that participants identified with i) “self avatars” over “opposite avatars”, ii) avatars moving congruently with self-motion over incongruent motion, and importantly iii) identification with the “opposite avatar” over the “self avatar” when the opposite avatar’s motion was congruent with self-motion. Our results suggest that both self-motion and biological sex are relevant to the body schema and body image and that congruent bottom-up visual feedback of self-motion is particularly important for the sense of self and capable of overriding top-down self-identification factors such as biological sex.


2021 ◽  
Vol 11 (12) ◽  
pp. 1625
Author(s):  
Alessandra Giordano ◽  
Michele Boffano ◽  
Raimondo Piana ◽  
Roberto Mutani ◽  
Alessandro Cicolin

Purpose: the evaluation of body image perception, pain coping strategies, and dream content, together with phantom limb and telescoping phenomena in patients with sarcoma who underwent surgery for limb amputation. Material and Methods: consecutive outpatients were evaluated at T0 (within 3 weeks after surgery) and T1 (4–6 months after surgery) as follows: demographic and clinical data collection; the Groningen Questionnaire Problems after Arm Amputation; the West Haven-Yale Multidimensional Pain Inventory; the Body Image Concern Inventory, a clinical trial to identify telescoping; and a weekly diary of dreams. Dream contents were coded according to the Hall and Van de Castle coding system. Results: Twenty patients completed the study (15 males and 5 females, mean age: 53.9 ± 24.6, education: 7.8 ± 3.4). All subjects experienced phantom limb and 35% of them experienced telescoping soon after surgery, and 25% still after 4–6 months. Both at T0 and T1, that half of the subjects reported dreams about still having their missing limbs. At T1 the patients’ perceptions of being able to deal with problems were lower, and pain and its interference in everyday life were higher yet associated with significant engagement in everyday activities and an overall good mood. The dream content analysis highlighted that males were less worried about health problems soon after amputation, and women showed more initial difficulties that seemed to be resolved after 4–6 months after surgery. Conclusions: The dream content analysis may improve clinicians’ ability to support their patients during their therapeutic course.


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