The Bodyguard Hypothesis

2017 ◽  
Author(s):  
Frédérique de Vignemont
Keyword(s):  
The Body ◽  
Sense Of Agency ◽  
Special Significance ◽  
Rubber Hand ◽  
Sense Of Ownership ◽  
Body Map ◽  
Self Defence

How are the sense of ownership and the sense of agency related? Does one need to be able to control one’s body to experience it as one’s own? One may suggest that the sense of bodily ownership is grounded in action-orientated representations of the body. However, this agentive hypothesis cannot explain how one can experience as one’s own a rubber hand that is not under control, while not experiencing as one’s own tools that are under control. The chapter then argues that one needs to distinguish between two kinds of hot body maps: the working body map involved in instrumental actions, and the protective body map involved in self-defence. It is proposed that one experiences as one’s own the body represented in the protective body map, which represents the body that has a special significance for the evolutionary needs of the organism.

scholarly journals Body ownership and agency altered by an electromyographically controlled robotic arm

2018 ◽  
Vol 5 (5) ◽  
pp. 172170 ◽  
Author(s):  
Yuki Sato ◽  
Toshihiro Kawase ◽  
Kouji Takano ◽  
Charles Spence ◽  
Kenji Kansaku
Keyword(s):  
Cognitive Neuroscience ◽  
The Body ◽  
Sense Of Agency ◽  
Robotic Arm ◽  
Body Ownership ◽  
Fundamental Issue ◽  
Rubber Hand ◽  
Sense Of Ownership ◽  
Robotic Prosthesis ◽  
Wrist Flexors

Understanding how we consciously experience our bodies is a fundamental issue in cognitive neuroscience. Two fundamental components of this are the sense of body ownership (the experience of the body as one's own) and the sense of agency (the feeling of control over one's bodily actions). These constructs have been used to investigate the incorporation of prostheses. To date, however, no evidence has been provided showing whether representations of ownership and agency in amputees are altered when operating a robotic prosthesis. Here we investigated a robotic arm using myoelectric control, for which the user varied the joint position continuously, in a rubber hand illusion task. Fifteen able-bodied participants and three trans-radial amputees were instructed to contract their wrist flexors/extensors alternately, and to watch the robotic arm move. The sense of ownership in both groups was extended to the robotic arm when the wrists of the real and robotic arm were flexed/extended synchronously, with the effect being smaller when they moved in opposite directions. Both groups also experienced a sense of agency over the robotic arm. These results suggest that these experimental settings induced successful incorporation of the prosthesis, at least for the amputees who took part in the present study.

scholarly journals Rubber Hand Illusion does not arise from comparisons with internal body models: a new multisensory integration account of the sense of ownership

2018 ◽  
Author(s):  
Piotr Litwin
Keyword(s):  
Multisensory Integration ◽  
Human Body ◽  
The Body ◽  
Rubber Hand Illusion ◽  
Multisensory Perception ◽  
Top Down ◽  
Rubber Hand ◽  
Sense Of Ownership ◽  
Body Model ◽  
Internal Body

Human body sense is surprisingly flexible – precisely administered multisensory stimulation may result in the illusion that an external object is part of one’s body. There seems to be a general consensus that there are certain top-down constraints on which objects may be incorporated: in particular, to-be-embodied objects should be structurally similar to a visual representation stored in an internal body model for a shift in one’s body image to occur. However, empirical evidence contradicts the body model hypothesis: the sense of ownership may be spread over objects strikingly distinct in morphology and structure (e.g., robotic arms or empty space) and direct empirical support for the theory is currently lacking. As an alternative, based on the example of the rubber hand illusion (RHI), I propose a multisensory integration account of how the sense of ownership is induced. In this account, the perception of one’s own body is a regular type of multisensory perception and multisensory integration processes are not only necessary but also sufficient for embodiment. In this paper, I propose how RHI can be modeled with the use of Maximum Likelihood Estimation and natural correlation rules. I also discuss how Bayesian Coupling Priors and idiosyncrasies in sensory processing render prior distributions interindividually variable, accounting for large interindividual differences in susceptibility to RHI. Taken together, the proposed model accounts for exceptional malleability of human body perception, fortifies existing bottom-up multisensory integration theories with top-down models of relatedness of sensory cues, and generates testable and disambiguating predictions.

scholarly journals Bodily ownership of an independent supernumerary limb: An exploratory study

2021 ◽  
Author(s):  
Kohei Umezawa ◽  
Yuta Suzuki ◽  
Gowrishankar Ganesh ◽  
Yoichi Miyawaki
Keyword(s):  
Human Brain ◽  
Sensory Feedback ◽  
Body Representation ◽  
The Body ◽  
Artificial Limbs ◽  
Cognitive Measures ◽  
Rubber Hand ◽  
Artificial Limb ◽  
Sense Of Ownership ◽  
Induced Changes

AbstractCan our brain perceive a sense of ownership towards an independent supernumerary limb; one that can be moved independently of any other limb and provides its own independent movement feedback? Following the rubberhand illusion experiment, a plethora of studies has shown that the human representation of ‘self’ is very plastic. But previous studies have almost exclusively investigated ownership towards ‘substitute’ artificial limbs, which are controlled by the movements of a real limb and/or limbs from which non-visual sensory feedback is provided on an existing limb. Here, to investigate whether the human brain can own an independent artificial limb, we first developed a novel independent robotic ‘sixth finger.’ We allowed participants to train using the finger and examined whether it induced changes in the body representation using behavioral as well as cognitive measures. Our results suggest that unlike a substituted artificial limb (like in the rubber hand experiment), it is more difficult for humans to perceive a sense of ownership towards an independent limb. However, ownership does seem possible, as we observed clear tendencies of changes in the body representation that correlated with the cognitive reports of the sense of ownership. Our results provide the first evidence to show that an independent supernumerary limb can be embodied by the human brain.

Ownership and the Space of the Body

2018 ◽  
Author(s):  
José Luis Bermúdez
Keyword(s):  
Cognitive Science ◽  
The Body ◽  
Rubber Hand Illusion ◽  
Main Body ◽  
Experimental Paradigm ◽  
Rubber Hand ◽  
Bodily Experience ◽  
Sense Of Ownership ◽  
The Third ◽  
Body Section

In the last 20 years, a robust experimental paradigm has emerged for studying the structure of bodily experience, focusing primarily on what it is to experience one’s body as one’s own. The initial impetus came from the rubber hand illusion (RHI) first demonstrated by Botvinick and Cohen, subsequently extended by various researchers to generate illusions of ownership at the level of the body as a whole. This paper identifies some problems with how ownership is discussed in the context of bodily illusions, and then shows how those problems can be addressed through a model of the experienced space of the body. Section 1 briefly reviews the bodily illusions literature and its significance for cognitive science and philosophy. Section 2 expresses reservations with the concept of ownership in terms of which the RHI and other illusions are standardly framed. I offer three hypotheses for the source of our putative “sense of ownership”. The main body of the paper focuses on the third hypothesis, which is that judgments of ownership are grounded in the distinctive way that we experience the space of the body.

scholarly journals Rubber Hand Illusion does not arise from comparisons with internal body models: a new multisensory integration account of the sense of ownership

2018 ◽  
Author(s):  
Piotr Litwin
Keyword(s):  
Multisensory Integration ◽  
Human Body ◽  
The Body ◽  
Rubber Hand Illusion ◽  
Multisensory Perception ◽  
Top Down ◽  
Rubber Hand ◽  
Sense Of Ownership ◽  
Body Model ◽  
Internal Body

Human body sense is surprisingly flexible – precisely administered multisensory stimulation may result in the illusion that an external object is part of one’s body. There seems to be a general consensus that there are certain top-down constraints on which objects may be incorporated: in particular, to-be-embodied objects should be structurally similar to a visual representation stored in an internal body model for a shift in one’s body image to occur. However, empirical evidence contradicts the body model hypothesis: the sense of ownership may be spread over objects strikingly distinct in morphology and structure (e.g., robotic arms or empty space) and direct empirical support for the theory is currently lacking. As an alternative, based on the example of the rubber hand illusion (RHI), I propose a multisensory integration account of how the sense of ownership is induced. In this account, the perception of one’s own body is a regular type of multisensory perception and multisensory integration processes are not only necessary but also sufficient for embodiment. In this paper, I propose how RHI can be modeled with the use of Maximum Likelihood Estimation and natural correlation rules. I also discuss how Bayesian Coupling Priors and idiosyncrasies in sensory processing render prior distributions interindividually variable, accounting for large interindividual differences in susceptibility to RHI. Taken together, the proposed model accounts for exceptional malleability of human body perception, fortifies existing bottom-up multisensory integration theories with top-down models of relatedness of sensory cues, and generates testable and disambiguating predictions.

scholarly journals How Sense of Agency and Sense of Ownership could Affect Anxiety: A Study Based on Virtual Hand Illusion

2018 ◽  
Vol 34 (3) ◽  
pp. 430-437
Author(s):  
Jing Zhang ◽  
Wei Chen ◽  
Yanyan Qian
Keyword(s):  
Rating Scale ◽  
Sense Of Self ◽  
First Grade ◽  
Effect Study ◽  
Sense Of Agency ◽  
Second Grade ◽  
Rubber Hand ◽  
Sense Of Ownership ◽  
Virtual Hand ◽  
Second Grade Students

By using computer program we created a virtual environment to study the possible impacts of sense of agency and sense of ownership on anxiety. The aim of the present study is to investigate whether our setup could achieve the similar effect as traditional rubber hand illusion had, and how sense of self (mainly sense of agency and sense of ownership) affects participants' anxiety. Study 1 the sample consisted of 24 first grade student(12 female, 12 male) aged 18-21 (M=19.98, SD=0.82), who moved a 3D virtual hand in a synchronous or asynchronous situation. Study 2 included 48 first or second grade students (24 female , 24 male) aged 18-22 (M=20.67, SD=1.05), who passed the SCL-90 rating-scale and completed the SCL-90 rating-scale again after they performed a catching/avoiding task. In study 1, all the results only provided evidence for a VHI but no other effect. Study 2 showed that asynchronous conditions had higher anxiety scores than synchronous one in terms of modality and sex, different virtual images would lead to participants' different anxious feelings. Sex itself was not a differentiating factor, however, mean and women reacted differently in different situations. Results indicated that, in general, sense of agency has more impacts on anxiety level compared with sense of ownership. However, sense of agency seemed to affect male more than female while sense of ownership placed more influence on female than on male. This finding may because the different contribution styles and empathy abilities between men and women.

scholarly journals Experiential ownership and body ownership are different phenomena

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caleb Liang ◽  
Wen-Hsiang Lin ◽  
Tai-Yuan Chang ◽  
Chi-Hong Chen ◽  
Chen-Wei Wu ◽  
...  
Keyword(s):  
Conscious Experience ◽  
Distinct Type ◽  
Body Part ◽  
The Body ◽  
Body Ownership ◽  
Rubber Hand ◽  
Person Perspective ◽  
The One ◽  
First Time ◽  
Full Body

AbstractBody ownership concerns what it is like to feel a body part or a full body as mine, and has become a prominent area of study. We propose that there is a closely related type of bodily self-consciousness largely neglected by researchers—experiential ownership. It refers to the sense that I am the one who is having a conscious experience. Are body ownership and experiential ownership actually the same phenomenon or are they genuinely different? In our experiments, the participant watched a rubber hand or someone else’s body from the first-person perspective and was touched either synchronously or asynchronously. The main findings: (1) The sense of body ownership was hindered in the asynchronous conditions of both the body-part and the full-body experiments. However, a strong sense of experiential ownership was observed in those conditions. (2) We found the opposite when the participants’ responses were measured after tactile stimulations had ceased for 5 s. In the synchronous conditions of another set of body-part and full-body experiments, only experiential ownership was blocked but not body ownership. These results demonstrate for the first time the double dissociation between body ownership and experiential ownership. Experiential ownership is indeed a distinct type of bodily self-consciousness.

scholarly journals Multisensory integration involved in the body perception of community-dwelling older adults

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Hide ◽  
Y. Ito ◽  
N. Kuroda ◽  
M. Kanda ◽  
W. Teramoto
Keyword(s):  
Older Adults ◽  
Multisensory Integration ◽  
Fall Risk ◽  
Community Dwelling ◽  
The Body ◽  
Risk Of Falling ◽  
Body Perception ◽  
Rubber Hand ◽  
Timed Up And Go ◽  
Community Dwelling Older Adults

AbstractThis study investigates how the multisensory integration in body perception changes with increasing age, and whether it is associated with older adults’ risk of falling. For this, the rubber hand illusion (RHI) and rubber foot illusion (RFI) were used. Twenty-eight community-dwelling older adults and 25 university students were recruited. They viewed a rubber hand or foot that was stimulated in synchrony or asynchrony with their own hidden hand or foot. The illusion was assessed by using a questionnaire, and measuring the proprioceptive drift and latency. The Timed Up and Go Test was used to classify the older adults into lower and higher fall-risk groups. No difference was observed in the RHI between the younger and older adults. However, several differences were observed in the RFI. Specifically, the older adults with a lower fall-risk hardly experienced the illusion, whereas those with a higher fall-risk experienced it with a shorter latency and no weaker than the younger adults. These results suggest that in older adults, the mechanism of multisensory integration for constructing body perception can change depending on the stimulated body parts, and that the risk of falling is associated with multisensory integration.

Posture Analysis Using Nordic Body Map and Rapid Office Strain Assessment Methods to Improve Work Posture

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Melia Agustin ◽  
Hendy Tannady ◽  
Octa Ferdian ◽  
Samuel Imanuel Gunawan Alamsjah
Keyword(s):  
Musculoskeletal Disorders ◽  
Severe Pain ◽  
Service Sector ◽  
The Body ◽  
Educational Services ◽  
Posture Analysis ◽  
Risk Of Injury ◽  
Work Posture ◽  
Body Map ◽  
A Company

<p><em>Jaya Launch Pad is a company engaged in educational services. It is undeniable that service sector companies such as Jaya Launch Pad also have a workforce whose work posture may be less ergonomic, which can lead to musculoskeletal disorders. Musculoskeletal disorders can be experienced by people of all ages. Therefore, this study focuses on work posture. This research occurred because of complaints experienced by staff. The number of samples used in this study was 1 person. This was influenced by the Covid-19 pandemic situation so that there was only 1 staff when the observation was made. The research method used was the nordic body map (NBM) to determine which parts of the body are experiencing complaints, and the rapid office strain assessment (ROSA) to measure the risk of injury due to the posture of sitting at a computer for 8 hours. The result is that the complaint assessment using the NBM questionnaire has a score of 52 (needs improvement at a later date) with 4 categories of severe pain, namely back, waist, buttocks, and buttocks. Meanwhile, the score from the ROSA table is 6 which means it is risky / dangerous so that it needs improvement. Therefore, a proposed condition is given in the form of a replacement of work facilities in the form of a work chair with adjustable height and adjustable armrests. This improvement is assumed to be able to reduce the level of staff complaints, and the calculation result of the rapid office strain assessment (ROSA) is 4 which means no risk so that this improvement is accepted and can solve the work posture problem of staff at Jaya Launch Pad.</em></p><p><em> </em></p><p> </p>

scholarly journals Perception of visual-tactile asynchrony, bodily perceptual aberrations, and bodily illusions in schizophrenia

2020 ◽  
Author(s):  
Regine Zopf
Keyword(s):  
The Body ◽  
Detection Sensitivity ◽  
Body Ownership ◽  
Body Perception ◽  
Rubber Hand ◽  
Bodily Experiences ◽  
Asynchrony Detection ◽  
Body Perceptions ◽  
Proprioceptive Drift ◽  
Insight Into

Body perception can be dramatically altered in individuals with schizophrenia resulting in experiences of undefined bodily boundaries, loss of body ownership, and size changes for parts of the body. These individuals may also be more susceptible to the rubber hand illusion (RHI: an illusion of body perception that can also be induced in neurotypical populations), but the findings are mixed. Furthermore, the perception of timing information about multisensory stimuli, which is thought to be fundamental for body perception, has been reported to be altered in schizophrenia. We tested here whether altered perception of the temporal relationship between visual and tactile signals in schizophrenia can predict self-reported perceptual aberrations and RHI susceptibility (indexed by both illusion self-ratings and a more objective proprioceptive-drift measure). We found that the sensitivity to detect temporal asynchronies is reduced in schizophrenia and this predicts bodily perceptual symptoms. In contrast, we found no evidence for a direct relationship between asynchrony detection sensitivity and RHI susceptibility. Instead, our findings suggest that experiencing more bodily perceptual symptoms increases the likelihood of endorsing unusual bodily experiences, resulting in higher RHI self-ratings but not higher proprioceptive-drift scores. Overall, our findings provide evidence for both direct and indirect links between temporal and body perception and thus new insight into the mechanisms that may underlie unusual body perceptions in schizophrenia.

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