Body 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. (shrink)

We investigate two issues about the subjective experience of one's body: first, is the experience of owning a full-body fundamentally different from the experience of owning a body-part?Second, when I experience a bodily sensation, does it guarantee that I cannot be wrong about whether it is me who feels it? To address these issues, we conducted a series of experiments that combined the rubber hand illusion (RHI) and the “body swap illusion.” The subject wore a head (...) mounted display (HMD) connected with a stereo camera set on the experimenter's head. Sitting face to face, they used their right hand holding a paintbrush to brush each other's left hand. Through the HMD, the subject adopted the experimenter's first-person perspective (1PP) as if it was his/her own 1PP: the subject watched either the experimenter's hand from the adopted 1PP, and/or the subject's own hand from the adopted third-person perspective (3PP) in the opposite direction (180°), or the subject's full body from the adopted 3PP (180°, with or without face). The synchronous full-body conditions generate a “self-touching illusion”: many participants felt that “I was brushing my own hand!” We found that (1) the sense of body-part ownership and the sense of full-body ownership are not fundamentally different from each other; and (2) our data present a strong case against the mainstream philosophical view called the immunity principle (IEM). We argue that it is possible for misrepresentation to occur in the subject's sense of “experiential ownership” (the sense that I am the one who is having this bodily experience). We discuss these findings and conclude that not only the sense of body ownership but also the sense of experiential ownership call for further interdisciplinary studies. (shrink)

Which is my body and how do I distinguish it from the bodies of others, or from objects in the surrounding environment? The perception of our own body and more particularly our sense of body ownership is taken for granted. Nevertheless experimental findings from body ownership illusions (BOIs), show that under specific multisensory conditions, we can experience artificial body parts or fake bodies as our own body parts or body respectively. The (...) aim of the present paper is to discuss how and why BOIs are induced. We review several experimental findings concerning the spatial, temporal and semantic principles of crossmodal stimuli that have been applied to induce BOIs. On the basis of these principles, we discuss theoretical approaches concerning the underlying mechanism of BOIs. We propose a conceptualization based on Bayesian causal inference for addressing how our nervous system could infer whether an object belongs to our own body, using multisensory, sensorimotor and semantic information, and we discuss how this can account for several experimental findings. Finally, we point to neural network models as an implementational framework within which the computational problem behind BOIs could be addressed in the future. (shrink)

Recent studies of the rubber hand illusion (RHI) have shown that the sense of body ownership is constrained by several factors and yet is still very flexible. However, exactly how flexible is our sense of body ownership? In this study, we address this issue by investigating the following question: is it possible that one may have the illusory experience of owning four hands? Under visual manipulation, the participant adopted the experimenter’s first-person perspective (1PP) as if it (...) was his/her own. Sitting face to face, the participant saw four hands—the experimenter’s two hands from the adopted 1PP together with the subject’s own two hands from the adopted third-person perspective (3PP). We found that: (1) the four-hand illusion did not occur in the passive four-hand condition. (2) In the active four-hand condition, the participants tapped their index fingers, imitated by the experimenter. When tactile stimulations were not provided, the key illusion was not induced, either. (3) Strikingly, once all four hands began to act with the same pattern and received synchronous tactile stimulations at the same time, many participants felt as if they had two more hands. These results show that the sense of body ownership is much more flexible than most researchers have suggested. (shrink)

Manipulating sensory and motor cues can cause an illusionary perception of ownership of a fake body part. Presumably, the illusion can work as long as the false body part’s position and appearance are anatomically plausible. Here, we introduce an illusion that challenges past assumptions on body ownership. We used virtual reality to switch and mirror participants’ views of their hands. When a participant moves their physical hand, they see the incongruent virtual hand moving. The result (...) is an anatomically implausible configuration of the fake hand. Despite the hand switch, participants reported significant body ownership sensations over the virtual hands. In the first between-group experiment, we found that the strength of body ownership over the incongruent hands was similar to that of congruent hands. Whereas, in the second within-group experiment, anatomical incongruency significantly decreased body ownership. Still, participants reported significant body ownership sensations of the switched hands. Curiously, we found that perceived levels of agency mediate the effect of anatomical congruency on body ownership. These findings offer a fresh perspective on the relationship between anatomical plausibility and assumed body ownership. We propose that goal-directed and purposeful actions can override anatomical plausibility constraints and discuss this in the context of the immersive properties of virtual reality. (shrink)

The recent distinction between sense of agency and sense of body-ownership has attracted considerable empirical and theoretical interest. The respective contributions of central motor signals and peripheral afferent signals to these two varieties of body experience remain unknown. In the present review, we consider the methodological problems encountered in the empirical study of agency and body-ownership, and we then present a series of experiments that study the interplay between motor and sensory information. In particular, we (...) focus on how multisensory signals interact with body representations to generate the sense of body-ownership, and how the sense of agency modulates the sense of body-ownership. Finally, we consider the respective roles of efferent and afferent signals for the experience of one’s own body and actions, in relation to self-recognition and the recognition of other people’s actions. We suggest that the coherent experience of the body depends on the integration of efferent information with afferent information in action contexts. Overall, whereas afferent signals provide the distinctive content of one’s own body experience, efferent signals seem to structure the experience of one’s own body in an integrative and coherent way. (shrink)

Lee and Schwartz procedures of separation offer a much needed interpretation of the literature on moral cleansing. However, body ownership as a grounded mechanism of separation and connection has been neglected. We argue that embodiment may be employed to connect the self to desirable aspects of cognitive and emotional interactions and disembodiment to disconnect from undesirable elements.

The Body Ownership Thesis states that each person owns her body. I address a prominent objection, the Generation Problem: the Body Ownership Thesis apparently implies that parents own their children: as we own the fruit of our property, if a parent owns her own body, she must own her child and her child's body. I argue that a person does not own the fruit of her property when that fruit is a person or (...) the body of a person. Persons have conclusive title to their bodies, but only defeasible title to the fruits of their bodies. (shrink)

The Body Ownership Thesis states that each person owns her body. I address a prominent objection, the Generation Problem: the Body Ownership Thesis apparently implies that parents own their children: as we own the fruit of our property, if a parent owns her own body, she must own her child and her child’s body. I argue that a person does not own the fruit of her property when that fruit is a person or (...) the body of a person. Persons have conclusive title to their bodies, but only defeasible title to the fruits of their bodies. (shrink)

The Body Ownership Thesis states that each person owns her body. I address a prominent objection, the Generation Problem: the Body Ownership Thesis apparently implies that parents own their children: as we own the fruit of our property, if a parent owns her own body, she must own her child and her child's body. I argue that a person does not own the fruit of her property when that fruit is a person or (...) the body of a person. Persons have conclusive title to their bodies, but only defeasible title to the fruits of their bodies. (shrink)

Our understanding of body ownership largely relies on the Rubber Hand Illusion (RHI) paradigm where synchronous stroking of the real and fake hands leads to an illusion of ownership of RH provided its physical, anatomical, and spatial plausibility. Self-attribution of a fake hand also occurs during visuomotor synchrony, when the visual feedback of self-initiated movements follows the trajectory of the instantiated motor command. In both cases, the experience of ownership is established through bottom-up integration and top-down (...) prediction of multisensory (proximodistal) cues within the peripersonal space. It seems, however, that depending on whether the signals are externally or self-generated, top-down expectation signals are qualitatively different. On the one hand, in RHI, the sensory correlations are modulated by empirically induced priors about the internal model of the body. On the other hand, in mRHI, body ownership is actively shaped by processes allowing for continuous comparison between the actual and predicted sensory consequences of the actions. Ample research demonstrates that the differential processing of the predicted and the actual reafferent information is addressed by the central nervous system via an internal Forward Model (FM). Indeed, results from mRHI suggest that in action-contexts mechanism underlying body ownership could be similar to the FM. Crucially FMs integrate across all sensory input including not only proximodistal (visuomotor) but also purely distal sensory signals (visuoauditory). Thus if body ownership results from a consistency of FM, it would be affected by the (in)congruency of purely distal signals provided that they inform about the action-consequences relevant to the task. Here we explicitly address this question. To test our hypothesis, we devise an embodied VR-based task where action outcomes were signaled by distinct auditory cues. By manipulating the cues with respect to their spatial, temporal and semantic congruency, we show that purely distal feedback violating predictions about action outcomes compromises both body ownership and performance. These results demonstrate that body ownership is influenced by cues which not only pertain to the body itself but also those arising outside of the body, and suggest that in goal-oriented tasks body ownership might result from the consistency of forward models. (shrink)

This article examines the inflationary view of the body ownership. It reviews a growing body of empirical research on the sense of body ownership that suggests that the deflationary depends on the integration of somatosensory signals. It discusses the results of recent research on out-of-body experiences and shows that the neurocognitive processes involved in the Rubber Hand Illusion are also involved in OBE. It suggests that this experience of bodily ownership may be a (...) critical component of self-specificity. (shrink)

We investigated how motor agency in the voluntary control of body movement influences body awareness. In the Rubber Hand Illusion , synchronous tactile stimulation of a rubber hand and the participant’s hand leads to a feeling of the rubber hand being incorporated in the participant’s own body. One quantifiable behavioural correlate of the illusion is an induced shift in the perceived location of the participant’s hand towards the rubber hand. Previous studies showed that the induced changes in (...) body awareness are local and fragmented: the proprioceptive drift is largely restricted to the stimulated finger. In the present study, we investigated whether active and passive movements, rather than tactile stimulation, would lead to similarly fragmented body awareness. Participants watched a projected image of their hand under three conditions: active finger movement, passive finger movement, and tactile stimulation. Visual feedback was either synchronous or asynchronous with respect to stimulation of the hand. A significant overall RHI, defined as greater drifts following synchronous than asynchronous stimulation, was found in all cases. However, the distribution of the RHI across stimulated and non-stimulated fingers depended on the kind of stimulation. Localised proprioceptive drifts, specific to the stimulated finger, were found for tactile and passive stimulation. Conversely, during active movement of a single digit, the proprioceptive drifts were not localised to that digit, but were spread across the whole hand. Whereas a purely proprioceptive sense of body-ownership is local and fragmented, the motor sense of agency integrates distinct body-parts into a coherent, unified awareness of the body. (shrink)

Bodily and mental self-ascriptions are forms of first-person thought where a subject attributes physical properties and psychological states to herself. The body-ownership view argues that a necessary and sufficient condition on such self-ascriptions is the existence of causal links between a spatio-temporal body and the self-ascribed properties or states. However, since P.F. Strawson’s influential attack, this view has been dismissed as a bad philosophical idea. The goal of this brief piece is to outline the body-ownership (...) view and neutralise two classic lines of objection against it: on the one hand, that the stance is incoherent; and, on the other, that it has counterintuitive implications. (shrink)

Bodily and mental self-ascriptions are forms of first-person thought where a subject attributes physical properties and psychological states to herself. The body-ownership view argues that a necessary and sufficient condition on such self-ascriptions is the existence of causal links between a spatio-temporal body and the self-ascribed properties or states. However, since P.F. Strawson’s influential attack, this view has been dismissed as a bad philosophical idea. The goal of this brief piece is to outline the body-ownership (...) view and neutralise two classic lines of objection against it: on the one hand, that the stance is incoherent; and, on the other, that it has counterintuitive implications. (shrink)

When subjects view stimulation of a rubber hand while feeling congruent stimulation of their own hand, they may come to feel that the rubber hand is part of their own body. This illusion of body ownership is termed ‘Rubber Hand Illusion’ . We investigated sensitivity of RHI to spatial mismatches between visual and somatic experience. We compared the effects of spatial mismatch between the stimulation of the two hands, and equivalent mismatches between the postures of the two (...) hands. We created the mismatch either by adjusting stimulation or posture of the subject’s hand, or, in a separate group of subjects, by adjusting stimulation or posture of the rubber hand. The matching processes underlying body ownership were asymmetrical. The illusion survived small changes in the subject’s hand posture, but disappeared when the same posture transformations were applied to the rubber hand. Mismatch between the stimulation delivered to the subject’s hand and the rubber hand abolished the illusion. The combination of these two situations is of particular interest. When the subject’s hand posture was slightly different from the rubber hand posture, the RHI remained as long as stimulation of the two hands was congruent in a hand-centred spatial reference frame, even though the altered posture of the subject’s hand meant that stimulation was incongruent in external space. Conversely, the RHI was reduced when the stimulation was incongruent in hand-centred space but congruent in external space. We conclude that the visual–tactile correlation that causes the RHI is computed within a hand-centred frame of reference, which is updated with changes in body posture. Current sensory evidence about what is ‘me’ is interpreted with respect to a prior mental body representation. (shrink)

Emerging evidence is now challenging the view that patients diagnosed with schizophrenia experience a selective deficit in their sense of agency. Additional disturbances seem to exist in their sense of body ownership. However, the factors underlying this disturbance in body ownership remain elusive. Knowledge of these factors, and increased understanding of how body ownership is related to other abnormalities seen in schizophrenia, could ultimately advance development of new treatments. Research on body ownership (...) in schizophrenia has mainly been investigated with the rubber hand illusion (RHI). Schizophrenia patients show higher susceptibility to the RHI, which may be explained by a stronger reliance on multisensory information over weaker stored body representations. This review shows that a coherent sense of body ownership arises from the integration of both bottom-up sensory processes and higher order, top-down bodily- and perceptual representations. Multisensory integration, temporal binding, anticipation, intention and efferent signals all partly modulate the complex experience of body ownership. Specifically, we propose that patients with schizophrenia have weaker stored body representations, and rely to a greater extent on external stimuli, such as visual information, due to imprecise or highly variable internal predictions on the consequences of action. Moreover, the reduced sense of agency in schizophrenia may additionally contribute to the disturbed sense of body ownership, as evidence from healthy participants suggests that agency and body ownership are interrelated. Vice versa, a reduced sense of body ownership may also contribute to a reduced sense of agency. Future studies should explicitly target the precise relation between the two in schizophrenia. (shrink)

Objects which a human agent controls by efferent activities can be perceived by the agent as belonging to his or her body. This suggests that what an agent counts as “body” is plastic, depending on what she or he controls. Yet there are possible limitations for such momentary plasticity. One of these limitations is that sensations stemming from the body and sensations stemming from objects outside the body are not integrated if they do not sufficiently “match”. (...) What “matches” and what does not is conceivably determined by long–term experience with the perceptual changes that body movements typically produce. Children have accumulated less sensorimotor experience than adults have. Consequently, they express higher flexibility to integrate body-internal and body-external signals, independent of their “match” as suggested by rubber hand illusion studies. However, children’s motor performance in tool use is more affected by mismatching body-internal and body-external action effects than that of adults, possibly because of less developed means to overcome such mismatches. We review research on perception-action interactions, multisensory integration, and developmental psychology to build bridges between these research fields. By doing so, we account for the flexibility of the sense of body ownership for actively controlled events and its development through ontogeny. This gives us the opportunity to validate the suggested mechanisms for generating ownership by investigating their effects in still developing and incomplete stages in children. We suggest testable predictions for future studies investigating both body ownership and motor skills throughout the lifespan. (shrink)

This paper analyzes in the use of virtual reality when used to induce full-body ownership in violent offenders in order to elicit empathetic feelings by allowing them to embody the virtual body of a victim of domestic abuse. The authors explore potentially harmful effects to individuals participating in this kind of therapy and question whether consent is fully informed. The paper concludes with guidelines for ethical research and rehabilitation using this innovative technology.

Multisensory stimulation has been shown to alter the sense of body-ownership. Given that perceived similarity between one’s own body and those of others is crucial for social cognition, we investigated whether multisensory stimulation can lead participants to experience ownership over a hand of different skin colour. Results from two studies using introspective, behavioural and physiological methods show that, following synchronous visuotactile stimulation, participants can experience body-ownership over hands that seem to belong to a different (...) racial group. Interestingly, a baseline measure of implicit racial bias did not predict whether participants would experience the RHI, but the overall strength of experienced body-ownership seemed to predict the participants’ post-illusion implicit racial bias with those who experienced a stronger RHI showing a lower bias. These findings suggest that multisensory experiences can override strict ingroup/outgroup distinctions based on skin colour and point to a key role for sensory processing in social cognition. (shrink)

Multisensory stimulation has been shown to alter the sense of body-ownership. Given that perceived similarity between one’s own body and those of others is crucial for social cognition, we investigated whether multisensory stimulation can lead participants to experience ownership over a hand of different skin colour. Results from two studies using introspective, behavioural and physiological methods show that, following synchronous visuotactile stimulation, participants can experience body-ownership over hands that seem to belong to a different (...) racial group. Interestingly, a baseline measure of implicit racial bias did not predict whether participants would experience the RHI, but the overall strength of experienced body-ownership seemed to predict the participants’ post-illusion implicit racial bias with those who experienced a stronger RHI showing a lower bias. These findings suggest that multisensory experiences can override strict ingroup/outgroup distinctions based on skin colour and point to a key role for sensory processing in social cognition. (shrink)

We previously showed that the illusory sense of ownership and agency over a moving body in immersive virtual reality can trigger subjective and physiological reactions on the real subject’s body and, therefore, an acute improvement of cognitive functions after a single session of high-intensity intermittent exercise performed exclusively by one’s own virtual body, similar to what happens when we actually do physical activity. As well as confirming previous results, here, we aimed at finding in the elderly (...) an increased improvement after a longer virtual training with similar characteristics. Forty-two healthy older subjects completed a parallel-group randomized controlled trial including an adapted version of the virtual training previously used: while sitting, participants observed the virtual body in a first-person perspective or a third-person perspective performing 20 min of virtual high-intensity intermittent exercise. This was repeated twice a week for 6 weeks. During the vHIE, we measured the heart rate and administered questionnaires to evaluate illusory body ownership and agency. Before the beginning of the intervention, immediately after the first session of vHIE, and at the end of the entire intervention, we evaluated the cognitive performance at the Stroop task with online recording of the hemodynamic activity over the left dorsolateral prefrontal cortex. While we confirm previous results regarding the virtual illusion and its physiological effects, we did not find significant cognitive or neural improvement immediately after the first vHIE session. As a novelty, in the 1PP group only, we detected a significant decrease in the response time of the Stroop task in the post-intervention assessment compared to its baseline; coherently, we found an increased activation on left dorsolateral prefrontal cortex after the entire intervention. While the current results strengthen the impact of the virtual full-body illusion and its physiological consequences on the elderly as well, they might have stronger and more established body representations. Perhaps, a longer and increased exposure to those illusions is necessary to initiate the cascade of events that culminates to an improved cognitive performance. (shrink)

ABSTRACT There has been much discussion about the sense of ownership recently. It is a very controversial topic and even minimal consensus seems hard to achieve. In this paper we attempt to assess the prospects of achieving a better understanding of what is meant by 'sense of body ownership'. In order to do so, we begin by addressing an objection on which the notion itself might depend, coming from the distinction between 'inflationary' and 'deflationary' accounts of the (...) sense of body ownership. Once the path is clear, we will consider some influential ways of approaching the issue, which propose grounding the sense of ownership in the spatiality of bodily sensations, the affective dimension of bodily experience, and in its spatial dimension, among other things. We expect the results of our discussion will allow us to both identify the strongest candidates for an account of the sense of body ownership and to determine the challenges that must be met by competing explanations. RESUMEN Recientemente se ha discutido mucho sobre el sentido de propiedad. Se trata de un tema muy controversial, en el que incluso consensos mínimos parecen difíciles de alcanzar. En este artículo intentamos abordar las perspectivas que existen de lograr una mejor comprensión de lo que significa "sentido de propiedad del cuerpo". Para tal fin, empezamos abordando una objeción de la que podría depender la noción misma, derivada de la distinción entre explicaciones 'inflacionarias' y 'deflacionarias' del sentido de propiedad del cuerpo. Una vez se haya despejado el camino, consideraremos algunas aproximaciones reconocidas al asunto, las cuales proponen fundamentar el sentido de propiedad en la espacialidad de las sensaciones corporales, en la dimensión afectiva de la experiencia corporal, en su dimensión espacial, entre otras. Esperamos que los resultados de nuestra discusión nos permitan al mismo tiempo identificar los candidatos más fuertes para explicar el sentido de propiedad del cuerpo y determinar los retos que deben enfrentar las explicaciones en contienda. (shrink)

The self-ownership thesis asserts, roughly, that agents own their minds and bodies in the same way that they can own extra-personal property. One common strategy for defending the self-ownership thesis is to show that it accords with our intuitions about the wrongness of various acts involving the expropriation of body parts. We challenge this line of defense. We argue that disgust explains our resistance to these sorts of cases and present results from an original psychological experiment in (...) support of this hypothesis. We argue further that learning that disgust is responsible for pro-self-ownership intuitions should reduce our confidence in those intuitions. After considering and rejecting some prominent “debunking” arguments predicated on disgust’s evolutionary history, we provide alternative reasons for thinking that disgust is not a reliable source of moral judgments. Rejecting the reliability of disgust as a mechanism for producing moral beliefs coheres with our considered judgments about the general kinds of considerations that are morally relevant and a range of particular moral problems. (shrink)

This is the first book in healthcare ethics addressing the moral issues regarding ownership of the human body. Modern medicine increasingly transforms the body and makes use of body parts for diagnostic, therapeutic and preventive purposes. The book analyzes the concept of body ownership. It also reviews the ownership issues arising in clinical care (for example, donation policies, autopsy) and biomedical research. Societies and legal systems also have to deal with issues of (...) class='Hi'>body ownership. A comparison is made between specific legal arrangements in The Netherlands and France, as examples of legal approaches. In the final section of the book, different theoretical perspectives on the human body are analyzed: libertarian, personalist, deontological and utilitarian theories of body ownership. (shrink)

Using human dead body for medical purposes is a common practice in medical schools and hospitals throughout the world. Iran, as an Islamic country is not an exception. According to the Islamic view, the body, like the soul, is a "gift" from God; therefore, human being does not possess absolute ownership on his or her body. But, the ownership of human beings on their bodies can be described as a kind of "stewardship". Accordingly, any kind (...) of dissection or mutilation of the corpse is forbidden, even with the informed consent of the dead or his/her relatives. The exception of this principle is when such procedures are necessary for saving lives of other persons. In this article using the human dead body for medical education, research and treatment is discussed and the perspective of Iranian Shiite religious scholars in this regard is explained. (shrink)

How does Descartes characterize the peculiar way in which each of us is aware of our bodies? I argue that Descartes recognizes a sense of bodily ownership, such that the body sensorily appears to be one's own in bodily awareness. This sensory appearance of ownership is ubiquitous, for Descartes, in that bodily awareness always confers a sense of ownership. This appearance is confused, in so far as bodily awareness simultaneously represents the subject as identical to, partially (...) composed by, and united to her body, without distinguishing these relations. Finally, the appearance of ownership is grounded in multiple other ways in which the body sensorily appears: namely, in the fact that the body appears to be inescapable, modified by bodily sensations, and an object of special concern. (shrink)

Does advocating women's reproductive rights require us to believe that women own property in their bodies? In this chapter I conclude that it does not. Although the concept of owning our own bodies — ‘whose body is it anyway?’ — has polemical and political utility, it is incoherent in philosophy and law. Rather than conflate the entirely plausible concept of women’s reproductive rights and the implausible notion of property in the body, we should keep them separate, so that (...) the weakness of the second concept does not contaminate the purity of the first. (shrink)