Embodiment, ownership and disownership

Abstract

There are two main pathways to investigate the sense of body ownership, (i) through the study of the conditions of embodiment for an object to be experienced as one’s own and (ii) through the analysis of the deficits in patients who experience a body part as alien. Here, I propose that E is embodied if some properties of E are processed in the same way as the properties of one’s body. However, one must distinguish among different types of embodiment, and only self-specific embodiment can lead to feelings of ownership. I address issues such as the functional role and the dynamics of embodiment, degrees and measures of ownership, and shared body representations between self and others. I then analyse the interaction between ownership and disownership. On the one hand, I show that there is no evidence that in the Rubber Hand Illusion, the rubber hand replaces the biological hand. On the other hand, I argue that the sense of disownership experienced by patients towards their body part cannot be reduced to the mere lack of ownership.

Introduction

Our body may be the object we know the best, from which we constantly receive a flow of information from vision, touch, proprioception, the vestibular and the interoceptive systems. Not only do we receive more information on our body than on any other objects, but we also have an internal access to it that we have to no other bodies. What makes our body so special may thus be that unlike other physical objects and other bodies, we perceive it from the inside. Only in our body, or at least in what we represent as our own body, do we feel bodily sensations. We also care for our body like we care for no other bodies, let alone other objects. Finally, it seems that it is only our own body that obeys our will with no intermediary.

Yet, the relation between the body and the self is complex, giving rise to vivid philosophical debates (see Table 1).

Some debates have been going on for centuries like questions about the ontological nature of the self and personal identity or about the epistemological certainty we have that this is our own body with no possible doubt. Other debates have emerged from recent scientific progress like issues about the moral and legal status of body parts in a time of research on biological materials or questions about the sensory and cognitive underpinnings of the sense of body ownership following a booming of studies in cognitive psychology and neuropsychology these last 10 years.

Here, I shall set the agenda for the investigation of the sense of ownership of body parts.¹ I shall focus on two main pathways, through the study of embodiment and through the study of disownership (see Table 2). However, the relation between embodiment, ownership and disownership is too often left unarticulated. In the paper, I shall bring out some of the main lines of force in this literature and lay the foundation for a proper theory of the sense of ownership. Two questions are of particular interest. First, are embodiment and ownership a matter of all-or-nothing or does it come in degrees or in various types? Second, what is the relationship between experiences of ownership and experiences of disownership?