Why are out-of-body experiences interesting for philosophers?: The theoretical relevance of OBE research

Abstract

After decades of only sparse scientific interest, we are currently witnessing a renaissance of empirical research into out-of-body experiences (OBEs) and full-body illusions. Being a philosopher of mind, I obviously have only a limited judgment of how good this research actually is from a purely scientific point of view. What I can do, however, is to draw attention to a series of theoretical aspects that make OBEs a particularly relevant target of investigation in the ongoing search for the neural correlate of self-consciousness and in the wider context of an empirically grounded theory of the human mind. Firstly, and most basically, this type of research has a great potential for conceptual differentiation. By more clearly distinguishing different types of neurological disorders affecting the sense of self, it will help to improve the taxonomy of selfrelated disorders. Introducing more fine grained conceptual distinctions will have diagnostic, and perhaps also therapeutic value, because it contributes to our taxonomy of hallucinations and deviant forms of self-modeling (see Metzinger, 2003, chapter 7) involving dimensions like ‘‘self-location’’ and ‘‘selfidentification’’. The four main types are autoscopic hallucination, heautoscopy, OBE, and the feeling of a presence – all due to multisensory disintegration and damage to temporo-parietal and temporo-occipital cortex (Blanke and Mohr, 2005; Blanke and Castillo, 2007). Autoscopic phenomena show that not only identification with and localization of body parts, but also of the global conscious representation of the entire body can be disturbed. In autoscopic hallucinations and heautoscopy patients see a second own illusory body in extrapersonal space, but the two phenomena differ in terms of self-identification