Neuroscience of Bodily Self-Consciousness

We review recent research about human subjectivity and self-consciousness that has focused on cognitive psychology and neuroimaging of bodily self-consciousness. Multidisciplinary research on the fields of neurology, cognitive neuroscience and virtual reality opens new avenues to investigate brain mechanisms underlying a fundamental sense of the bodily self. Clinical evidence for the implication of right temporo-parietal junction for bodily self-consciousness has received support by studies in which virtual-reality based own body illusions are evoked in healthy participants to study the underlying processes. A series of experiments will be reviewed in which it was shown that the experiences of self-location, self-identification and the first-person perspective can be manipulated experimentally and rely on the integration of multisensory stimuli (touch, vision, proprioception, vestibular information). Specific protocols are available to predictably influence the different aspects of bodily self consciousness. We predict that the understanding of fundamental brain mechanisms of bodily self-consciousness will lead to unprecedented empirical insights that are of broad relevance for science, virtual reality, engineering, the humanities, as well as medicine and psychotherapy. A Neuroscience Approach to Subjective Experience «The body is always there» (James, 1891) has become a famous expression as it highlights the fact that the human brain continuously receives information from the body (as opposed to vision or sound) which is afferent to the brain. All human beings are confined to a biological container (i.e. their body) in which subjective experience originates. French philosopher René Descartes (1637) radically rejected the idea of unity between body and subjective experience when postulating his famous «Cogito ergo sum» (engl. «I think so I am»), which capitalized one of the major philosophical debates around the bodymind problem. Dualists, such as Descartes, claim that body and mind are very distinct substances of very distinct quality. Most present philosophers and neuroscientists reject such dualist models and study the brain mechanisms underlying the self and selfconsciousness empirically or conceptually based on this data (for recent discussion see Metzinger, 2007). Neuroscientists have always been fascinated by the scientific study of subjective experience and the related concepts of consciousness and awareness (e.g. Grüsser and Landis, 1991), but only recently a vast array of experimental procedures has become available to study the brain mechanisms of self-consciousness. Previous cognitive neuroscience research on the self has focused on high-level aspects such as language, conceptual knowledge or memory. In the present review we will highlight some recent discoveries related to low-level contributions to self-consciousness, Neuroscience of Bodily Self-Consciousness Christian Pfeiffer*, Estelle Palluel**, Olaf Blanke*** *Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne E-mail: [email protected] Christian Pfeiffer, is doctoral student in the Laboratory of Cognitive Neuroscience at the Swiss Federal Institute of Technology (www.lnco.epfl. ch). He was trained in cognitive neuroscience and psychology at the Radboud University Nijmegen (The Netherlands) and at the Free University of Berlin (Germany) where he received his MA degree in psychology. Pfeiffer is a certified practitioner of the Feldenkrais Method. His main research interest is the neuroscientific study of bodily self-consciousness, body representation and brain plasticity. Actual research focusses on multisensory contributions to a phenomenal first-person perspective and involve the use of functional neuroimaging and neuroscience robotics. **Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne E-mail: [email protected] Estelle Palluel, is post-doctoral fellow in the Laboratory of Cognitive Neuroscience. She obtained her MA and PhD degree in Kinesiology at the Joseph Fourier University of Grenoble (France). Palluel holds a Marie Curie grant for post-doctoral studies. Her main research interests are body representations, self-consciousness, somatosensation and virtual reality. She utilizes electrical neuroimaging, behavioral measures and virtual reality for the scientific study of proprioceptive contributions to bodily self-consciousness. http://lnco.epfl.ch ***Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne E-mail: [email protected] Olaf Blanke, Dr. med., is director of the Laboratory of Cognitive Neuroscience at EPFL (www.lnco.epfl.ch) and consultant neurologist at the Department of Neurology (University Hospital of Geneva). He received a Medical degree from the Free University of Berlin University and a PhD in neurophysiology. Blanke pioneered the neuroscientific study of human self-consciousness and subjectivity by using a broad range of methods such as the neuropsychology and electrophysiology of self-consciousness in neurological disease as well as brain imaging in healthy subjects. His main interest at present is the development of a data-driven neuroscientific theory of self-consciousness and subjectivity. Another main line of research concerns balance and body perception, and their application to engineering-based technologies such as virtual reality, robotics, and neuro-rehabilitation.