Multisensory brain mechanisms of bodily self-consciousness

• Published in: Nature reviews. Neuroscience Vol. 13; no. 8; pp. 556 - 571
• Main Author: Blanke, Olaf
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2012; Nature Publishing Group
• Subjects: 631/378/1697; 631/378/2649/1398; Animal Genetics and Genomics; Animals; Behavioral psychophysiology; Behavioral Sciences; Biological and medical sciences; Biological Techniques; Biomedical and Life Sciences; Biomedicine; Brain; Brain - physiology; Brain research; Consciousness; Consciousness - physiology; Fundamental and applied biological sciences. Psychology; General aspects. Models. Methods; Hands; Humans; Illusions - physiology; Illusions - psychology; Life sciences; Neurobiology; Neurons; Neurosciences; Neurotransmission and behavior; Photic Stimulation - methods; Physiological aspects; Primates; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; review-article; Self Concept; Vertebrates: nervous system and sense organs; Virtual reality; Switzerland; Human; Vertebrata; Experience; Mammalia; Central nervous system; Primates; Multisensory integration; Models; Review; Encephalon
• ISSN: 1471-003X; 1471-0048; 1471-0048; 1469-3178
• DOI: 10.1038/nrn3292

Key Points A powerful approach to study self-consciousness has been to target brain mechanisms that process bodily signals (bodily self-consciousness). Bodily self-consciousness depends on three factors: self-identification with the body, self-location and the first-person perspective. Visuotactile and visuovestibular conflicts that induce changes in bodily self-consciousness have been tested using video, virtual reality and robotic devices. Experimental changes in illusory self-identification with a fake or virtual body are associated with changes in touch and pain perception, as well as physiological changes. Activity in the bilateral premotor cortex and posterior parietal cortex that is probably due to the activation of multisensory neurons integrating visual and somatosensory signals has been associated with self-identification. Neurological data in patients with heautoscopy reveal that damage to the left temporoparietal cortex leads to abnormal self-identification and self-location. Activity in the temporoparietal cortex and posterior parietal cortex that is probably due to the activation of multisensory neurons integrating vestibular, visual and tactile signals has been associated with self-location and the first-person perspective. Neurological data in patients with out-of-body experiences reveal that damage to the right temporoparietal cortex (posterior superior temporal gyrus) leads to abnormal self-location and first-person perspective. The interaction of these multisensory signals with other bodily signals, especially those related to interoceptive signals, and their respective importance for bodily self-consciousness and consciousness in general should be targeted by future research. Future neuro-rehabilitation procedures for amputees, stroke patients and patients with spinal cord injury are likely to benefit from the described automatized multisensory stimulations between augmented artificial bodies and residual own-body signals. Bodily self-consciousness includes the conscious experience of identifying with the body, of where 'I' am in space, and of the perspective from where 'I' perceive the world. Olaf Blanke discusses the cortical mechanisms that underlie these experiences, highlighting data from neuroimaging, neurology and virtual reality. Recent research has linked bodily self-consciousness to the processing and integration of multisensory bodily signals in temporoparietal, premotor, posterior parietal and extrastriate cortices. Studies in which subjects receive ambiguous multisensory information about the location and appearance of their own body have shown that these brain areas reflect the conscious experience of identifying with the body (self-identification (also known as body-ownership)), the experience of where 'I' am in space (self-location) and the experience of the position from where 'I' perceive the world (first-person perspective). Along with phenomena of altered states of self-consciousness in neurological patients and electrophysiological data from non-human primates, these findings may form the basis for a neurobiological model of bodily self-consciousness.