Multisensory mechanisms underlying bodily self-consciousness

Recent philosophical and neuroscientific theories converge on the assumption that the basic foundations of self-consciousness lie in those brain systems that represent the body. Neurological cases in which this basic bodily self-consciousness is disturbed such as out-of-body experiences can inform us about underlying functional brain mechanisms and suggest the importance of multisensory integration of different bodily inputs into a coherent body- and self-representation. Using simple virtual reality techniques we conducted a number of behavioural and brain imaging studies in healthy participants that were inspired by these clinical findings. The results demonstrate that experimental generation of multisensory conflicts can induce measurable changes in bodily self-consciousness, in particular in relation to self-location (where the consciously experienced "I" is localized). These changes were further associated with a change in tactile representation as well as modified pain-thresholds. The brain imagine studies suggest that a broad network of the sensorimotor and medial-frontal cortex, the temoporo-parietal-junction and the precuneus is involved in normal and abnormal self-location.