Thursday, April 18, 2013
Behavioral Social Neuroscience Seminar
Multisensory Mechanisms of Body Self-Perception
Henrik Ehrsson, Associate Professor, Department of Neuroscience , Karolinska Institutet
Ask any child if his hands belong to him and the answer will be "Of course!" But how does the brain actually identify its own body? Henrik Ehrsson will describe how cognitive neuroscientists have recently begun to address this fundamental question. A key idea is that parts of the body are distinguished from the external world by the patterns they produce of correlated information from different sensory modalities (vision, touch and muscle sense). These correlations are hypothesized to be detected by neuronal populations in premotor and posterior parietal areas that integrate multisensory information from the space near the body. Dr. Ehrsson and his team have recently used a combination of functional magnetic resonance imaging and human behavioral experiments to present experimental evidence in support of these predictions. To change the feeling of body ownership, perceptual illusions were used where healthy individuals experienced that a rubber hand was their own, that a mannequin was their body ("body-swap illusion"), or, that they are outside their physical body and looking at it from the perspective of another individual ("out-of-body illusion"). By clarifying how the normal brain produces a sense of ownership of one's body, we can learn to project ownership onto artificial bodies and simulated virtual ones; and even make two people have the experience of swapping bodies with one another. This could have ground-breaking applications in the fields of virtual reality and neuro-prosthetics.