Two Legs, Two Hands, One Head, Who Am I?

Henrik Ehrsson (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 that integrate multisensory information from the space near the body. 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 important applications in the fields of virtual reality and neuro-prosthetics.

Henrik Ehrsson is a professor of cognitive neuroscience interested in the problem of how we come to sense that we own our body. He currently leads a group at the Karolinska Institutet consisting of five PhD students, three postdocs and one research engineer (www.ehrssonlab.se). The main methods used in his laboratory include functional magnetic resonance imaging (fMRI), behavioral paradigms, psychophysiology, virtual/video reality and transcranial magnetic stimulation. Dr. Ehrsson and his team members have published over 60 original peer-reviewed scientific works, including articles in journals such as Science, Neuron, PNAS, Current Biology, The Journal of Neuroscience and Brain.

Five selected publications

Bergouignan L., Nyberg, L, Ehrsson, H.H. Out-of-body-induced hippocampal amnesia.Proceedings of the National Academy of Sciences, 111:4421-6, 2014

Guterstam, A., Gentile, G., Ehrsson, H.H. The invisible hand illusion: multisensory integration leads to the embodiment of a discrete volume of empty space. J. Cog. Neurosci. 2103

Petkova, V.I., Björnsdotter, M., Gentile, G., Jonsson, T., Li, T.Q., & Ehrsson, H.H. From part to whole-body ownership in the multisensory brain. Curr. Biol. 21 1-5, 2011

Petkova, V.I. & Ehrsson, H.H. If I were you: perceptual illusion of body swapping. PLoS ONE, 3(12):e3832, 2008

Ehrsson, H.H. The experimental induction of out-of-body experiences. Science, 317: 1048, 2007