The question as to what is and what is not part of your body seems to be a trivial one to answer, it is ‘obvious’. But this is not the case, since it is possible to induce very simply the illusion of quite dramatic body changes and distortions. The most famous is the ‘rubber hand illusion’ where you can temporarily feel that that a rubber hand is your own, when your corresponding real hand is hidden, and both are touched synchronously for a few seconds. For example, see the explanation by Dr Olaf Blanke in New Scientist
The technique has has also been extended to give people the feeling that they are outside of their own body, and you can see a discussion of this by Dr Henrik Ehrsson
In the EVENT Lab in Barcelona we are working on exploiting the power of fully immersive virtual reality to explore these illusions. We believe that virtual reality offers a very powerful methodology for research into this important area of how the brain represents the body. Moreover, the issue of body representation has the capability to profoundly change the technology of virtual reality itself. We have also been exploring the use of these techniques to give people experiences that would otherwise be impossible or very difficult – for example, what would it be like to have to stand in one of those infamous ‘stress positions’ during an interrogation, something that we have heard about a lot on the news? This has been explored in the idea of ‘immersive journalism’, which directly used virtual reality and ideas from body representation to give people the impression that they were in a stress position even when they were not. You can watch a short video about this on
Finally we have been exploring the connection between ‘brain computer interfaces’ (BCI) and body representation. Our first experiment reported in NeuroReport Inducing a virtual hand ownership illusion through a brain-computer interface showed that when people move a virtual arm by motor imagery that they have a feeling similar to that of the ‘rubber arm illusion’ – they report subjectively that the virtual arm appears to be theirs. However, the illusion is not as strong as the full ‘rubber arm illusion’.
Mel Slater is can be contacted at melslater@ub.edu, and some related information is available on Mel’s Presence blog.
You may also like his recent paper in Frontiers in Neuroscience – Inducing Illusory Ownership of a Virtual Body
About Mel Slater
Mel Slater was an ICREA Research Professor at the Universitat Politècnica de Catalunya , in the Llenguatges i Sistemes Informàtics Department since January 2006. He remains Profesor Asociado at UPC, although his ICREA position has been transferred to the University of Barcelona in the EVENT Lab. He founded the Virtual Environments and Computer Graphics group in the Department of Computer Science, University College London, where he still has several projects and PhD students.
And if you want to see more of Mel, check him out on YouTube “3 Questions Mel Slater”
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