Using a camera and goggles researchers were able to induce a feeling that the virtual body was their own body.
This is much the same as when I do mirror visual feedback. My brain interprets the single limb and it's mirror image as a whole body.
When the camera was switched off and the volunteers were asked to stand where they thought they were during the experiment, the volunteers stood where they perceived the virtual body to be.
With chronic pain such as CRPS/RSD it is known that there is an altered body schema and the neurotag is smudged. This basically means that the brain hasn't a clear focused image of the body and where it hurts. The pain spreads out just as if you rubbed a black dot and made it smudgy so pain, instead of being focused on one spot has spread out and is hard to explain. I wonder if the this sense of being where the virtual body was imaged as in this experiment, could help explain why many people with CRPS/RSD have problems with spacial awareness and bump into things.
"Dr Henrik Ehrsson found volunteers had a physiological response - increased skin sweating - when they felt their virtual self was being threatened - appearing to be hit with a hammer."
If you can induce an autonomic nervous system response such as sweating from a threat to the virtual body it helps me understand why my body is calmed by seeing my mirrored limb without threat or pain. This idea of seeing the whole body or the body as a whole clarifies for me the need, when doing mirror therapy to see the both sides of the body (left and right) as if viewing a whole body. This differs from thinking of just seeing the mirror image of a good side.
At present the Interfaces group in Manchester in the UK are doing research on using virtual reality technology to relieve chronic pain. They already have succeeded in reliving phantom limb pain.
The potential use of this technology is far reaching from relieving pain and symptoms of Complex Regional Pain Syndrome and other chronic pain to performing "virtual" surgery.
G. Riva, C. Botella, P. Légeron and G. Optale (Eds.) Amsterdam, IOS Press,© 2004, 2005, 2006 produced a very comprehensive document "
Cybertherapy, Internet and Virtual Reality as Assessment and Rehabilitation Tools for Clinical Psychology and Neuroscience". It explains that what was first used for training in big companies is now used for treatment. Over time some of the limitation have been overcome and it is now used as a tool in treatnment of psychological disorders such as post traaumatic stress disorder. In fact, Hodges and Rothbaum have developed the first software for treatment of Vietnam War Veterans and for victims of the world trade center disaster.
To read this article and others, particularly the work of the Advanced Interfaces Group, go to "articles of interest" to the left of this blog and click on the link.