Clinical neurologist with the Prince of Wales Medical Research Institute
, Dr Lorimer Moseley
, says it shows for the first time that body images can be formed independent of any outside sensory input.
"The experiment shows that the brain can create a completely new way of working the body and it can do that without any external feedback.
Moseley's work, done with Swiss neuroscientist Dr Peter Brugger, appears in the journal Proceedings of the National Academy of Science.
When we try to identify an image of a left or right hand we mentally rotate our hands to adopt the position shown.
and Brugger took advantage of this innate ability, measuring how long it took.
says that they were surprised to find that afterwards, the amputees had difficulty envisaging their phantom limbs doing the more routine tasks again.
The researchers believe this implies that our body image must obey Newton's laws, and we may make adjustments to ensure they continue to do that even when the mind is making the rules for itself.
More broadly, it demonstrates that profound changes can occur to body image and self awareness that are independent of outside input.
But what is the practical significance of being able to teach imaginary wrists to do impossible things?
In the near future, the findings could potentially be used to help guide amputees experiencing acute pain in phantom limbs to internally adjust their body image in a way that will remove the pain, says Moseley
In this way, an amputee who may be experiencing pain caused by the sense that their phantom arm is stuck behind their head, can be helped to reset the body image to have the phantom arm in a more comfortable position.
says there may be broader applications in the future in using the knowledge that we may potentially adjust images internally in ways that could have physiological effects. http://www.abc.net.au/science/articles/2009/10/27/2725151.htm