Amputees could feel artificial limb if put in the virtual world

London, Mar 17 (ANI): Amputees with an artificial limb are more likely to feel their prosthetic limb if they are put in a virtual environment, according to researchers at University College London (UCL).

Anthony Steed, a computer scientist at UCL, studied how the rubber hand illusion Movie Camera works in virtual worlds.

In the standard illusion, a false hand is placed on a table in front of a volunteer whose real hand is out of view, and both are stroked at the same time.

After a while people feel a sensation in the rubber hand, even when it is the only one being touched.

And now, it has been discovered that people relate to virtual appendages so strongly that much of the set-up work normally needed to pull off the illusion is unnecessary in virtual environments.

For example, people automatically experience ownership of their virtual limbs, without needing simultaneous stroking in the real world, claims Steed.

In the experiment, twenty volunteers were asked to play simple games in a virtual environment that gave a real-world perspective in which the avatar's hands were represented as if they were the volunteer's own.

The volunteers were hooked up to a monitoring system, which recorded the movements of muscles and nerve-endings firing. At a random point in the game, a lamp on the virtual table toppled onto the volunteer, and their reactions were monitored.

Majority of the volunteers made gestures with their arm suggesting they were trying to move it out of the way - despite there being no real risk.

Later, the volunteers acknowledged they had behaved as if the virtual hand were their own, reported Steed.

On repeating the experiment using an arrow to represent the arm, there was no empathic response.

"The strength of the rubber hand illusion depends critically on the representation of the hand," New Scientist quoted Steed as saying.

The experiments suggest virtual reality may be helpful for people learning to use a prosthetic limb, said Kristina Caudle at the Brain Imaging Lab at Dartmouth College, Hanover, New Hampshire.

Getting accustomed to moving and feeling ownership of a virtual limb might make it easier for an amputee to accept their prosthetic limb.

The study will be presented at the Virtual Reality 2010 conference in Waltham, Massachusetts, later this month. (ANI)