Scientist Report Mental 'Body-Swapping'

[Guest guest]

Very interesting. I wonder if this could be used to lessen the

feeling of pain or lessen sensativities.

http://www.washingtonpost.com/wp-

dyn/content/article/2008/12/02/AR2008120202527.html?nav=hcmodule

Scientists Report Mental 'Body-Swapping'

Tuesday, December 2, 2008; 12:00 AM

TUESDAY, Dec. 2 (HealthDay News) -- The illusion of body-swapping --

making people perceive the bodies of mannequins and other people as

their own -- has been achieved by Swedish neuroscientists.

In one experiment, the team fitted the head of a mannequin with two

cameras connected to two small screens placed in front of volunteers'

eyes, so that they had the same view as the mannequin.

When the mannequin's camera eyes and a participant's head were

directed downwards, the participant saw the mannequin's body where

the person would normally have seen their own body.

The researchers created the illusion of body-swapping by touching the

stomach of both the mannequin and the volunteer with sticks. The

person saw the mannequin's stomach being touched while feeling (but

not seeing) a similar sensation on their own stomach. As a result,

the person developed a strong belief that the mannequin's body was

actually their own.

" This shows how easy it is to change the brain's perception of the

physical self. By manipulating sensory impressions, it's possible to

fool the self not only out of its body but into other bodies, too, "

project leader Henrik Ehrsson, of the Karolinska Institute in

Stockholm, said in a news release.

In another experiment, a camera was mounted on one person's head and

screens were mounted in front of another person's eyes. When the

person with the camera and the person with the screens turned towards

each other to shake hands, the person with the screens perceived the

camera-wearer's body as his/her own.

" The subjects see themselves shaking hands from the outside, but

experience it as another person. The sensory impression from the

handshake is perceived as though coming from the new body, rather

than the subject's own, " study co-author Valeria Petkova said in the

news release.

This illusion worked even when two people looked different or were of

different sexes. It did not work when a non-humanoid object -- such

as a chair or large block -- was used.

The research, published online Wednesday in the journal PLoS One,

could prove useful in virtual reality applications and in robot

technology, the team said.

More information

There's more on how the brain works at McGill University.

SOURCE: Public Library of Science, news release, Dec. 2, 2008