In the studies published in Thursday’s Science journal, two teams of researchers managed to induce the effect in healthy people by scrambling their senses of vision and touch with the aid of the goggles.
“We ... describe an illusion during which healthy participants experienced a virtual body as if it were their own, and localized their ‘selves’ outside their body borders at a different position in space,” wrote Olaf Blanke, a researcher at the Ecole Polytechnique Federale de Lausanne in Switzerland.
One team, led by Henrik Ehrsson at University College London, had volunteers sit in a chair in the middle of a room wearing virtual-reality goggles showing the view from a video camera placed behind them.
A researcher moved a rod up to the camera at the same time as the person's chest was touched, and then the rod disappeared from view.
This created the illusion that the person was sitting a few steps back, where the camera stood.
In Blanke's experiment, subjects wearing virtual-reality goggles watched an image of a mannequin representing their own body placed directly in front of them while a researcher scratched their back.
Afterwards, the volunteers were blindfolded and guided backwards. When they were asked to return to their original positions, they went toward the place where they had seen their virtual body — the mannequin.
The researchers said mixing up the senses of sight and touch was key to the experiments.
As the story notes, the studies could shed more light on the sense of one’s self, from the basic proprioception, or knowing where one’s body is in relation to exterior space, to the grounding of a psychological self that has given rise to ideas of a “soul.”