Swiss scientists have projected volunteers into the body of an avatar or virtual human, taking virtual reality to a new level.
They even made men feel like women and women like men. Scientists at the Ecole Polytechnique Fédérale de Lausanne (EPFL) reported their work to the American Association for the Advancement of Science annual meeting in Washington.
The research aims to investigate how people inhabit and own their body – in other words, to understand self-consciousness. It also has practical applications ranging from better pain treatments and rehabilitation of patients with brain injury to new virtual reality games.
The scientists fitted their subjects with electrode-studded skullcaps to monitor brain activity and exposed them to different three-dimensional environments through head-mounted stereoscopic visors, which had the effect of projecting them into another body.
The researchers then disturbed the volunteers’ normal sense of identity and where they were, by physically touching their real body, both in and out of sync with the avatar.
The results showed big changes in the volunteers’ brain activity as they settled into their avatar body and then had their perceptions disrupted.
“You feel a strange disembodiment as you occupy the avatar,” said Michael Mitchell, a volunteer. “It is a very weird feeling.”
Olaf Blanke, the study leader, said: “Traditional approaches have not been looking at the right information in order to understand the notion of the 'I' of conscious feeling and thinking. Our research approaches the self first of all as the way the body is represented in the brain and how this affects the conscious mind.”
Professor Blanke believes the concept of “bodily self” came before more advanced ideas of self-consciousness in human evolution.
The next steps in the project will be to enhance the feeling of inhabiting another body, altering signals of balance and limb position in the experimental set-up. Pain control is a promising application.
“We found that subjects can bear more intense pain when they are in the body of an avatar than in their own body,” Prof Blanke said. “The pain threshold increased by 16 per cent on average – and this analgesic effect might be useful for controlling currently un-treatable forms of pain.”
The research could also help the development of prosthetic devices, controlled by the patient’s thoughts.
“Ownership is at the core of neuro-prosthetics,” said Jose Milan of EPFL.
“The prosthetic device must give the patient a sense of ownership.”
But for Prof Blanke the main motivation is more cerebral: “To solve the mystery of ‘I’ once and for all.”