Photos: Virtual reality, avatars probe consciousness

The work is building on clinical studies of neurological patients who have reported out-of-body experiences. These episodes often show themselves through increased activity in the temporoparietal and frontal regions of the brain that translate touch and vision into coherent perception.

As well as the electrodes, subjects are fitted with a stereoscopic visor that puts them in a virtual world, where they interact with other avatars and experience their own avatar from a first- and third-person perspective.

The questions the research is trying to answer include where people feel they are located in space and what they perceive to be their body, both of which are fundamental aspects of consciousness.

EPFL's Blanke said traditional approaches have not been looking at the right information 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," he added.

Subjects are able to stand, move their heads and walk while wearing the virtual reality headsets. To affect the responses of subjects, researchers touch them on the arm or shoulder, either at the same time as another avatar in the environment or slightly out of sync, to gauge the different reactions.

Shown above is the view a subject has of another avatar touching them on the shoulder. The way they react to the visual and tactile sensations is measured by the electrodes attached to their head.

The research team has also looked at how brain activity reacts to men being projected onto female avatars and vice versa, as well as people being swapped between first-person and third-person perspectives.

The work being carried out by EPFL's Blanke and his team could lead to improvements in neuro-rehabilitation and pain management, and in treating neurological and psychiatric disease. It could also contribute to the development of robotics and virtual reality.

The next step in the research is to study the brain's response to changes to the balance and position of subjects' limbs - which are two important body cues - while in virtual environments.

When subjects are in situations where they are unable to distinguish between the real and virtual self, the researchers believe they will be in a position to ascertain factors that create self-awareness.