Scientists take their first virtual stroll using mind control

In a paper to be presented today at the 8th Annual International Workshop on Presence, which is hosted by UCL, the researchers found it's possible for able-bodied people to use a Brain-Computer Interface to walk forward in a virtual environment by imagining their feet moving.

Three volunteers took part in experiments over five months using different virtual environments. Results show that after 10 minutes training they had an 80 per cent success rate, and with further tutelage their success rate increased up to a hundred percent.

The researchers say the ability to carry out acts just by thinking about them opens the door to novel computer interfaces such as controlling desk-top PCs with your mind and controlling robotic limbs just by thinking about moving them.

Previously the focus of research has been on navigating through a virtual world using hand-held devices, such as a joystick. They generate the illusion of walking but the participant is thinking of moving their index finger rather than feet, which reduces the sense of being present in the virtual environment.

Direct brain-computer communication is a novel approach in developing an additional communication channel for human-machine interaction. Users imagine different types of movement - such as right hand, left foot or tongue movement - which result in a characteristic change in the electroencephalogram (EEG) over the sensorimotor cortex of a participant. The Brain-Computer Interface detects changes in the ongoing EEG while thinking about movements and transforms them into a control signal.

Three healthy participants aged between 25 and 30 who did not have a history of neurological disease took part in the experiments. Each trial lasted for eight seconds and was conducted in blocks of 40, with four such blocks being conducted over a day.

The participants had to imagine feet or right hand movement in response to a visual cue-stimulus across three types of Brain-Computer Interface:

• a normal computer monitor
• a head-mounted display
• a 'virtual Cave' environment.

The virtual Cave surrounds the user with stereo (3D) projection on three walls and floor. The images on adjacent walls are seamlessly joined together so that the participants don't see the physical corners, but the continuous virtual world that is projected in stereo.

During the experiments the participants where told by a trigger to think about either their feet or their hand. Only when they thought about their feet when they were told to, were they able to move forward in the virtual environment. If they thought about their hand when they were supposed to be thinking about their feet, they moved backwards in the virtual environment. Results show there was a success rate of 80 to 100 per cent.

Dr Doron Friedman, of the UCL Department of Computer Science and one of the authors of the study, says:

"Researchers have been working on Brain-Computer Interfaces for a number of years but we've pushed the boundary by allowing participants to navigate in an immersed virtual reality environment. Compared with experiments using desktop monitors it makes the experience 'more real' for the individual and a corresponding increase in performance is observed."

The paper 'Walking from Thoughts: Not the Muscles are Crucial, But the Brainwaves!' will be presented on Wednesday 21 September at midday by Robert Leeb of Graz University of Technology, Austria

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Judith H Moore, UCL Media Relations Manager, Tel: +44 (0) 20 7679 7678, Mobile : +44 (0)77333 075 96, Email: judith.moore@ucl.ac.uk

Notes to editors

Authors of the study: Robert Leeb (1), Claudia Keinrath (1), Doron Friedman (2), Christop Guger (3), Christa Neuper (1,4), Maia Garau (2), Angus Antley (2), Anthony Steed (2), Mel Slater (2), Gert Pfurtscheller (1,5)

(1) Laboratory of Brain-Computer Interfaces, Institute of Computer Graphics and Vision, Graz University of Technology, Austria

(2) UCL Department of Computer Science, University College London , UK

(3) g.tec - Guger Technologies OEG, Austria

(4) Department of Psychology, University of Graz , Austria

(5) Ludwig-Boltzmann Institut fur medizinische Informatik und Neuroinformatik, Graz University of Technology, Austria