Canadian boffins say they have developed a headset which can read the wearer's mind by shining infrared light into the brain.
"Preference is the basis for everyday decisions," says Sheena Luu of the University of Toronto. "This is the first system that decodes preference naturally from spontaneous thoughts. If we limit the context - limit the question and available answers, as we have with predicting preference - then mind-reading becomes possible."
The Toronto bioengineering researchers say that their brainprobe hat system is the first which requires no training for the user. Rather, the system learns how to interpret an individual's brain activity.
In trials, a group of adults were fitted with headbands which shone infrared light into their pre-frontal cortexes and measured how much of it was absorbed.
"When your brain is active, the oxygen in your blood increases and depending on the concentration, it absorbs more or less light," Luu said. "In some people, their brains are more active when they don't like something, and in some people they're more active when they do like something."
After a few dummy runs to learn how each individual's brain responded to a given situation, according to Luu & Co, the machine was able to tell whether a user liked or didn't like a drink presented to them with 80 per cent accuracy.
Such systems have already been tried out, according to Toronto Uni, but they normally require a user to perform a specific mental activity - for instance singing a song in their head - to establish a pattern of brain activity that machines can recognise. The Canadian boffins believe that theirs is the first system which can perceive basic, untrained responses.
Luu and her colleagues believe that this means the system would be particularly suitable for disabled children. Lacking any conventional means of communication to start with, it is hard to train such users to work with a normal brain interface.
Working with the Bloorview children's rehabilitation hospital, Canada's largest, the Toronto bioengineers hope to create a small wireless infrared brain-sensor "that rests on the forehead".
They intend to use the new forehead mindprobe to "open up the world of choice to children who can't speak or move".
Luu and her colleagues publish their research in the Journal of Neural Engineering, here. ®