Real-time, brain-scanning speller gives the silent a voice


June 29, 2012

Researchers have developed technology that automatically decode distinct brain patterns to allow individuals to spell out sentences (Image: Shutterstock)

Researchers have developed technology that automatically decode distinct brain patterns to allow individuals to spell out sentences (Image: Shutterstock)

Researchers at Maastricht University in The Netherlands have developed a device that gives a voice to those who are completely unable to speak or move at all. Building on previous work using functional magnetic imaging (fMRI) technology, which allowed individuals to give yes/no responses or answer multiple-choice questions, the new approach allows for full, unscripted back-and-forth conversations.

FMRI is a non-invasive technique that measures brain activity by detecting the changes in blood oxygenation and flow that occur in response to neural activity. It has previously been used to assess consciousness in people described as being in an unconscious, vegetative state and enable them to answer yes/no questions. This was then expanded to allow individuals to answer the equivalent of multiple-choice questions having four or fewer possible answers.

Maastricht University’s Bettina Sorger and colleagues have now taken this approach one step further by creating a real-time, brain-scanning speller. Sorger’s team came up with a letter-encoding technique in which participants were asked to perform a particular mental task for a set period of time to signify a specific character. This produced 27 distinct brain patterns corresponding to each letter of the alphabet and a space character.

The letter-encoding technique required almost no pre-training and the 27 distinct brain patterns could be automatically decoded in real time. Communication experiments carried out by the team saw participants holding a mini-conversation consisting of two open ended questions and answers. Every participant tested was able to successfully produce answers within a single one-hour session.

Because MRi machines are bulky and expensive pieces of equipment, Sorger hopes the fMRI technology she and her team have developed can be transferred to a more portable and affordable method of measuring blood flow, such as functional near-infrared spectroscopy (fNIRS).

The team’s research is detailed in a report published online in Current Biology.

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag. All articles by Darren Quick
1 Comment

For those of us who are familiar with the early history of Star Trek this research is now where the story restores a voice to Captain Christopher Pike, the first commander of the Enterprise, followed as we all Know by Captain James Tiberius Kirk.

It never ceases to amaze me how technology catches up with and possibly surpasses imagination. If we can imagine it we can probably go there, even going where no one has gone before... Now if only someone can figure how to make a synthetic crystal using multiple pairs of lithium atoms to enable the thorium fusion-fission cycle to generate power for a drive system capable of warping space-time...

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