Thoughts to actions

A new device to be strapped to the head detects which part of a brain is activated; technology could help those with locked-in syndrome or paralysis lead a better life








Mumbai Mirror Bureau


Researchers try out the new device which, when strapped to the side of the head, sends a beam of light through the skull to track brain activity. The gadget detects simple yes/no answers for paralytic patients, helping them communicate better with the help of a computer


Peggy Chun is a popular artist known for bold watercolour paintings that capture the spirit of her home in Hawaii. But in 2002, the painter was diagnosed with Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease. This neurologic disorder progressively destroys a person's motor neurons: Chun can feel, see, smell, taste, think and imagine, but can no longer move in any way. She is, in medical parlance, "locked-in".

But now, a team of US scientists has developed a device - to be strapped to the head - that can help Chun communicate again, albeit in simple yes-and-no answers.

ALS is the most frequent cause of locked-in syndrome, which begins with numbness in the extremities and progresses upward until all motor function disappears.

"Usually the last thing you lose is eye movement," says University of Virginia cognitive psychologist Dennis Proffitt. "When you lose that, you are cognitively alert, you can think, you can feel, but you can't move a thing. As a result, you can't communicate in any way. It's awful."

Proffitt, whose research focuses on creating computer interfaces that help improve human cognitive processes, is working with colleagues at Georgia Tech and a company called Archinoetics to develop the technology that may make life for locked-in patients more bearable.

The device involves an interface that uses functional Near InfraRed imaging (fNIR) to assess activity in Broca's area - a part of the brain where verbal working memory occurs.

Just above the left ear, researchers strap a device that projects a light beam through the skull and measures changes in blood volume and oxygenation when Broca's area is engaged.

Then, the researchers ask subjects to count in their head when they want to activate the verbal working memory and initiate a "yes" response. When they want to say "no", subjects think of clouds or rest or think "la la la". It's an easy process and does not require a lot of training.

"It was hard for us to think of something we could ask a person to do - something easy to control, something you can turn on and off - that we could measure in this way," explains Proffitt. "What we came up with was subvocal speech ... talking to yourself."

But he quickly stresses: "It's not reading your thoughts. We can't do that."

Scientists know the kinds of things the brain is doing because different parts of the brain are activated when a person performs different functions. Proffitt's system simply detects whether or not a particular area of the brain is actively engaged at the time.

"You could be counting, or you could be reciting a poem. We couldn't tell the difference," Proffitt says. "We just know the kind of thing you're doing."

The system is still primitive, Proffitt admits, but it's a start.

"Right now, it's an on/off switch. What we want to do is to get continuous control so the person is not just activating (verbal working memory) but can say by how much. So, not just ‘yes' or ‘no', but small to large...," he says. "If we could achieve that in the next few years, it would be a huge improvement in what we will be able to do with the technology."

But Peggy Chun isn't waiting for the technology to evolve. She's using the system now as a tool for creativity.

With the sensor in place over her left ear, the artist activates Broca's area to select shades from a palette that show up on a computer screen as horizontal gradations of colour. She calls her new oeuvre "brain art".



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