[tt] Mapping brain could translate thoughts into speech

[Hughes, James J.]

http://technology.newscientist.com/channel/tech/mg19626304.000-mapping-b
rain-could-translate-thoughts-into-speech.html

Mapping brain could translate thoughts into speech

    * 15 November 2007
    * NewScientist.com news service
    * Jim Giles, San Diego

Forty-one neurons is a drop in the ocean compared with the hundred
billion or so cells that are present in our brains. But those few
neurons could help Eric Ramsey talk again. It is eight years since a car
accident left Ramsey "locked-in" - aware but paralysed and unable to
communicate other than through eye movements. By listening in on a tiny
population of cells in his brain, neuroscientists hope to give him back
his "voice" - a first for someone with his problems.

Ramsey had a wireless electrode implanted 6 millimetres or so below the
surface of his brain in 2004 (see Diagram). The electrode records the
electronic pulses sent by 41 neurons that surround it in an area of the
brain involved in generating speech. By analysing the signals created
when Ramsey imagines speaking, the team has developed software that may
one day turn his thoughts into speech.

For now, the team is focusing on the building blocks of words. In a
series of experiments over the last few years, Ramsey has imagined
saying three vowel sounds: "oh", "ee" and "oo". By watching his brain
activity, the researchers have been able to identify distinct patterns
associated with the different sounds. Although the data is still being
analysed, they believe that they can correctly identify the sound Ramsey
is imagining around 80 per cent of the time, says Jonathan Brumberg of
Boston University, who presented the results at the Society for
Neuroscience meeting in San Diego, California, on 5 November.

Over the coming weeks, a computer will begin analysing and translating
Ramsay's thoughts into sounds that he will hear immediately - giving him
feedback in real time. That should allow him to tune his thoughts so
that he can consistently produce the vowel he wants. "That will be
really exciting," says Joe Wright of Neural Signals, a company based in
Duluth, Georgia, that has helped develop the technology Ramsey is using.
"We hope it will be a breakthrough."

After that, the researchers will extend the range of sounds to other
vowels and also consonants, with the ultimate aim of enabling Ramsey to
hold conversations. The electrode is implanted in an area of brain that
generates the movements of the tongue and mouth when speech is being
generated. Since no one else has attempted this before, they acknowledge
that there is a long way to go. "Conversation is what we're hoping for,
but we're pretty far from that," says Wright.

Ramsey is an ideal person to put this treatment to the test, since he
was just 19 at the time of the accident, has a normal life expectancy
and is capable of participating in several sessions a week. Previous
studies have usually involved people who are locked-in as a result of a
terminal illness such as amyotrophic lateral sclerosis, a handful of
whom have had electrodes implanted to help them move cursors on a
computer screen, for example.

Progress with such volunteers has been steady, says Dawn Taylor, a
biomedical engineer at Case Western Reserve University in Cleveland,
Ohio, and they can move cursors with a skill approaching that of an
able-bodied person.