FWP writes:
> I think we'll learn a lot about chip implants when Professor War-borg does
> his next experiment early next year. If I understood it correctly, this
> time he is going to determine if the afferent connections work well enough
> to upload significant amounts of information directly from chip to
> brain. Anyay, the article is in Wired, Feb/01.
That's at http://www.wired.com/wired/archive/8.02/warwick.html.
Coincidentally I received the August issue of Wired today and it describes
research next to which Warwick's little arm chip is little more than a
sideshow stunt. The article, by wheelchair-bound John Hockenberry, tells
about work to expand the capabilities of the disabled via mind-machine
interface:
"When you meet Johnny Ray, it's a challenge to see the former drywall
contractor and amateur musician trapped inside his body, but he's there.
Ray, a 63-year-old from Carrollton, Georgia, suffered a brain-stem stroke
in 1997, which produced what doctors call "locked-in syndrome": He has
virtually no moving parts. Cognitively he's intact, but he can't make
a motion to deliver that message or any other to the world."
...
"[Dr. Roy] Bakay... wouldn't describe anything he does as show business,
but to me the results of his work sound like a real-world version of
the nifty plug Neo/Keanu sported in The Matrix.
"'We simply make a hole in the skull right above the ear, near the back
end of the motor cortex, secure our electrodes and other hardware to
the bone so they don't migrate, and wait for a signal,' Bakay says.
The implant is an intriguing hybrid of electronics and biology - it
physically melds with brain tissue.
"'We use a small piece of glass shaped like two narrow cones into which
a gold electrical contact has been glued,' Bakay says. 'The space in
the cones is filled with a special tissue culture, and the whole thing
is placed inside the motor cortex.' The tissue culture is designed to
'attract' brain cells to grow toward the contact. When brain cells meet
gold, the electrical activity of individual cells is detectable across
the electrode. Gold wires carry signals back out of the skull, where they
are amplified. This produces a far more sensitive and usable signal than
you get from surface technology like the taped-on electrodes used in EEGs.
"To get a broad sense of what the patient's brain is doing, neurologists
perform magnetic resonance imaging and compare changes in the motor
cortext with voltages monitored through the electrodes. Then the doctors
get really clever. The patient is encouraged to think simple thoughts
that correspond to distinct conditions and movements, like hot/cold or
up/down. Gradually, the doctors extract and codify electrical patterns
that change as a patient's thoughts change. If a patient can reproduce
and trigger the signal using the same thought patterns, that signal can
be identified and used to control, say, a cursor on a computer screen.
The technique is very crude, but what Bakay and his colleagues have
demonstrated is a truly alternative brain-body interface pattern."
At first Ray has to imagine arm motions to trigger the cursor, but over
time his brain adapts:
"As the brain cells in and around Ray's implant did what he asked
them to do, the imagined sensation of moving his body parts gradually
disappeared altogether. One day when his skill at moving the cursor
seemed particularly adept, the doctors asked Ray what he was feeling.
Slowly, he typed, 'nothing.'
"Ray was interacting directly with the cursor similar to how he might once
have interacted with his hand. 'People don't think "move hand" to move
their hands unless they are small children just learning,' Bakay explains.
'Eventually the brain just eliminates these intermediate steps until the
hand feels like a part of the brain.' The description reminds me of how
I've heard Isaac Stern describe his violin as an extension of his body.
I think of my wheelchair the same way.
"The fact that Ray's cursor is indistinguishable from almost any other
prosthesis raises an important philosophical question: Because of the
implant, is a Dell Pentium cursor now more a part of Johnny Ray than
one of his own paralyzed arms?"
These people are the real cyborgs, with actual brain implants interfacing
to their nervous system, allowing them to control the world around them
in new ways.
Hal
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