It started with a game of Pong. Now the
science of brain implants promises a future in which blindness and
paralysis can be conquered. . Illustration by Daniel Bejar.
When a knife wound permanently damaged his spinal cord and left him
paralyzed from the neck down in 2001, Matthew Nagel found his world
reduced to a keyhole view, to what he could hear and see from his
wheelchair.
But after two seemingly hopeless years, scientists wired his
thoughts to a computer, and he began to do things quadriplegics
were once only able to dream about.
A sensing device in Nagel's brain gave him the power to do simple
tasks like playing computer games and sending e-mails. By thinking
about where he wanted to place and move the cursor on a computer
monitor, Nagel could do so. In a separate exercise, his thoughts
were wired to an artificial hand that opens and closes on his
order, flexing in ways his own hands no longer can.
"It was easy," says Nagel in a weak but confident voice, adding
that he had the basics down pat after just a few days of trial and
error.
"This is really the first time that human thoughts have been linked
to a computer," says
Ali Rezai, MD, director of the Center for
Neurological Restoration at the Cleveland Clinic, who has been
following the development of the BrainGate Neural Interface System
being used in Nagel's trial. And the education that scientists have
gained by working with Nagel is giving hope to people with a host
of medical problems. It's possible that the same technology can
give them a future to look forward to as well.
The system, with its big computer cord that's attached to a
computer post implanted in the skull, is still somewhat crude and
requires more testing before it can be rolled out, but Nagel is a
living example of what BrainGate technology can do for
quadriplegics. Drop the wires, enhance the software, and add some
new tech accessories, and the simple brain games that trial
volunteers are playing today will be replaced by a system that
offers new ways to have fun, new worlds of communication, and new
opportunities to work and to be creative again.
But that's just the launch phase for this science program.
Connect these devices to ongoing research efforts that use
deep-brain stimulation techniques to manage
epilepsy and other
neurological disorders, and they can start to predict and manage
the electrical storms that afflict the brain. Go even further, out
to a point where scientists really understand the way the brain
communicates, and sensors can be designed to begin feeding back
information in ways that can offer a radically new method of
sensory input, one which eventually could provide sight for the
blind.
TO UNDERSTAND WHAT scientists are doing and
where they're headed, you have to start in the motor-cortex zone of
the brain.
This complex group of brain cells is the central command post for
turning thought into action, and it works through a form of mental
Morse code. Every time you move your arm or leg, neurons inside the
motor cortex emit bursts of electronic signals that direct the
action. By placing a miniaturized sensor that sends out 100
hair-thin electrodes into this crossroad of brain cells, scientists
can tap into that communication stream. A small computer attached
to a wheelchair wirelessly transmits the data to a computer that
can mathematically translate the electronic pulses into the cursor
movements on the screen.
"It's the rate of firing of individual cells that seems to carry
this information," says Tim Surgenor, president and CEO of
Cyberkinetics Neurotechnology Systems, which developed BrainGate
and has been testing the neurotechnology in its first human
trials.
Whatever the source of their affliction, the four people who've
participated in clinical tests so far, including Nagel, had lost
the ability to move their arms and legs. But their brains have
retained the fully functioning signaling system that is needed to
communicate with the computer, even though that system's connection
with their muscles has been severed.
The first tests revolve around the simplest of tasks: playing a
game of Pong by changing the position of the paddle bar on the
screen, communicating by selecting and clicking on words and
phrases, and operating a wireless wheelchair or a robotic device.
But completing these objectives is a radical step forward for a
group of people who had lost all ability to control their
surroundings. And it's been a remarkably easy mental leap for the
volunteers to make.
"When using the mouse on your computer, you don't think about
moving your hand - just think about where the cursor is," says
Surgenor. "Soon, they're just thinking of where the cursor
goes."
And off it goes.
"For someone who can't speak, can't breathe, and can't move to be
able to affect their environment through their thoughts is just
magic," says James Allen Heywood, CEO and d'Arbeloff founding
director of the ALS Therapy Development Institute. Heywood's
brother, Stephen Heywood, tried the BrainGate technology, signing
up early in 2006 after he, formerly an architectural designer, had
been completely paralyzed and silenced by amyotrophic lateral
sclerosis (ALS), also called
Lou Gehrig's disease.
Stephen was able to go beyond just dreaming about designing homes
again - the technology was allowing him to take real steps in that
direction. But he suddenly died following a respiratory failure
unconnected to BrainGate and thus was unable to further test the
new technology.
For Stephen, BrainGate was a way to talk to his wife and children
after all communication had gone silent. "It gives you a reason for
living," says Surgenor. "If they can't communicate, many patients
decide not to continue on a respirator."
SCIENTISTS HAVE KNOWN for more than a
century where to find the communications hub in the brain. Having
the capability to use that knowledge, though, has been a long time
coming.
More than 15 years ago, a group of academics around the country,
including John Donoghue, a professor of neuroscience at Brown
University, began to wire the brains of primates to computers.
Those early primate studies opened the window on what they needed
to do to make the technology work with people. But new advances in
microelectronics, mathematical code deciphering, and software were
needed in order for them to be able to make it work in any
practical sense.
"We're able now to pick up a surprising amount of information,"
says Donoghue, whose research was the foundation of Cyberkinetics,
the company he cofounded in 2001, where he works one day a week as
chief scientific officer. "But it's a tiny sample of what's going
on. Just reaching for a cup of coffee uses tens or hundreds of
millions of neurons. We're picking up close to 100."
To make the technology accessible to all quadriplegics, Donoghue is
working to replace the wiring with
wireless communications. He's
also using more sophisticated sensors, which pick up even more
information, so that patients can refine their control of
prosthetic devices and robotics. And the professor is seeing the
research gain speed as his team gains new knowledge with every new
patient and as other researchers leap into the fray.
"It's coming very quickly," he says. "A number of groups have
miniaturized essential components. The challenge is sealing it to
withstand a harsh environment."
"The ability to link brain signals to a computer or an artificial
arm is just the beginning," says Dr. Rezai, who has been pushing
the envelope on deep-brain stimulation, implanting devices in the
brain that emit gentle pulses of electrical stimulation to keep the
body's command-and-control unit humming. Ultimately, researchers
will be able to detect other electrical storms in the brain,
including ones associated with Parkinson's disease,
depression, and
anxiety. "The Cyberkinetics system and others are giving us
snapshots of the nervous system," he says.
Right now, the system is used to detect the normal signals
associated with movement. Donoghue and others, though, are working
on other ways to utilize the technology.
"There's a lot of blue-sky thinking," says Surgenor. "There's
interest in providing information to the brain that would augment
feeling and hearing."
One group of researchers, led by Mark Humayan, a retinal surgeon
and biomedical engineer at the Doheny Eye Institute at the
University of Southern
California, has been using the technology to
translate camera images into the brain's electronic language of
sensory perception and is beginning to gain some fuzzy images,
which the researchers hope to gradually refine into sight.
This kind of technology, says Heywood, can transform lives,
possibly even society.
On a recent flight back from
Los Angeles, Heywood was reading
iWoz, the memoir of computer legend Steve Wozniak, and he reached the page where the software whiz described himself as being the first person to type a word on a computer keyboard and have it appear on a screen.
“Stephen and [Matt Nagel] were the first people to think without typing and have their words come up on-screen,” he says. “This is world-changing technology.”