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Man Moves Objects With His Mind Using New Sensor

Adrianne Appel
for National Geographic News
July 12, 2006
 
A paralyzed man has moved objects through mind power alone, thanks to electrodes implanted in his brain, scientists announced today.

The brain sensor has allowed him to move a computer cursor to open email, grasp candy with a robotic arm, and open and close a prosthetic hand—just by thinking about it.

He also opened email and turned up the volume on a television while engaged in conversation.

The electrodes connect to a computer with software that "translates" brain signals into appropriate movement.

(Related: "Cap Harnesses Human Thought to Move PC Cursor" [December 7, 2004].)

The experiments show that it is possible to capture the language of the brain, reroute that language outside the brain, and then decode the signals into movement commands, according to researchers.

"We're just at the start, just getting off the ground," study co-author John Donoghue said.

Donoghue is a neuroscientist at Brown University in Providence, Rhode Island, and Cyberkinetics Neurotechnology Systems, Inc., a Salt Lake City, Utah-based company he and his students created. His BrainGate research appears in tomorrow's issue of the journal Nature.

Active Brain

Donoghue says he hopes to make the device, called BrainGate, available as early as 2008. Ideally, BrainGate would help people move their limbs to accomplish simple tasks of daily living, like feeding themselves.

"I don't want to give the impression that people will walk—that is very complicated," Donoghue said.

The patient involved in the experiments is a 25-year old man whose spinal cord was severed as a result of a knife wound he received in 2001. He received the implant system in 2004.

He is "very excited by this," Donoghue said.

Ninety-six electrodes, which sit on a 0.2-square-inch (4-square-millimeter) panel, were implanted into the patient's motor cortex, a part of the brain responsible for movement.

The electrode panel is attached by a cord to a penny-size titanium disk on the outside of his skull.

The disk serves as an attachment for wires that connect to a computer, which has been programmed to interpret the messages of the man's firing brain neurons.

Three other patients have since received the implant.

The research is the first evidence that the motor cortex of people with spinal cord injuries can function fairly normally even years after their injuries, according to the researchers.

"When asked to think right or think left, the patients were able to change their neural activity immediately. And their use of the device is seemingly easy," Donoghue said.

"Patients can control the computer cursor and carry on a conversation at the same time, just as we can simultaneously talk and use our computers," Donoghue said.

The researchers used magnetic resonance imaging (MRI) to observe the activity of the brain.

"This is a pilot trial, and we are learning how to make the device work," Donoghue added.

The team noticed an odd drop-off in sensor activity after about six months, probably due to a short circuit, Donoghue says.

The implant of the second patient, a 55-year-old who has been paralyzed since 1999, lost significant signal activity after about 11 months.

(Photos: "Beyond the Brain.")

More to Come

The next step after the pilot study is to make the device wireless, automated, and miniature, Donoghue said.

Elsewhere, other researchers are moving ahead with experiments that involve restoring lost movement in humans.

A team at Stanford University in Palo Alto, California, is attempting to develop an electrode-computer system whose efficiency is closer to that of the human body's system of regulating movement. Their study also appears in tomorrow's Nature.

At Rutgers University in Piscataway, New Jersey, associate professor William Craelius specializes in creating prototypes of bionic arms.

He says perhaps his work and Donoghue's can be tapped to create a hybrid system of human movement.

As far as what Donoghue's team is doing, Craelius said, "It's a very difficult thing. It's working remarkably well."

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