Innovation in Neuroscience: Turning Thoughts into Action
You probably do it hundreds of times a day: move your mouse to control the cursor on a computer screen, without giving it a second thought.
But just what is going on in your brain when you perform that simple motion, and how is that electrical activity transferred from your brain to your muscles? If we can figure that out, would it be possible to skip the step of using your arms—to "throw" your thought, as it were—and control your mouse remotely?
John Donoghue isn't into telekinesis; he's a professor of neuroscience at Brown University and director of its Brain Science Program. But the answers he's finding to the question of how we move from thought to action could help people with spinal cord injuries, Lou Gehrig's disease or other conditions that impair movement to communicate and better control their world using only their thoughts.
Through Cyberkinetics Neurotechnology Systems Inc., the Massachusetts company he co-founded with his fellow collaborators and researchers—Dr. Gerhard Friehs, MD of Neurosurgery, Nicho Hatsopoulos PhD, a faculty member at U. Chicago, and Misha Serruya, MD PhD, and neurology resident—Donoghue and his colleagues are developing a brain implant system called BrainGate that can decode neural signals and translate them into external movement.
A recent clinical trial made the front page of the New York Times when a former high school football star, paralyzed below the neck, used the BrainGate system to control a computer, a television set and a robot with his thoughts.
"If your brain can do it, we can tap into it," Donoghue told the Times.
Donoghue's dramatic discovery is hardly the work of a lone genius—and how the discovery was made is as compelling as what he's achieved. Turning thought into action was a collaborative effort between mathematicians, doctors, neuroscientists and computer scientists, all working together to figure out how the brain works.
Through this collaborative endeavor, the team's efforts helped "shift the notion of such 'implantable neuromotor prosthetics' from science fiction towards reality," a peer wrote of Donoghue's work when it first appeared in the journal Nature.
Donoghue, 57, says he always has been fascinated with how we turn thought into action. "It's one of the great questions. It's sort of the essence of what is man," he says.
By placing sensors in a monkey's brain while it does simple tasks, Donoghue and his team at Brown learned to decode neural impulses—the signals the brain was sending that were manifested in specific arm movements. Plotting the spikes of brain activity, they ultimately were able to "crack" the neuron's code, and, with the help of experts in applied math and computer science, build a sort of decoder chip that could, in effect, read thoughts.
So how did Donoghue and his team go from 'reading thoughts' to actual movement? A small sensor implanted in the brain of Matthew Nagle, the paralyzed football star, eavesdropped on the electrical signals his neurons emitted as he imagined moving his arm to hit various targets. The sensor was connected to a sort of docking station in Nagle's skull, and from there via cables to a computer. (Yes, we are entering 'Matrix' territory here.)
With practice, Nagle was able to "think" a computer cursor into opening email and playing video Pong, change the channel or volume on a television set, move a robot arm and even open and close a prosthetic hand.
The device needs to be perfected, Donoghue notes—it has to be more automated, the signal must be more stable and clearly it will have to be wireless. But he says Cyberkinetics hopes to win FDA approval and bring BrainGate to market by 2008.
One noteworthy finding is that the neurons required to perform a motion remain intact long after the paralyzed patient has lost the ability to move—a breakthrough that Donoghue hopes will allow him one day to take the brain signal and feed it into stimulators that will then feed it into a patient's muscles, in effect repairing the damaged circuitry of the patient's nervous system.
"We're able to take some fundamental knowledge and help people who have really challenging and difficult lives because of circumstances beyond their control," Donoghue says. "The fact that we can help them out in any way is immensely rewarding. That's about as rewarding as you can get."