A tiny chip implant is enabling paralysed and injured people to move objects by the power of their thoughts – and, in time, researchers hope it could help them walk again
The robotic arm clutched a glass and swung it over a series of coloured dots that resembled a Twister gameboard. Behind it, a woman sat entirely immobile in a wheelchair. Slowly, the arm put the glass down, narrowly missing one of the dots. “She’s doing that!” exclaims Professor John Donoghue, watching a video of the scene on his office computer – though the woman onscreen had not moved at all. “She actually has the arm under her control,” he says, beaming with pride. “We told her to put the glass down on that dot.”
The woman, who is almost completely paralysed, was using Donoghue’s groundbreaking technology to control the robot arm using only her thoughts. Called BrainGate, the device is implanted into her brain and hooked up to a computer to which she sends mental commands. The video played on, giving Donoghue, a silver-haired and neatly bearded man of 62, even more reason to feel pleased. The patient was not satisfied with her near miss and the robot arm lifted the glass again. After a brief hover, the arm positioned the glass on the dot.
This is the remarkable world of the brain-computer interface, or BCI, of which BrainGate is one of the leading devices and Donoghue one of its most successful pioneers. It is a branch of science exploring how computers and the human brain can be meshed together. It sounds like science fiction (and can look like it too), but it is motivated by a desire to help chronically injured people. They include those who have lost limbs, people with Lou Gehrig’s disease, or those who have been paralysed by severe spinal-cord injuries. But the group of people it might help the most are those whom medicine assumed were beyond all hope: sufferers of “locked-in syndrome”.
These are often stroke victims whose perfectly healthy minds end up trapped inside bodies that can no longer move. The most famous example was French magazine editor Jean-Dominique Bauby who managed to dictate a memoir, The Diving Bell and the Butterfly, by blinking one eye. In the book, Bauby, who died in 1997 shortly after the book was published, described the prison his body had become for a mind that still worked normally.
Donoghue believes that BrainGate would have opened Bauby’s prison door, even if just a little. “I would have every expectation that if we had put BrainGate in his brain, it would have immediately started giving us signals,” Donoghue says.
Donoghue and his team have devoted years of research to BrainGate, first successfully testing the technology on monkeys and then moving to a groundbreaking set of clinical trials using human subjects. Now the project is involved with a second set of human trials, pushing the technology to see how far it goes and trying to miniaturise it and make it wireless for a better fit in the brain. BrainGate’s concept is simple. It posits that the problem for most patients does not lie in the parts of the brain that control movement, but with the fact that the pathways connecting the brain to the rest of the body, such as the spinal cord, have been broken. BrainGate plugs into the brain, picks up the right neural signals and beams them into a computer where they are translated into moving a cursor or controlling a computer keyboard. By this means, paralysed people can move a robot arm or drive their own wheelchair, just by thinking about it.
In his book Bauby called his immobilised body a diving bell and his mind a butterfly trapped inside. He described his sadness at being unable to talk back when his loved ones spoke to him on the phone. “How dearly I would love to be able to respond with something other than silence to those tender calls,” he wrote. The woman on the video that Donoghue just played has almost the exact same condition Bauby had. Now she is able to talk to Donoghue over the internet, moving a cursor over a keyboard with her mind and communicating much faster than Bauby did.
Donoghue works from inside a rambling old mansion perched on top of a hill. But the offices of the Brown Institute for Brain Science are not really the stuff of old horror movies. The pleasant-looking building is part of Brown University in the pretty college town of Providence, Rhode Island, on the New England coast.
It is here that he and his team are decoding the language of the human brain. This language is made up of electronic signals fired by billions of neurons and it controls everything from our ability to move, to think, to remember and even our consciousness itself. Donoghue’s genius was to develop a deceptively small device that can tap directly into the brain and pick up those signals for a computer to translate them. Gold wires are implanted into the brain’s tissue at the motor cortex, which controls movement. Those wires feed back to a tiny array – an information storage device – attached to a “pedestal” in the skull. Another wire feeds from the array into a computer. A test subject with BrainGate looks like they have a large plug coming out the top of their heads. Or, as Donoghue’s son once described it, they resemble the “human batteries” in The Matrix.
BrainGate’s highly advanced computer programs are able to decode the neuron signals picked up by the wires and translate them into the subject’s desired movement. In crude terms, it is a form of mind-reading based on the idea that thinking about moving a cursor to the right will generate detectably different brain signals than thinking about moving it to the left.
The technology has developed rapidly, and last month BrainGate passed a vital milestone when one paralysed patient went past 1,000 days with the implant still in her brain and allowing her to move a computer cursor with her thoughts. The achievement, reported in the prestigious Journal of Neural Engineering, showed that the technology can continue to work inside the human body for unprecedented amounts of time.
Donoghue talks enthusiastically of one day hooking up BrainGate to a system of electronic stimulators plugged into the muscles of the arm or legs. That would open up the prospect of patients moving not just a cursor or their wheelchair, but their own bodies. “We are working on a system where there is a stimulator in another part of the body wired to the muscle, and when it’s activated you can get opening and closing of the hand and movement of the arm.”
It is a remarkable idea with humble beginnings. The first BrainGate patient, a quadraplegic called Matthew Nagle, was plugged into a computer in 2004. Nagle, a keen young sports fan, had been stabbed while trying to help a friend in a fight. The blade had severed his spinal cord. Donoghue had no idea if Nagle’s motor cortex would still be able to send the right signals for movement. “The big moment was when we first turned on the recording electrode so we could peer into the brain. Except for brief moments in the operating room, we never had the opportunity to do that in humans,” Donoghue says of BrainGate’s big breakthrough moment.
It was tense. If Nagle’s motor cortex was no longer working healthily, the entire BrainGate project could have been rendered pointless. But when Nagle was plugged in and asked to imagine moving his limbs, the signals beamed out with a healthy crackle. “We asked him to imagine moving his arm to the left and to the right and we could hear the activity,” Donoghue says. When Nagle first moved a cursor on a screen using only his thoughts, he exclaimed: “Holy shit!”
Nagle rapidly became a poster boy for BrainGate, eventually learning to play simple computer games, operate a TV and send and receive emails. Sadly, he died in 2007 of an infection. “It was awful. Just awful when Matt died. We were all very much attached,” Donoghue says. “I am trying to make people who are in a terrible state have a much better life. Right now, anything that we can do for them is a huge improvement.”
That is no doubt true. But BrainGate and other BCI projects have also piqued the interest of the government and the military. BCI is melding man and machine like no other sector of medicine or science and there are concerns about some of the implications. First, beyond detecting and translating simple movement commands, BrainGate may one day pave the way for mind-reading. A device to probe the innermost thoughts of captured prisoners or dissidents would prove very attractive to some future military or intelligence service. Second, there is the idea that BrainGate or other BCI technologies could pave the way for robot warriors controlled by distant humans using only their minds. At a conference in 2002, a senior American defence official, Anthony Tether, enthused over BCI. “Imagine a warrior with the intellect of a human and the immortality of a machine.” Anyone who has seen Terminator might worry about that.
Donoghue acknowledges the concerns but has little time for them. When it comes to mind-reading, current BrainGate technology has enough trouble with translating commands for making a fist, let alone probing anyone’s mental secrets. “There are unrealistic fears. So I am not too worried that we are going to tap into your brain,” he says.
As for robot warriors, Donoghue was slightly more circumspect. At the moment most BCI research, including BrainGate projects, that touch on the military is focused on working with prosthetic limbs for veterans who have lost arms and legs. But Donoghue thinks it is healthy for scientists to be aware of future issues. “As long as there is a rational dialogue and scientists think about where this is going and what is the reasonable use of the technology, then we are on a good path,” he says.
Donoghue comes across as a pragmatic and careful scientist. Perhaps that comes from his humble background as the son of a working‑class Boston Irish bricklayer father and a housewife mother. Or from an academic career spent almost entirely in the same institution. But he does allow himself to dream, just a little, of where BrainGate’s technology might go one day. His team are already working on a miniaturised and wireless version. Although it has not been implanted in a human yet, that new version of BrainGate will remove the need for a “plug” in the skull and could allow patients to be permanently hooked up. The prototype looks like a large, flattened memory stick and will go inside the head. It would communicate wirelessly with a computer worn on a belt.
So no wonder Donoghue can dream of a future where BrainGate and other devices can restore full mobility to those from whom physical movement has been stolen. “The really way-off treatment, which I will never see, is that we connect BrainGate, maybe four arrays in the two leg and two arm areas of the brain, and put it out to all the muscles with stimulators and then the subject is playing basketball or something,” he says. “There is no reason why with enough knowledge and enough time that we couldn’t do that.”
It will not be soon though; almost certainly not in Donoghue’s lifetime. “One hundred years from now, when people are walking around with an artificial nervous system made of wires and chips, people will say, ‘I bet they didn’t imagine this.'”
One person who did think about it was Bauby. At the end of The Diving Bell and the Butterfly he dreams of one day being let out of his prison. “Does the cosmos contain keys for opening up my diving bell? A subway line with no terminus? A currency strong enough to buy my freedom back? We must keep looking.” Bauby died before there was much hope for that. Others similarly stricken in the future may be luckier.