10 February 2013
From “Paralyzed and using thoughts to touch friend,” we learn that research has now been published on how an electrode implant has enabled Tim Hemmes, a 30-year-old paralyzed from the shoulders down, not only to control the movement of a character on a computer screen, but to control a robotic arm, using his thoughts alone.
How is that possible? The researchers got him to watch videos of arm movement for six weeks, to see where they should plant the electrodes in his brain.
They used that information to place a postage stamp-size electrocortigraphy (ECoG) grid of 28 recording electrodes on the surface of the brain region that fMRI showed controlled right arm and hand movement. Wires from the device were tunneled under the skin of his neck to emerge from his chest where they could be connected to computer cables as necessary.
Impulses he might have sent to the muscles his brain had lost touch with can now be sent to the computer-controlled system.
”When Tim reached out to high-five me with the robotic arm, we knew this technology had the potential to help people who cannot move their own arms achieve greater independence,” said Dr. Wang, reflecting on a memorable scene from September 2011 that was re-told in stories around the world. “It’s very important that we continue this effort to fulfill the promise we saw that day.”
Indeed. There have also been some remarkable cases coming out of the University of Western Ontario in Canada as well: When severely brain-injured Scott Routley, given two years to live in 1999, lived for more than twelve years, doctors started to ask some questions: Was he aware and trapped or just alive but not aware?
Neuroscientist Adrian Owen decided to find out. As Alanna Mitchell reports, he wheeled Mr. Routley into a real-time fMRI scanner:
The doctor asked the patient to choose one of two kinds of mental imagery to answer the question of whether he was in pain. In effect, the fMRI said Mr. Routley had answered “no.”
The moment was a double first: the first time in the world any patient of this sort had been able to tell doctors anything medically relevant, and the first time such a patient had been able to communicate instantaneously.
The question of whether the patient is aware but trapped or just not aware is quite important because, as Mitchell puts it,
In some parts of the world, the two different states are the dividing line between pulling the plug and leaving it in. But what if the mind was aware and responsive, just unable to show that by moving the body?
One wonders what would have happened if Dr. Owen had had a chance to examine Terri Schiavo, a Florida woman in a “vegetative” state, whose husband wanted her feeding tube disconnected in 2005, despite her parents’ opposition. There was actually much more evidence available that she was aware of her surroundings:
“I spent about 10 hours across about three months [examining Terri] and the woman is very aware of her surroundings. She’s very aware. She’s alert. She’s not in a coma. She’s not in PVS,” Hammesfahr told CNN Tuesday night. “With proper therapy, she will have a tremendous improvement. I think, personally, that she’ll be able to walk, eventually, and she will be able to use at least one of her arms.”
Portions of a four-hour videotaped examination of Terri by Hammesfahr were shown to the court during the evidentiary hearing. In the video, Terri appears to interact with her mother with a reaction of happiness, follow commands to open and shut her eyes and lift limbs, and tracks a Mickey Mouse balloon across the room with her eyes.
After a huge controversy, Schiavo died, following a court order giving the decision to her husband.
As for Dr. Owen, he took a different approach in another “vegetative” case:
In 2006, he had his sensational breakthrough paper. It presented the findings of a scan of a 23-year-old woman who had been in a traffic accident and was deemed vegetative. While she was in the scan, he asked her to imagine first one and then a second complex task: playing a game of tennis and then visiting all the rooms in her house.
When he asked her to imagine playing tennis, the correct bits of her brain lit up. When he asked her to imagine visiting all the rooms in her house, a different bit lit up. In fact, her scans were indistinguishable from those of the healthy volunteers.
Future breakthroughs in this area may not only give us hope for those previously deemed hopeless but help us understand more clearly the relationship between the mind, the brain, and the body.
See also: Free will: What should we make of claims that neuroscience shows it does not exist?
Philosopher of mind John Searle on the central feature of consciousness—subjectivity