The man who controls computers with his mind

By FERRIS JABR

NEW YORK: On the evening of Oct. 10, 2006, Dennis DeGray’s mind was nearly severed from his body. After a day of fishing, he returned to his home in Pacific Grove, Calif., and realised he had not yet taken out the trash or recycling. It was raining fairly hard, so he decided to sprint from his doorstep to the garbage cans outside with a bag in each hand. As he was running, he slipped on a patch of black mold beneath some oak trees, landed hard on his chin, and snapped his neck between his second and third vertebrae.

While recovering, DeGray, who was 53 at the time, learned from his doctors that he was permanently paralysed from the collarbones down. With the exception of vestigial twitches, he cannot move his torso or limbs.

“I’m about as hurt as you can get and not be on a ventilator,” he told me.

For several years after his accident, he “simply laid there, watching the History Channel” as he struggled to accept the reality of his injury.

Some time later, while at a fund-raising event for stem-cell research, he met Jaimie Henderson, a professor of neurosurgery at Stanford University. The pair got to talking about robots, a subject that had long interested DeGray, who grew up around his family’s machine shop. As DeGray remembers it, Henderson captivated him with a single question: Do you want to fly a drone?

Henderson explained that he and his colleagues had been developing a brain-computer interface: an experimental connection between someone’s brain and an external device, like a computer, robotic limb or drone, which the person could control simply by thinking.

DeGray was eager to participate, eventually moving to Menlo Park to be closer to Stanford as he waited for an opening in the study and the necessary permissions.

In the summer of 2016, Henderson opened DeGray’s skull and exposed his cortex — the thin, wrinkled, outermost layer of the brain — into which he implanted two 4-millimeter-by-4-millimeter electrode arrays resembling miniature beds of nails.

Each array had 100 tiny metal spikes that, collectively, recorded electric impulses surging along a couple of hundred neurons or so in the motor cortex, a brain region involved in voluntary movement.

After a recovery period, several of Henderson’s collaborators assembled at DeGray’s home and situated him in front of a computer screen displaying a ring of eight white dots the size of quarters, which took turns glowing orange.

DeGray’s task was to move a cursor toward the glowing dot using his thoughts alone.

The scientists attached cables onto metal pedestals protruding from DeGray’s head, which transmitted the electrical signals recorded in his brain to a decoder: a nearby network of computers running machine-learning algorithms.

Only a few dozen people on the planet have had neural interfaces embedded in their cortical tissue as part of long-term clinical research. DeGray is now one of the most experienced and dedicated among them. Since that initial trial, he has spent more than 1,800 hours spanning nearly 400 training sessions controlling various forms of technology with his mind. He has played a video game, manipulated a robotic limb, sent text messages and emails, purchased products on Amazon and even flown a drone — just a simulator, for now — all without lifting a finger. Together, DeGray and similar volunteers are exploring the frontier of a technology with the potential to fundamentally alter how humans and machines interact.