Scientists reported in Nature this week that monkeys could overcome a temporarily paralyzed wrist in order to continue playing a computer game, a finding that could point towards new treatments for people that have sustained spinal cord injuries or a stroke.
Amazingly, the animals pulled off the feat by controlling the activity of a single cell in their brains.
Chet Moritz and colleagues at the University of Washington tested two pigtail macaques (see picture) in their study. The monkeys had learned to play a game in which they manipulated their wrists up and down in order to move a cursor towards a target on a computer screen.
The scientists then implanted probes to track firing patterns in the monkeys’ brain cells and observed as the monkeys played the game. They noted that certain brain cells fired at different frequencies when the monkeys raised or lowered their wrists.
The researchers then used anesthetic to temporarily block nerves that normally activate wrist the monkeys’ wrist muscles, and connected the brain cell probe directly to an electrical stimulator affixed to the monkeys’ wrist muscles. In no time, the monkeys learned to use the artificial bypass tract to move their wrists so they could continue playing the game.
The finding is, “an important step forward.” Case Western Reserve scientist Dawn Taylor told the Associated Press. Taylor works in the field but was not involved in this study.
But Moritz cautioned that human applications are at best a decade away. “There’s no way to say with confidence that it will work,” he added.