A Revolution in How Robots Learn

A disproportionate amount of the primary motor cortex, a region of the brain that controls movement, is devoted to body parts that move in more complicated ways. An especially large portion controls the face and lips; a similarly large portion controls the hands. A human hand is capable of moving in twenty-seven separate ways, more by far than any other body part: our wrists rotate, our knuckles move independently of one another, our fingers can spread or contract. The sensors in the skin of the hand are among the densest in the body, and are part of a network of nerves that run along the spinal cord. "People think of the spinal column as just wires," Arthur Petron, a roboticist who earned his Ph.D. in biomechatronics at M.I.T., said.