AP Science Writer Monkeys taught to play a computer game were able to overcome wrist paralysis with an experimental device that might lead to new treatments for patients with stroke and spinal cord injury. Remarkably, the monkeys regained use of paralyzed muscles by learning to control the activity of just a single brain cell. The result is "an important step forward," said Dawn Taylor of Case Western Reserve University in Cleveland, who studies the concept of using brain signals to overcome paralysis. She wasn't involved in the new work. The device monitored the activity of a brain cell and used...