QUOTE : In experiments he reported in 1982 and 1985, Libet asked volunteers to decide to flick or flex their wrist whenever they chose. These movements were to be performed, as Libet put it, “capriciously, free of any external limitations or restrictions.” Devices on the subjects’ scalps detected the readiness potential that marks neuronal events associated with preparation for movement. Libet found that this readiness potential began, on average, 550 milliseconds before the activation of the muscles moving the wrist. But not all readiness potentials were followed by movements. “The brain was evidently beginning the volitional process in this voluntary act well before the activation of the muscle that produced the movement,” Libet noted in 1999. That is, the readiness potential he was detecting appeared too long before muscle activation to correspond directly with a motor command to the muscle.