On August 20, 1974, in a game between the California Angels and the Detroit Tigers, The Guinness Book of Records clocked Nolan Ryan’s fastball at 100.9 miles per hour. If you work the numbers, you’ll see that Ryan’s pitch departs the mound and crosses home plate—60 feet, 6 inches away—in four-tenths of a second. This gives just enough time for light signals from the baseball to hit the batter’s eye, work through the circuitry of the retina, activate successions of cells along the loopy superhighways of the visual system at the back of the head, cross vast territories to the motor areas, and modify the contraction of the muscles swinging the bat. Amazingly, this entire sequence is possible in less than four-tenths of a second; otherwise no one would ever hit a fastball. But even more surprising is that conscious awareness takes longer than that: about half a second. So the ball travels too rapidly for batters to be consciously aware of it.
One does not need to be consciously aware to perform sophisticated motor acts. You can notice this when you begin to duck from a snapping tree branch before you are aware that it’s coming toward you, or when you’re already jumping up when you first become aware of a phone’s ring.