Most baseball coaches and a few parents have learned the futility of instructing a young batter to “keep their eye on the ball.” Studies have shown that it is very difficult, if not impossible, for human eyes to track the trajectory of the pitch all the way across the plate. Even at the slower speeds of Little League pitchers, the shorter distance to the plate forces batters to pick-up early cues of the ball’s flight and speed, then make predictions of where and when it will cross the plate.  With less than a half second to to make the swing/no-swing decision, if the muscle activity isn’t triggered early in the pitch, the bat just won’t get around in time.

This time lag between incoming visual stimuli, motion planning in the brain and activation of the muscles, known as sensorimotor delay, is common throughout sports.  Think about a goalkeeper moving to stop a hockey puck or soccer ball; a tennis player returning a blistering serve; or a receiver adjusting to the flight of a football.  Their eyes tell them the speed and path of the object they need to intercept, then their brain instructs the body to move in the predicted path to arrive just in time.