Researchers figure how athletes hit balls when they don't have time to react
The human brain is far slower than a major league fastball or a blistering tennis serve — but it has figured out a workaround.
New research by University of California, Berkeley scientists solves a puzzle that has long mystified anyone who has watched, in awe, as elite athletes respond to incoming balls that can surpass 90 mph.
The brain perceives speeding objects as farther along in their trajectory than seen by the eyes, giving us time to respond, according to research by Gerrit Maus, lead author of a paper published in Wednesday's issue of the journal Neuron.
This clever adjustment — compensating for the sluggish route from the eyes to neural decision-making — “is a sophisticated prediction mechanism,” he said.
“As soon as the brain knows something is moving, it pushes the position of the object moving forward, so there's a more accurate measure of where this object actually is,” Maus said.
This is useful in survival situations far more important than sports — such as when we're crossing a street in front of a speeding car.
Former Yankees catcher Yogi Berra pondered the mystery, once asking: “How can you think and hit at the same time?”
You can't, because there's not time for both.
“But you don't need to think about it, because the brain does it automatically,” Maus said.
At the average major league speed of 90 mph, a baseball leaves the pitcher's hand and travels 56 feet to home plate in just 0.4 seconds, or 400 milliseconds.
Tennis is even faster. Last May, courtside radar guns measured a serve by British player Samuel Groth at 163 mph.
In that split second, there's a lot of work for the body to do. Eyes must find the ball. The sensory cells in the retina determine its speed and rush this information to the brain. Then the brain sends messages through the spinal cord that tell muscles in the arms and legs to respond.
“By time the brain receives the information, it's already out of date,” Maus said.