New York:Researchers have confirmed what many tennis players have long complained that professional referees misjudge the balls which bounce off the line or close to it. But they say it is not mere incompetence as some would allege but the result of programming of brain.
Researchers at UC Davis University in California found it is the result of brain's perception of the world lags a few milliseconds behind reality.
To compensate, brain estimates where the object should go next, based on its speed and direction of travel. Mostly those guesses work very well, but if the object is moving very fast and making sudden changes of direction -- like a bouncing tennis ball -- they can give the wrong answer.
While the brain is processing the image of a moving object received from the eyes, the object has already moved on, researchers led by David Whitney, associate professor at Center for Mind and Body and the Department of Psychology, found.
The common flaw in the visual system -- also known as a "perceptual bias"-- has rarely been documented in sports, the researchers say.
Whitney and his team reviewed a random set of 4,457 points from the 2007 Wimbledon tournament. All instances when the tennis ball landed close to or on the line were recorded, and three trained observers individually watched each play. They also examined instant replays.