The average person can focus on only three objects at once, yet he or she can follow a soccer game and accurately estimate, in just half a second, how many players from each team are on the field. Justin Halberda, a Johns Hopkins University psychologist, explains that “people can focus on more than three items at a time if those items share a common color.” The color coding enables them to perceive separate individuals as a single set.
Halberda showed volunteers arrays of colored dots for 500 milliseconds—too brief for counting—then asked how many dots of a given color they had observed. Even with scenes of 35 dots in several colors, participants were 87 percent accurate, which indicates the human brain can carry out parallel processing of sets in a short time. Color, Halberda says, seems to be the easiest “sorting tool,” but he is now looking at arrays differing in size, shape and brightness. If another feature holds up, perhaps Italy’s il Azzurri and France’s les Bleus can both wear their blue home uniforms in the next World Cup soccer final.