Here's a good excuse to use the next time your boss catches you surfing Facebook on the computer; new research from the University of Illinois shows that brief diversions may actually help you concentrate and improve your overall work performance.

Alejandro Lleras, who wrote a study on the topic for the journal Cognition, says instead of thinking of attention as an finite resource that runs out after a lenghty period of focus, its more like a gas tank that refills during short breaks from the task at hand:
To prove his theory, Lleras had 84 students focus on various numbers flashing on a computer for an hour. One group received no breaks or distractions. Other groups were told to memorize numbers and wait for those numbers to pop up on the screen. The groups that received diversions, in the form of their memorized numbers popping up, sustained their concentration.

Other groups saw their attention spans wane after 20 minutes.
Here's a way to test this theory: Stare at one penny and place another coin 10 inches away; the penny in your peripheral vision will eventually disappear. If you blink or move, the second penny reappears because the change has jolted the brain. Think of it as 'refreshing' the thought process. Since sustained attention to a thought can cause it to disappear, giving yourself something else to think about will help you sustain the original thought once you return to it.

via PhysOrg