Entrepreneurs often claim to need minimal sleep. Yet the vast majority of people actually require six to seven hours, according to Michael Chee, director of the Centre for Cognitive Neuroscience at Duke-NUS Graduate Medical School in Singapore.

In a 2008 study, Chee and his team used functional MRI technology to observe sleep-deprived brains. They appear to function normally at certain times, which is what tricks people into thinking they need less sleep. However, lack of sleep suppresses activity in parts of the brain that control attention and filter distractions. Chee's team showed both sleep-deprived and well-rested subjects a series of large letters made up of smaller letters and asked them to identify either the large or small letters by pressing one of two buttons. Responses from the sleep-deprived group were both slower and less accurate.

Lack of sleep also affects your ability to control your emotions. In 2007, researchers at Harvard Medical School and the University of California, Berkeley, used functional MRI imaging to see how sleep-deprived brains react to viewing disturbing images and found that they are more than 60 percent more reactive than well-rested brains. The good news is that prolonged sleep can boost performance. Cheri Mah of the Stanford Sleep Disorders Clinic and Research Laboratory has studied the influence of sleep on college basketball players. Her research showed that when the players slept for at least 10 hours a night, longer than usual, their shooting accuracy improved 9 percent.

Sleep isn't the only break people need. Recent studies have shown that spending time in nature dramatically improves higher-level cognition. Last year, psychologists at the University of Utah and the University of Kansas published a study on how hiking influences creativity. The subjects took a standard creativity test, in which they were given three words and asked to think of another word that could link them all together. For instance, if the words were round, tennis, and manners, the answer could be table, because it fits for all three: roundtable, table tennis, and table manners.

One group took the test before a four-day hike. The other group took it just after the hike. The results were staggering: The posthike group scored 50 percent higher than the prehike group. "Some combination of disconnecting from the constant rat race of multitasking and interacting with nature showed significant restorative properties," says co-author David Strayer. "When you clear your mind, you come at a problem from a new perspective, and the solution becomes obvious."