Acute stress primes brain for better cognitive and mental performance

You always think about stress as a really bad thing, but it's not," said Daniela Kaufer, associate professor of integrative biology at the University of California, Berkeley. "Some amounts of stress are good to push you just to the level of optimal alertness, behavioral and cognitive performance."

http://www.sciencedaily.com/releases/2013/04/130416204546.htm