Most of us know that the way we feel emotionally and physically can influence how we do on tests. That's why we're told to get lots of rest and eat a good breakfast before taking a big exam. And previous studies have found that people do worse on tests and solving problems when they're tired, hungry, or upset.

Insomnia complaints among college students are significantly associated with a decline in school performance based on self-reported grade-point average (GPA), according to a research abstract that will be presented on Monday at SLEEP 2008, the 22nd Annual Meeting of the Associated Professional Sleep Societies (APSS).