Smoking cigarettes may actually have some cognitive benefits, thanks to the power of nicotine. The chemical improves mental focus, as scientists have known since the 1950s. Nicotine also aids concentration in people who have ADHD and may protect against Alzheimer's disease. Back in 2000, a nicotine-like drug under development by the pharmaceutical company Astra Arcus USA was shown to restore the ability to learn and remember in rats with brain lesions similar to those found in Alzheimer's patients. More recently Granholm, the scientist investigating trans fats and memory, found that nicotine enhances spatial memory in healthy rats. Other researchers have found that nicotine also boosts both emotional memory (the kind that helps us not put our hands back in the fire after we've been burned) and auditory memory.

There's a catch: Other studies show that nicotine encourages state-dependent learning. The idea is that if, for example, you study in blue sweats, it helps to take the exam in blue sweats. In other words, what you learn while smoking is best recalled while smoking. Since lighting up in an exam room might cause problems, cigarettes probably aren't the key to getting on the dean's list.