A report by Scientific American sheds light on the idea that scents can hinder or enhance mental and physical performance.
"A number of studies have shown that the odors people like make them feel good, whereas odors people dislike make them feel bad. These mood responses have also been reported physiologically. For example, skin conductance, heart-rate and eye-blink rates in response to various liked or disliked scents coincide with the mood the person is experiencing.
Downstream from how odors influence our moods is the way that moods influence how we think (cognition) and how we act (behavior). In terms of cognition, mood has been shown to influence creativity with the typical finding that people in a positive mood exhibit higher levels of creativity than individuals in a bad mood. Odors can also produce the same effects. When people were exposed to an odor they liked creative problem solving was better than it was when they were exposed to an unpleasant odor condition."