Lavender

For many of us, it's as plain as the nose on our faces—different smells conjure up specific memories. But what is it exactly that makes us connect the smell of barbecues with summer?

Odors are very powerful emotional stimuli, explains Bruce Turetsky, a University of Pennsylvania associate psychiatry professor. In fact, he says, different scents may "have a greater ability to bring up an emotional memory in you than seeing a picture or hearing a voice." So if sense of smell can be linked to emotional memory, can it also be connected to emotional disorders?