When you "smell" troubles

Research shows odors linked with negative experiences are more easily recalled -- a handy survival trait. The discovery could shed light on disorders such as post-traumatic stress syndrome.
From the Associated Press
March 29, 2008


Know how a whiff of certain odors can take you back in time, to either a great memory or bad one?

It turns out that emotion plays an even bigger role with the nose than previously believed and that your sense of smell actually can sharpen when something bad happens.

Researchers at Northwestern University in Illinois proved the surprising connection by giving volunteers electric shocks while they sniffed novel odors.

The discovery, reported in Friday's edition of the journal Science, helps explain how our senses can steer us clear of danger. More intriguing, it could shed light on disorders such as post-traumatic stress syndrome.

The research team recruited 12 healthy young adults. The volunteers repeatedly smelled sets of laboratory chemicals with odors distinctly different from ones in everyday life. An "oily, grassy" smell is the best description that lead researcher Wen Li, a Northwestern postdoctoral fellow in neuroscience, could give.

Two of the bottles in a set contained the same substance. A third bottle had a slightly different scent that normally would be indistinguishable. By chance, the volunteers correctly guessed the odd odor about one-third of the time.

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