t h e  h u m a n  o l f a c t o r y  s y s t e m

        The basic workings of the human olfactory system are quite complex. Odors waft up the nasal cavity to a patch of nerve cells

above the eyes. From there, scent signals go to the olfactory bulb, higher brain areas involved in discrimination (frontal lobe)

and primitive areas linked to emotions (limbic system). This is a pretty straightforward concept, but considering

that sensor cells in the nose last around 30 to 60 days before dying, how are scents remembered after the sensor cells that initially

identified the scent have died? Researchers have discovered that new nerve cells send out long extensions that find their way to the

same spots in the olfactory bulb where their predecessors connected.

    This begins to explain how scents are remembered over long periods of time, but how do these scents have such an amazing

ability to evoke particular memories and emotions from the past? Psychologist Rachel Herz has conducted numerous studies

based on the connection between scent, memory and emotion. She explains that the primary olfactory cortex, which receives

information about smells from nerves in the nose, links directly to the amygdala, which controls expression and experience

of emotion, and the hippocampus, which controls the consolidation of memories. This helps to explain why odor evoked

memories may seem clearer or more intense than other memories because they appear to be more emotional than memories

triggered by visual, audio or other types of cues. Studies also suggest that the sense of smell is not very accurate in recalling

factual information surrounding memories, but that the emotions associated with the memories prompt a more accurate


on to research...

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