There is this earthy, sweet, musky smell of ferns that I associate with our wonderful vacation home in northern Michigan. If I smell it, I am completely moved to Beulah, no matter where I am.
Or the smell of an outboard motor and lake, I am back at my parents' Minnesota cabin, re-living the summers turtle hunting and swimming. (We always practiced “catch and release” with the turtles.)
So with summer ending and these marvelous transporting odors being put away for the season, I decided to investigate the world of olfactory recognition. (That's a normal thing to do, correct?) Amazingly, the biochemistry of smell is still rather poorly understood, even though the 2004 Nobel Prize in medicine was awarded because of research into smell receptors.
My inspiration was not just the ferns, but a recent article in the Washington Post detailing two studies published in the journal Current Biology by researchers from New Zealand, listed here and here. The biologists were trying to find genetic links for the smell recognition of specific molecules. What I found truly fascinating was that the scientists used emotional response to measure the ability to detect a smell. Subjects described feelings and events when exposed to different concentrations of a molecule. In a scientific chart are phrases like "eat lots of chocolate" and "Grandmother's gift." So my pleasant thoughts from summer smells could be used to identify odor receptors. I can see a graph with "walks in the wood" or "canoe trip" as descriptors for my response to these odors.
My husband insists that my 'fern' smell is actually that of the nearby pine trees, and he may be correct, but the combination of fern and pine results in that marvelous Beulah bouquet. Aromas are not just from a single molecule, but from a sets of molecules and each person perceives odors differently, hence the necessity to “measure” smell with emotion. Though humans have a few hundred odor receptors, we can discern the difference between thousands of different smells. I am reminded of the eighty-eight keys on the piano and how many different combinations can be played, smelling is like that. Some of us play chopsticks and others play Chopin.
The New Zealand biologists’ work suggests humans around the world experience similar differences with respect to smell: it looks like nature seems to beat nurture in this realm. So go out and smell the world and appreciate your own unique aroma experience. I will head to the upper lower peninsula of Michigan and enjoy the smells of fall.