The Powerful Connection Between Smell & Memory

One thing I didn’t get a chance to work into my post about the unexpected memory bomb triggered by my spice drawer was the tight, deep connection between smell and memory. I first learned about this relationship in college when I read A Natural History of the Senses by Diane Ackerman for a class. It’s still one of my favorite books. Here’s some of what she has to say about smell:

Smell is the most direct of all our senses. When I hold a violet to my nose and inhale, odor molecules float back into the nasal cavity behind the bridge of the nose, where they are absorbed by the mucosa containing receptor cells bearing microscopic hairs called cilia. Five million of these cells fire impulses to the brain’s olfactory bulb or smell center. Such cells are unique to the nose. If you destroy a neuron in the brain, it’s finished forever; it won’t regrow. If you damage neurons in your eyes or ears, both organs will be irreparably damaged. But the neurons in the nose are replaced about every thirty days and, unlike any other neurons in the body, they stick right out and wave in the air current like anemones on a coral reef.

And:

Unlike the other senses, smell needs no interpreter. The effect is immediate and undiluted by language, thought, or translation. A smell can be overwhelmingly nostalgic because it triggers powerful images and emotions before we have time to edit them. What you see and hear may quickly fade into the compost heap of short-term memory, but, as Edwin T. Morris points out in Fragrance, “there is almost no short-term memory with odors.” It’s all long term. Furthermore, smells stimulate learning and retention. “When children were given olfactory information along with a word list,” Morris noted, “the list was recalled much more easily and better retained in memory than when given without the olfactory cues.” When we give perfume to someone, we give them liquid memory. Kipling was right: “Smells are surer than sights and sounds to make your heart-strings crack.”

And:

Smell was the first of our senses, and it was so successful that in time the small lump of olfactory tissue atop the nerve cord grew into a brain. Our cerebral hemispheres were originally buds from the olfactory stalks. We think because we smelled.

Our sense of smell, like so many of our other body functions, is a throwback to that time, early in evolution, when we thrived in the oceans. An odor must first dissolve into a watery solution our mucous membranes can absorb before we can smell it. Scuba-diving in the Bahamas some years ago, I became aware of two things for the first time: that we carry the ocean within us; that our veins mirror the tides. As a human woman, with ovaries where eggs lie like roe, entering the smooth, undulating womb of the ocean from which our ancestors evolved millennia ago, I was so moved my eyes teared underwater, and I mixed my saltiness with the ocean’s. Distracted by such thoughts, I looked around to find my position vis-a-vis the boat, and couldn’t. But it didn’t matter: Home was everywhere.

I could basically quote the whole smell chapter…it’s interesting throughout. Great book — if you’ve never read it, I’d recommend checking it out.

• A Natural History of the Senses
• books
• Diane Ackerman
• senses
• smell