The Nose Knows

by Julie Miller

During my university days there was a particular building on campus that caused me to immediately think of my grandmother each time I entered it. The building happened to be an administrative one at the time I was a regular on the campus, so it was not one I needed to enter often. I can distinctly recall, however, that each time I did have reason to go there, I would pause a moment - caught by something familiar that I could not quite place at first. Then I would sniff, ponder briefly, and think, "Oh! Dot's house!" and smile.

Despite the fact that five generations of my family attended that university (and that the building in question has probably been there for all five generations), I have no reason to believe that my grandmother has ever been inside this particular building. So why that sudden insistent memory of grandma Dot each time I crossed the threshold? Scent memory.

Some perfect mix of time, the chemistry of aging fabrics, and an era when professors could still smoke any place they pleased had lent this building a scent identical to my grandparents' home. It was the scent of my grandfather's cherry pipe tobacco, my grandmother's Camel cigarettes, old carpet, furniture polish, and who knows what else. And it conjured feelings of warmth and comfort on cue. This is not an uncommon experience when it comes to certain scents.

Many people have found that memories triggered by odors are some of the strongest and most vivid they have experienced. Catching a faint whiff of a fondly remembered cologne can stop a person in his or her tracks and spark a nostalgic interlude thinking of an old flame. Realtors recommend that sellers burn cinnamon candles or even put out freshly baked bread so that the scents will invoke pleasant memories of happy homes for the buyers. Some people who have spent unpleasant stays in hospitals or cared for very ill or dying loved ones have deep aversions to antiseptic smells that bring back the unhappy memories.

Those of us who are fortunate have five sources of sensory input to tell us about the world around us, let us learn, and signal the brain to create memories for future use: sight, hearing, touch, taste, and smell. We tend to consciously rely on sight and hearing the most, without ever really thinking about how important our sense of smell can be. We aren't dogs. We don't build the majority of our social interaction and learning around scents. But we do use it in many subtle and often unconscious ways. We learn very early to associate certain smells with danger - the scents of burning, the scents of organic solvents, the scents of tainted foods or rotting items. Our scent memory saves us from illness and poison all the time.

Ask a pregnant woman about her sense of smell and she will probably tell you it is dramatically heightened. Scents that she normally might not even have noticed suddenly have the ability to trigger waves of nausea. It is likely that pregnancy hormones create changes that allow a pregnant woman to detect the scents of poisons in smaller concentrations than normal so that she may protect the unborn child from even small amounts of toxic substances. The unfortunate side effect to that is that trips to the grocery store can become extremely unpleasant for a few months.

Up until the last decade or so, very little research was focused on looking at the relationship between scent and learning/memory. It is finally an area that is finding a research niche with people like Dr. Leonard Belluscio, a scientist associated with the Duke University Medical Center Department of Neuroscience (see the related link below) in North Carolina. The system of the body that deals with the sense of smell is called the olfactory system. Dr. Belluscio studies the olfactory system using molecular biology in combination with physiology and imaging techniques. He uses mice and sophisticated imaging tools to observe how the brain reacts as the animals are exposed to various scents over time.

Other important studies involving scent and memory include a valuable one being conducted by scientists at Columbia University in New York. These researchers are using the link between memory and odors to study and test for the onset of Alzheimer's Disease (related link below). There is even a "Sense of Smell Institute" devoted to studying olfaction (related link below), which seems to be tied to the fragrance industry. It might seem frivolous, but it could lead to real benefits for learning processes and human health.

Educators are always looking for innovative ways to draw students into lessons and enhance their retention. Programs exist to incorporate many forms of visual, auditory (sound), and kinesthetic (movement) stimulation into lesson planning. Perhaps scent would be a valuable ally in the classroom, as well. It's easy to bring general memories of school days to mind with the scents of chalk dust, old text books, or maybe even the fragrance a favorite teacher wore. But what if something like a strawberry candle could bring back a geometry theorem or a history lesson?

The next time the scent of freshly cut grass transports you back to the summers of your childhood, remind yourself of how valuable your sense of smell can be.

Sources and Related Links

Sense of Smell Institute: Elucidating the Proust Phenomenon (2003)
Olfaction and Memory
Is Science on the Scent of Predicting Early Alzheimer's?
Profile of scientist Leonardo Belluscio: Regarding sense of smell and memory