The Evolving Science Behind Our Sense of Smell

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GrapevineThe advances of science in the realm of wine continue to refine, and even redefine, our understanding of wine appreciation.

Our perception of wine is influenced more by our sense of smell than by our sense of taste. Our olfactory sensors are present in the nasal passages and in the back of the throat. They bombard our brain with significantly greater impulses than those sensors in our mouth and on our tongue. Yet we often find it difficult to express words that describe the aromas in a glass of wine.

Scientists at Northwestern University have unraveled one aspect of the mystery of aroma perception. Research has discovered the connection between how the brain processes aromas versus visual or auditory signals. What we see is generally the same as the next person. What we hear is generally the same also. (Yes, I know, there are exceptions and anomalies, just as with every other aspect of our interface with fellow citizens of Earth.)

Yet with our sense of smell, our perception of the reality of aromas can be widely disparate from the next person.

Scientists have concluded that a component of our brain, the piriform cortex, controls and manages our olfactory sensors. Yet the electric impulses sent by these olfactory sensors are assimilated in a different manner than those in which our brain manages our other four senses.

The cerebral cortex – specifically the gyrus region – directly manages visual and auditory signals and creates the words we use to identify these senses.

The piriform cortex is an outlier, intercepting olfactory signals on their pathway to the gyrus region. Electrical impulses from our olfactory senses are transmitted to the piriform cortex, resulting in rather garbled output as it relays signals to the gyrus region. This unique pathway influences the formation of words in the gyrus region. The process varies from person to person, creating vocabularies that may differ greatly.

Scientists have concluded this is a primary factor in the disparate descriptions we assign to aromas. Each time the olfactory sensors are bombarded by aromas, the signals to the brain are interpreted “on the run” through the piriform cortex, making it difficult to translate a smell into a descriptive word. 

What does all of this science mean to the average wine consumer?

  1. It explains why it is sometimes difficult to verbalize aromas.
  2. It explains why we may not have the same perception of a wine as a wine critic. This can be intimidating if we don’t smell the violets, or graphite, or Meyer lemon, that professional wine critics pinpoint in their wine critiques. We are not inferior; we are simply different.

The challenge is how to improve our sense of smell. It is more a sensory refinement than a scientific procedure. If we continually and diligently focus on identifying aromas in our glasses of wine, our brain will build a data bank of these perceptions. Eventually, each impression of the characteristics of a wine will be stored as a fixed memory, enabling us to describe instinctively a particular aroma. Just as the cerebral cortex creates and stores language memory, the piriform cortex enhances the aroma impulses in creating aroma memories.   

And, of course, our memory plays a significant role in our sense of smell. When we encounter an aroma of a particular food or wine, our brain searches our memory banks for similar past experiences. This is why we can verbalize the vanilla scent in a Chardonnay or the hint of chocolate in a Cabernet Sauvignon. This is how I enjoy wines, which I proclaim each week: “Continuous experimenting results in instinctive behavior.” Now I have the weight of science behind my credo.

Life is a series of experiments and outcomes. From each of them we learn and build the foundation of our interactive lives. With food and wine experiments, we bring to the table hundreds, perhaps thousands, of individual sensory experiences each time we drink and dine. Our learned sensory instincts hopefully guide us to an enjoyable outcome. Science increasingly explains how we got there.

Nick Antonaccio is a 45-year Pleasantville resident. For over 25 years, he has conducted wine tastings and lectures. Nick is a member and program director of the Wine Media Guild of wine journalists. He also offers personalized wine tastings and wine travel services. Nick’s credo: continuous experimenting results in instinctive behavior. You can reach him at or on Twitter @sharingwine.

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