The Richness Of Smell

We’ve all experienced it. A hint of perfume which reminds you of a past lover. The aroma of a dish which takes you back to childhood for a few delightful moments. The scent of a room which calls up rich experiences which unfolded there. Smell has a uniquely powerful connection to memory.

Smell is also a very rich sense. Due to the fact that it was an early innovation from an evolutionary perspective compared to other senses, it is rooted deep into our nervous system. And it shows. Recent studies estimate that humans are capable of distinguishing among more than a trillion scents. If you were to smell one every second, you would still have hundreds of billions left at the end of your lifetime. Compare this to the perception of color, estimated at around a hundred million shades. That’s several orders of magnitude lower. Perception of sound pitch is even less precise, with only several thousands of frequencies.

The iconic neurologist Oliver Sacks described the compelling case of a person experiencing hyperosmia, a heightened sense of smell:

“I found each one unique, evocative, a whole world.” He found he could distinguish all his friends by smell: “I went into the clinic, I sniffed like a dog, and in that sniff recognized, before seeing them, the twenty patients who were there. Each had his own olfactory physiognomy, a smell-face, far more vivid and evocative, more redolent, than any sight-face.” He could smell their emotions — fear, contentment, sexuality — like a dog. He could recognize every street, every shop, by smell — he could find his way around New York, infallably, by smell.

What if we could leverage these unique properties of smell in order to inform powerful memorization techniques? What if scents could help us organize and manage our memories so that we could tap into them more efficiently?

Leveraging Smell

It is now trivial to capture the visual aspect of our experiences. We grab our phone and take a picture. However, capturing the olfactive side of experiences turns out to be much more difficult. Camera sensors capture one thing: light. Our noses, on the other hand, have to sense billions of different molecules. That turned out to be quite an engineering feat, as creating machines that sense smell as precisely as we do are still years away.

If that wasn’t enough, smell not only is more difficult to detect than sight, but it is also harder to reproduce. We often go back and look over pictures in order to remind ourselves of past times. Even apps designed solely for storage of pictures incorporate looking back features by prompting you with the pictures you took a year ago, for instance. What hardware does this require? Screens. They emit one thing: light. However, if we were to reproduce a specific smell, we would need a tiny biochemical lab. All this, in your pocket.

Therefore, if it’s difficult to both capture and reproduce smell, how can we still use its powerful connection to memory to our advantage? A promising direction is the idea of intentionally bringing an external scent into an experience in order to create an association with it. This would translate to using a known substance with a specific smell during a moment you want to later recall. That known substance may be anything from a commercial perfume to a scented candle. It could even be a substance specifically created for the purpose of the memory technique we are building. The only requirement is that you know how to procure more of it in the future.

Why would it be a priority for it to be easy to procure? Because this would easily enable an aided recollection further down the road. If you used a specific scented candle when you read a book, you might want to stock up on it when you want to recall that experience. If you used a specific perfume on a trip, you might want to keep some of it for when you want to look back on it in a vivid way.

Essentially, you can use scents as tags. External cues which you add onto a piece of information in order to retrieve it in a more orderly manner. That piece of information may be a fact, an experience, or something else entirely. Just procure more of the scent later and enjoy the throwback.

If you plan on using many of these tags in your memory technique, you might try to be systematic about maximizing the number of scents you can bring to life based on a limited pool of substances. You might try to collect a few powerful scents which you would then combine with each other in many ways. For example, binary combinations of 20 different scents can be used to create over a million combinations, plenty for safely tagging your favorite experiences.

A rich world of sensation awaits, its potential untapped. What kind of experiences would afford tagging in your life? What would your olfactive tags be?