Some research suggests that “olfactory training” — practicing to improve your olfaction, or sense of smell — can actually improve your cognitive abilities. So in the interest of self-improvement, I open my pack of what look like markers and sniff at them one by one. I get whiffs of citrus, lavender, driftwood. From a marker enigmatically labelled “hairy,” I register a greasy smell. From another, ominously labelled “barnyard/fecal”, comes the distinct smell of ass.

More appealing is a little bottle that, when opened, emits a scent of plum so vivid it brings to mind the deeper red closer to the pit, the exact feeling of cutting a piece, the interplay of taut skin and juicy flesh as you bite and chew. It brings to mind not a Platonic plum, but a specific plum I must have enjoyed on some long lost summer day. And yet the particles I inhale to recapture that sense memory were never part of a real fruit. They are a re-creation of the molecular structure of scent particles emitted by a real plum in a different country from where I sit, transported to summer on a January day, courtesy of Osmo Labs, which sent me the samples.

Yes, friends. Digital smell has arrived.

Of all the senses, olfaction — smell —  must be the most primal and evocative, the most magically elusive. With just around 350 olfactory receptors, we can each smell a vast array of different individual molecules, called odorants (one model suggests there could be as many as 40 billion such smellable molecules!).

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Research suggests that there are multiple benefits to increasing the diversity of our olfactory environment, which for humans is limited compared to our visual or even auditory or tactile worlds. The Monell Center, a Philadelphia-based independent research center devoted to smell and taste, quotes one of their neuroscientists, Joel Mainland, on olfaction: “Before COVID, [people] didn’t take it seriously. Now, more people are realizing how important their sense of smell is. It’s not a throwaway sense!”

By no means. Disorders of the olfactory system, and growing evidence of how serious they can be, inspired the use of such olfactory training beyond perfumiers or scientists specializing in smell. My sister-in-law, who like thousands of others lost her sense of smell after an early COVID-19 infection, has gradually regained much of it through a disciplined program of smelling things, such as citrus or coffee.

"That’s the only part of the brain that leaves the skull and touches the air."

But many questions about smell remain unresolved. How do we distinguish so many odors? What is the relationship between a molecule’s structure and the scent it evokes? And most importantly, as technology moves virtually everything from analog to digital experiences, why can we not yet send Stinkygrams? Why is the Cloud not scented? Why does 4D cinema suck so bad? As yet, nobody knows — but we’re getting closer to the answer, perhaps making digital smell a future mainstream wing of the digital experience.

Smell is quite different from sight, where the brain relies on information relayed from a limited range of wavelengths of light that is registered by just three types of cones in our eyes, allowing us to perceive a palette of about a million colors. In olfaction, those under-400 olfactory receptors combine, in ways that have been mysterious to researchers, to produce the staggering variety of odors we can perceive.

“You and I have about 350 olfactory receptors but our sets are different from each other,” Mainland, of the Monell Center, told Salon in a video interview from Philly, which he says has become a de facto capital of olfactory research in the U.S. He found, however, that when you set up panels of 15 to 20 people to sample different scents, the average from one group of that size to another really smooths out the variation between individuals. The panels don’t tend to differ from each other significantly, which is allowing scientists to begin developing databases of odors.

Another way in which it’s different from sight: color (probably) doesn’t actually exist out there in the world, but smell........

© Salon