What are the dimensions of olfactory talent? Everyone’s first guess—that smell sensitivity separates perfumers from the rest of us—is certainly wrong. What does set experts apart is the ability to think about odors in a certain way. For the olfactively gifted smells are easily discernable, almost palpable objects hedged round with associations and synaesthetically linked to sounds, colors and shapes. In other words, pure nose power is overshadowed by the cognitive talents of memory and imagination.
As a scientist working in the perfume industry I tackled the topic empirically. Along with my colleagues Sarah Kemp and Melissa Crouch, I created an olfactory version of a standard research questionnaire used to measure the vividness of a person’s mental imagery. We gave the Vividness of Olfactory Imagery Questionnaire (or VOIQ) to perfumers and other fragrance professionals, and compared their scores to those of non-experts. The perfumers had more vivid mental impressions of smell. In another study, I found that high odor imagers bought and used fragranced products more than low odor imagers.
Since then other researchers have found that VOIQ score predicts all sorts of odor-related behaviors. For example, psychologists Richard Stevenson and Trevor Case studied smells during dreaming.
They discovered multiple links between dream smelling and smell ability in the waking world. First, olfactory dreamers experience both visual and olfactory imagery more vividly than non-olfactory dreamers. Second, people with more vivid mental imagery for smells have more vivid smell dreams. A follow-up experiment found a third link: olfactory dreamers are better at identifying odors in a smell test.In recently published experiments, psychologist Catherine Rouby and co-workers at the Claude Bernard University of Lyon, France take things even further. Rouby gave the VOIQ (and its original visual version, the VVIQ) to 30 people, who then rated the smell of carvone, isoamyl acetate, and limonene for intensity, pleasantness and familiarity.
All of this suggests to me that some people are simply more tuned into odors than others. Smell-oriented people—those who identify odors accurately and imagine them vividly—tend to dream in smell as well. Olfactory talent shows itself all around the clock.
A second study also began with 30 people who took the VOIQ and VVIQ, but only the eight top-scoring good imagers and eight bottom-scoring poor imagers proceeded to the next stage: rating cineole, isoamyl acetate, and heptanal for intensity, pleasantness and familiarity. While doing so the subjects wore a nose mask equipped with an airflow sensor that measured sniffs.
Rouby’s team found that good visual and olfactory imagery go hand in hand. They also found that good olfactory imagers rate smells as more intense, familiar and edible than do poor olfactory imagers. They also sniff longer at all odors, regardless of the pleasantness of the odors.
To the French team these results support “the hypothesis of deeper or more complete odor processing and better access to odor semantics in good olfactory imagers.” That’s a more precise and graceful way of saying that good olfactory imagers are “more tuned into odors.”
Rouby’s results are further confirmation of the tight reciprocal links between sniffing behavior and the experience of real and imagined odors. People routinely sniff when asked to imagine a particular smell; in doing so, they activate an entire sensorimotor sequence that enhances the vividness of the imagined odor, just as eye movements during visual imagery help us “see” a specific picture in our mind.
All in all, what emerges from the new sensory neuroscience of smell is a view of odor perception as cognitive and motoric—hardly the all-emotion all-the-time caricature that used to prevail.