Olfactory Research
The Code of Scents

Olfactory test

Fragrances, olfactory research tells us, are as complicated as words with magical effect. It takes a long time to learn them, but when pronounced correctly, they unfold their enchantment. So-called olfactory marketing companies have already taken up the scent.

A friend has asked you to get something from his flat. You have never been there before. As you stand at the door and unlock it, you are suddenly greeted by a fragrance. The door opens and you enter – not the flat of your friend, but of your grandfather. For an instant, you see everything quite clearly before you. It is as if you have climbed into a time-machine that has, in the space of seconds, catapulted you thirty years into the past.

Almost everyone is familiar with such flashbacks. Researchers call this capacity episodic or autobiographical memory. On the basis of tiny hints, long forgotten experiences suddenly re-emerge again before the mind’s eye. And scents almost invariably play a decisive role.

“There are biological reasons for this”, says Hanns Hatt, a renowned olfactory researcher at the University of Bochum. Our olfactory cells, he explains, are almost directly wired to the limbic system, one of the deeper regions of the brain, which is responsible for the processing of memories and emotions. “In all the other sensory organs, stimulus transmission runs through a lot more intermediate stations.”

Every scent consists of 350 “letters”

Researchers are therefore not surprised that odours have a very special influence on our perceptual system. And this even less since it has become clear that odourant molecules act not only on the olfactory cells of the nose but also enter the bloodstream through the lungs. “Basically, when scents are concerned, we’re always dealing with chemical substances that could have pharmacological effects. And don’t, like sound or light, act only through the activation of biological sensors”, says Hatt. Just recently he and his team have found out that the fragrance of jasmine at the molecular level acts very similarly to Valium.

Hatt’s team of researchers was also the first to succeed in assigning a corresponding odourant molecule to each of the 350 human olfactory receptors. “They fit like a key in the lock.” Since then it has been clear that everything we smell is composed of a comprehensive olfactory alphabet of 350 letters. To each receptor there is a matching aromatic substance that can be perceived only by it. Twenty of these molecular pairings have been discovered so far.

Genes play no significant part.

According to olfactory research, then, the perception of odour is nothing else but the learning of a complex system of signs. A good wine activates perhaps 150 various olfactory receptors. “If you want to identify it”, says Hatt, “you have to memorize a sequence of 150 signs – like a word with 150 letters. That’s why it’s so challenging to tell two wines apart whose tastes differ perhaps by only a few ‘letters’.”

Interestingly, genes here seem to play no significant part. Up to now no scent has been identified whose evaluation is genetically determined. “Each odour is learned in accordance with a person’s experience”, stresses Hatt. “It must be assumed that an odourant molecule can trigger something different in each person.”

Smell is a medium of communication

It could therefore be said that how people perceive scents is largely determined by the world of experience characteristic of their culture. Or, as Robert Müller-Grünow puts it, “Smell is a medium of communication”.

Müller-Grünow is executive director of the company Scentcommunication. The Cologne-based firm specializes in using fragrances as a marketing instrument for industrial clients. If scents have emotional effects and these effects in turn strongly influence experiences, so the idea underlying Scentcommunication’s approach, then why shouldn’t it be possible to use them in a targeted manner? “Companies really do give thought to everything – to colours, spaces, materials, light. Why should smell be left to accident?”

More and more companies are commissioning “corporate fragrances”, including major firms such as Samsung and German Railways. Corporate image is now also to be conveyed by a scent – whether innovative strength or high quality products, professionalism or a pleasant travelling experience. “Central is always the question what is actually happening in the situation in which the fragrance is to be experienced?” says Müller-Grünow.

Once the scent has finally been designed, it has to be technically implemented. And this, depending on the demand profile, is sometimes highly complex. If fragrances are to be applied professionally, says Müller-Grünow, they have to be deployed as precisely and as unobtrusively possible, with specially developed atomizers. “We’ve now achieved a technical quality that enables us to use scents as adeptly as images and sounds.”

Olfactory marketing – the total manipulation?

Should this alarm us? Must we soon expect to be manipulated at every turn, lulled by adroitly mixed olfactory cocktails and gently adjusted to the interests of the company or institution on whose premises we happen to find ourselves? Patrick Hehn, an olfactory marketing expert at the Institute for Sensory Research and Innovation Consulting (isi), dismisses this fear. “I don’t see that people can be rendered will-less by fragrances.”

On the contrary. In a study Hehn investigated whether it is possible to boost the consumption of chocolate by using olfactory marketing. Interestingly, customers whose nostrils were treated to a pleasant fragrance of chocolate bought less of the sweet than did the control group who were not. The researcher’s explanation: Important for purchasing decisions is what is called experience-based knowledge. And since experience tells us that packaged chocolate doesn’t have a scent, says Hehn, the test buyers drew the following reasonable conclusion: “If chocolate in a supermarket smells like chocolate, then something must be wrong with it”.