Synaesthesia and Perfume: When Smell Meets the Other Senses

Synaesthesia is a fairly rare neurological phenomenon in which the stimulation of one sense simultaneously triggers a connection to another sense. Some people can see colours, or even numbers, associated with sounds or smells. But how does it manifest? What kinds of sensory associations are known to scientists? How is this phenomenon experienced? Master Parfums tells you everything.

Synaesthesia, a Little-Known Phenomenon

Syn [together] – Aesthesis [sensation]

Synaesthesia is a cognitive manifestation by which the stimulation of one sense triggers a simultaneous response from one or more other senses.

While almost all types of sensory association are possible, some forms are more common than others.

For example, some people may see colours when they hear sounds, or feel textures when they perceive colours. Others have a taste experience at the mere mention of a word, and still others associate colours with the letters of the alphabet and even with numbers… For some, sound information can also be perceived through smell, so that music has a certain smell.

As you will have understood, synaesthesia can manifest in different ways for different people and can vary in intensity depending on the situation.

Scientific Research on Synaesthesia

This phenomenon, which remains very mysterious, has attracted the attention of the scientific community since the 19th century. Part of the problem with research on synaesthesia is the way people describe their experiences. What is intense for some may be moderate for others, and the subjective dimension of the description remains difficult to grasp.

Everything we experience exists in the form of a pattern of “chemical-electrical signals” circulating in the brain. As a rule, different areas of the brain represent different types of information.

The occipital lobe, for example, contains information about vision, and part of the temporal lobe contains information about sound. Synaesthesia may be caused by unusual crosstalk* (*a fault in the transmission or reproduction of a signal) between brain regions that are normally separate.

Although scientists do not fully understand the causes of this phenomenon, they think it may come from a particular connection between the brain regions that handle the different senses. Synaesthesia could be hereditary and can vary in intensity in different people.

The discourse around synaesthesia remains nuanced because, unfortunately, few studies address the subject.

Although it is caused by cognitive processes, it is generally not an inconvenience in everyday life.

How Is Synaesthesia Experienced?

People who experience synaesthesia do not realise it immediately, since it most often occurs in childhood, and this continues until they discover that others do not have the same experience of perceptions. This is “developmental synaesthesia.”

Synaesthesia can be a gift for some people, but it can also cause confusion or anxiety for others. Some synaesthetes have described their sensory association as captivating and enriching, adding an extra dimension to their perception of life.

Others, on the contrary, feel so different that they are frightened by it, and their social life can be disrupted as a result.

It is just a different way of perceiving the world, and it would seem that synaesthetes are more creative.

Scientists continue to conduct studies on this phenomenon to understand more about brain functions and human sensory perception.

Smell-Colour-Texture Synaesthesia

Synaesthesia associating smell and colour, and sometimes a texture, is a phenomenon that is still little known but fascinating. This unusual condition allows some people to see and associate colours when they smell odours. For these individuals, of whom I am one, each smell has a particular associated colour, with variations nuanced by intensity and depth, creating a unique and very precise experience of the sensory environment.

As for me, I systematically see a colour when a perfume, a simple or complex smell, is identified. Over time I have noticed that these colours were not only nuanced in intensity but that they sometimes had a texture, making the smell even more concrete and precise.

The smells I see as green do not necessarily come from things that are green.

For example, on smelling a note of vetiver, it is the colour khaki that imposes itself. But on smelling a note of fresh leaf or stem, I see a silver-coloured satin texture… And since I cannot explain it, I only very rarely allude to it.

It is the same principle for perfumes with the standard complexity of an olfactory pyramid.

I will see an overall colour for the whole perfume, and there will be nuances of texture as the fragrance evolves. Obviously, for a few years now I have been trying to separate “my” colours from those provoked by cognitive biases: the colour of the perfume’s juice, that of the bottle, the storytelling, the brand’s logo, etc.—which could modify or influence my own perceptions. I have been aware of this for several years, and it helps me step back and consider the nature of these connections that I have always lived with.

However, the reverse does not hold: I do not perceive a smell when I see a colour, unless I force myself to, but naturally nothing will happen.

Scientists still do not know exactly how smell-colour synaesthesia is triggered, but they think it may be due to an abnormal connection between the brain areas responsible for smell and vision. However, it is important to note that synaesthesia is not an illness or a deficiency. On the contrary, many synaesthetes consider their ability to feel colours with smells as an enriching gift.

Synaesthesia and Memory

Smell-colour synaesthesia can also influence the way synaesthetes perceive and remember smells. For example, a smell that is associated with a particular colour could be more easily memorised and associated with a specific event or person.

Olfactory memory no longer plays on a single front, since other senses come to reinforce and facilitate learning and memorisation thanks to this mnemonic asset.

This experience is obviously very personal and subjective.

Nevertheless, it is important to note that certain colours are often universally associated with basic smells, such as the smell of lavender, which is often associated with its violet colour, while the smell of lemon is often associated with its yellow colour. This is not synaesthesia but rather a tacit consensus of a given society or culture. This is called collective memory.

Synaesthesia in Perfumery

The brand L’Orchestre Parfum has developed a collection of perfumes built around the plurality of the senses, associating a piece of music with each of the fragrances. A playlist is made available, and for each perfume it is proposed to listen to a piece of music composed with inspiration drawn from the fragrance.

To find out more, watch our video on the subject!