Mis à jour : mars 2
"Our language is worthless when it comes to describing smells." - Patrick Süskind, Le Parfum.
The first smell that struck me this morning was the soft, round, slightly milky smell of my puppy who came to wake me up with her kisses. This scent instantly induced a protective instinct in me and the desire to dip my face into the little fur. Then I thought back to my old Bernese Mountain Dog who used to do the same with his gutter breath and my repulsion, even though he was the most affectionate dog in the world.
Smell has always played a major role in my perception of the world; sniffing any object before using it, hating highly-scented places, and running away from public toilets has always been part of my daily life.
One day I lost my sense of smell when I had sinusitis and, miraculously, my mind suddenly became soothed, as if, deprived of odors, it could partially rest. This respite only lasted a while, until I realized that I no longer smelled flowers either, nor my children, nor the emotion of a companion.
Without smelling, I no longer felt anything.
So, imagine my interest when I heard about the Odeuropa project this morning. Funded to the tune of 2.8 million euros, this initiative aims to reproduce smells using artificial intelligence and to preserve them as cultural heritage for future generations.
Chemists and perfumers will recreate, thanks to indications found in historical texts or paintings, smells characteristic of certain periods, such as the stench of cities caused by the industrial revolution.
The idea is to set up a museum of smells that will allow its visitors to relive a historical event, such as the Battle of Waterloo.
But how is this possible? A brief scientific summary: At the origin of all olfactory perception, there is a molecule. This molecule penetrates our nose, where the eyelashes of neurons are responsible for capturing them, hence the importance of not putting one's finger in there too often.
Smells are assimilated by 400 receptors present in the neurons located at the bottom of the nasal cavity. Each of these receptors can recognize several molecules, and one molecule can activate several receptors. The combinations are therefore almost infinite.
The ‘decoding’ of smell is done in our brain by an emotional reaction: I like or dislike. This is because the area of the brain activated by smell, the orbito-frontal cortex and the amygdala, are also involved in the decision-making and reward processes, and are implicated in reactions of fear, pleasure, and memory.
In 2017, the Institut Curie presented the results of KDog, a project that involved using dogs' sense of smell to screen for breast cancer. The results were beyond what could be expected because after only six months of training, the result was faultless. This idea of diagnosing by smell is nothing new, since Hippocrates, 400 years before our era, had already highlighted the modification of body odor by diseases.
Until the 18th century, most doctors based their diagnoses on the smells emanating from their patients. An absence of smell was a sign of good health. Augustin Galopin (Le Parfum de la femme et le sens olfactif dans l'amour, 1886), for his part, categorized feminine smells, gratifying the most musky scents with an immoral connotation.
Today, an Israeli company has created the Sniffphone, an electronic nose mimicking the characteristics of the animal nose. This application is capable of detecting cancers at an early stage with a high success rate. This large electronic sniff will also allow us to smell pollution that our numb conks no longer perceive.