Allied with our health and an inexhaustible source of pleasure, smell speaks directly to our emotional brain. The most voluptuous of the senses, said Diderot. We are not going to tell you otherwise.
Long despised, considered negligible compared to sight or hearing, the sense of smell has taken a kind of revenge with the health crisis. By playing us the wrong trick of disappearing – anosmia being one of the symptoms of Covid – he reminded us how much we cared about it! Because know it, the sense of smell is one step ahead of the other senses: it speaks directly to our limbic system, our emotional brain. It thus greatly influences our emotional state and our behaviors, while providing us with information and bringing us pleasure. “The association of perfume and emotion is not an invention of poets or perfumers,” notes British anthropologist Kate Fox. You wondered why the smell of coffee reassures you, that of saffron makes you travel or that of clean linen instantly gives you well-being and serenity? Science has its idea.
I breathe so I am… in a good mood!
Researchers at Sacred Heart University in Tokyo examined the effect of odors on newborns under mild stress. The experiment was conducted on 83 five-day-old infants, who were to be sampled by heel prick blood. Thanks to various clues, the researchers established that the diffusion of an artificial scent of lavender or milk, at the time of sampling, induced a decrease in cortisol, the stress hormone. The relaxing action of certain scents is now widely used by the medical world. For example, soothing scents (citrus, vanilla, etc.) are diffused in the waiting rooms of many dental offices. In the same spirit, research engineers at the National Polytechnic Institute of Toulouse have developed 2020 a concept called Oncosmo. By combining sounds and extracts of lavender and mint, plants known to de-stress, they seek to help cancer patients better live their chemotherapy sessions.
Support when self-esteem makes pschitt
Another power and not the least, some wakes could influence the perception we have of our own body. Researchers at University College London and the Universities of Sussex and Carlos III in Madrid have shown that breathing lemon, for example, provides a feeling of lightness. Their experiment took place in two stages: they first asked the participants to evaluate perceived aromas by associating them with more or less coated silhouettes, shapes, sounds, temperatures, and sensations of pleasure or displeasure. Participants were then invited to walk on-site, equipped with motion sensors while being shown these same fragrances. Result: not only does the smell of lemon make you lighter – unlike vanilla, for example, which gives a feeling of gravity – but it also gives the impression of walking with a more upright posture…
Traveling into the past at a glance
Some scents have marked us so much that they have the gift of reconnecting us to our childhood in the blink of an eye or to make us relive significant episodes of our lives. In 2014, scientists at the Lyon Neuroscience Research Center tried to understand this link between memory and smells. During the first three days of the experiment, different images were presented to volunteers on a computer while a particular scent was broadcast for each of them. On the fourth day, while the researchers made the different aromas used felt, the volunteers managed to find the memory associated with a third of them. With one notable constant: the more intense the emotion aroused by the smell, the more precise and detailed the memory.
This ability to awaken memory has long been of interest to the medical world. The first olfactory workshop, called Feeling to Remember Better, was opened for patients at the Raymond-Poincaré Hospital in Garches in 2001, some of whom had suffered a stroke or head trauma.
The best way to feel connected to others
That smells good in my region! How many of us recognize in the scent of food, a tree, or a landscape, a familiar scent. Thus, smells build our identity and connect us to a collective. Research has also made the link between cultural belonging and the perception of smells.
This is evidenced by this study, conducted by French and Quebec scientists, published in the journal Chemical Senses in 2016. Participants from both countries were asked to smell smells characteristic of their culture and others not characteristic with, and then without, labels. The results speak for themselves: North American participants recognize specifically Quebec scents such as wintergreen (aromatic plants) and especially rate them better. It must be said that in North America, they are found in sweets and sodas, while in Europe, they slip into medical products such as balms for muscle care… For the French, it is lavender that stands out. Hold on…
Trust and be wary of fumes!
“An odor can provide an alarm signal to detect dangers in our environment,” note Moustafa Bensafi and Catherine Rouby, researchers in neuroscience and psychology of olfaction at the Center for Research in Neurosciences of Lyon*. Our olfactory system detects rotten or moldy food, odors of industrial pollutants, or city gas additives.” On the other hand, it is proven that people whose sense of smell is defective are more prone to domestic accidents. Example with this study carried out on patients suffering from disorders of smell and taste, by scientists from the University of Virginia. Tests conducted over several years found that 37% of patients with olfactory impairment had experienced at least one hazardous event (e.g. ingestion of spoiled food, inability to detect a gas leak), compared to 19% of patients without impairment. No doubt, having pif is definitely a chance in life!
* In Odorat et cerveau, comment (ré)éducation son nez ?, ed. Edp Sciences, 2021.
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