Interview with Dr. Gabriel Lepousez

When you want to know just how scent affects our brain, the person to ask is Dr. Gabriel Lepousez. A researcher at one of France’s most prestigious scientific institutes, the neuroscientist focuses on the mechanisms underlying sensory perception and memory. From the beginning of the Edeniste project, Dr. Lepousez has guided and supported Audrey in her enterprise. For Edeniste, he discusses the vital connections between our nose and our emotions, and recent discoveries can help us innovate in fragrance.

What does your research focus on?

I focus on the mechanisms underlying sensory perception and memory, especially the olfactory system. Perception and memory are absolutely connected: we always smell in the light of what we’ve previously experienced. We compare what we see on the outside with what’s stored inside. It’s a top-down process: our perception is guided by first-hand knowledge, preconceptions, beliefs, the words we use to recall a memory. These biographical and cultural elements orient, influence, bias our perception. We never perceive reality: we always perceive the outside world through what the brain will retrieve and rebuild. That’s the paradox: in fact, we just see what we want to see.

How do smells influence our emotions?

The olfactory system is the only sensorial system to be directly connected to the seat of emotion, the part of the brain called the amygdala. Between the perception of a smell in the mucous membrane of the nose and the center of emotions, there are only two synapses, whereas there are four to six for all the other senses. Olfaction truly has an intimate, almost unconscious connection with emotions. If you make me smell something, I’ll always be able to tell whether I like or dislike the smell, even without knowing what it is, whereas with sight, for instance, I need to identify an object before I judge it. 

When do the areas in the brain that allow us to recognize a smell kick in?

Exactly at the same time. Our smell library is stored in a structure called the piriform cortex, which stocks olfactory memories and retrieves them to associate them with other elements – images, words, tastes. In parallel, the limbic system associates the smell with an emotional coloring. This emotional coloring then connects with the more general memory of the hippocampus, which is the memory of events and things. The stronger the emotion, the more anchored and easily recalled the memory is. That’s where olfaction has a role to play, in its capacity to control emotions.

How have you guided Audrey in developing Edeniste?

Audrey is driven by curiosity. She would have been a very good scientist. I felt she was ready to explore cross-disciplinary areas. I thought it was a great idea to understand how the brain works to reinject that knowledge in perfumery. We discussed how smell can connect with emotions, expresses itself in our body and influences our state of mind. That’s the ambition of Edeniste: to turn perfume into a way to experience aesthetic pleasure, but also to regulate our emotional states.

The project seems especially relevant in the current context, when Covid has taught us what an important role the sense of smell plays in our quality of life.

Covid has shown us that when you lose your sense of smell, you can experience emotional disorders such as depression and anxiety. Anxiety is the prediction of danger, while in depression there are no emotional fluctuations, no pleasure, no pain, everything is gray. Smell can recolor our emotional state and regulate it, add a little comfort when I’m anxious, a little energy when I’m depressed. The purpose is not to manipulate our emotions: fragrance is just a modulator, an amplifier, a catalyst that allows us to rebalance our moods.