‘A fragrance is an extension of a person’s personality’: The science of scent and memory

Illustration by Photo Illustration by The Globe

Smells are tricky and little understood. They take us by surprise at unexpected moments and then rocket us across time and space. Whenever I smell the pages of a brand new book, I’m immediately transported to the deep quiet of my childhood bedroom where I would read late into the night. Or if I catch a whiff of lilac, memories of my mom, who used to spend hours each spring sitting under a tree in our backyard, come rushing in.

Clearly, scent is powerful stuff. As Helen Keller noted back in 1908 in her book The World I Live In, smell is the “fallen angel” of our five senses. She knew it was a “potent wizard that transports us across thousands of miles and all the years we have lived,” but she also recognized we took it for granted, preferring to focus instead on sight, sound, touch and taste.

So why has scent – used for thousands of years by cultures around the world to communicate with gods and higher powers – been the underdog of our five senses? Afif Aqrabawi, a neuroscientist at MIT’s Picower Institute for Learning and Memory, says the science of smell – specifically how scent, memory and emotion are intertwined – has been a mystery that researchers are only now beginning to understand.

“Fifty years ago, if you wanted to understand the brain you had to wait for a person to die. Now you can take fluorescent proteins and have them artificially expressed in any part of the brain and follow those connections,” says Aqrabawi, whose research, first at the University of Toronto and now at MIT, found a direct pathway between smell and memory, as well as identified the precise cells that store the memory associated with smells.

Plus, he says, scent is difficult to communicate. “How do you describe a scent? It’s almost impossible. That barrier to communicate the perceptions around smell has led us to ignore it. The reality is smell completely dominates our interactions in life.”

Scientists believe humans can distinguish more than one trillion scents, and our sense of smell is believed to affect 75 per cent of our daily emotions. A study by the Rockefeller University found we are 100 times more likely to remember something we smell over something we see, hear or touch. Furthermore, the New York-based Sense of Smell Institute found that while visual recall of images sinks to approximately 50 per cent after only three months, humans recall smells with 65 per cent accuracy after an entire year.

As Michael Leon, professor emeritus and neurobiologist at the University of California, Irvine, explains: Odours take a direct route to the brain’s limbic system, including the amygdala and the hippocampus, the regions related to memory and emotion. “All of the senses contribute to keeping the memory segment of our brain healthy, but the olfactory system is the only one with a direct superhighway to memory. All the other senses have to take a side street,” he says.

It wasn’t until the pandemic, when people lost their ability to smell after being infected by COVID-19 – which meant they suddenly could not experience everyday aromas such as frying bacon, brewing coffee or freshly mown grass – that many finally gave smell the respect it deserves.

“Our sense of smell is vital to our overall health,” says the neuroscientist, who recently completely a trial at UCI that successfully improved the cognitive performance of people by exposing them to seven different scents, for two hours during the night through a diffuser. Scientists have long known that the loss of smell can predict the development of a long list of neurological and psychiatric disease, Leon adds, including Parkinson’s, schizophrenia, depression and substance abuse.

The general populace may be ignorant to the nose’s inherent superpowers, but perfumers and creatives have always understood scent’s amazing ability to trigger a rush of emotions. This phenomenon even has a name, the Proustian effect, in honour of the French author Marcel Proust, who rhapsodized about a tea-soaked madeleine that instantaneously took him back to a time he shared sweets with a beloved aunt. Another artist, Andy Warhol, also exploited the power of smell to evoke memories. He would wear a perfume for three months and then never again, so that its scent reminded him of that specific period in his life.

Not surprisingly – given the sway that fragrance has over people’s lives (whether they’re aware of it or not) – the business of scent is huge and growing. The global perfume market is expected to reach US$69-billion by 2030, up from US$45-billion in 2022, according to Fortune Business Insights. While the home fragrance sector (candles, room mists, essential oils etc.) is projected to grow to US$27.6-billion by 2027, up from US$22.9-billion in 2019.

“In crafting INTERNAL AFFAIRS, I delved into a personal reflective journey," says Anston Singh. "The infusion of fruit notes resonates deeply with my childhood... I'm transported back to a pivotal moment – receiving CK ONE as a gift from my brother during Christmas. Its unisex, fresh citrus essence left an indelible mark, sparking my lifelong fascination with scents. Choosing citrus as a key note in this fragrance is not just a creative decision; it's a nod to the transformative power of that initial encounter that forever changed the way I perceive the world.”Supplied

Anston Singh, a Toronto-based entrepreneur who created the popular Black-owned, unisex fragrance Internal Affairs and started selling it at the height of the pandemic in 2020, says fragrance will always endure because it can convey how people are feeling, be it confident, lighthearted, contemplative, even sad. “A fragrance is an extension of a person’s personality,” says Singh, whose perfume is sold at Saks Fifth Avenue. “It helps them communicate and connect with others.”

Those subliminal connections are also at the heart of the US$200-million scent marketing industry. In recent years, businesses ranging from sports stadiums, hotels, medical offices and retail stores have all begun pumping scent into their spaces to distinguish their brand and to tap into customers’ emotions on a deeper level in hopes of enhancing the overall experience.

Even tourism – and elite cultural institutions – is getting into the game, with the Louvre, the Museo Nacional del Prado and Amsterdam Museum offering olfactory tours or scented art exhibits. For instance, in Amsterdam’s City Sniffers: A Smell Tour of Amsterdam’s Ecohistory launched in 2022, a self-guided tour includes a scratch-and-sniff map with various historical smells such as perfumed pomander, a scented ball thought to ward off the plague.

Perfumers and home fragrance companies understand that people have deeply personal connections to certain scents and they market accordingly. For instance, six fragrances are commonly believed to be the world’s most happy aromas – citrus, jasmine, vanilla, mint, lavender and pine. Toronto-based home fragrance company Lohn leans on these when making their candles, essential oils and room mists.

Katerina Juskey, co-founder of Lohn with Victoria Mierzwa, says feedback from their customers proves those “happy aromas” produce the desired results. “I don’t want to make any health claims about our products – because that area is very highly regulated – but we have had e-mails from customers telling us that our candles help them with depression, anxiety and alleviate stress.”

One fragrance called Jaro, with notes of mandarin and petitgrain (an essential oil distilled from the leaves and bark of the orange tree and other citrus plants), really strikes an emotional chord. “We were spraying it at the One of a Kind craft show a few years ago and customers kept coming up saying, ‘That reminds me of my childhood’ or ‘That reminds me of my grandmother’s garden,’ ” says Juskey, who has a masters degree in scent design and creation from Guerlain’s Perfumery School in Versailles. “People were buying it like crazy.”

When entrepreneurs Elsa Bustamante and her business partner, Youmna Aoukar, launched their wellness company, Inara, an experiential fragrance brand that combines scent, sound and meditation, they turned to perfumers at the International Flavors & Fragrances in New York to create scents that target specific emotions.

In June, Inara launched four scents: Calming, Grounding, Heart Expansion and Self Expression. For US$80, customers get the scent, a soundtrack and a guided meditation. The idea, Bustamante explains, is that the “scent creates a new memory imprint in your mind. Every time you wear the scent as a talisman, it will take you back to that peaceful state of mind.”

"Sweet Grass is an ode to the prairies and deeply connected to many moments growing up in Alberta," says Josh Smith, founder of Libertine Fragrance. "It serves as a reminder while so much of the perfume industry venerates major cities like London or New York, there is so much beauty to be found in quiet places as well."Morris Nguyen/Supplied

Josh Smith, an ex-forester turned self-taught perfumer based in Edmonton, believes the most powerful smells are not exotic luxuries but the familiar features of our everyday. “Our noses, for the most part, are out of practice,” says Smith, founder of Libertine Fragrance. “We don’t give much more than a fleeting thought to scent in our lives, but it’s there all around us.”

My Scent Memory

The magical memory-jogging power of scents is proven and we asked notable creatives – whose sense of smell helps to inform their work – what scent instantly transports them to a specific moment in time.

Jessica Rosval

Montreal-born head chef of the deluxe bed and breakfast Casa Maria Luigia in Italy and co-author of Slow Food, Fast Cars: Casa Maria Luigia – Stories and Recipes with Massimo Bottura and Lara Gilmore (Phaidon).

“Memories of coming in the house during the cold Canadian winters after building snow forts for hours, to the smell of my mom’s chicken and dumpling stew, or matzah ball soup that has been simmering away for hours. The smell of that broth instantly warms my heart. Today in Modena, a small town in the centre of Italy, I can come back from a whirlwind trip to any corner of the world, and a bowl of the traditional tortellini in chicken broth has its way of making me feel right at home.”

Suzanne Barr

Toronto-born chef and author of My Ackee Tree: A Chef’s Memoir of Finding Home in the Kitchen (Penguin Canada), and founder of Suzanne Barr Food, an online culinary community that she runs from Fort Lauderdale, Fla.

“The smell of curry spice automatically takes me back to my mother when she would premarinate the curry goat meat in this red bowl. It reminds me of opening the fridge on Sunday morning before my mom would start making breakfast. I would grab juice and my stomach would growl because I knew it was going to be a feast to really enjoy and embrace. My mom has been gone now for well over 25 years but when I smell curry, onions and garlic together in the fridge in that raw state, it reminds me of being a little girl and looking forward to Sunday night dinners.”

Gretchen Rubin

The New York Times bestselling author of The Happiness Project and Life in Five Senses: How Exploring the Senses Got Me Out of My Head and Into the World (Crown).

“Every time I catch the sharp, distinctive scent of petunias, I’m transported back to childhood. I’m in Nebraska, in the hot summer sun, helping my grandmother to water the mass of purple petunias that grow in a large brick planter on her front porch. She has been gone such a long time, but the fragrance of petunias makes me feel like I’m standing right beside her, once again.”

Lindsey Taylor

A floral and garden designer based in upstate New York and author of Art in Flower: Finding Inspiration in Art and Nature (Monacelli).

“Perhaps my most treasured scent experience is that of the elusive gardenia. Their exotic heady scented flowers take me instantly back to childhood when I would visit my grandparents in Florida. They had a healthy big shrub near their front door that was often in bloom when we arrived from the north. My granny would float the elegant white flowers in low bowls of water inside, filling the air with that deep otherworldly smell.”

Shezad Dawood

British multidisciplinary artist whose new multisensory exhibition, Night in the Garden of Love, is at Toronto’s Aga Khan Museum.

“I remember being on a jury at the Architectural Association in the nineties and a fellow juror was one of the women behind the amazing ‘anti-perfume’: Comme des Garcons Odeur 53, developed by perfumers Martine Pallix and Sophie Chapuis. Containing notes of freshly mown grass, nail polish and metal, it was intended as an ‘abstract’ perfume that adapts to the wearer, and so never smells the same. For me it kicked off a fascination with how you could push the envelope of scent as a creative process, and work with subjective memory. For the exhibition, we created a distinctive fragrance with eight middle notes called Xyloflor. I was obsessed with the scents of jasmine and brugmansia, which evoke evening for me as a child, in my grandmother’s garden, before I was called back into the house.”