It’s not every day that you’re asked to “smell this” while on your way to study in the library, but last fall Professor of English Zoran Kuzmanovich approached multiple students and faculty members with just that request.
It was research, people.
He was developing a new course, “Fragrance and Fascination,” which saw its inaugural semester this spring. He arranged on a library table a collection of different fragrances, asked passers by to identify them, and used that exercise as a starting point for a larger conversation about olfaction—What did they know about fragrance? What did they want to know? He was building his class from the bottom up.
“I needed to hear what people did not know in order to teach what they needed to know,” he said.
The exercise yielded a long list of questions, some technical, some philosophical, spanning the multiple facets of olfaction. For example:
- Why do I love some fragrances and hate others?
- How many different smells can a human nose distinguish?
- Does aromatherapy work?
- How does a person lose his sense of smell?
- Can odors manipulate human behavior?
- Can fragrances really bring back memories?
The list of questions—more than four dozen in all—served as a foundation for the class structure, which incorporated more than a dozen faculty lecturers and guest speakers from different disciplines and areas of expertise, including biology, environmental studies, literary theory, economics, classics, art, history and chemistry, among others.
“I was surprised to realize how little we actually know about our sense of smell,” said Joey Howard ’17, a student in the fragrance class. “We know a lot about our sight and hearing, but that’s just not the case with smell.”
Basic anecdotal experience suggests our sense of smell is more than just a biological function, and research shows the same—in fact, the way we smell and our response to different scents is the result of an intersection of biology, chemistry, psychology, history and cultural experience, which makes comprehensive study of the process challenging.
But there are some things we do know.
Location, Location, Location
For starters, let’s talk brain real estate.
Generally speaking, brain “neighbors” relate to each other, a concept that makes architectural sense: In designing a brain, parts located close to each other can communicate most efficiently, with less gray matter to get through.
In the case of olfaction, the neural receptors that receive scent information and translate it for the brain to process are located close to the amygdala, which is the part of the brain that dictates emotional and motivational responses, as well as the way we store memories. If you’ve ever wondered why certain scents evoke strong emotional responses or trigger vivid memories, this proximity of the olfactory neurons and the amygdala may have something to do with it.
So how do we smell those scents?
Scent molecules, called odorants, are small, volatile molecules—that is, they exist as gasses at room temperature and repel water. Each odorant has a unique shape, molecular makeup, behavior and even vibration frequency. In short, when we inhale, the odorants travel up our nasal passages and are grabbed by cilia (hair-like nerve appendages) located on olfactory neurons. These neurons are located in mucousy patches at the top of our nasal passages, and when they interact with different odorants they initiate different cellular chain reactions, sending specific messages to the brain based on the unique types of odorants they encounter. The brain de-codes these messages to make sense of the scents.
While scientists can outline the physical journey of the molecules and their neural translation into information, research suggests that what your brain does with that information and your personal response to that scent is determined by numerous other factors, including your previous experience with and/or exposure to that scent.
“Some scientists believe our emotions affect the electrochemical events in our brains through smells and the associations we form with them,” Kuzmanovich explained. “We can get conditioned in favor of or against a smell.”
Rachel Hertz, a psychologist, cognitive neuroscientist and leading expert on the psychological science of smell, was one of the guest speakers for the class. She argued in her February lecture that while our preference/dislike for different tastes is inherent and has evolutionary reasons (for example, “sweet” signals carbohydrates, whereas “bitter” signals poison and rot), our responses to different odors are not hardwired. Instead, they are the result of associative learning, she said.
The challenge in studying olfaction lies not so much in deciphering neural function as the brain interprets smells but in separating the psychology from the chemistry, the cultural influence from the personal preference, the innate from the induced, cognitive from intuitive, and so on. Or rather, it lies in examining the intersection of them all.
That is precisely what students and faculty members attempted to do during the “Fragrance and Fascination” class and what researchers continue to do today.
“There were so many ‘a-ha’ moments because each class had a unique point of view and subject matter,” Annie Sadler ’17 said. She and her classmates learned about representations of odor in ancient texts, studied myths and cultural beliefs surrounding scent, looked at the economic impact of the fragrance industry worldwide, and even made their own fragrances. The diversity in the curriculum and unique approach to research drew Sadler to the class.
“I really like approaching things from many different angles, looking at how things intersect across disciplines,” she said. “It’s more like the real world.”
Kuzmanovich saw first-hand the power of fragrance as he cared for his dying mother two years ago.
“How do you communicate with someone who is dying without letting their impending death affect every aspect of communication?” he said. “You find things you can do together. You pay attention to small things that interst both of you.”
And in his mother’s case, Kuzmanovich turned to fragrance. Both avid gardeners with a greenhouse full of exotic, fragrant plant species, they developed a ritual he calls olfactory autobiography, in which smelling a particular flower led to sharing of memories triggered by that flower. The practice also sparked curiosity about the way certain memories became triggered by particular flowers.
“I would bring in different flowers, she would identify them, and we would discuss and organize the memories she had developed around the scents of those flowers,” he said. “Was that before or after we immigrated to the U.S.? Was that when we were in France?” Together, they developed a sort of subjective calendar of events long forgotten.
Though his mother had lost much physical ability, including sight, she had not lost her sense of smell, a fact that was rather remarkable, as research shows we lose as much as 80 percent of our olfactory ability as we age.
Kuzmanovich’s experience with his mother ignited new curiosity, prompting him to delve further into the study of fragrance and olfaction, and ultimately to develop his “Fragrance and Fascination” class, which is dedicated to his mother.