Neuroscience Unearths How Olfaction Drives Primal Motivation
Scent-driven behaviors may be linked to olfactomotor pathways in the brain.
Posted Oct 31, 2018
Scent is the most ancient and mysterious of our five senses. Anecdotally, our primordial sense of smell often feels as if it has the power to override executive functions in ways that drive us to automatically take action. We all know that the smell of sizzling bacon can draw our feet towards a greasy spoon or inspire us to drag ourselves out of bed on a lazy Sunday morning. Every autumn, the first whiff of someone in the neighborhood burning firewood can trigger a primal remembrance of how good it feels to be safe and sound in a cozy den by the hearth of a fire, surrounded by the warmth of our "clan." The smell of Thanksgiving dinner inspires millions of us to travel countless miles to get "home" and to be back in our family kitchen every third Thursday of November. The list of smells that drive locomotive behavior goes on and on.
Some smells are like magnets that draw us closer to a person or a place, like moths to a flame. Olfactory-driven behaviors, such as finding your way back home (homing), hunting for food, and being physically attracted to a potential mate, are paramount for the survival and reproduction of the human species and most animals. Madison Avenue ad execs realized the link between olfaction and behavior long ago. For example, since the early 1970s, fragrance companies have marketed perfume and colognes such as Jovan Musk as a way to attract a mate by tapping into the “unusual powers of sexual attraction” hidden in certain fragrances.
On the flip side, we are repulsed by offensive odors that offer an early warning to steer clear of certain people and potential danger. Any smells associated with sickness or death instantly become hardwired into our olfactory memories as a signal to run (don’t walk!) away as fast as you can.
Surprisingly, despite this well-known mountain of anecdotal evidence linking scent and odor-induced behaviors, neuroscientists are just beginning to figure out how scent triggers motor behaviors in the brain. Recently, a collaborative team of scientists from the University of Montreal and the University of Windsor, in Ontario, Canada, set out to pinpoint specific neural pathways associated with odor-guided behaviors.
As a first step for isolating how motor centers in the brain are linked to the olfactory bulb, the researchers used the lamprey, a primitive, eel-like fish with a vertebra. Their paper, “GABAergic Modulation of Olfactomotor Transmission in Lampreys,” was recently published in PLOS Biology. This study makes the novel discovery that odors can activate locomotor centers in the brain via two distinct neural pathways.
The Canadian researchers found that an inhibitory circuit that releases GABA into the olfactory bulb of lampreys strongly modulates their behavioral response to an odor. Although this study used an animal model, it has some human implications. Unearthing the existence of specific segregated olfactory subsystems in a basal vertebrate (lamprey) sheds light on how olfactory systems may have evolved in Homo sapiens.
“It is well-known that animals are attracted to odors, whether it be a dog tracking its prey or a shark attracted to blood. On the other hand, we are only beginning to understand how the brain uses odors to produce behavior. Our study revealed a new brain highway dedicated to transmitting smell information to the regions controlling movements,” first author Gheylen Daghfous of the Department of Neuroscience at the University of Montreal said in a statement: “This work sheds new light on the evolution of the olfactory systems in vertebrates."
Deconstructing the Motivational Power of Smell: Scents that “Feel Like Home” and “Make Us Feel Good” Can Inspire Locomotion
In the late 1970s, I became cognizant of the link between wearing a specific fragrance and creating a target mindset linked to behavior. At the time, my mom (who is also a role model) was very politically active as part of the pro-ERA (Equal Rights Amendment) movement. My mother loves perfume and has a vast fragrance collection that spans decades. Her signature scents from the "women's lib" era are permanently linked in my mind to her psychological empowerment and full-throated support and involvement with the League of Women Voters throughout the '70s.
In I979, prime-time TV was filled with advertisements for a perfume called “Enjoli,” which used the Peggy Lee classic, “I’m a Woman” as the jingle. These ads were misguided (and bordered on being offensive) but also seem laughable now. Clearly, the marketing idea is to send a message that if a woman wore this 24-hour fragrance she could metamorphose into a type of modern-day superhero who could work a 9-to-5 job, (e.g., “I can bring home the bacon, fry it up in a pan.”) and still be a housewife who took care of the kids, cooked, and cleaned, but all-the-while stayed feminine enough to never let her partner forget he’s a man.
Obviously, the gender stereotypes in this ad are mind-boggling and this message seems politically incorrect. Nevertheless, in a weird way, the Enjoli commercials triggered a fragrance-related aha! moment for me as an adolescent male. As someone who was beginning to realize I was gay around 1979, these ads inspired me to use cologne as a tool for coping with my insecurity about seeming effeminate. My rationale was that I could achieve the exact opposite type of metamorphosis as the woman in these ads by using a “macho” fragrance to create an emboldened alter-ego who was stereotypically masculine. Of course, lots of people probably associated wearing any type of cologne with being gay, but I didn’t care. I quickly learned from first-hand experience and trial-and-error that there were specific fragrances that triggered a mindset that made me feel in control and less anxious on a psychophysiological level. (For more see, "Aromatherapy Alleviates Anxiety Via Your Vagus Nerve.")
In the early 1980s, when I was still a teenager, there were lots of “powerhouse” colognes for men that were marketed to embody hyper-masculine stereotypes (e.g., Drakkar Noir, Brut, and Jacomo de Jacomo.) These potent fougère scents tend to smell very dated in the 21st century. But, as cliché as it is, I confess: I wore way too much overpowering cologne during the "me" decade. To add insult to olfactory overkill, during the summer of 1982, when I was 16, I lived in Spain as an exchange student during a period when the European tradition of bathing oneself in copious amounts of cologne was probably at an all-time high in modern history.
Coincidentally, just before my boarding school classmates and I arrived in Europe that June, the legendary Spanish fragrance company founded by Antonio Puig and family in Barcelona released a men’s cologne called “Quorum” (1982). This scent became a runaway hit and was insanely popular among adolescent Spaniards. Everywhere you went in España during “Verano ochenta y dos” you'd catch random whiffs of Quorum. As someone who collects fragrance, I bought a bottle of this powerhouse a few days after arriving in Spain and sprayed myself from head-to-toe with Quorum every morning.
When I sniff my vintage bottle of this stuff now, it's unimaginable that I dosed myself with so much of this cloying cologne as a teenager. Quorum is the epitome of an overbearing '80s fragrance; one whiff practically gives me a migraine. That said, all of the “diversifying experiences” I had as a high school exchange student in 1982—such as mingling with people from around the globe at the Joy Eslava Discoteca in Madrid or traveling to new cities throughout Spain on a tour bus with my “summer abroad” classmates and meeting other foreigners—were encoded with direct what, when, and where memories linked to this scent. For me, Quorum captures the adventurous spirit of Don Quixote in a bottle.
When I returned home to the United States in the fall of '82, I kept wearing lots of Quorum as a way to maintain the personality traits of openness to experience, extraversion, and less neuroticism that became ingrained during my summer in Spain. I also continued collecting more fragrances and played around with layering them in different combinations as a way to consciously fine-tune my “Big Five” personality traits on demand from day-to-day depending on the circumstances.
Although I mastered the art of using fragrance to facilitate different target mindsets in the early ‘80s, it wasn’t until the spring of ‘89 that I made the connection that olfaction is somehow directly correlated to locomotion-related regions of my brain, as Daghfous et al. recently examined in their lamprey study.
On March 21, 1989, after months of eagerly awaiting new music from the “Queen of Pop,” I made a pilgrimage to Tower Records on 4th and Broadway in Manhattan to buy the digital CD, vinyl LP, and audio cassette of “Like a Prayer.” Within milliseconds of entering through the record store’s revolving doors, I realized that Madonna must have persuaded Sire Records to spray every copy of her new album with nose-blind amounts of patchouli. (BTW: My original LP of “Like a Prayer” from '89, which I’ve stored in a plastic sleeve for three decades, still smells of patchouli.)
After leaving Tower Records on this balmy first day of spring, I went over to Printing House gym overlooking the Hudson River to sit by the pool and then go for a run on the treadmill. The smell of Coppertone mixed with patchouli on my fingertips while running full throttle on a treadmill that day while listening to songs like “Cherish," “Express Yourself,” and “Like a Prayer,” (Shep Pettibone Mix) directly tapped into locomotor regions of my brain in new ways.
As an ultra-endurance triathlete who spent all of the 1990s and early 2000s competing in extreme conditions around the globe, it was this 1989 experience of patchouli mixing with Coppertone while running on a treadmill that opened my eyes to a direct link between olfaction and locomotor regions in the brain. Additionally, the realization that I could use the power of scent to override crippling anxiety and take action (even when I was petrified) at any given starting line of a race was key to becoming a so-called "world-class athlete."
Over the next 15 years as an ambassador for Kiehl's and their "Spirit of Adventure," I used a combination of small dabs of patchouli and Coppertone as a source of motivation to run farther and faster. Eventually, in 2004, I harnessed the power of olfactory-driven locomotion in ways that helped me run 153.76 miles in 24 hours and break a Guinness World Record. (For some prescriptive advice on using scent as a source of motivation to take action see, “Using the Power of Smell to Step Outside Your Comfort Zones.”)
I realize now, after reading the new study on hardwired olfactomotor pathways and the GABAergic modulation of olfactomotor transmission, that there is a neuroscientific explanation for how and why I intuitively relied on fragrance as an ultra-endurance athlete to give me the motivation to take action and keep moving. These smells may have tapped into what Daghfous and co-authors describe as “a neural pathway extending from the medial part of the olfactory bulb (medOB) to locomotor control centers in the brain stem via a single relay in the caudal diencephalon,” which they speculate is linked to odor-driven behaviors in all vertebrates.
Gheylen Daghfous, François Auclair, Felix Clotten, Jean-Luc Létourneau, Elias Atallah, Jean-Patrick Millette, Dominique Derjean, Richard Robitaille, Barbara S. Zielinski, Réjean Dubuc. "GABAergic Modulation of Olfactomotor Transmission in Lampreys." PLOS Biology (First published: October 4, 2018) DOI: 10.1371/journal.pbio.2005512