I love Equine Ink. Liz’s June 14 post about Eau de Grassy Meadows touched on a couple of interesting points about smell.
I have always been extremely susceptible to aroma. Being a migraine sufferer from an early age, I have a nervous system that is keenly attuned to all kinds of smell. Chemical smells such as exhaust, polish, cleaners, etc., even in small doses undetectable to ordinary humans, can produce a migraine that lasts for days. Needless to say, it pays to be mindful of my surroundings. Just yesterday Linda and I were in Office Max, where they had recently polished the floors. Spic and span. One step in and “I gotta get outta here. Bye!” Linda did her shopping while I lurked outside like a teenager sneaking a cigarette.
The flip side of this sensitivity is an appreciation for smell that goes beyond the ordinary. I smell things others don’t notice, and those aromas find their way into my limbic system and stay there, producing a kind of olfactory memory of time and place that later evokes precise memories and emotional associations.
The association of fragrance and emotion is not an invention of poets or perfume-makers. Our olfactory receptors are directly connected to the limbic system, the most ancient and primitive part of the brain, which is thought to be the seat of emotion. Smell sensations are relayed to the cortex, where ‘cognitive’ recognition occurs, only after the deepest parts of our brains have been stimulated. Thus, by the time we correctly name a particular scent as, for example, ‘vanilla’ , the scent has already activated the limbic system, triggering more deep-seated emotional responses.¹
In humans and most mammals (including horses), the olfactory bulb is part of the limbic system, the part of the brain associated with emotion and memory. Intimately connected with the amygdala, the small organ thought to produce emotion, and the hippocampus, the part of the brain believed to be responsible for associative learning, the olfactory bulb plays an important part in the formation of early emotional learning. Some evidence suggests that this learning begins in the womb.
The interconnectedness of the organs of the limbic system does not guarantee that smell will produce emotional memories, however. For that, conditioned response is necessary. Linking a smell to an event, person or place forges a memory. How many times have you pulled out your swimsuit to store for the winter and inhaled the aroma of sunscreen and chlorine, only to be reminded of the languid days of summer? The memory of summer carries with it your personal emotional memories as well. There are times during the darkest hours of winter when I will pull out my swimsuit to inhale these feelings.
Conditioned response explains why not everyone likes the same smells. Negative emotions associated with smells reveal the unpleasant aspects of conditioned response and the limbic system. We all have things we can’t bear to smell, and the bad memories to go with them. Lilies remind you of funerals? Stale cigarette smoke of your despised great auntie?²
© Jennifer Walz | Dreamstime.com
As prey animals, horses rely on their senses to an even greater degree than humans do. Likewise conditioned response seems to play a greater role in their behavior. One might postulate that horses react very strongly to aromas. Do they?
Yes! You have only to observe them. Horses use smell as a social tool. Mares recognize their foals by smell. Stallions mark just about everything by the smell of their urine and feces.
The list goes on and on.
Prey animals need their sense of smell not only for social and emotional reasons, but also for protection from predators. Their anatomy has evolved specifically to provide for this protection. Compared to humans’, horses’ nostrils are very large. When flared to gather more scent, equine nostrils funnel aromatic molecules through long nasal passages containing millions of olfactory receptors, just like humans.
Veterinarians and comparative anatomists have attempted to assess the relative capacities of equine and human senses of smell without success. One thing is certain, however: humans don’t recognize one another by sniffing poop.
One of the tools horses have in their superior kit of smelling tools is a second olfactory system, an accessory olfactory organ, if you will. Lurking under the horse’s nasal cavity are the vomeronasal organs (VNO). These tubular, cartilaginous organs are roughly 12 centimeters long and lined with mucous membranes containing sensory fibers of the olfactory nerve. The VNOs expand and contract like a pump with stimulation from strong odors, following their own pathways to the brain, functioning virtually as separate sensory organs. Why two sensory organs when humans get along fine with just one set? The VNOs purpose is the detection and analysis of pheromones, whose purpose is to indicate another horse’s sexual status. As such, the VNO is also a sexual organ, assisting stallions to identify mares in season.³
The Flehmen response in stallions and, more rarely, in geldings provides evidence that smell affects equine behavior.
The posture is called “flehmen” (roughly translated, it means “testing”), and it appears to help horses trap pheromone scents in the VNOs so they can be analyzed more closely. After a horse draws in the organic odor (by several seconds of olfactory investigation), he curls his lip up to temporarily close the nasal passages and hold the particles inside. Then an upward head tilt seems to help the airborne molecules linger in the VNOs. A horse performing a flehmen is giving you an outward demonstration of a stimulated vomeronasal organ.⁴
The Flehmen Response, courtesy Peter Meade, www.petermeadephotography.co.uk
If humans could exhibit a Flehmen response, or any visible response to indicate that an aroma caused intense emotional reaction, I would certainly do so upon smelling the scent Liz described in her post, Eau de Grassy Meadows. Like Marcel Proust and his famous madeleines, grass, hay, sunshine and flowers, combined with good old fashioned horse sweat have a way of transporting horsewomen to a place no man and his pheromones can.
Liz jokingly ponders bottling this intoxicating admixture, knowing that she’d make a fortune selling it to armchair horsewomen, crippled horsewomen (like me), and wannabe horsewomen. Or simply those who can’t get enough of the elixir of real life.
While you wait for her to get her enterprise off the ground, you can mix your own Eau de Grassy Meadow here. Demeter Fragrances make the most amazingly bizarre scents ever. I have a bottle of Tomato that I pull out on a cold winter’s afternoon, when the light is oblique and grey, and the taste of a summer tomato is a distant and compelling memory. A spritz in the air lifts my spirits and reminds me that, like all things, this too shall pass, and the wonders of summer will return. Eventually.
Fresh Hay and muck, sweet animal sweat--that’s as real as it gets.
I propose the following Demeter fragrances as essential ingredients in Eau de Grassy Meadow, aromatically recreating a splendid trail ride:
- riding crop
- fresh hay
- riding crop
Take a look at what the Demeter Fragrance Library has to offer. You might find it includes something that evokes a deep-seated emotional response in you. The Nose Knows.
¹ Social Issues Research Center
² information from How Stuff Works
³ The Horse.com, A Nose for News–Equine Sense of Smell by Karen Briggs, February 01 2001, Article # 62
⁴ adapted from The Horse.com, A Nose for News–Equine Sense of Smell by Karen Briggs, February 01 2001, Article # 62