Our experience of the holidays just wouldn't be the same without our noses-in fact it would be sadly bland, and I'm not just talking about food. The scents that emanate from certain dishes, certain plants, certain candles and a host of other specific holiday items are intimately tied to our emotions and our past.
Imagine yourself in the following scene: You walk into the warmly lit parlor and before you turn the corner to see the ever-familiar parental living room, you inhale and wafts of fire-place smoke, pine needles, sugary cinnamon, and roasted turkey all mingle together in your nose. You feel heady and happy, like a child again, and with a blend of elation and nostalgia turn the corner to see the holiday scene unfold as you knew it would. But what if all you could do is see this scene without the feelings that the aromas brought with it? Your holiday homecomings would probably be strangely empty.
Why are scents so deeply connected to our emotions and nostalgia? The answer lies in the unique connection between the sense of smell, our brain and our biology.
The chemical profile of an odor is first detected by neurons in your nose. The signals then travel to the brain where they are decoded by two blueberry sized structures-- the olfactory bulbs. From the olfactory bulbs, an odor's signature is sent to other parts of the brain. First and foremost to the limbic system, where associative-learning and our basic drives comes from and most importantly where our ability to experience emotion originates-- a structure in the limbic system called the amygdala. When the amygdala is activated we experience emotion, and when the amygdala has been damaged our ability to process and remember emotional information is lost. In my recent experiments on scent-evoked memory using neuroimaging techniques, I found that when participants recalled a significant personal memory to the smell of a special perfume, the amygdala was much more activated than when they recalled the same memory to the sight of the perfume bottle. None of our other senses have this direct and intimate connection with the areas of the brain that process emotion, associative learning and memory.
In addition to the distinctive neuroanatomical connection between our sense of smell and emotion, there is evolutionary evidence that the perception of smell was linked with emotional experience early on. The structures of the limbic system evolved from tissue that was originally dedicated to odor processing. In other words, the ability to experience and express emotion grew directly out of the brain's ability to process smell. I have often wondered whether we would have emotions if we did not have a sense of smell; I smell therefore I feel?
The feelings that holiday scents evoke have special meaning to us because of our personal associations with them. There is nothing inherently pleasing or nostalgic about the fragrance of pine needles, cinnamon, or sugar cookies. It all has to do with our past personal connections to them. Holiday scents are typically culturally determined but your personal ones may have nothing to do with North American traditions, and they could also be unique to you. If you come from somewhere where a wintry festival of lights doesn't exist then the scents of your holiday could be hibiscus blossoms or curry powder. Moreover, holiday scents don't necessarily make you feel joyous. If you are someone with unhappy memories of Christmas past then the scents connected to this day are going to make you feel bad, not good.
Scents have a singularly potent ability to instantly transport our hearts and mind to times gone by, but only if you have a history with that scent, and a scent can only transport you to your personal past, not a Hallmark ideal. Hopefully there are some aromas connected to your holidays that bring a special smile to your face, and if you can't wait until Christmas, Chanukah or Kwanzaa to experience them, go and get that special scent treat now for your own personal rush down memory lane.
Rachel Herz is the author of The Scent of Desire and on the faculty at Brown University.