Among other definitions, “Smell,” in Merriam Webster’s Collegiate Dictionary, Tenth Edition, is described as
As a verb
1. To perceive the odor or scent of through stimuli affecting the olfactory nerves.
As a noun
1. The property of a thing that affects the olfactory organs: odor.
While the eye receives light waves and the ear receives sound waves, the nose receives chemical signals (Okami, 2013). Aromas in the air are created by chemical compounds. These aroma-causing chemicals pass into the nasal cavity, coming into contact with the olfactory epithelium, a patch of mucous membrane containing about 20 million sensory neurons (Okami, 2013). Much like rods and cones in the eye convert electromagnetic radiation into neural signals, there are olfactory receptors in the epithelium that translate the chemicals into neural impulses. These receptor cells are extremely specialized to particular odors, with each type of receptor responding with greater intensity to a particular odor. These translated signals are sent to the relevant micro region in olfactory bulb in the frontal cortex for interpretation. [See blog on touch for similar specialization in the somatosensory strip.]
Cats sense of smell is fourteen times as strong as humans. In addition to having many more olfactory receptors, cats have an extra scent organ, the vomeronasal organ, located in the roof of their mouths.
As cats explore their worlds, to open the passage to the vomeronsal organ, they almost look as if they are gaping. The cat’s muzzle wrinkles, the chin lowers, and the tongue hangs a bit. Other animals, such as salamanders and lemurs, have this organ and it is often particularly tuned to pheromones, hormone-like chemicals that can play a role in mating.
While we may not have as many receptor cells or an extra organ, take advantage of today to focus on smell. Good smells, bad smells, neutral odors. Smell is much bigger than the nose. It is associated with flavor, memory, mood, stress, and attention. Below are suggestions to help in paying more attention to how smell operates.
Concrete tools to broaden olfaction
1. When you next sit down to eat, pay attention to the smells emanating from your foods. Like olfaction, sense of taste is based on chemical signals. Smell plays a role in your food’s flavor. When your smell is off, like when you have a cold, food will become bland. The first step to broadening your olfactory sense is to figure out when you are using it. Play with spices in your food to modulate flavor.
2. Smell plays a role in memory. This is partially because the olfactory bulb is part of the brain’s limbic system near the hypothalamus which plays a key role in memory. Marcel Proust’s Remembrance of Things Past uses the smell of madeleines to flood the narrator with a memory of childhood bedtime rituals. Reflect on moments in your past and smells associated with those memories. Try to find those smells to see if your memory is deepened. Also, as you go about your day, pause to take in smells and pay attention to any triggered memories.
3. Smell influences people’s moods. The limbic system, where the olfactory bulb is located, also houses the amygdala, associated with emotions including fear. Marketers have picked up on this. One reason there is often fresh pie or cookies at an open house is that the freshly baked scent puts people at ease: this space seem comfy and livable and thus a must-buy. A quick way to induce an aroma chemical is to put a few drops of essential oils in a bowl of hot water. For calming and relaxation, use lavender or jasmine. To stimulate, rather than calm, rosemary, cinnamon, and peppermint are aromas associated with invigoration. So, the next time you feel hyperaroused, use oils or take a warm bath with scented salts or place an eye pillow with a lavender satchel on your forehead.
4. Smell affects work performance. Arousing fragrances such as peppermint will increase alertness and can improve performance on work-related tasks. One company uses a citrus scent to stimulate its workers at the start of the day, floral scents to boost their concentration in the late morning and woody scents such as cedar and cypress to relieve fatigue following lunch and in the evening. See for yourself if there are certain chemical compounds that improve your focus and sustained attention.