Olfaction, or the act of smelling, is linked to human behavior and directly affects our physiological and emotional responses. When we detect an odor, that odor stimulates our olfactory nerve, which then transmits an impulse to our amygdala. Our amygdala responds by signaling attraction or avoidance. Sometimes, odors will provoke specific memories, which may also affect our response. Depending on the odor and our experience(s) with it, our responses may be subtle or substantial.
Generally, when we are attracted to an odor, we prolong the experience of it. For example, at a farmers’ market, one may smell natural lavender lotion. After experiencing the scent, the individual applies it to his hands, prolonging the experience. This is an attraction response.
Conversely, an unpleasant odor emanating from a garbage pail may motivate an individual to hold his breath and quickly dispose of the garbage. The response in this example is avoidance.
These emotional and physiological responses may also play a role in fatigue. Fatigue has many definitions but here is defined as a feeling of weariness or lack of energy (1). It is a decline in task performance efficiency and may involve the desire to rest, a feeling of discomfort, and a decline in motivation (2). Saito et al found that the olfactory system may be involved in attenuating fatigue. Subjects were given a fatigue-inducing test with and without exposure to a new odorant. When exposed to the odorant, subjects demonstrated greater response accuracy than without (2).
While more studies are warranted, it may be advantageous to surround ourselves with attractive odors that positively stimulate our minds and bodies. This benefit may be amplified by using personal diffusers and aromatherapy, which allow us to change the odors according to mood, surroundings, and other needs.
The sense of smell, or olfaction, may play a larger role in our performance, physiological and emotional state than we once thought.
Angelique Cohen, MD, MBA, is a physician advisor at Saint Thomas Health in Nashville, Tenn. Her clinical specialty is otolaryngology, head, and neck surgery. Dr. Cohen has successfully practiced medicine since 1996 and owned her own practice in Illinois before relocating to Nashville where she serves in a dual capacity.