The Science of Scent

Written by Leanna Serras

Of all the senses, the sense of smell is probably the first to respond to stimuli. If something is burning in the kitchen, you will smell it even when you are in the living room where you cannot see it. You will smell the aroma of some delicious cooking even before you can taste it. When you pick up a scent, do you know how you are able to smell it? Scent is caused by odor particles which are so tiny that they cannot even be seen with a microscope. Let's learn more about the science of scent.

Odors are picked up by the nose which filters, moistens, and smells the air which is inhaled. When you inhale, you take in the air which is then filtered by tiny little hairs in your nostril. Known as cilia, these tiny little hairs keep the dirt from reaching the nasal cavity where the air has to pass through before it reaches the lungs. Now, the process gets more complex. Coming out of the nasal cavity, the air reaches the olfactory bulb after passing through a layer of mucous. Smells are recognized in the olfactory bulb because the smell molecules fit into the corresponding nerve cells like "lock and key". At this point, the nerve cells send signals to the brain via the olfactory nerve. The signals are then processed in the brain and interpreted as the smell of roasted chicken or popcorn.

More than all the other senses, the sense of smell is strongly associated to the areas in the brain where associative and emotion learning is processed. The olfactory bulb is an integral part of the limbic system. Within this system, there are the amygdala and the hippocampus which are known to be structures that are essential to your memory, mood, and behavior. Due to the olfactory bulb's association with the brain's emotional center, the science of scent offers an interesting insight into behavioral science, neuroscience, and advertising.