Why Do Smells Trigger Memories?

What is it about our sense of smell that works to better trigger our memory and our emotions?

Sabrina Stierwalt, PhD,
Episode #206

When we come into contact with an odor, or molecules from volatile substances drifting through the air, the neurons that make up your olfactory receptor cells send a signal to a part of your brain called the olfactory bulb. Axel and Buck found roughly 1,000 genes played a role in coding for different types of olfactory receptors, each of which focus on a small subset of odors. Thus each receptor is not responsible for understanding all possible smells. Those signals are then passed to what are called microregions within the olfactory bulb where again, different microregions specialize in different odors. The olfactory bulb is then responsible for interpreting those signals into what we perceive as smells.

Your olfactory bulb runs from your nose to the base of your brain and has direct connections to your amygdala (the area of the brain responsible for processing emotion) and to your hippocampus (an area linked to memory and cognition). Neuroscientists have suggested that this close physical connection between the regions of the brain linked to memory, emotion, and our sense of smell may explain why our brain learns to associate smells with certain emotional memories.

So many of these odor-driven memories may further be childhood memories because those years are when we experience most smells for the first time. There is not yet research to suggest that we can tap into the link between scents and memory to help us cram for tests or remember where we put our car keys as adults.  

Smell may trigger memories better than sight

Additionally, the areas of the brain responsible for collecting auditory and tactile signals (i.e. our senses of sound and touch) do not have the same direct connection. This may further explain why smells tend to trigger stronger emotional memories than our other senses.

Do those with a better sense of smell have better memories? 

Although smell-o-vision, an experience where movie theaters piped in smells coordinated with whatever was on the screen, hasn’t really been used since the 1950s (except for some special showings of Willy Wonka and the Chocolate Factory), scents are commonly used in advertising. Real estate agents may bring freshly baked pies to their open houses to fill potential clients with memories of family togetherness and feelings of comfort.

Our brain is clearly an extremely complicated organ, and the multitude of factors influencing our memories can be very difficult to disentangle. For example, do those with a better sense of smell have better memories? We will have to wait for more research to find out.

Until next time, this is Sabrina Stierwalt with Everyday Einstein’s Quick and Dirty Tips for helping you make sense of science. You can become a fan of Everyday Einstein on Facebook or follow me on Twitter, where I’m @QDTeinstein. If you have a question that you’d like to see on a future episode, send me an email at everydayeinstein@quickanddirtytips.com

Image courtesy of Shutterstock


About the Author

Sabrina Stierwalt, PhD

Dr. Sabrina Stierwalt is an extragalactic astrophysicist at the California Institute of Technology and Adjunct Faculty at the University of Virginia.

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