How Scent Activates Memory
Does the smell of fresh bread trigger childhood memories from hanging out in your grandmother’s kitchen? Or does the smell of fresh-cut grass bring those summer days all rushing back?
You remember how you felt and where you were. It’s like deja-vu… and yup, there is some scientific basis to it all.
Interestingly, scents are linked to the memory and emotional parts of your brain. How? Let’s find out.
The Neuroscience Behind Scents & Your Memory
This whole connection comes down to your brain anatomy and structure. Generally, sensory information, such as hearing, touching, tasting, or seeing, gets sent to the thalamus. From there, the thalamus delegates this information to various parts of the brain.
For instance, it may send it to the hippocampus, which remembers what you tasted or saw. It may also go to the amygdala, which creates an emotional response to what you’re seeing, tasting, or hearing.
When you smell something, this process doesn’t work the same way. When a scent enters your nose, it gets processed by the olfactory bulb. In other words, this sensory information doesn’t get processed by the thalamus.
Related Article: Why Are We Attracted to Certain Scents?
The olfactory bulb is connected to the hippocampus and amygdala. As briefly aforementioned, the hippocampus is involved in memory formation, whereas the amygdala is responsible for emotional processing. Since the olfactory bulb is in such close proximity to these two areas, strong emotional and memory connections are made. Your other senses don’t create as strong of a connection because they pass through the thalamus first.
But wait a second - what is so special about smell?
Smell goes all the way back to single-celled organisms. It’s one of the few evolutionary marvels since it’s made it this far. And because of this, we have over 1000 smell receptors. Meanwhile, the body only has four light and four touch receptors. Inevitably, evolution felt smell was important.
Then There’s the Olfactory Bulb…
Get this: In 2017, scientists made headway in understanding the olfactory bulb. They suggested that memories might actually be stored in this structure of the brain. The study went onto demonstrate (after a few trial and error moments) that the brain does, in fact, store memories in the olfactory bulb.
The catch? The researchers realized that the olfactory bulb needed instructions from a higher brain area, particularly the orbitofrontal cortex.
And this is why the memories come back so easily when you smell a familiar scent. They’re readily available!
What Happens When Smells Trigger Negative Emotions?
Then, there’s the downside. You smell something and overwhelming fear takes over. Unfortunately, some smells can trigger a negative emotional reaction. This is particularly true for those with PTSD, post-traumatic stress disorder.
When this is the case, it’s best to seek out professional help. A professional counselor or therapist can help you overcome fear and PTSD.
For less intense or severe circumstances, you can also turn to self-care practices to help cope. For instance, meditation can help calm you and gain back control of your mind. When the fear sets in, you have more control over your emotional state. Breathing techniques and relaxation exercises may also prove to be a good go-to.
What About When You Lose Your Sense of Smell?
Luckily, there are other parts of the brain responsible for archiving and forming memories. You don’t rely on the olfactory bulb or your scent of smell entirely.
Yet, there are cases where someone can lose their sense of smell, and it can have a significant impact - maybe not on your memories, but on your ability to perceive situations. This is called ansomia.
Ansomia may be a permanent or temporary loss of smell. You may experience this temporarily when you’re congested from a cold or from a sinus infection. Other causes include smoking, the flu, allergies, tumors, bone damage, or other structural damages or injuries. For instance, brain or neural damage may occur, causing you to lose your sense of smell.
Thus, in these cases, you won’t have that connection from scent to memory, since you evidently can’t smell anything. Yet, knowing there’s such a condition might give you another line to add to your daily gratitude journal - some people lose their sense of smell. Be happy you have yours!
The Body is an Incredible Machine!
Scents are attached to memory - who knew? The body and brain are fascinating. We don’t know as much about it as we let on. In fact, many parts of the brain continue to have mysteries attached to them.
But at least now you know a little more about your sense of smell and your memories. Fascinating, isn’t it?