[Light hearted music]
[Humming]
[Sniffing sound]
[Happy sigh] Pumpkin pie!
[Person] I wonder why the smell of pumpkin pie always takes me back to fall evenings at grandma’s house.
[Triumphant music] [Narrator] A very good question indeed, my friend.
[Narrator] This is actually a term called “Odor-evoked autobiographical Memory”
[Narrator] These are memories that are brought by scent.
[Narrator] They are usually more vivid and trigger significant emotional experiences.
[Narrator] But to actually understand this phenomenon, we need to start our journey with the nose.
[Person] Wait, at my nose?!
[Narrator] Yes! Your own nose! This is where all the magic begins
[Person] Huh, what magic?
[Narrator] The magic of how smell can trigger your memories!
[Narrator] Now, let us get started. To the nose!
[Narrator] It all starts with the nostril. Let’s start by following these particles coming from your food.
[Narrator] Right behind your nose is a big space called the nasal cavity
which connects with the back of your throat.
[Narrator] Look up at that thin layer of mucous! That’s where we are heading.
[Narrator] Right underneath the mucus, we find the olfactory epithelium!
[Narrator] The reason why you can smell different things around you is because of the olfactory epithelium!
[Narrator] It’s a very special tissue.
[Narrator] The olfactory epithelium contains special receptors that notice the smell
and sends the signal along the olfactory nerve to the olfactory bulb.
[Narrator] After receiving these signals, the olfactory bulb sends the signals using a pathway called the olfactory tract
directly to multiple structures in the brain for processing.
[Person] But how is this related to my memory?
[Narrator] Good question!! Now that you asked this question, we are going to look closer into how this process happens
[Narrator] Odor takes a direct route to the limbic system.
The limbic system is a part of the brain that is responsible for emotion and memory.
Two important structures of the limbic system are the amygdala and the hippocampus.
The hippocampus is linked to memory and cognition
and the amygdala is responsible for processing the emotions associated with a smell.
[Narrator] The olfactory bulb, amygdala, and hippocampus are all very connected with one another.
Information from the olfactory bulb is sent directly to the amygdala
which in turn sends information to the hippocampus.
The hippocampus is able to then take the olfactory information it receives
and integrate it into long-term memories.
This is why you remember a detailed memory so quickly after you smell something.
[Narrator] When you are first forming a memory, the information is encoded.
Encoding refers to the fact that every single experience you have changes your brain,
forming new connections and pathways.
[Narrator] For these memories to be made long-term, however,they must be consolidated.
Consolidation simply refers to the strengthening of an encoded memory.
[Narrator] Once this long-term memory is formed, it can be retrieved.
Retrieval of memories is often driven by things you encounter in your environment
that are closely associated with that memory.
[Person] Ohh, so like the smell of pumpkin pie?
[Narrator] Yes, exactly!
Smell can become an important part of how a memory is encoded in the brain.
As a result, when you smell something that reminds you of a memory,
it cues a vivid and emotional recall of that particular memory
—just like the smell of pumpkin pie taking you back to childhood memories at your grandma’s house.
[Person] Okay, okay. Wow! This is so interesting. Okay,
I think I might just need a moment to process all of this.
[Person] So, what you’re saying is, when I smelt pumpkin pie,
the odor molecules were converted into electrical signals of information.
These signals were then sent to the olfactory bulb, the amygdala and then the hippocampus
which all connected the smell to my memories.
All of this information was then stored together in my brain and every time I smelt my Grandma’s pie,
it strengthened this memory and made it into a long-term memory!
So now, whenever I smell pumpkin pie, it acts as some sort of cue
that causes me to remember the fall evenings at grandma’s house.
Is that what you’re saying?
[Narrator] Eureka you’ve got it! That’s the simplified version anyways.
There is much more detail but you’ve got the basics down.
[Narrator] And that my friend, is how smell triggers memories!
It’s how the nose knows!
[Ba Dum Tss]
Anywho, before I leave, I have to know…
Have you ever had a memory elicited by smell before?
Let us know in the comments below.
[Oven buzzer]
[Sniff and happy sigh]