The limbic system is the memory and emotion part of our brain. That’s why memories make us feel something, whether it’s happiness, sadness, anger, thirst, hunger or fear.
WHO IS HELEN KELLER?
Helen Keller was born in 1880. She was an American author and educator. An illness at 18 months old left her blind and deaf, yet she overcame her struggles and dedicated her life to helping others. She was the first person with deaf blindness to earn a college degree and she had a keen sense of smell whereby she could recognise people from their scent alone. She could even tell where they’d just come from, what their job was, and what they’d been eating. It’s been disputed whether she had a better sense of smell than other people. Perhaps it was because she learned to appreciate her nose’s abilities to detect things her eyes and ears couldn’t.
DID YOU KNOW?
Your sense of smell is 10,000 times more sensitive than your other senses and 15% more powerful than sight for recalling memories. Unlike when you hear, see, touch or taste something familiar, it can take a minute or longer to think about what it reminds you of, whereas smell can recall these memories instantly.
Imagine walking into a room with a freshly baked vanilla cake. What memory do you think it might trigger or how do you think it might make you feel?
It all depends on the circumstances of the event. Perhaps your grandmother baked you a cake, and you remember spending quality time with her, enjoying a slice or two. In that case, the smell will make you feel happy. But if it was a time when you were scolded for taking a bite of the cake before everybody else, then perhaps the smell might be a melancholy one.
A powerful scent memory of mine occurred in France whilst washing my hands with a neroli scented soap. The fragrance instantly transported me back to a time, 12 years previously, to the New York hotel where I fell in love with my husband. In a split second I was there again, in that room, with that overwhelming feeling of romance, from smell alone.
What’s your most impactful scent memory?
Smell is also about language and communication.
Think about the smell of freshly mowed grass. Why does it only smell strongly when it’s just been cut? The scent is actually a defence response from the leaves.
Plants can’t avoid being harmed, so they release what is called a green leaf volatile odor or GLV.
Scientists have shown that when a caterpillar eats a leaf, this aromatic compound, known as GLV is released into the air and signals to predators to come and eat the caterpillar that’s destroying its leaves.
Many humans have fond memories of the smell of freshly cut grass and find it comforting, but in reality, it’s the grass crying out for help and trying to protect itself.
Go outside, pick a single stalk of grass and smell it.
It probably doesn’t have much of a scent.
Now break it in half and smell the part where it broke.
Give it a few seconds because it won’t happen immediately. Can you smell the green leaf volatile odor being released?
Amazing, isn’t it?
Next time you detect the scent of freshly cut grass, you’ll think differently about smell, and perhaps never want to mow your lawn again…
DID YOU KNOW?
If you can’t smell, you can’t taste. 90% of taste comes from smell!
Not everyone can smell. Some people suffer from a condition called anosmia, a permanent or temporary loss of the sense of smell. You may have experienced a mild form of this ‘smell blindness’ when you’ve had a cold and your nose is completely bunged up. It’s a common side effect of Covid19, where patients have lost their ability to smell. It affects some people so much that they lose their appetite, and when it starts to return, they complain that the foods they used to enjoy, now smell putrid, hence they can’t stand the taste anymore.
Grab a spoonful of something yummy and let it tickle your taste buds, savoring every bite.
Now taste it again, this time holding your nose.
Can you taste anything?
If you can, how different does it taste?
Taste and smell are closely linked, and smell enhances the ability to taste. People with anosmia might still detect salty or spicy food, but that’s probably because it makes the tongue tingle.
HOW DO YOU SMELL?
You smell through your nose, but where do those smells go and how do you recognise them?
Earlier we mentioned the limbic system. This is linked to the ‘olfactory system’ or ‘smelling system.’
Olfactory comes from the Latin olfacere, which means ‘To smell’.
This system is part of your brain, and one part of it is called an ‘olfactory bulb’ or ‘smelling bulb.’
This bulb is about the size of a postage stamp and sits in your brain, between your eyebrows.
Your nose is the only open pathway that leads directly to the brain.
Volatile smell molecules are so light they travel like this:
1. Through your nose.
2. Past a membrane, called epithelium, with 400 smell receptors.
3. Connects with the smelling bulb that contains 10-20 million cells.
4. Communicates to the limbic system (feeling and memory part of the brain).
5. Makes you remember things or triggers feelings and emotions.
DO WE ALL LIKE AND DISLIKE THE SAME SMELLS?
No. Quite the opposite.
You know how you don’t mind the smell of your own farts?
You may even like them! Yet, anyone coming close to you after you’ve just let one rip will make them run a mile up wind!
It’s the same with other smells and that’s because of culture and environment, where they grew up and what they grew up eating and smelling.
Do you know someone who loves smelly cheese, but the scent makes you want to puke?
A French cheese called Époisses, smells so strong that it’s been banned from public transport in Paris.
IT’S NOT JUST CHEESE THAT STINKS.
Durian fruit is an Asian fruit that has been said to smell like rotting flesh, a spewing sewer, or overflowing garbage cans.
The smell is so foul that Singapore banned it from being eaten in public places, and those that do will be fined $500!
Yet Asian folk who’ve grown up eating it don’t mind the odor and some even love it!
What smells do you love that others around you can’t stand?
DID YOU KNOW?
Not everything has a smell that we can detect.
Even some of the world’s most beautiful flowers have no fragrance.
For something to have an aroma, it must have volatile molecules that are light enough to evaporate into the air and up your nose.
Pick up a piece of jewellery, a plastic flower, or a water bottle and smell it. It probably won’t have an aroma because the molecules are not light enough to evaporate.
DO ANIMALS HAVE A BETTER SENSE OF SMELL?
Animals and insects use their sense of smell to find their perfect mate, find food and detect danger. Something that we humans did thousands of years ago!
We have 10-20 million receptor cells in our smelling system and bloodhounds have around 50 million!
Dogs are often trained to find criminals, missing people and dead bodies. They can even smell fear.
But that doesn’t mean that humans have an inferior sense of smell. We just take it for granted and don’t understand how powerful it is.
AMAZING THINGS YOUR NOSE DOES:
- Detects smoke and gas leaks.
- Recognises tens of thousands of smells.
- Tells you when your food is burning.
- Make you feel happy and joyous.
- Helps you breathe when you’re eating or drinking
- Tells you when your food has gone off.
- Helps you to remember things, times, places and people.
I hope this article has helped you to appreciate how bloody brilliant your beautiful nose is.
My recommended books about smell: