Smells, which cannot be reproduced or described, but can be remembered so accurately that when they smell again, they evoke a special memory.
The smell of the old wardrobe will remind people of the childhood when I crawled in and out of my grandmother's closet;
The taste of hometown cuisine, no matter where you go, will make people feel a burst of emotion;
When I was packing up the old clothes of my deceased loved ones, I buried my face in it and sucked it hard, as if I had returned to the time when we were together.
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Why can smells evoke such deep memories and bring such ups and downs?
One of the more convincing assumptions is that smell is the most special of all sensations.
Because it is the only sensation that reaches the emotional and memory centers of the brain directly.
The nose is the most special, it is particularly pampered by the brain.
The processing of other sensations first reaches an area of the brain called the thalamus, which acts like a "switch" that transmits information we see, hear, or feel to other parts of the brain before it can be processed again.
But only the smell does not need to be detoured, and the odor signals grabbed by our noses are first transmitted to the brain's olfactory bulb, and the nerve fibers output by the olfactory bulb bypass the thalamus and reach brain regions such as the amygdala and the hippocampus through a brief one or two synapses.
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The amygdala is the area that processes emotions, and the hippocampus is the area where learning and memory are carried out.
Thus, as soon as a familiar smell is smelled, the hippocampus of the brain is instantly activated, and the emotional arousal of the amygdala is also unfolded.
This leads to a close connection between emotions, memories and smells.
Studies have found that for both children and adults, smelling objects leave a sharper imprint on their brains, as well as deeper memories.
The researchers showed subjects a series of items that could emit smells or sounds, and a week later asked them to recall those items, finding that most people were able to recall items that smelled.
Some studies have also found that odors elicit the "strongest" emotional response to date compared to responses to visual, lexical, and olfactory stimuli.
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Humans have about 400 complete odor receptors, and the genes of these receptors add up to more than 900,000 different variants, giving us the ability to recognize a trillion odors.
Our bodies are immersed in a universe of billions of scents, and the air is filled with evidence of the scents of our birth, growth, and learning to love and be loved, and we inevitably experience all kinds of departures, farewells, and losses in it.
The smell is like a fingerprint password, no image, no sound, and after smelling it, it is silently stored in the hippocampus as if it did not exist.
I don't know how many years later, when I smell the same smell again, the memories pour down, and the emotions are like sails, like a world away.
Time has passed, but the smell helps you remember.
As it is, the human body is wonderful
🛸 Curious Tour Stop 044
This article is reviewed by experts
bibliography
[1] Brann D H, Datta S R. Finding the Brain in the Nose[J]. Annual Review of Neuroscience, 2020, 43: 277-295.
[2] Yeshurun Y , Lapid H , Dudai Y , et al. The Privileged Brain Representation of First Olfactory Associations[J]. Current Biology, 2009, 19(21):1869-1874.
[3] Anne-Lise S , Jean-Pierre R , Jane P . A review on the neural bases of episodic odor memory: from laboratory-based to autobiographical approaches[J]. Frontiers in Behavioral Neuroscience, 2014, 8.
Planning and production
Curated by: Tagay, April | Executive Producer: Murphy, Feidi
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Cover image source: Dr. Lilac design team