Déjà Vu and Your Nose Are What?

Scientists say high-emotion memories are triggered by familiar surroundings and events. You and I think of that as having a feeling of déjà vu — or as our table overheard when a Young Modern loudly proclaimed she was having a zsa zsa de va moment. Vu or va, the situation is one where we get a distinct feeling that we’ve been in these very circumstances before — when we absolutely have not.

Déjà vu is from a French phrase meaning “I have already seen this”

While rummaging around the interweb, I found there is more than one déjàs. Here are a few of them:

Déjà visité. “I have already been in this place.” I had visited it long ago.
Déjà pensé. “I have already had this thought.” Not coincidently, pensive is our word for deep and serious thought.
Déjà entendu. “I have already heard this.” I thought this was called nagging.
Déjà gôuté. “I have already tasted this.” This is where we get our word gout, a form of arthritis associated with diets heavy on red meat. Gout most commonly affects our big toes, but can affect our other joints, too.

But we have not been there, thought that, heard it, or tasted it

Brain scientists tell us these are all illusions. Some science-haters say the explanation for déjà vu is reincarnation, a word that means “to be embodied again.” Does this mean if you were in Detroit when you died, that your next life would also begin in Detroit? If so, make plans now.

Neurologist Jean Khoury says déjà vu is a false sense of familiarity

“Your brain creates a sensation as if you have lived a certain situation before, but you’re unable to retrieve it from your memory and cannot identify the actual situation.” Because it isn’t there. And when you realize it’s not real, it’s your awareness that you’ve been tricked that makes déjà vu unique, says BBC Science Focus.

Cleveland Clinic says our feeling of déjà vu can have neurological causes

Our nervous system includes our brain, spine, and all of our 100 billion nerves and nerve endings. The magnitude of that number reminds me of how we all knew when S.K. Ball, The Arkansas Philosopher, was really annoyed with someone: “I ain’t got but one nerve left and you done got on it,” she’d spit.

An easy way to visualize our body’s nervous system

Think of it like a tree. The command center (our brain and spinal cord) is the tree’s trunk. Nerves split off like limbs growing out from the trunk, then into ever-smaller branches, stems, and twigs. This neural network of ours receives information from our 100 billion sensors.

What does déjà vu have to do with our sense of smell?

Signals from the things we see, hear, and feel have to go through our brain’s switchboard. Only then do they get recognized as sights, sounds, and touches. Scents are different because they have a straight shot to the hippocampus. And that very short path is why scents, smells, and aromas can transport us back in time as surely as if Scotty had beamed us down.

Hippocampus

The word sounds like a university for giant water mammals. It’s a Latin word for seahorse, actually, and is the name for a deep down part of our brain that deals with our memories and emotions. The hippocampus got its name because its shape resembles a seahorse.

“As humans, we navigate the world mainly using sight”

That’s what Cleveland Clinic Psychiatrist Drew Cumming says in Scent and Sensibility: The Link Between Smell and Memory. He adds, “The primitive areas of our brains still have connections from when our ancestors relied on smell to survive. These connections are the basis for scent memories.”

Live Science says the connection between scents, memories, and emotions is extraordinarily intimate

This intimacy is why memories triggered by scents are “experienced as more emotional and more evocative,” said Rachel Herz, professor of psychiatry and human behavior at Brown University in Rhode Island and author of the book The Scent of Desire. Herz added that a long-forgotten scent can make people wistful for an event in the past and even bring some to tears.

Scents are visceral in ways that seeing and touching are not

Herz says one of the special things about scents is that they bring back memories that cannot not be recalled any other way. The smell of a warm, freshly-baked apple pie or a rose or a cup of coffee are associated with positive emotions. Things like the smells of war are more problematic for former soldiers than for Lt. Colonel Kilgore, who loved the smell of napalm in the morning.

Our sense of smell is closely connected with our sense of taste

When we eat, molecules of food travel to the back of our mouths, then up into back of the nasal cavity where smells are perceived. These specialized nerve cells are called olfactory receptors and humans have more than 5 million of them. What people think are the flavors of our food are actually their aromas.

Try this easy smell-and-taste experiment

Have friends close their eyes (blindfold them if you must) and eat a bit each of vanilla and chocolate ice cream. Ask them to identify which is which. All of them should be able to chose correctly because the taste of vanilla and chocolate are so very different.
Have them close their eyes again, this time keeping their noses pinched shut tightly.
Have them eat a bit each of vanilla and chocolate ice cream.
Ask them which is which.

They’ll know both flavors taste sweet, but they won’t be able to tell chocolate from vanilla. Why is this? With their noses closed off, they are unable to smell the food.

I smell something fishy

This expression is used to convey a sense of suspicion, skepticism, and a feeling that something’s not right somehow. It had its origin in open-air fishmarkets 200 years ago. It’s easy to understand for those who have smelled all the stages of fish from still on the hook to stink. The smell of decaying fish makes humans want to retch, but is heavenly for scavengers.

Psychology Today says Smells Ring Bells

In one of the more obvious findings from a 2001 study, identical odors were rated as more pleasant when identified with a positive label than a negative one. The study subjects enjoyed a test food labeled “parmesan cheese” more than the same food labeled “vomit.” Good of them to clear that up for us.

Some thoughts on smells

“A book has got smell. A new book smells great. An old book smells even better. An old book smells like ancient Egypt.” – Ray Bradbury, author known mostly for his science fiction works.
“Smell is a potent wizard that transports you across thousands of miles and all the years you have lived.” – Helen Keller, blind and deaf activist and author.
“An idealist is one who, on noticing that roses smell better than a cabbage, concludes that it will also make better soup.” – H. L. Mencken, cultural critic, satirist, and scholar of American English.

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Bonus: Something doesn’t smell right

When I am unfortunate enough to encounter cat urine and feces, I am immediately transported back to my days as a social worker. The incident I recall with the greatest clarity was when we went to a house that knocked us over with a vile smell before we could even get out of the car. Inside, eyes watering from the ammonia, I had to breathe through my mouth and wrestle mightily with my gag reflex because more cats than we could count used the entire house as their toilet.