You've read this before, you swear. Was it yesterday, or last week—maybe even a year or so ago? You aren’t sure, but you swear you’ve seen it and you’ve read these exact words.
WHAT’S DÉJÀ VU?
Déjà vu. It’s that eerie experience when you feel you’re reliving a moment
from the past: you hear the same random conversation about a rare species of buffalo or you see the exact print of your mom’s hand-embroidered jean jacket on another woman in the buffet line...whatever it is, your senses are screaming at you. You know it’s happened before, you’ve seen it before, you’ve heard it before...didn't you? Or was it just a dream? Déjà vu literally translates to “already seen”, in French. And while psychics would call this feeling of haunting nostalgia a unique phenomenon, scientists who study the brain
would assure you that it’s totally normal.
OUR COMPLEX BRAINS
Neuroscientists would argue that there is logic to this seeming mystery. After all, science has known for a long time that memory is made up of various components: long and short-term memory storage, episodic happenings, and the stowing of fact-based data. Déjà vu is merely a form of optical illusion in the brain, knotted in the neural circuits of the hippocampus—the area of the brain
where all of these various memory types are stored.
After reading our article on how memories are formed, you know that the brain possesses innumerable memories. However, only those that we use regularly are strong enough to “remember” in our conventional sense of the word. While some childhood memories
are stored in the brain, we may go our whole lives “not remembering” until—Ah ha!—something triggers the memory and forces the chemical connection to claim its legitimacy.
WHEN MEMORIES OVERLAP, THE BRAIN DECEIVES US
Certain memories are so closely tied together that they might even overlap in our minds. For example, a particular conversation you had with a friend last week about the new Beyonce album might link with a recent conversation you had with your Mom about one of the album’s songs, Formation. The two memories are so closely associated in your head, that you can’t differentiate if they were even two distinct conversations, or who you talked to about which specific topic. Or how about that time you ate a burrito from Taco Bell after a weeklong camping trip of only eating dried foods? That might remind
you of the same sensation you felt when eating the world’s best burrito while on summer break in Austin, Texas last year. While the memories might appear nearly the same in your mind
, they’re far from identical. Being able to differentiate divergent recollections is what disallows déjà vu. And when this pattern-separation fails, déjà vu ensues. The neocortex of your brain may be aware that you’ve never experienced this moment prior to now, while the hippocampus is certain that you have indeed lived this episode before.
BUT MAYBE DÉJÀ VU IS A GOOD THING!
The good news? Déjà vu is a sign that your mind is at work. While your brain sometimes fails you, it’s arguably better than if it were to not try at all. Recent research shows that déjà vu is simply an indicator that your brain is attempting to check its own memory. And although some things get fuzzy in translation, eventually the skewed retrieval will become clear, thus strengthening the memory connections involved. So, next time you’re thinking to yourself this happened to me already, no, it probably didn’t. Alas, we won’t blame you if you want to read this article again just in case.