GeneralScience

What is déjà vu?

Have you ever had that sneaking suspicion that you’re going through the motions of a scenario that’s already happened? Say, you have a dream where your mailman asks you a specific question after he rings the bell and you answer the door. Then, in real life, the doorbell rings, it’s your mailman, and he asks you that exact question. If this happens to you, you might get an eerie feeling or even have the hair on your arms stand up. But don’t despair. You’re not Bill Murray who’s stuck in an endless loop of Groundhog Days.

What exactly is déjà vu?

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First off, the term “déjà vu” is French. The literal translation means “already seen”. But in everyday life, déjà vu refers to the weird feeling you get when you’re in a situation where it feels like you’ve already lived it, and are somehow living it again. Like in the example we gave in our introduction, even though you didn’t really live through the mailman asking you a question twice, it felt like it.

There’s more than one kind of déjà vu

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It turns out that déjà vu is actually quite nuanced and can happen in a variety of ways. In particular, there are two very common forms of déjà experiences: déjà visite (already visited) and déjà vecu (already experienced or lived through).

What causes déjà vu?

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This is where things can get a little scary. Research shows that there’s a direct relation between déjà vu and seizures. Specifically, the phenomenon is linked to temporal lobe epilepsy and has been described in people with a known medical history of the condition — and in people with no prior history. The feeling of having lived an experience twice typically happens just before the seizure begins. But it can also take place during the seizure.

Before you have a freakout and call your doctor, know that plenty of people have gone on the record as having lived through déjà vu who didn’t have a history of epilepsy or suddenly experience a seizure. In healthy people, déjà vu is believed to be caused by a memory mismatch, where a new experience is stored in long-term memory and completely bypasses the short-term memory. In this scenario, you have that weird sensation that you’ve been through an experience before when in reality, it’s just your brain’s memory system having a glitch. There are also other, less scary, causes of déjà vu that might have more to do with your daily habits than your medical history.

Distraction-driven déjà vu

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One of the most common causes of déjà vu is being overly distracted. In today’s world of always being connected, trying to multitask, and essentially being a Jack or Jill of all trades and master of none, it’s not surprising that you could often feel like you’re living in a freaky feedback loop. If you don’t enjoy déjà vu, it might be time to practice being more present in the moment. Trust us, whoever’s on the other end of that group chat or social media thread will understand.

Sleep-deprived déjà vu

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We already know that your body needs at least eight hours of sleep for you to perform at your optimal levels. But most people aren’t getting those 40 winks. So, is it any wonder that if you’re walking through life in a perpetual sleep-deprived haze that you might feel like you’re reliving experiences when in truth, you’re just too exhausted to parse reality from dreams? If you’re constantly struggling with an “I’ve been through this before” feeling and are also not getting enough shut-eye, it’s time to prioritize getting more sleep.

Déjà vu is foreshadowing real-life events

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Spooky right? But yes, there have been documented cases of people’s sense of déjà vu actually serving as a premonition of things to come. While this might feel like an absurd thing, the reality is that we know dreams are often our mind’s way of making sense of daily life, stressors, and changes. So, it’s not entirely unreasonable that you could have experienced a vivid scenario while you were asleep that ends up playing out in real life.