Did I tell you this already? Because I kind of feel like I
might have. That feeling that you sometimes get, where you swear you’ve lived a
moment before, is called déjà vu. Translated from French, it literally means “already
seen.”
It is that super elusive feeling where you ask yourself, “Did
I already experience this? Because it feels so familiar.” You can’t quite
recall when or why, but you know that some part about what you’re experiencing has
happened before. It’s weird.
There are several theories on why déjà vu occurs. Though
some think of it in paranormal terms, such as time travel, the ability to see
the future or even evidence of past lives, science has a different point of
view. There are certain medical conditions that cause that “seen it” feeling, like epilepsy or migraines.
Scientists have studied both mental disorders and genetics as possible causes, but no direct link has been found. It was noted in one case to
occur as a drug interaction between amantadine and phenylpropanolamine, but that doesn’t seem to
be a widespread cause.
Scientists have, however, come up with a few likely causes.
One is that people experience some sort of sensory input, such as seeing or
hearing something, and the brain ignores it. Then, the brain perceives it again,
and while processing it, decides that it is somehow familiar. So it’s one event, experienced twice and misunderstood as a memory of a different time.
Another cause is your brain incorrectly tagging an event as a memory that isn’t one. Recognition memory is the ability to recognize you’ve
experienced an event before. When déjà vu occurs, recognition memory is
triggered even though the experience is new.
Next is cryptomnesia, where you learn something, forget it and then a new experience unlocks part of the memory. The past and present
events may not even be similar, but there’s something that connects the two
events in your brain, so it’s basically data processing, in a sense.
Last is the dream explanation, also called déjà rêvé. Some people get the feeling
things have happened before because they dreamed something like it. So, it’s
not a real memory, but the memory of a dream.
In any case, all déjà vu theories involve our brains playing
tricks on us. Once again, our brains are here to deceive. Silly brains.
Stop if you heard this one before, too, but did you also know the French
have many other terms associated with memories? There’s jamais vu, where you
think you haven’t experienced a situation before, which you actually have. Déjà vécu is a delusion form of déjà vu where you think you have already lived through events or activities, causing you to
skip them in real life. Presque vu is the feeling like you’re on the brink of a
revelation, and déjà entendu is the feeling that you’ve been told something
before. So, there are even more ways our brains can trick us. Hopefully, this is
something you will never forget.