Random Thought #3: Why do we experience Déjà Vu?
You know when you're in the middle of doing something and then you get this weird feeling that you've done it before and it feels more familar than it should be? Yeah, well that feeling is called déjà vu. I experience déjà vu a lot. It happens while I'm doing the most basic thing, like walking with a friend and we're talking about something, and then I suddenly feel like I've already had this conversation before in another time. I get this feeling that I had seen into the future and it's honestly one of the weirdest feelings I experience. So I searched up "I did something and I felt like I had already done it or saw it before", and then the word déjà vu popped up, so I decided to look into it.
Déjà vu, pronounced day-zhaa voo, is French for “already seen.” It describes the strange experience where you feel that something is very familiar but you also know that this feeling of familiarity should not be as strong as it is.
It's hard to say how many people experience déjà vu. According to studies, the percentage of people who experience it is probably somewhere between 30% (about 8 in a class of 30) and 100% (everyone in a class of 30) . People from the ages 15-25 tend to experience it the most out of everyone else. There are two reasons why they can't determine an exact percentage. One, they can't ask everyone in the world so they have to use the results of surveys of small groups of people. The problem with this is that surveys can give very different results depending on the people they ask. Two, people can give different answers depending on how you explain what déjà vu is. Most people report that they experience déjà vu somewhere between every few weeks and every few months. So technically, this means that déjà vu is not very common so if you do experience it, you're one of the lucky people, like me. ;)
Scientists still don't know what exactly causes déjà vu. They have a two theories based on clues that they get from the groups of people who report déjà vu more than most. One of these groups consists of people who have a condition called “temporal lobe epilepsy.” Epilepsy causes brain cells to send out-of-control electrical signals that affect all the brain cells around them, and sometimes even all the cells in the entire brain. The signals can move through cells in the brain like dominoes, each one knocking over the ones that it is next to. This is called a “seizure” and it can result in people with epilepsy briefly losing control of their thoughts or their movements. In people with temporal lobe epilepsy, seizures start in the temporal lobe. This is the part of the brain that is responsible for making and remembering memories.
Déjà vu, pronounced day-zhaa voo, is French for “already seen.” It describes the strange experience where you feel that something is very familiar but you also know that this feeling of familiarity should not be as strong as it is.
It's hard to say how many people experience déjà vu. According to studies, the percentage of people who experience it is probably somewhere between 30% (about 8 in a class of 30) and 100% (everyone in a class of 30) . People from the ages 15-25 tend to experience it the most out of everyone else. There are two reasons why they can't determine an exact percentage. One, they can't ask everyone in the world so they have to use the results of surveys of small groups of people. The problem with this is that surveys can give very different results depending on the people they ask. Two, people can give different answers depending on how you explain what déjà vu is. Most people report that they experience déjà vu somewhere between every few weeks and every few months. So technically, this means that déjà vu is not very common so if you do experience it, you're one of the lucky people, like me. ;)
Scientists still don't know what exactly causes déjà vu. They have a two theories based on clues that they get from the groups of people who report déjà vu more than most. One of these groups consists of people who have a condition called “temporal lobe epilepsy.” Epilepsy causes brain cells to send out-of-control electrical signals that affect all the brain cells around them, and sometimes even all the cells in the entire brain. The signals can move through cells in the brain like dominoes, each one knocking over the ones that it is next to. This is called a “seizure” and it can result in people with epilepsy briefly losing control of their thoughts or their movements. In people with temporal lobe epilepsy, seizures start in the temporal lobe. This is the part of the brain that is responsible for making and remembering memories.
Déjà vu researchers report that people with temporal epilepsy say that they experience déjà vu right before their seizure. Based on this, they think that
déjà vu is linked to the temporal lobe of
the brain. For people who don't have epilepsy though, they believe for them that déjà vu could be a
mini-seizure in their temporal lobe, but one that doesn't cause any other
problems because it stops before it goes too far. This idea links back to
the fact that déjà vu could also be caused by a strong feeling of
familiarity. The familiarity is signaled by brain cells in the temporal
lobe, but is noticed and ignored by another part of the brain that
checks whether all the signals coming to it make sense. The part of the
brain that does this checking may be in the frontal lobe, the part of
the brain that is important for making decisions.
So while déjà vu is not uncommon, it's still an unusual experience that effects major parts of your brain. Clearly scientists still don't know a lot about déjà vu, but I'm just glad that I'm actually not losing my mind and that I'm still normal.
Here is where I got my info: https://kids.frontiersin.org/article/10.3389/frym.2015.00001
https://www.health.com/mind-body/deja-vu-causes
This is a really interesting post! I also experience deja vu but I've never really searched it up. It's cool to hear about the research that already has been done. I've always found it really crazy whenever I do experience deja vu and sometimes I would even be a little freaked out, but knowing that it's somehow connected with our brains and how it sends signals makes me feel a little less confused.
ReplyDeleteI often experience deja vu. For example, I totally remember writing this blog comment BEFORE it was due at 9:00. In all honesty though, it was incredibly interesting to learn about something that has bugged me a for a long time. Great, clear, and informative post!
ReplyDeleteDeja vu is pretty weird. I only remember experiencing it once, in elementary school. I remember walking down the stairs and seeing a woman and her child walk by me. It literally felt like I had already lived through that moment the day before, but it wasn't the case. I also once heard that people can experience deja vu on the off-chance that one of your eyes registers/receives information before the other. Therefore, your brain thinks that it has already seen something even though it really didn't. It's a pretty strange phenomenon.
ReplyDeleteWeird. IDK if this has ever happened to me (how can you tell if your own brain is doing something weird from inside of it?) but sometimes when I walk home from the bus stop, I get the feeling I've had the same thoughts before. I reach a stop sign, I'm thinking about cookies, wait didn't I have this conversation with myself yesterday?
ReplyDeleteconsidering how often you think about cookies... probably.
DeleteNice post. I love how this blog always finds something different to talk about, and this post was cool too. The info you shared was interesting for sure, but I'm more under the impression that we all exist on an infinite number of universes, and deja vu is just us remembering something that happened to a different version of ourselves, I guess we'll never know.
ReplyDeleteThis is really interesting. I would have thought that scientists would have figured out déjà vu by now. It's really annoying that the brain is still such a mysterious organ, but I guess it would be hard to prove a theory about the source of déjà vu or other brain tricks. It's cool to know how it could be happening though.
ReplyDeleteI used to experience this phenomenon with some regularity, but that when when I was about ten years old. Now, I still occasionally get the feeling that I've thought, seen, or heard, or done something before, but the feeling isn't as intense as it used to be. It's more like a vague recollection rather than an overwhelming sense of "oh my god, this exact thing happened before. I know it. But it really didn't, did it? What's happening!? I'm in the Twilight Zone!" like I used to feel.
u know what would be really funny would be if for ur next blog post u just posted this again lmfao
ReplyDeletelol it honestly would
DeleteThis was such a good blog post Salma. I love how you dissect topics like these. I honestly use to go through the same experiences but I never thought of what it could be. Really enjoyed reading this and keep up the good work.
ReplyDelete