How Does Déjà Vu Work?

Have you ever been to a new place and felt like you have been there already? Let’s say you have gone for surfing for the very first time. You have never done it before, but you suddenly get a flash of memories where you are enjoying yourself in the open sea, giant waves all around you. 

If that has happened with you then let me set you at ease. It was a déjà vu. It is the sense of having already seen something when you are seeing or experiencing it, but you know that you haven’t actually seen or experienced it in the past. This is why people are caught off guard and wonder how does the brain work up something so eerily familiar to what you are experiencing.

Déjà vu is a mystery and scientists are having a hard time trying to find out the reasons behind this glitch in the brain. However, experts have a few theories about the most likely causes. They are as follows: 

Split perception

The theory of split perception suggests déjà vu happens when you see something two different times. The first time you see something, you might take it in out of the corner of your eye or while distracted. Your brain can begin forming a memory of what you see even with the limited amount of information you get from a brief, incomplete glance. So, you might actually take in more than you realize. If your first view of something, like the view from a hillside, didn’t involve your complete attention, you might believe you’re seeing it for the first time. But your brain recalls the previous perception, even if you didn’t have total awareness of what you were observing. So, you experience déjà vu.

Minor brain circuit malfunctions

Another theory suggests déjà vu happens when your brain “glitches.” In other words, it can happen as a sort of mix-up when the part of your brain that tracks present events and the part of your brain that recalls memories are both active. Your brain falsely perceives what’s happening in the present as a memory, or something that already happened. This type of brain dysfunction generally isn’t cause for concern unless it happens regularly. When your brain absorbs information, it generally follows a specific path from short-term memory storage to long-term memory storage. The theory suggests that, sometimes, short-term memories can take a shortcut to long-term memory storage. This can make you feel as if you’re retrieving a long-ago memory rather than something that happened in the last second. You observe something, but the information you take in through your senses is transmitted to your brain along two separate routes. One of these routes gets the information to your brain a little more rapidly than the other. This delay may be extremely insignificant, as measurable time goes, but it still leads your brain to read this single event as two different experiences. Déjà vu can happen in response to an event that resembles something you’ve experienced but don’t remember. Maybe it happened in childhood, or you can’t recall it for some other reason. Even though you can’t access that memory, your brain still knows you’ve been in a similar situation. This process of implicit memory leads to the somewhat odd feeling of familiarity. If you could recall the similar memory, you’d be able to link the two and likely wouldn’t experience déjà vu at all.

Studying déjà vu is tough. Most often, déjà vu experiences are fleeting, they end as abruptly as they began. It is possible that if you don’t know about déjà vu you may not even realize what happened. You may feel a bit weird but you will brush it off. Moreover, déjà vu happens without any warning and also in people without any underlying health conditions. There is no evidence on how common this phenomenon is, but varying estimates suggest that almost 60 -80% of the total population experience déjà vu. 

That makes it very common and usually there’s nothing to worry about. At times déjà vu can accompany seizures in people with temporal lobe epilepsy. Déjà vu commonly happens before a focal seizure. Focal seizures, though very common, are not easily recognized as seizure. They start in just one part of the brain and may last for a minute or two or may end after a few seconds. One might also experience other symptoms, such as:- 

• twitching or loss of muscle control

• sensory disruptions or hallucinations, including tasting, smelling, hearing, or seeing things that aren’t there

• repeated involuntary movements, like blinking or grunting

• rush of emotion you can’t explain

If you’ve experienced any of these symptoms, or regularly experience déjà vu (more than once a month), it’s generally a good idea to see a healthcare provider to rule out any underlying causes.

Déjà vu can be one symptom of dementia. Some people living with dementia may even create false recollections in response to repeated experiences of déjà vu. Dementia is serious, so it’s best to talk to a healthcare provider about any symptoms in yourself or a loved one right away.

Always remember that you are important, so take care of yourself no matter how fleeting a problem is.