Déjà vu: The Feeling of Having Felt it Before.
Rashida Bharmal
St. Xavier's College (Autonomous),
Mumbai, Maharashtra, India

What is deja vu?
Do you feel that you've been asked this question in the past and yet can't figure out when? In a certain occasion/situation have you ever felt that you have experienced exactly the same situation before? Or you have had a similar conversation with your friends in the past. Such occurrences which have not taken place but make you feel as if they have is termed as déjà vu. The probability of you experiencing a déjà vu once in your life is quite high. Déjà vu is a French word which that means already seen.
I had conducted a survey of 23 people who are mostly college students.

Out of those 23 students 2 people had no idea what déjà vu meant.

Triggers and their solutions:
Déjà vu can be triggered by stress and fatigue. It is seen that tourists are more likely to experience déjà vu. This happens due to its connection with our memory. As for those who think it happens due to some mental illness, that's surely a myth. Deja vu occurs in healthy people too. But there are certain factors that might want you to visit a doctor.
Lowering your fatigue and stress might help in reducing déjà vu episodes. Below are some methods which can help you reduce your stress and fatigue:
Sleep: try to sleep for at least 7 to 8 hours during the night.
Relax: Try relaxing from your daily chores. You can try meditation or yoga to relieve stress.
Exercise regularly: This helps you stay fit and makes your brain active which lessens stress. You can try any exercises that you are comfortable with. Example: cycling, swimming, gym etc.
Diet: always keep your diet in control. Eat healthy foods and stay hydrated.
Journaling: Maintain a diary and note down your thoughts and daily happenings.
Caffeine: lower your consumption of caffeine.
In my survey, many of them have experienced a déjà vu, while some are sure of experiencing it others are unsure if what they experienced was actually a déjà vu.


56.6% of the participants rarely experience déjà vu. While 30.4% of them are known to experience it a few times in a month.

Most of them have said to not experience déjà vu at a particular time.
The Neuroscience behind Déjà vu:
It is very unfortunate that we don't know much about the science behind déjà vu. 60 per cent of those who have reported experiencing déjà vu have not just encountered a glitch in the Matrix.
Though neuroscientists have confirmed that having the occurrence of déjà vu doesn't by any means portray that we are mentally sick, it is not in any form an error in our memory. However, it's almost the opposite. It mostly occurs when the frontal regions of the brain try to rectify a damaged memory.
On the contrary, the occurrence of déjà vu is most probably meant to be good in a majority of people. It is an indication that the regions of the brain which work as fact-checking areas are functioning well and also prevents you from forgetting things.
A healthy person tends to forget stuff every day and that will continue to happen. You should expect this to happen since your brain is a very complex entity and it comprises trillions of neurons.
It is very disheartening that there is not even one single agreed model or theory that provides us with information about what happens in our brain during a déjà vu. Though most of the theories suggest a similar idea. The theories state that déjà vu happens when regions of the brain as that of the temporal lobe provide signals to the frontal regions of the brain that a past experience is taking place again.
After transferring these signals, the frontal regions of the brain which work as decision making regions successfully check as to whether or not those signals are consistent with what is possible. It will question the brain if it has been here before.
If the brain detects that you have been in that place before, it may proceed in recollecting your memories of that place. If your brain cannot recollect it, it will form a déjà vu.
Why does it occur?
Déjà vu might be occurring due to a certain kind of "mismatch" as to how we are all at once sensing and discerning the surroundings around us. For example, when we smell a new book we are instantly reminded of all the other amazing books that we have read in our minds. This is just a random guess and it doesn't give an explanation as to why deja vu doesn't showcase true past events.
Déjà vu might be occurring due to some internal glitch in the brain in the long term and short term circuits of the brain. The knowledge our brain absorbs about our situations and surroundings may take a shortcut route to our long term memory storage, avoiding the normal storage transfer mechanisms. Hence while experiencing a déjà vu, we feel as if that situation has occurred previously in our life.
The rhinal cortex is the region of our brain which is responsible for detecting familiarity. This region of the brain might get activated without the activation of the hippocampal or the memory circuits. This might be able to shed some light on why déjà vu moments are so blurry when we try to remember when and where we experienced such a situation. Epilepsy patients are found to experience déjà vu before having an epileptic seizure. In such patients, déjà is induced experimentally by the simulation of the rhinal cortex, not the hippocampus.
We might never get to know if such theories are even true. This is due to the fact that déjà vu experiences are totally unexpected and are very rare for many of us. Proper research on this topic is next to impossible.
Feel free to share your experiences of déjà vu with us.
References:
What causes déjà vu? The quirky neuroscience behind the memory illusion. https://www.sciencefocus.com/the-human-body/deja-vu/
My déjà vu is so extreme I can’t tell what’s real any more. https://www.sciencefocus.com/the-human-body/my-deja-vu-is-so-extreme-i-cant-tell-whats-real-any-more/
The Neuroscience of Déjà vu. https://www.psychologytoday.com/us/blog/brain-babble/201208/the-neuroscience-d-j-vu
Why Do Some People Get Déjà Vu More Often Than Others? https://www.psychologytoday.com/us/blog/brain-babble/201510/why-do-some-people-get-d-j-vu-more-often-others?amp
Déjà Vu Linked to Feelings of Prediction. https://www.psychologytoday.com/us/blog/quirks-memory/201803/d-j-vu-linked-feelings-prediction?amp
What causes déjà vu? https://www.sciencedaily.com/releases/2016/04/160413113530.htm
Feel Like You’ve Been Here Before? It Might Be Déjà Vu. https://www.pennmedicine.org/updates/blogs/health-and-wellness/2019/july/deja-vu
Deja Vu and Dreaming: Is There A Connection? https://sleepsherpa.com/deja-vu/