A known nook in the street of a city you’ve never been to. A familiar-looking stranger on the bus. A recognisable conversation that was never exchanged. Stopping in your tracks you’re left wondering: Haven’t I done this before? At some point of time in our lives, we’ve all experienced such fleeting moments when we think we’ve done something or been somewhere before when in fact we haven’t. This eerie sensation that feels like a “glitch in the Matrix” is called déjà vu. For years it was believed to be a paranormal experience, beyond the scope of science. However, scientists and psychologists have unearthed the secret to this trick our brains play on us.
What is Déjà vu?
Déjà vu is the uncanny sense of familiarity of experiencing something that in actuality has never happened before. It is a French phrase which translates to “already seen”. This unnerving feeling seems difficult to shake off and is surprisingly common. Though there are no conclusive statistics on this, it is estimated that around two-thirds of individuals experience déjà vu at least once, and it is more likely to be experienced by young adults.
The Science Behind
The real question remains, what causes a déjà vu? Experiences of a past life? Premonitions of impending doom? Before you go on to believe that you’re a supernatural with psychic powers, read on to see what scientists and theorists have to say about it.
Déjà vu is known to be associated with many explanations on how the brain perceives certain information, some of which are included below
- Split perception:
Often while viewing things, you catch glimpses of certain things from the corner of your eyes and don’t pay much attention to it. However, your brain perceives that information and possibly builds a descriptive image out of this brief sighting. The next time you see the same view while paying complete attention to the same, you get the feeling that you’ve seen this image/view before but can’t recall when and how, as you weren’t paying full attention the first time around.
- Brain circuit malfunctions:
This one is exactly how it sounds – short circuits in your brain! As we all know, certain neural networks exist in our brains, which have a predefined path to process any kind of information, similar to an electric circuit. However, at times these circuits scramble and the present events are perceived as memories. It’s almost like your brain is ‘living in the past’.
Another theory suggests that the paths for short term memory and long term memory get mixed up, and the occurrence of last-second gets stored as a long term memory.
The brain circuit malfunction is known to be the most credible theory and has garnered a lot of attention from the research community owing to its logical and neurology based explanation.
What are false memories? Is déjà vu a false memory?
As the name suggests, false memories are memories of occurrences that never happened. False memories are nothing but fabrications of your mind that trick you into believing you have done something or been somewhere in the past when you haven’t. For example, while cooking you may think, or better yet, be sure that you turned off the gas below the pan only to find out that you’re left with a delicious piece of char.
Déjà vu isn’t believed to be a kind of false memory. Evidence suggests that false memories employ the hippocampus of the brain, whereas déjà vu is incepted in the temporal lobe.
Should you be concerned about déjà vu occurrences?
Déjà vu has been firmly attributed with the occurrence of a small temporal lobe seizure- similar to those that occur in epilepsy. They are said to occur before or during epileptic seizures, especially focal seizures. In such situations, they are often accompanied by other symptoms like twitching muscles, hallucinations, involuntary movements, etc.
They’re usually not a cause of worry, however, one may require professional advice if such symptoms occur routinely.
With this, we can safely conclude that déjà vu isn’t a supernatural psychic experience, but a trick our mind plays on us. Truly, the brain is a marvellous spectacle of science. We wonder what other strange phenomena are yet to be unravelled with the genius of our scientific minds!
1. Brown, A.S. The Déjà Vu Illusion. CURRENT DIRECTIONS IN PSYCHOLOGICAL SCIENCE. 2004;13(6): 256-259.
2. Okado, Y et al. Neural activity during encoding predicts false memories created by misinformation. Learning & memory. 2005;12(1): 3-11.
3. Chauvel. Deja Vu: What It Is, When It May Be Cause for Concern. [Online]. Available from: https://health.clevelandclinic.org/deja-vu-what-it-is-and-when-it-may-be-cause-for-concern/ [Accessed 12th February 2021].