Did you ever visit a shop for the first time, and had it feel eerily familiar? And perhaps you’re in a deep conversation with some friends, and immediately you get the impression that you’ve had this exact conversation before, even though you know you haven’t. If you’ve ever found yourself in one of these cases, you’ve definitely experienced a déjà vu.
Sixty to 70% of us have admitted to getting this experience at least once in our lives. The sight, the sound, the taste, or even the scent of something makes us believe we’ve gone through it before, even when we know we didn’t.
There are over 40 theories on what is déjà vu and what causes it, and they vary from reincarnation to glitches in our memory systems, all of which shed some light on this little-understood phenomena.
Déjà vu is a French term that literally means “already seen” and has many variations, including déjaa vécu, already experienced; déjà senti, already thought; and déjà visité, already visited. The French scientist Emile Boirac, one of the first to study this unusual phenomenon, named the subject in 1876. Since then, it has been commonly portrayed in music, literature, and movies; — it may be as elusive as a white rabbit leaping back to its burrow.
There are also references to déjà vu that are not real déjà vu. Scientists have their own interpretations, but in general, it is defined as a feeling that you’ve seen or experienced something before when you know you haven’t.
A “Glitch” In The System?
“Déjà vu occurs when people have the sensation of memory without the presence of memory,” says the psychologist Dr. Akira O’Connor of the University of St. Andrews in the U.K. The “mismatch” when something new feels familiar results in a “false familiarity.”
The most popular misuse of the word déjà vu appears to be with precognitive experiences; — those where someone thinks they actually know what’s going to happen next, and they do. A key difference is that déjà vu is felt, not before, but after an event. Precognitive experiences indicate things that are going to happen in the future, not what you’ve already experienced.
Hallucinations caused by sickness or drugs often increase consciousness and are associated with déjà vu. False memories brought on by schizophrenia can also be associated with it. Unlike true déjà vu, which usually lasts from 10 to 30 seconds, these false memories or hallucinations can last much longer.
Given the fascination and curiosity around déjà vu in popular culture, these theoretical phenomena are still not fully understood in scientific terms. Studying the term has proven problematic due to the transient existence of these elusive experiences and the lack of scientific procedures to trigger them in the psychological laboratory.
Reference: https://science.howstuffworks.com/science-vs-myth/deja-vu.htm#pt4
