Image via WikipediaDéjà vu (French pronunciation), literally "already seen") is the experience of feeling sure that one has already witnessed or experienced a current situation, even though the exact circumstances of the previous encounter are uncertain and were perhaps imagined.
The term was coined by a French psychic researcher, Émile Boirac (1851–1917) in his book L'Avenir des sciences psychiques ("The Future of Psychic Sciences"), which expanded upon an essay he wrote while an undergraduate. The experience of déjà vu is usually accompanied by a compelling sense of familiarity, and also a sense of "eeriness", "strangeness", "weirdness", or what Sigmund Freud calls "the uncanny". The "previous" experience is most frequently attributed to a dream, although in some cases there is a firm sense that the experience has genuinely happened in the past.[1]
The experience of déjà vu seems to be quite common among adults and children alike. References to the experience of déjà vu are found in literature of the past,[2] indicating it is not a new phenomenon. It has been extremely difficult to invoke the déjà vu experience in laboratory settings, therefore making it a subject of few empirical studies. Certain researchers claim to have found ways to recreate this sensation using hypnosis.[3]
Scientific Researches
The most likely explanation of déjà vu is not that it is an act of "precognition" or "prophecy", but rather that it is an anomaly of memory, giving the false impression that an experience is "being recalled".[4][5] This explanation is substantiated by the fact that the sense of "recollection" at the time is strong in most cases, but that the circumstances of the "previous" experience (when, where, and how the earlier experience occurred) are quite uncertain or known to be impossible.
Likewise, as time passes, subjects can exhibit a strong recollection of having the "unsettling" experience of déjà vu itself, but little or no recollection of the specifics of the event(s) or circumstance(s) they were "remembering" when they had the déjà vu experience. In particular, this may result from an overlap between the neurological systems responsible for short-term memory and those responsible for long-term memory (events which are perceived as being in the past). The events would be stored into memory before the conscious part of the brain even receives the information and processes it.[citation needed]
Another hypothesis being explored is that of vision. The hypothesis suggests that one eye may record what is seen fractionally faster than the other, creating the "strong recollection" sensation upon the "same" scene being viewed milliseconds later by the opposite eye.[6]
However, this hypothesis fails to explain the phenomenon when other sensory inputs are involved, such as hearing or touch. If one, for instance, experiences déjà vu of someone slapping the fingers on his left hand, then the déjà vu feeling is certainly not due to his right hand experiencing the same sensation later than his left hand considering that his right hand would never receive the same sensory input.
Also, people with only one eye still report experiencing déjà vu or déjà vécu (a rare disorder of memory, similar to persistent déjà vu). The global phenomenon can therefore at least in certain cases be narrowed down to the brain itself (i.e., one hemisphere being late compared to the other one).
See Twilight Zone (1959), Season 1, Episode 10: Judgment Night
(available now on Netflix Instant Play - I am undergoing a Twilight Zone Marathon... 138 Episodes!).
This is a great opportunity to throw in one of my all-time favorite videos/songs (Actually the video is kinda dorky - oh so 80's! Do you remember it?):
