Déjà vu
Have you ever felt suddenly that you have been in the exact same
situation before? Or had the same conversation with the same person, and felt
the exact same way? Feelings of dejavu can be overwhelming and intense,
and the recipient is often left feeling “weirded out” and convinced that they’ve had the experience before,
even though they know that’s impossible. Dejavu is a French word
meaning “already seen.” According to professional studies, dejavu
is quite common with “. . . 70% or more of the population report[ing] having experienced it at least once” (Wikipedia,
Internet par. 2). Researchers have distinguished several different types of dejavu
and developed many theories as to the origin and cause of this extraordinary phenomenon.
According to Dr. Arthur Funkhouser, the term “dejavu”
is “. . . a buzz-word, being often found in books, newspaper accounts and magazine articles concerned with a wide variety
of topics” (Funkhouser, Internet par. 1). He says the term is inaccurate
and vague. He proposes three types of dejavu that more accurately describe
the phenomenon: déjà vécu, déjà senti, and déjà visité (Funkhouser, Internet par. 4).
The first type, déjà vécu, means “already experienced” or “already lived through,” and
is what most people know as dejavu (Funkhouser, Internet par. 5). The
term dejavu, though, is inaccurate because, if you recall, it means “already seen,” and refers only to
our sense of sight. As we all know, the experience can involve smells, sounds,
tastes, and emotions. In the book David Copperfield, Charles Dickens explains
it like this:
“We have all some experience of a feeling, that
comes over us occasionally, of what we are saying and doing having been said and done before, in a remote time—of our
having been surrounded, dim ages ago, by the same faces, objects, and circumstances—of our knowing perfectly what will
be said next, as if we suddenly remember it!” (Chapter 39).
These occurrences can be so real, so exact that every detail seems familiar: a friend’s laugh, a bird flying
by, a dog’s bark, a sneeze, the t-shirt a stranger is wearing, and the smell of the lady at the table behind you, all
exactly the way you remember them. The detail is simply too intense for these
to be recollections of past experiences or the incorporation of something we’ve read, as some have suggested (Funkhouser,
Internet par. 6).
The second deja experience
is called déjà senti, and it means “already felt.” Déjà
senti differs from déjà vécu in that the “implied precognition” is not apparent and it is strictly
cerebral, meaning that it includes only familiar thoughts, not smells, tastes or anything physical. Furthermore, the experience is quickly forgotten soon after it occurs (Funkhouser, Internet par. 7). This phenomenon is often experienced by people afflicted with temporal lope epilepsy
and in 1889 a patient of Dr. John Hughlings Jackson described it in this way:
“What is occupying
the attention is what has occupied it before, and indeed has been familiar, but has been for a time forgotten, and now is
recovered with a slight sense of satisfaction as if it had been sought for. ... At the same time, or ... more accurately in
immediate sequence, I am dimly aware that the recollection is fictitious and my state abnormal. The recollection is always
started by another person's voice, or by my own verbalized thought, or by what I am reading and mentally verbalize; and I
think that during the abnormal state I generally verbalize some such phrase of simple recognition as 'Oh yes - I see', 'Of
course - I remember', but a minute or two later I can recollect neither the words nor the verbalized thought which gave rise
to the recollection. I only find strongly that they resemble what I have felt before under similar abnormal conditions”
(Wikipedia, Internet par. 4).
The
experience of deja senti this person is describing is also called biological dejavu and usually occurs in the
few moments before a person has an epileptic seizure. This has given researchers
the opportunity to study the phenomenon in a somewhat more controlled environment and to pinpoint the parts of the brain that
control this kind of activity (Obringer, Internet par. 8).
Funkhouser’s third
classification is déjà visité, or “already visited.” As the
name implies, this occurs when someone visits a new place but seems to be familiar with it to the point of knowing their way
around. In 1863, Nathaniel Hawthorn wrote about a déjà visité experience
he had during a visit to a ruined castle in England. Later he realized that he had
read about the place in a 200 year old paper by Alexander Pope (Funkhouser, Internet par.9).
Two other explanations for déjà visité are out of body experiences or reincarnation, but these are personal
beliefs rather than explanations.
Weather or not you believe
in reincarnation or out-of-body experiences, or believe that these could even be explanations for dejavu, there is
no doubt that what we call dejavu is mysterious and invokes in us a sense of the paranormal. One physicist, however, has a hypothesis that may explain the phenomenon physiologically. In 1963 Robert Efron at the Veteran’s Hospital in Boston
conducted a study and proposed that dejavu is caused by a delayed neurological response (Obringer, Internet page 3,
par 6). The temporal lobe, which is responsible for processing information in
the brain, actually receives signals from the rest of the body twice, “. . . once directly and once again after its
detour through the right hemisphere of the brain” (Obringer, Internet page 3, par, 7).
There is a milliseconds-long delay in between the arrival of the two signals, and if for some reason, the second signal
is delayed slightly longer, the brain might process the two signals as two separate events, explaining the “. . . sudden
sense of familiarity” (Obringer, Internet page 3, par, 7).
Other theories
exist. Dr. Alan Brown, with Duke University, proposed the cell phone theory which
states that while we are distracted with something else, the brain processes our surroundings subconsciously, and then when
we are less distracted, the situation seems oddly familiar (HowStuffWorks, Internet page 3, par, 2). Dutch psychiatrist Hermon Sno proposed the Hologram Theory in which he states “. . . that memories
are like holograms, meaning that you can recreate the entire three-dimensional image from any fragment of the whole”
(HowStuffWorks, Internet page 3, par, 4). In other words, when we see something
that is similar to some memory of our past, the brain “. . .
recreates an entire scene from that fragment” (HowStuffWorks, Internet page 3, par, 4). Another theory supported by many researchers is that precognitive dreams are responsible for dejavu experiences.
Of all the proposed theories, I think Efron’s Delayed Response theory is the most likely. The others seem like desperate grasps at explanations and have little or no physiological basis. While I would love to believe that precognitive dreams are possible and solely responsible for dejavu,
but I cannot deny the physiological theory. Maybe it’s a combination of
both. Whether its déjà vécu, déjà senti, or déjà
visité, they are all extremely hard to document, and even harder to research. Without
a solid explanation for these strange and mysterious occurrences, we have no choice but to savor the eerie sensation and wonder
when the next time we’ll recognize the unrecognizable.
.
Bibliography
"DéJà Vu." Wikipedia. 7 Nov. 2006. 7 Nov. 2006 <http://en.wikipedia.org/wiki/D%C3%A9j%C3%A0_vu>.
Funkhouser, Arthur. "Perspectives - Vol. 1, No. 1 - Three Types of Deja Vu." Mental Help Net. 12 Jan. 2006.
7 Nov. 2006 <http://www.mentalhelp.net/poc/view_doc.php?type=doc&id=264&cn=0>.
Obringer, Lee A. "How Deja Vu Works." Howstuffworks. 7 Nov. 2006 <http://science.howstuffworks.com/deja-vu.htm>.
