Déjà Vu: a paranormal phenomenon??------------------------------------------------
Déjà vu a term we all have heard of, a phenomenon we all have experienced, but never tried to delve into the reasons that cause it, or have usually ignored it , shrugging the feeling aside as just momentary deviation of our mind. But for others it just can’t be ignored. The frequency with which people experience déjà vu varies from person to person: while some experience it once or twice in their entire life while in contrast for others it’s a phenomenon that is encountered very often like a repeated reverberation.
Déjà vu is a French term and means, literally, "
already seen." Those who have experienced the feeling describe it as an overwhelming sense of familiarity with something that they shouldn't be familiar at all. It is an uncanny feeling or illusion of having already seen or experienced something that is being experienced for the first time.
Say, for example, you are visiting an amusement park for the first time, and suddenly it seems as if you have been in that very spot before. Or maybe you are having dinner with a group of friends, discussing some current buzz, and you have the feeling that you've already experienced this very thing -- same friends, same dinner, same topic…whew. How’s it possible?? But it does happen this way. As much as 70% of the population reports having experienced some form of déjà vu. A higher number of incidents occur in people 15 to 25 years old than in any other age group.
As per scientists, the first incidence would be termed as
déjà visité ("already visited") and the second one as
déjà vecu ("already experienced or lived through").We often have experiences the novelty of which is unclear. In such cases we may ask ourselves, "Have I read this book before?”” This place looks familiar; have I been here before?" Yet, these experiences are not accompanied by an uncanny feeling. We may feel a bit confused, but the feeling associated with the déjà vu experience is not one of confusion; it is one of strangeness. There is nothing strange about not remembering whether you've read a book before, especially if you have read thousands of books over your lifetime.
In contrast, in the déjà vu experience, however, we feel strange because we don't think we should feel familiar with the present perception
. That sense of
inappropriateness and eeriness is not present when one is simply unclear whether one has read a book or visited a place before. So what actually causes déjà vu??
Déjà vu has been firmly associated with temporal lobe epilepsy. Reportedly, déjà vu can occur just prior to a temporal-lobe epileptic attack. People suffering an epileptic seizure of this kind can experience déjà vu during the actual seizure activity or in the moments between convulsions.
Since déjà vu occurs commonly in individuals with and without a medical condition, there is much speculation as to how and why this phenomenon happens. Several psychoanalysts attribute déjà vu to simple fantasy or wish fulfillment, while some psychiatrists ascribe it to a mismatching in the brain that causes the brain to mistake the present for the past. Many parapsychologists believe it is related to a past-life experience. Obviously, none of these theories appears worth believing.
If we assume that the experience is actually of a remembered event, then déjà vu probably occurs because an original experience was neither fully attended to nor elaborately encoded in memory. If so, then it would seem most likely that the present situation triggers the recollection of a fragment from one's past. The experience may seem uncanny if the memory is so fragmented that no strong connections can be made between the fragment and other memories.
Thus, the feeling that one has been there before is often due to the fact that one really has been there before. One has simply forgotten most of the original experience because one was not paying close attention the first time. The original experience may even have occurred only seconds or minutes earlier.
On the other hand, the déjà vu experience may be due to having seen pictures or heard vivid stories many years earlier. The experience may be part of the dim recollections of childhood.
However, it is possible that the déjà vu feeling is triggered by a neurochemical action in the brain that is not connected to any actual experience in the past. One feels strange and identifies the feeling with a memory, even though the experience is completely new.
In recent years, déjà vu has been subjected to serious psychological and neurophysiologic research. The most likely explanation of déjà vu is that it is not an act of "precognition" or "prophecy", but rather an anomaly of memory; it is the impression that an experience is "being recalled”. 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. Hence as time passes, we exhibit a strong recollection of having the "unsettling" experience of déjà vu itself, but little to no recollection of the specifics of the events or circumstances 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 (events which are perceived as being in the present) and those responsible for long-term memory (events which are perceived as being in the past). In other words, the events would be stored into memory before the conscious part of the brain even receives the information and process it. The delay is only of a few milliseconds, and besides, already happened at the time the conscious of the individual is experiencing it.
A model for one such explanation is the
hologram. In a hologram, a kind of three-dimensional photograph, each point in the image contains all the data necessary to reconstruct the image as a whole. Even the smallest fragment will give the complete picture, but the smaller the fragment, the less sharp the picture will be.
If memories are indeed stored in the brain as holograms, each part of the memory contains all the sensory and emotional data needed to recall the entire original experience. A single detail--the sound of a child's voice can evoke the complete remembered scene. According to this model, deja vu occurs when a detail from a current experience so strongly resembles a detail from a previous experience that a full-blown memory of the past event is called forth. As a result of the mismatching, the brain mistakes the present for the past. You feel certain you've seen the picture before.
Another potential explanation involves a
defect in the processes of perception and cognition. This theory proposes that sensory impressions of a current experience get deviate in the brain and are not perceivedimmediately. The information is, however, stored as a memory. This split-second delay in cognition creates the unsettling impression that the event "is being experienced and recalled simultaneously,"
Whether it's a slippage of timing, a mental hologram or something else entirely, deja vu will remain one of the mind's most tantalizing and elusive phenomena.
