What is Deja Vu?

[Samsara]

There was mention of deja vu in another thread.


I've had deja vu experiences in the past however, not as frequently as another member has reported. Out of curiosity, I decided to research the subject one evening in an effort to keep my mind engaged in some form of positive distraction.

The second article is particularly interesting.

I had to print out the articles since, reading on-line seriously hinders my ability to comprehend the contents and I will admit that I must re-read these articles to gain a deeper comprehension. But no doubt, there is some interesting material within that some of us may be able to work with in regard to explaining why past traumas, ruminations could become so dramatic during WD.

Note: I utilized the word "could".



With that said, I do believe there is some merit to a few sections within the second article.

BTW, apparently, there are different types of deja vu experiences.




Samsara



http://serendip.brynmawr.edu/exchange/node/1682


What is déjà vu?


Brain Image Gallery


What is déjà vu? The term 'déjà vu' means, literally, 'already seen.' Learn about déjà vu and theories on why it happens. See more brain pictures.

Photographer: Sebastian Kaulitzki | Agency: Dreamstime.com

The term déjà vu is French and means, literally, "already seen." Those who have experienced the feeling describe it as an overwhelming sense of familiarity with something that shouldn't be familiar at all. Say, for example, you are traveling to England for the first time. You are touring a cathedral, 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 political topic, and you have the feeling that you've already experienced this very thing -- same friends, same dinner, same topic.



The phenomenon is rather complex, and there are many different theories as to why déjà vu happens. Swiss scholar Arthur Funkhouser suggests that there are several "déjà experiences" and asserts that in order to better study the phenomenon, the nuances between the experiences need to be noted. In the examples mentioned above, Funkhouser would describe the first incidence as déjà visite ("already visited") and the second as déjà vecu ("already experienced or lived through").

As much as 70 percent of the population reports having experienced some form of déjà vu. A higher number of incidents occurs in people 15 to 25 years old than in any other age group.

Déjà vu has been firmly associated with temporal-lobe epilepsy. Reportedly, déjà vu can occur just prior to a temporal-lobe seizure. People suffering a seizure of this kind can experience déjà vu during the actual seizure activity or in the moments between convulsions.

Since déjà vu occurs 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, there is more investigation to be done.

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[Samsara]

http://serendip.brynmawr.edu/exchange/node/1682


Déjà vu and the Brain, Consciousness and Self


Submitted by SerendipUpdate on Thu, 01/03/2008 - 12:35pm

UGH! I Just Got the Creepiest Feeling That I Have Been Here Before:

Déjà vu and the Brain, Consciousness and Self
Julia Johnson

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! (Dickens in David Copperfield - chapter 39 (1))

It happens to me and it has probably happened to you. It is sudden and fleeting, leaving as unexpectedly as it came. While the experience is striking in its clarity and detail, it is difficult to recapture or recount. Generally, it is left unexplained and is described in a vague sense, often simply as, "Wow, I just got the strangest déjà vu."

Because it is so difficult to research and seems to have no deleterious effects on daily and long-term nervous system function, déjà vu has been left largely to the wayside of neurobiological investigation. In all of its ambiguity, déjà vu is still a perplexing phenomenon that has not yet been fully explained. The value of truly understanding the source of déjà vu and its circuitry is in uncovering one of the many keys to the role of the conscious self in the functioning of the brain.

What is déjà vu and how does it work? Déjà vu is considered a common phenomenon. Surveys show that about one third of the population has had the most common form of déjà vu sensations (1). Due to the subjective and often indescribable nature of the associated feelings, it has been difficult, to determine who is actually experiencing déjà vu. In general, however, déjà vu is "any number of hard-to-explain sometimes upsetting occurrences of unexpected recognition, in which the person involved has trouble identifying an antecedent for the events and/or places which seem so strangely and intensely familiar (1)." Déjà vu has been defined as "familiarity without awareness (13)." While the situational cues of a déjà vu are familiar, there is a definite lack of awareness about the specific source of the memory.

Arthur Funkhouser (1) defines three types of déjà vu in an attempt to more clearly delineate between associated, but different, neurological experiences. These are déjà vecu (already experienced), déjà senti (already felt) and déjà visité (already visited). Déjà vecu is the most common déjà vu experience and involves the sensation of having done something or having been in an identical situation before and knowing what will happen next. These sensations are often felt through several senses: seeing, hearing, taste, touch and proprioceptive perceptions. The experience is often incredibly detailed and is usually connected to very normal activities.

Although the episode itself lasts from only a fraction of a second to several minutes, it can often be remembered in minute detail long after the episode has occurred. One experiencer says, "There came this strange, almost physical up-welling of visual experience, a visual warping, and at the same time an eerie realization that everything happening now had happened before, maybe many times (11)."

Déjà senti is different from déjà vecu in that the episode of recollection feels more like the recovery of long sought after information. The sensation is one of satisfaction at having retrieved a memory although the memory was not actively sought. This form of déjà vu does not involve any feelings of premonition and the episodes quickly dissipate from memory. Déjà senti has been strongly associated with the partial seizure experiences reported by temporal lobe epilepsy patients. The extended nature of these episodes has allowed for more detailed descriptions of the feelings associated with a déjà senti event. "It was as if one of my dreams had simply been sucked out of the actual, physical environment and set to playing again in every detail (11)." Déjà visité is a more rare event in which a person visits a new place and feels that it is familiar. It is associated more with spatial dimensions while déjà vecu is associated with situations and processes. Déjà vu experiences can be in one of the three forms described above or can be a mixed version with a combined déjà vu effect [The above from (1)].

What causes a déjà vu episode? There are several possible explanations for what is occurring during a déjà vu experience. One possibility is simply the occasional mismatch made by the brain in its continuous attempt to create whole sensical pictures out of very small pieces of information. Looking at memory as a hologram, only bits of sensory information are needed for the brain to reconstruct entire three-dimensional images. When the brain receives a small sensory input (a sight, a smell, a sound) that is strikingly similar to such a detail experienced in the past, the entire memory image is brought forward. The brain has taken the past to be the present by virtue of one tiny bit of sensory information. It is this mismatch of past and present sensory information that causes the sense of disconcertment and unease associated with a passing déjà vu [The above from (2) and (3)]. This theory provides a satisfactory explanation for the physical effects of déjà vu. These appear to be similar to the effects of mismatch between sensory input and corollary discharge signal information to the brain. It does not, however, seem to provide sufficient answers to individual (even my own) accounts of déjà vu, where the memory image pulled up is not necessarily from a true past event.

Another explanation for déjà vu is that there is a slight malfunctioning between the long and short-term memory circuits of the brain. Somehow, specific information shortcuts its way from short to long-term memory storage, bypassing the usual mechanisms used for storage transfer. The details concerning this shortcut are not yet well understood. When this new, recent piece of information is drawn upon, the person thinks that the piece is coming from long-term storage and so must have come from the distant past (6). A similar theory says that the error is in the timing of the perceptive and cognitive processes. Sensory information is rerouted on its way to memory storage and, so, is not immediately perceived. This short delay causes the sensation of experiencing and remembering something at the same time, a very unsettling feeling (2). One other explanation is that déjà vu is actually the process of remembering memory connections, of following the impulses and synapses (4). All of these neurobiologically based explanations for déjà vu seem plausible and intriguing and perhaps there is some overlap or combination that accounts for the different experiences we call déjà vu.

[Samsara]

continuation from previous post..........


Other explanations for déjà vu have been given by psychoanalysts, such as the manifestation of wish fulfillment. Here, déjà vu is the subconscious repetition of a past experience, but with a more positive ending (2). The realm of parapsychology proposes that déjà vu is a chance for reincarnates to get a sneak peak into a past life. Most scientists scoff at these "magical" explanations for neurological events, citing that they break many of the laws of nature (6). Some, however, point to more recent findings in physics, such as the possibility of particles that can travel backwards in time (tachyons), time loops and multiple universes. They say that these may give cause for more non-traditional ways of seeing causality and for the possibility of neurological "time travel" (1). This means that, maybe, just maybe, understanding déjà vu as a means of seeing into the past or future cannot be so immediately dismissed. It is certainly food for thought for the rising debate, anyway.

It is important to note the level of consciousness involved in a déjà vu episode. There are common threads that run through many déjà vu experiences. "When you are in the midst of such an occurrence, you are conscious that everything conforms with your 'memory' of it" (1) and "I know exactly what is going on around me when it happens. (9)." This implies that the participation of the entire brain capacity is not required to produce a déjà vu experience. Perhaps more importantly, there is a significant role played by at least a portion of the conscious person and the I-function. "It was like being in a long-running play, complete with the sense of being 'on' and standing

What is this role of the self in déjà vu? "To what extent is it possible for the core awareness to preserve ... images and emotions before they're swallowed up again and sealed tight? (11)" One epileptic déjà vu experiencer claimed that he could consciously recapture the feelings and notions associated with déjà vu simply by writing down the images that appeared during the experience. Later, he found that the memories had not vanished as before but could be brought back to a conscious level simply by reading the notes. The experience was brought back to him as if it was a conscious daydream (11). The striking implication here is that part of the conscious self, the I-function, is intimately involved and may be communicating with the processes of a déjà vu.

Perhaps to some, déjà vu is not worth its research weight in synapses. It may seem to many to be just an oddball, quirky brain trick that we learn to incorporate into our daily routine. Investigation into the implications of this neural event, however, seems to lead towards more in-depth knowledge of ourselves.

Quite a few of us who have "already-seen" would dare to see even more---would actually follow that dangerous, disappearing, inbound road consciously and witness for the first time what is usually jamais-vu and hidden, and I mean the steady dark frolic of neurons and the ghost that is called ego (11).

A better understanding of déjà vu may lead us closer to an understanding of the complex relationship between ourselves and our memories. It may light a path for a clearer view into how we incorporate ourselves into our memory and into how our memory is incorporated into our conscious selves. How can this be futile?

[stan]

Another explanation for déjà vu is that there is a slight malfunctioning between the long and short-term memory circuits of the brain. Somehow, specific information shortcuts its way from short to long-term memory storage, bypassing the usual mechanisms used for storage transfer. The details concerning this shortcut are not yet well understood. When this new, recent piece of information is drawn upon, the person thinks that the piece is coming from long-term storage and so must have come from the distant past (6). A similar theory says that the error is in the timing of the perceptive and cognitive processes. Sensory information is rerouted on its way to memory storage and, so, is not immediately perceived. This short delay causes the sensation of experiencing and remembering something at the same time, a very unsettling feeling (2). One other explanation is that déjà vu is actually the process of remembering memory connections, of following the impulses and synapses (4). All of these neurobiologically based explanations for déjà vu seem plausible and intriguing and perhaps there is some overlap or combination that accounts for the different experiences we call déjà vu.

i think that for me it would be this explanation

[Luc]

I have a feeling I've already read this thread...

[Luc]

i think that for me it would be this explanation

Yes, it seems like this one, plus, there are situations in life happening at different times, but being strinkingly similar to each other. This may too feel like the deja vu thing.

[Luc]

This one is cool, too ----> http://en.wikipedia.org/wiki/Jamais_vu

[stan]

yes, the opposite feeling exist also maybe; but i have no memory of "jamais vu"; and have for "déjà vu"

[Samsara]

This one is cool, too ----> http://en.wikipedia.org/wiki/Jamais_vu

thanks for that link.. Interestingly, I have had many more jamais vu experiences than I have deja vu.


Samsara

[Samsara]

i have a feeling i've already read this thread...

lol!