Deja vu
The most likely explanation of déjà vu isn't 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".[2][3] This explanation is supported 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 believed 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.[4] 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 since 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 nature of the 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).
Early researchers tried to establish a link between déjà vu and serious psychopathology such as schizophrenia, anxiety, and dissociative identity disorder, and failed to find the experience of some diagnostic value. There does not seem to be a special association between déjà vu and schizophrenia or other psychiatric conditions.[5] The strongest pathological association of déjà vu is with temporal lobe epilepsy.[6][7] This correlation has led some researchers to speculate that the experience of déjà vu is possibly a neurological anomaly related to improper electrical discharge in the brain. As most people suffer a mild (i.e. non-pathological) epileptic episode regularly (e.g. a hypnagogic jerk, the sudden "jolt" that frequently, but not always, occurs just prior to falling asleep)it is conjectured that a similar (mild) neurological aberration occurs in the experience of déjà vu, resulting in an erroneous sensation of memory. For someone who regularly has such seizures, there is typically a feeling of déjà vu associated with whatever sensations (particularly sounds) may be occurring
Certain drugs increase the chances of déjà vu occurring in the user. Some pharmaceutical drugs, when taken together, have also been implicated in the cause of déjà vu. Taiminen and Jääskeläinen (2001)[8] reported the case of an otherwise healthy male who started experiencing intense and recurrent sensations of déjà vu upon taking the drugs amantadine and phenylpropanolamine together to relieve flu symptoms. He found the experience so interesting that he completed the full course of his treatment and reported it to the psychologists to write up as a case study. Due to the dopaminergic action of the drugs and previous findings from electrode stimulation of the brain (e.g. Bancaud, Brunet-Bourgin, Chauvel, & Halgren, 1994),[9] Taiminen and Jääskeläinen speculate that déjà vu occurs as a result of hyperdopaminergic action in the mesial temporal areas of the brain. Many scientists[which?] are still working towards the actual link of déjà vu with hypnagogic epilepsy.
The similarity between a déjà-vu-eliciting stimulus and an existing, but different, memory trace may lead to the sensation.[5][10] Thus, encountering something which evokes the implicit associations of an experience or sensation that cannot be remembered may lead to déjà vu. In an effort to experimentally reproduce the sensation, Banister and Zangwill (1941)[11][12] used hypnosis to give participants posthypnotic amnesia for material they had already seen. When this was later re-encountered, the restricted activation caused thereafter by the posthypnotic amnesia resulted in three of the 10 participants reporting what the authors termed "paramnesias". Memory-based explanations may lead to the development of a number of non-invasive experimental methods by which a long sought-after analogue of déjà vu can be reliably produced that would allow it to be tested under well-controlled experimental conditions. Cleary[10] suggests that déjà vu may be a form of familiarity-based recognition (recognition that is based on a feeling of familiarity with a situation) and that laboratory methods of probing familiarity-based recognition hold promise for probing déjà vu in laboratory settings. Another possible explanation for the phenomenon of déjà vu is the occurrence of "cryptomnesia", which is where information learned is forgotten but nevertheless stored in the brain, and similar occurrences invoke the contained knowledge, leading to a feeling of familiarity because of the situation, event or emotional/vocal content, known as "déjà vu"...
Jamais vu
Jamais vu (from French, meaning "never seen") is a term in psychology which is used to describe any familiar situation which is not recognized by the observer.
Often described as the opposite of déjà vu, jamais vu involves a sense of eeriness and the observer's impression of seeing the situation for the first time, despite rationally knowing that he or she has been in the situation before. Jamais vu is more commonly explained as when a person momentarily does not recognize a word, person, or place that they already know. Jamais vu is sometimes associated with certain types of aphasia, amnesia, and epilepsy.
Theoretically, as seen below, a jamais vu feeling in a sufferer of a delirious disorder or intoxication could result in a delirious explanation of it, such as in the Capgras delusion, in which the patient takes a person known by him or her for a false double or impostor. If the impostor is himself, the clinical setting would be the same as the one described as depersonalisation, hence jamais vus of oneself or of the very "reality of reality", are termed depersonalisation (or surreality) feelings.Times Online reports (see semantic satiation):
Chris Moulin, of the University of Leeds, asked 95 volunteers to write out "door" 30 times in 60 seconds. At the International Conference on Memory in Sydney last week he reported that 68 percent of the volunteers showed symptoms of jamais vu, such as beginning to doubt that "door" was a real word. Dr. Moulin believes that a similar brain fatigue underlies a phenomenon observed in some schizophrenia patients: that a familiar person has been replaced by an impostor. Dr. Moulin suggests they could be suffering from chronic jamais vu.[13]
Déjà vu is similar to, but distinct from, the phenomenon called tip of the tongue, a situation in which when one cannot recall a familiar word or name, but with effort one eventually recalls the elusive memory. In contrast, déjà vu is a feeling that the present situation has occurred before, but the details are elusive because the situation never happened before.
Presque vu (from French, meaning "almost seen") is the sensation of being on the brink of an epiphany. Often very disorienting and distracting, presque vu rarely leads to an actual breakthrough. Frequently, one experiencing presque vu will say that they have something "on the tip of my tongue".
Presque vu is often cited by people who suffer from epilepsy or other seizure-related brain conditions, such as temporal lobe lability. This is described as a glitch of neuropatic nerves in the brain, mainly in the left hemisphere.[citation needed]
Déjà entendu, (literally "already heard") is the experience of feeling sure that one has already heard something, even though the exact details are uncertain and were perhaps imagined.[14][15]
Dikutip dari : http://en.wikipedia.org/wiki/D%C3%A9j%C3%A0_vu
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