Déjà vu

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For other uses, see Déjà vu (disambiguation).

Déjà vu, (Listeni/ˌdʒɑː ˈv/; French pronunciation: ​[de.ʒa.vy]) from French, literally "already seen," is the phenomenon of having the strong sensation that an event or experience currently being experienced has been experienced in the past, which is often not the case. The psychologist Edward B. Titchener in his book A Textbook of Psychology (1928), explained déjà vu as caused by a person having a brief glimpse of an object or situation, before the brain has completed "constructing" a full conscious perception of the experience. Such a "partial perception" then results in a false sense of familiarity.[1] Scientific approaches reject the explanation of déjà vu as "precognition" or "prophecy", but rather explain it as an anomaly of memory, which creates a distinct 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 uncertain or believed to be impossible.

Mystery déjà vu[edit]

Today, many researchers have theorized the cause of the déjà vu phenomenon. Most people know that déjà vu is the experience of familiarity with any conversation, place or event that we haven’t seen before or an event that has repeated again. The hypothesis of researchers report that déjà vu can come from three main sources:

1. Memory systems

The Medial Temporal Lobes are a region of the brain involved in storing long-term memory for events and facts. Research has proposed that the familiarity depends on “rhinal cortex” function. Recognition is linked to the “hippocampus” and because rhinal function is so complex, recollection may accidentally be directed to the hippocampus. This could cause a déjá vu experience.

2. An error in working of nervous system

In fact, many reports are proposed that déjà vu come from the irregular working of nervous system. This irregular experience was linked to process in the “medial temporal lobe” including the sensory recognition, conversation and also memory association. During sending information between each of nerve cell, if there are some “miss-firing” and send a confusing message to the brain and the feeling of déjà vu experience happen.

3. Mismatches and short circuits

The research proposed that déjà vu is reaction of the brain’s memory systems to a familiar experience. The information will pass short-term memory instead long-term memory. This can tell us déjà vu is happen by a mismatch between the sensory inputs and remember the new output. Finally, these hypothesis and theory are explained to us to know how and why déjà vu happens. There are many theories from other research to create ideas and explain the origin of déjà vu. However, to explain the exactly mechanisms of déjà vu, much more research, a new ideas of causing déjà vu and the believable information sources are needed.

As time passes, subjects may 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) which were the subject of the déjà vu experience itself (the events that were being "remembered"). This may result from an "overlap" between the neurological systems responsible for short-term memory and those responsible for long-term memory, resulting in (memories of) recent events erroneously being perceived as being in the more distant past. One theory is the events are stored into memory before the conscious part of the brain even receives the information and processes it.[4] However, this explanation has been criticized that the brain would not be able to store information without a sensory input first. Another theory suggests the brain may process sensory input (perhaps all sensory input) as a "memory-in-progress", and that therefore during the event itself one believes it to be a past memory. In a survey, Brown had concluded that approximately two-thirds of the population have had déjà vu experiences.[5] Other studies confirm that déjà vu is a common experience in healthy individuals, with between 31% and 96% of individuals reporting it. Déjà vu experiences that are unusually prolonged or frequent, or in association with other symptoms such as hallucinations, may be an indicator of neurological or psychiatric illness.[6]

Links with disorders[edit]

Early researchers tried to establish a link between déjà vu and serious mental disorders such as schizophrenia, anxiety, and dissociative identity disorder, but failed to find correlations of any diagnostic value. There does not seem to be a special association between déjà vu and schizophrenia or other psychiatric conditions.[7] The strongest pathological association of déjà vu is with temporal lobe epilepsy.[8][9] 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. Scientists have even looked into genetics when considering déjà vu. Although there is not currently a gene associated with déjà vu, the LGII gene on chromosome 10 is being studied for a possible link. Certain forms of the gene are associated with a mild form of epilepsy and, though by no means a certainty, déjà vu occurs often enough during seizures that researchers have reason to suspect a link.[10]



Memory-based explanations[edit]

The similarity between a déjà-vu-eliciting stimulus and an existing, but different, memory trace may lead to the sensation.[7][13] 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)[14][15] 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".


A recent study that used virtual reality technology to study reported déjà vu experiences supported this idea. This virtual reality investigation suggested that similarity between a new scene's spatial layout and the layout of a previously experienced scene in memory (but which fails to be recalled) may contribute to the déjà vu experience.[16][16] When the previously experienced scene fails to come to mind in response to viewing the new scene, that previously experienced scene in memory can still exert an effect—that effect may be a feeling of familiarity with the new scene that is subjectively experienced as a feeling of déjà vu, or of having been there before despite knowing otherwise.

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". Some experts suggest that memory is a process of reconstruction, rather than a recall of fixed, established events. This reconstruction comes from stored components, involving elaborations, distortions and omissions. Each successive recall of an event is merely a recall of the last reconstruction. The proposed sense of recognition (déjà vu) involves achieving a good ‘match’ between the present experience and our stored data. This reconstruction however, may now differ so much from the original event that we ‘know’ we have never experienced it before, even though it seems similar.[17]

Robert Efron of Boston's Veterans Hospital in 1963 proposed that déjà vu is caused by dual neurological processing caused by delayed signals in the brain. Efron found that the brain’s sorting of incoming signals is done in the temporal lobe of the brain's left hemisphere. However, signals enter the temporal lobe twice before processing, once from each hemisphere of the brain, normally with a slight delay of milliseconds between them. Efron proposed that if the two signals were occasionally not synchronized properly then they would be processed as two separate experiences, with the second seeming to be a re-living of the first.[18][19]

Dream-based explanation[edit]


Related phenomena[edit]

Jamais vu[edit]

Main article: Jamais vu




Times Online reports (see semantic satiation):


Presque vu[edit]

Presque vu (from French, meaning "almost seen") is the sensation of being on the brink of an epiphany, such as when attempting to recall a word or name.

Déjà entendu[edit]

Déjà entendu, (literally "already heard") is the experience of feeling sure that one has already heard something, even though the exact details are uncertain or were perhaps imagined.[22][23]

See also[edit]


  1. ^ Titchener, E. B. (1928). A Textbook of Psychology. New York: Macmillan.
  4. ^ Pierre Janet (1942). Les Dissolutions de la Mémoire. Quoted in Tolland. Disorders of Memory, 1969, p.152
  5. ^ Brown, A. S. (2004). "The déjà vu illusion". Current Directions in Psychological Science 13: 256–259. doi:10.1111/j.0963-7214.2004.00320.x. 
  6. ^ Wild, E (Jan 2005). "Deja vu in neurology.". Journal of neurology 252 (1): 1–7. doi:10.1007/s00415-005-0677-3. PMID 15654548. 
  8. ^ Neurology Channel
  9. ^ Howstuffworks "What is déjà vu?"
  14. ^ Banister H, Zangwill OL (1941). "Experimentally induced olfactory paramnesia". British Journal of Psychology 32: 155–175. doi:10.1111/j.2044-8295.1941.tb01018.x. 
  15. ^ Banister H, Zangwill OL (1941). "Experimentally induced visual paramnesias". British Journal of Psychology 32: 30–51. doi:10.1111/j.2044-8295.1941.tb01008.x. 
  16. ^ a b Cleary; Brown, AS; Sawyer, BD; Nomi, JS; Ajoku, AC; Ryals, AJ et al. (2012). "Familiarity from the configuration of objects in 3-dimensional space and its relation to déjà vu: A virtual reality investigation". Consciousness and Cognition 21 (2): 969–975. doi:10.1016/j.concog.2011.12.010. PMID 22322010. 
  18. ^ Robert, Efron. "TEMPORAL PERCEPTION, APHASIA AND DÉJÀ VU". Brain 86: 403–424. doi:10.1093/brain/86.3.403. 
  19. ^ How deja vu works by Lee Ann Obringer - How Stuff Works
  23. ^ Mental Status Examination Rapid Record Form

Further reading[edit]

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