Déjà vu
Encyclopedia
Déjà vu is the experience of feeling sure that one has already witnessed or experienced a current situation, even though the exact circumstances of the prior encounter are uncertain and were perhaps imagined. The term was coined by a French
psychic
researcher, Émile Boirac
(1851–1917) in his book L'Avenir des sciences psychiques ("The Future of Psychic Sciences"), which expanded upon an essay he wrote while an undergraduate. The experience of déjà vu is usually accompanied by a compelling sense of familiarity, and also a sense of "eeriness", "strangeness", "weirdness", or what Sigmund Freud
calls "the uncanny". The "previous" experience is most frequently attributed to a dream, although in some cases there is a firm sense that the experience has genuinely happened in the past.
" or "prophecy
", but rather that it is an anomaly of memory, giving the false impression that an experience is "being recalled". 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.
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. 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).
, 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. The strongest pathological association of déjà vu is with temporal lobe epilepsy
. 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 nearby.
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), Taiminen and Jääskeläinen speculate that déjà vu occurs as a result of hyperdopaminergic action in the mesial temporal areas of the brain. Many scientists are still working towards the actual link of déjà vu with hypnagogic epilepsy.
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 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"...
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):
, 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.
, a 1999 science fiction
-action film
written and directed by Larry and Andy Wachowski. The protagonist, Neo
, glances at a black cat and comments that he has just experienced déjà vu. Those with a knowledge of 'The Matrix' and its internal workings state that déjà vu means something within the Matrix was altered from its prior state and is referred to as a "glitch
".
The 2006 science fiction film Déjà Vu revolves around a US federal law enforcement officer using an instrument called Snowhite to view the past 4 and a half days of anywhere in the world (limited radius as permissible by the program) in order to solve a murder and a terrorist bomb attack on a ferry that was being boarded by about 500 citizens and military members.
A rapid and intense impression. I’ve been here! No, I have not… The experience of feeling sure that I have already witnessed it. TEMPORAO - Brazil, 2011
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
psychic
Psychic
A psychic is a person who professes an ability to perceive information hidden from the normal senses through extrasensory perception , or is said by others to have such abilities. It is also used to describe theatrical performers who use techniques such as prestidigitation, cold reading, and hot...
researcher, Émile Boirac
Émile Boirac
Émile Boirac was a French philosopher, parapsychologist, promoter of Esperanto and writer.-Biography:...
(1851–1917) in his book L'Avenir des sciences psychiques ("The Future of Psychic Sciences"), which expanded upon an essay he wrote while an undergraduate. The experience of déjà vu is usually accompanied by a compelling sense of familiarity, and also a sense of "eeriness", "strangeness", "weirdness", or what Sigmund Freud
Sigmund Freud
Sigmund Freud , born Sigismund Schlomo Freud , was an Austrian neurologist who founded the discipline of psychoanalysis...
calls "the uncanny". The "previous" experience is most frequently attributed to a dream, although in some cases there is a firm sense that the experience has genuinely happened in the past.
Scientific research
The most likely explanation of déjà vu isn't that it is an act of "precognitionPrecognition
In parapsychology, precognition , also called future sight, and second sight, is a type of extrasensory perception that would involve the acquisition or effect of future information that cannot be deduced from presently available and normally acquired sense-based information or laws of physics...
" or "prophecy
Prophecy
Prophecy is a process in which one or more messages that have been communicated to a prophet are then communicated to others. Such messages typically involve divine inspiration, interpretation, or revelation of conditioned events to come as well as testimonies or repeated revelations that the...
", but rather that it is an anomaly of memory, giving the false impression that an experience is "being recalled". 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
Short-term memory
Short-term memory is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds. A commonly cited capacity is 7 ± 2 elements...
and those responsible for long-term memory
Long-term memory
Long-term memory is memory in which associations among items are stored, as part of the theory of a dual-store memory model. According to the theory, long term memory differs structurally and functionally from working memory or short-term memory, which ostensibly stores items for only around 20–30...
(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.
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. 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).
Links with disorders
Early researchers tried to establish a link between déjà vu and serious psychopathology such as schizophreniaSchizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
, anxiety
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, and dissociative identity disorder
Dissociative identity disorder
Dissociative identity disorder is a psychiatric diagnosis and describes a condition in which a person displays multiple distinct identities , each with its own pattern of perceiving and interacting with the environment....
, 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. The strongest pathological association of déjà vu is with temporal lobe epilepsy
Temporal lobe epilepsy
Temporal lobe epilepsy a.k.a. Psychomotor epilepsy, is a form of focal epilepsy, a chronic neurological condition characterized by recurrent seizures. Over 40 types of epilepsies are known. They fall into two main categories: partial-onset epilepsies and generalized-onset epilepsies...
. This correlation has led some researchers to speculate that the experience of déjà vu is possibly a neurological
Neurology
Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
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
Hypnic jerk
A hypnic jerk, hypnagogic jerk, sleep start, or night start, is an involuntary myoclonic twitch which occurs during hypnagogia, just as a person is beginning to fall asleep, often causing them to awaken suddenly. Physically, hypnic jerks resemble the "jump" experienced by a person when...
, 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 nearby.
Pharmacology
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) reported the case of an otherwise healthy male who started experiencing intense and recurrent sensations of déjà vu upon taking the drugs amantadineAmantadine
Amantadine is the organic compound known formally as 1-adamantylamine or 1-aminoadamantane. The molecule consists of adamantane backbone that has an amino group substituted at one of the four methyne positions. This pharmaceutical is sold under the name Symmetrel for use both as an antiviral and an...
and phenylpropanolamine
Phenylpropanolamine
Phenylpropanolamine , also known as the stereoisomers norephedrine and norpseudoephedrine, is a psychoactive drug of the phenethylamine and amphetamine chemical classes which is used as a stimulant, decongestant, and anorectic agent. It is commonly used in prescription and over-the-counter cough...
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
Dopaminergic
Dopaminergic means related to the neurotransmitter dopamine. For example, certain proteins such as the dopamine transporter , vesicular monoamine transporter 2 , and dopamine receptors can be classified as dopaminergic, and neurons which synthesize or contain dopamine and synapses with dopamine...
action of the drugs and previous findings from electrode stimulation of the brain (e.g. Bancaud, Brunet-Bourgin, Chauvel, & Halgren, 1994), Taiminen and Jääskeläinen speculate that déjà vu occurs as a result of hyperdopaminergic action in the mesial temporal areas of the brain. Many scientists are still working towards the actual link of déjà vu with hypnagogic epilepsy.
Memory-based explanations
The similarity between a déjà-vu-eliciting stimulus and an existing, but different, memory trace may lead to the sensation. 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) used hypnosisHypnosis
Hypnosis is "a trance state characterized by extreme suggestibility, relaxation and heightened imagination."It is a mental state or imaginative role-enactment . It is usually induced by a procedure known as a hypnotic induction, which is commonly composed of a long series of preliminary...
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 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
Cryptomnesia
Cryptomnesia occurs when a forgotten memory returns without it being recognised as such by the subject, who believes it is something new and original...
", 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
Aphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....
, amnesia
Amnesia
Amnesia is a condition in which one's memory is lost. The causes of amnesia have traditionally been divided into categories. Memory appears to be stored in several parts of the limbic system of the brain, and any condition that interferes with the function of this system can cause amnesia...
, and epilepsy
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
.
Theoretically, as seen below, a jamais vu feeling in a sufferer of a delirious
Delirium
Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...
disorder or intoxication could result in a delirious explanation of it, such as in the Capgras delusion
Capgras delusion
The Capgras delusion theory is a disorder in which a person holds a delusion that a friend, spouse, parent, or other close family member has been replaced by an identical-looking impostor...
, in which the patient takes a person known by him or her for a false double
Body double
A body double is a general term for someone who substitutes for the credited actor of a character in any recorded visual medium, in shots where the character's body is shown but the face is either not visible or shown indistinctly, or in shots where the image of the credited actor's face is joined,...
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):
Presque vu (Tip of the tongue)
Déjà vu is similar to, but distinct from, the phenomenon called tip of the tongueTip of the tongue
The tip-of-the-tongue phenomenon is the failure to retrieve a word from memory, combined with partial recall and the feeling that retrieval is imminent...
, 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
Epiphany (feeling)
An epiphany is the sudden realization or comprehension of the essence or meaning of something...
. 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
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
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.
Déjà entendu
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.Film
Déjà vu provides a plot point in The MatrixThe Matrix
The Matrix is a 1999 science fiction-action film written and directed by Larry and Andy Wachowski, starring Keanu Reeves, Laurence Fishburne, Carrie-Anne Moss, Joe Pantoliano, and Hugo Weaving...
, a 1999 science fiction
Science fiction film
Science fiction film is a film genre that uses science fiction: speculative, science-based depictions of phenomena that are not necessarily accepted by mainstream science, such as extraterrestrial life forms, alien worlds, extrasensory perception, and time travel, often along with futuristic...
-action film
Action film
Action film is a film genre where one or more heroes is thrust into a series of challenges that require physical feats, extended fights and frenetic chases...
written and directed by Larry and Andy Wachowski. The protagonist, Neo
Neo (The Matrix)
Thomas A. Anderson is a fictional character and the main protagonist in The Matrix franchise, as well as having a cameo in The Animatrix short film, Kid's Story. He was portrayed by Keanu Reeves in The Matrix Trilogy and The Animatrix. Andrew Bowen provided Neo's voice in The Matrix: Path of Neo...
, glances at a black cat and comments that he has just experienced déjà vu. Those with a knowledge of 'The Matrix' and its internal workings state that déjà vu means something within the Matrix was altered from its prior state and is referred to as a "glitch
Glitch
A glitch is a short-lived fault in a system. It is often used to describe a transient fault that corrects itself, and is therefore difficult to troubleshoot...
".
The 2006 science fiction film Déjà Vu revolves around a US federal law enforcement officer using an instrument called Snowhite to view the past 4 and a half days of anywhere in the world (limited radius as permissible by the program) in order to solve a murder and a terrorist bomb attack on a ferry that was being boarded by about 500 citizens and military members.
Documentary
Synopsis:A rapid and intense impression. I’ve been here! No, I have not… The experience of feeling sure that I have already witnessed it. TEMPORAO - Brazil, 2011