Transcript Déjà vu

Déjà vu
Initial research and compilation by Ms. Victoria Ayre, DA
Déjà vu or “Already seen”
‘Paramnesia’ -from the Greeks
An individual feels as though an
event has already happened or has
happened in the recent past.
The feeling of déjà vu is usually
accompanied by a compelling sense of
familiarity and a sense of eeriness
The “previous” experience is
frequently characterized to real life.
Émile Boirac
(1851-1917)
French psychic researcher
Déjà vu coined after an essay
in his book, "L'Avenir des sciences
psychiques“ ("The Future of Psychic
Sciences“)
Literature in past references déjà vu,
indicating it is not a new phenomenon
Three Types of Déjà vu
Déjà vecu (already experienced or lived through)
Otherwise known as déjà vu, experiences occur
more frequently between the ages of 15 and 25
The events are so striking that they are often
remembered for years to come
Three Types of Déjà vu
Déjà senti (‘already felt’)
*Appears in temporal lobe epilepsy attacks
*Primarily--or even exclusively--a mental
happening
*There are no precognitive aspects in which the
person feels he or she knows in advance what
will be said or done
*It seldom or never remains in the afflicted
person's memory afterwards
Three Types of Déjà vu
Déjà visite (‘already visited’)
Seems to occur more rarely and is an
experience in which a person visits a new
locality and nevertheless feels it to be familiar
Déjà visite has to do with geography, with the
three spatial dimensions of height, width and
depth, while deja vecu has to do more with
temporal occurrences and processes
C.G. Jung published an account on Déjà visite in
his account on synchronicity
Scientific Research
70% of people report having
experienced déjà vu at least once
Experiencing déjà vu is quite common
among adults and children alike
Difficult to evoke déjà vu experience in
laboratory settings
Researchers are using science to
recreate the sensation of déjà vu
F i r s t T h e o r y…
Subject to
psychological and
neuropsychological
research
Déjà vu is an
anomaly of memory
Sense of recollection
at the time is strong
and circumstances of
previous experience
are uncertain
S e c o n d T h e o r y…
Vision is being explored
One eye may record what is
seen faster than the other
Creates that "strong
recollection" sensation
upon the "same" scene
being viewed milliseconds
later by the opposite eye
Déjà vu Linked With Disorders
Pharmacology
Reports say that certain drugs increase the
chances of déjà vu occurring in the user.
Hyperdopaminergic action in the mesial
temporal areas of the brain
Memory-based explanations
Memory trace may lead to the sensation.
Cryptamnesia: information learned is forgotten
yet stored in the brain, and occurrence of
similarities invokes the contained knowledge,
leading to a feeling of familiarity because of
the situation, event or emotional/vocal content
Neural theories
Could be caused by the mis-timing of neuronal
firing. Split second re-start to the neural
system
Alternative Explanations For Déjà vu
Parapsychology - cited for
evidence of psychic abilities
Dreams - déjà vu may be
the memory of dreams
Reincarnation - déjà vu
may be caused by
fragments of past life
memories being jarred to
the surface of the mind by
familiar surroundings or
people
Déjà vu and its Relatives
1) Jamais vu, “never seen” in French
Used to describe any
familiar situation which is
not recognized by the
observer
Described as opposite of
déjà vu
Déjà vu and its Relatives
2) Presque vu, “almost seen” in French
When one cannot recall a familiar word or name or
situation, but with effort one eventually recalls the
elusive memory
Also called “tip of the tongue”
Sensation of being on the brink of an epiphany
3) L'esprit de l'escalier, “staircase wit” in French
Remembering something when it is too late
The Déjà Vu “Feeling”
 Déjà vu feeling is common among psychiatric patients
Déjà vu feeling also frequently precedes temporal lobe
epilepsy attacks
Experiment in 1955
 Electrically stimulated the temporal lobes and found
that about 8% of his patients experienced “memories”
With this, he assumed he elicited actual memories
 However, these could have been the first signs of
artificially stimulated déjà vu
How does it work?
There are portions of the brain
that are specialized for the
past, the present and the
future.
 The temporal lobes are
concerned with the past, the
frontal lobes are concerned with
the future, and the underlying,
intermediate portions (the limbic
system) are concerned with the
present.
 The structure that overwhelms
our consciousness when we are
'in the present’ is the amygdala.
It assigns an emotional 'tone' to
our perceptions.
 The amygdala also recognizes
expressions on people's faces.
How does it work?
• Each instance the self is
able to manifest a new
emotional response, but
only if circumstances
have changed.
– Every 25 milliseconds.
– The duration of the
'present' in neurological
terms is so brief that we
don't experience it so much
as remember it.
Interesting Facts
• The youngest age of déjà vu
reported is age 5. This has major
theoretical implications for cognitive
development.
• There is a complex interchange with
age and incidence based on quality
of remembering.
Interesting Facts
• There is no single theoretical cause of
déjà vu that can explain its wide
variety of clinical manifestations.
• Most instances of associative déjà vu
are connected with a predisposing
milieu of anxiety and are triggered by
restricted paramnesia and
reintegration.
Interesting Facts
• There are 21 kinds of déjà vu.
• There is also a metaphorical journalistic
use of the term.
• The common occurrence of déjà vu in the
general population stresses the need for
the development of specific qualitative
features for valuable diagnosis of
temporal lobe epilepsy.
Interesting Facts
• There are 7 major phenomenological
classifications of the déjà vu experience:
– disorder of memory
– disorder of ego state
– ego defense
– temporal perceptual disturbance
– recognition disorder
– manifestation of epileptic firing
– subjective paranormal experience
“Right now, I’m having amnesia
and déjà vu at the same time, I
think I’ve forgotten this before,”
–Steve Wright
Sources
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http://www.goodreads.com/quotes/show/5305
http://home.cc.umanitoba.ca/~mdlee/dejavu.htm
http://www.pni.org/books/deja_vu_info.html
http://www.shaktitechnology.com/dejavu.htm
http://skepdic.com/dejavu.html
http://en.wikipedia.org/wiki/D%C3%A9j%C3%A
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