Have You Experienced Deja Vu? What Causes Deja-Vu?
Is Déjà Vu Real?
There are those who claim that déjà vu is a psychic phenomenon, closely related to, or an example of Extra Sensory Perception. There are those who hold up scientific evidence to support their theory of a malfunction in the brain's processing of an experience. Which of these answers is correct - what causes déjà vu?
Many people report having experienced déjà vu. Episodes can last from a few seconds to several minutes, and take a variety of forms, from feelings of familiarity in an unfamiliar place - somewhere that person has never been - to a conversation of seconds or minutes in length that is heard in the mind a split second before each word is spoken. Each of these experiences has left the same sense of wonder and mystery in its wake.
According to Scientific American:
"Researchers believe that a memory system that includes the prefrontal cortex and the hippocampus mediates conscious recollection whereas a memory system that includes the parahippocampal gyrus and its cortical connections mediates feelings of familiarity. Josef Spatt has recently argued that déjà vu experiences occur when the parahippocampal gyrus and associated areas become temporarily activated in the presence of normal functioning in the prefrontal cortex and hippocampus. This produces a strong feeling of familiarity but without the experience of conscious recollection."
I've Been Here Before...
Did the person really experience a strange/foreign place in another lifetime or in some kind of astral travel? Some would say, "Yes, absolutely."
Others would say, "Possibly, but there might be another explanation."
Almost everyone, though, would agree that the event was fascinating, whatever its origins.
According to a 1963 study by Robert Efron of Boston's Veterans Hospital:
"Déjà vu is caused by dual neurological processing caused by delayed signals. 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."
Anecdotal Accounts of Déjà Vu
What is Déjà Vu?
Déjà vu translated into English is, literally, "already seen." It refers to the feeling you have been in that place before, or have had that exact conversation before.
People who experienced déjà vu have reported that they absolutely knew what they would see or hear next, and then, that was exactly what happened. Some reported instances of knowing absolutely where to find a room, or an object in a house where they had never been before.
I, like many others, have had numerous experiences of déjà vu over the years. Upwards of 70 percent of people world-wide report having experienced some form of déjà vu. A higher number of such incidents occur in those 15 to 25 years old than in any other age group.
A Psychological View of Déjà vu
Is Déjà Vu a Paranormal Event?
Is time somehow out of joint for these souls? Have they actually traveled to these places? Have they had a moment of clairvoyance? Are they prescient? How best can these curious experiences be explained?
Some researchers into the paranormal would argue that these people have experienced the place or event in a past life perhaps, or in an astral travel, when their soul/spirit temporarily left their body, an event of which they are not consciously unaware. Now, when they re-visit that place, the information stored in their subconscious becomes accessible - the knowledge, impressions, and sensations of their previous visit.
There seems to be no way to predict when such an event will occur in most people. The incidents that are reported seem to have happened with equal frequency during both stressful and perfectly serene times.
Déjà vu, Presque vu, Jamais vu
- Australian Institute of Parapsychological Research, Inc
The Australian Institute of Parapsychological Research, is a non-profit scientific and community society founded in 1977. The organisation promotes research and public education into Parapsychological phenomena.
- Koestler Parapsychology Unit
The Koestler Unit is a section of the psychology department at the University of Edinburgh that focuses on parapsychology research, including paranormal experiences, psychic ability, and the "psychology of anomalous experiences."
- IRAAP: Articles by Loyd Auerbach
IRAAP: International organization of independent researchers of UFOs, bigfoot, crop circles, ancient civilizations, paranormal and the anomalous who communicate and share information with other interested researchers and individuals around the world
I've Heard/Seen This Before...
One of the most common types of déjà vu is the kind wherein time seems to disjoint, or split into two streams. Suddenly, you are hearing the words in your head a split second, or even a syllable before they are spoken. Then, just as suddenly, the flow of time seems to amend itself, and the streams of words/syllables merge into normalcy.
This could be due to a perceptual shift in the brain. Some researchers into perception and learning, particularly into how our brains process information, believe that the input (the hearing and seeing of the event or conversation) somehow gets out of synchronization with the processing of the information (what our brain tells us is happening).
In a normal state, you see the lips form the words, you hear the sounds, and almost instantaneously, your brain translates those sensations, those sights and sounds, into words and meaning.
In the case of déjà vu, there is a glitch somewhere in your perception of the input. A slight lag develops, causing you to perceive the "translation" before your brain tells you that you have actually seen and heard the words being spoken - that is, the translation seems to be happening before the information is received.
Even though it may only last for a few seconds, this is what some researchers feel gives you the unshakable feeling that you have already experienced the event that is unfolding, or that you have had this conversation before.
Interestingly, déjà vu has also been associated with temporal-lobe epilepsy, where it is reported to happen immediately before a seizure. People suffering a seizure of this kind sometimes experience déjà vu during the actual seizure activity or in the moments between convulsions.
Déjà Vu In the Media...
What About Prescience?
Prescience, or "pre-knowing" refers to the idea that a person may have the ability to see into the future in some way - that they may, in fact, know what is about to happen because they have already seen the event in a dream or vision.
Prescience, the least commonly experienced form of déjà vu, can also be explained by the perception/processing glitch, where the information is taken in, but not perceived as coming from your physical senses until after your brain has supplied the information seemingly out of thin air - or some subconscious memory.
Prescience is closely linked to another form of pre-knowing, in which the person has knowledge of a place that can only seemingly be explained by their having been there before. According to Swiss researcher and scholar, Arthur Funkhouser, this is an example of what he refers to as déjà visite, or "already visited," such as the experience related by a friend of mine.
I've Been Here Before...
On his first trip abroad, a graduation gift from his parents, who had never been abroad, my friend and his companions were walking down a street in mainland China. It was mid-summer, and rather hot, and my friend said he was suddenly overwhelmed by the feeling he had been there before.
He informed his companions that around the next corner and three houses down was house with a red door-gate. He gave a detailed description of the gate, of the design on the stone wall, and of a tree with beautiful pink blossoms that overhung the roadway.
As they walked up the street, and turned the corner, they found the house he had just described, exactly three from the corner. Their approach revealed that the only discrepancy between his description and what they found was the tree. It was not in bloom. Upon inquiring of their guide, though, they were told that the tree would indeed have such flowers when it bloomed in the spring.
There would seem to be no reasonable explanation for this event. None of the friends had ever been to China. That particular house was not featured in any of the guidebooks they carried or referred to in planning their trip. Nor could they find any pictures or references on any of the web-sites they had visited in making their preparations.
Déjà Vu - A Personal Anecdote
Less spectacular than my friend's experience, but nonetheless puzzling, was an incident that I experienced during a hospital stay.
About to be released after surgery to remove a thyroid adenoma, an encapsulated thyroid growth, I was standing at the sink in my hospital room, gathering up my personal effects. A nurse had just popped in to ask that I wait to leave until the surgeon could talk to me.
As I glanced up in the mirror, wondering why he might want to talk to me, a voice in my head supplied the answer. Inserted whole into my consciousness, a scenario played out - a radio script in which the surgeon entered, asked me to sit down, and explained he had found cancer. At that point, I laughed at my reflection for being overly dramatic, and continued gathering my things.
Several minutes later, just as I finished packing, my surgeon did enter, and in the exact tones, cadence, and wording of my "imagining" asked me to sit down. He touched my shoulder briefly in reassurance, and began explaining that they had found cancer.
For the next few moments, a sense of unreality prevailed as he repeated every word and gesture I had conjured in the mirror. That internal conversation replayed like an echo in my head, while the surgeon's voice spoke the same words aloud, as if he were reading from the script of my imagining. Finally, his words continued beyond my "script" of the event, and reality returned.
Perception or Paranormal?
Is this event explainable by a perceptual glitch? Possibly.
Could something in the nurse's manner or an unusual request from a busy surgeon have triggered a leap to the unwelcome but probable conclusion? We do tend to think the worst in such circumstances.
It is possible that the wording my imagination supplied during my internal conversation in front of the mirror was exactly the wording most commonly used to reassure patients who have just been diagnosed with cancer - possible, but a bit of a stretch.
It is also conceivable that the shock of hearing the word "cancer" could have triggered a perceptual glitch.
The concept of a glitch in perception that affects an event in progress is certainly plausible. It becomes more difficult to apply that theory where exact information has become somehow available in the brain several measurable minutes before the event occurs - such as in the time between my imaginary conversation, and the real conversation with the surgeon.
A perceptual glitch does not adequately explain this event, nor the case of my friend. How was either of our brains able to provide exact information, right down to color, texture, and in my case the exact wording and tone of voice, so far in advance of the actual event?
Once thought to have been caused by the brain making false memories, research by Akira O’Connor at the University of St Andrews, UK, and his team now suggests this is wrong.
As quoted in an article by Jessica Hamzelou:
"His team used MRI to scan the brains of 21 volunteers while they experienced this triggered déjà vu. We might expect that areas of the brain involved in memories, such as the hippocampus, would be active during this phenomenon, but this wasn’t the case. O’Connor’s team found that the frontal areas of the brain that are involved in decision making were active instead."
While certainly attractive to those who prefer a tidy and reasonable scientific explanation, the perceptual glitch theory has yet to be embraced as a viable cause in every reported case of deja vu, leaving the way open for other less scientific, but nonetheless fascinating theories.
One thing almost all the scientific research agrees on, is that déjà vu appears to happen when two parts of the brain that normally do not "talk to each other' or are not activated at the same time, are suddenly activated - in contact.
But science still has a long way to go, and there ares till more thigns under heaven and earth... and, as the imaginative film writers suggest below - what if it's really aliens?
- Alcock, James. "Déjà Vu", in The Encyclopedia of the Paranormal edited by Gordon Stein (Buffalo, N.Y.: Prometheus Books, 1996)
- Parapsychology: Research on Exceptional Experiences edited by Jane Henry (Routledge, London 2005)
- The Psychology of Déjà Vu by Dr. Vernon Neppe. (Witwatersrand University Press, Johannesburg, South Africa, 1983)
- Three Types of Déjà Vu by Arthur Funkhouser, Ph.D. (Scientific and Medical Network Review, 57:20 - 22, 1995) University of Manitoba
- Pacific Neuropsychiatric Institute (pni.org)
- Body Mind Spirit Directory (bodymindspiritdirectory.org)
Paranormal Studies and Investigations Canada (psican.org)
Comment and Link from Fellow Hubber Sambo Rambo
Check out this article from SamboRambo - another interesting take on the deja-vu phenomenon.
SamboRambo 3 days ago
Great hub! I've had deja-vu's, and maintained a reflective focus during them. But one time I had an outright preview, like you did, which elicited a different reaction. This was not a deja-vu, because I was so amazed, seeing everything happen word-for-word, action-for-action, that all I could do was laugh (as described in the hub).
Sometimes our "gifts" come more to the fore than on most other occasions. One of those gifts is probably clairvoyance. Perhaps I "received" the plans and thoughts of the woman who was planning this clever "trap." The same with you: Your doctor may have been planning - down to the moves - how to break the information to you.
Déjà Vu - As Only Monty Python Could Express It...
© 2011 RedElf