Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Deja Vu

  1. Sep 7, 2006 #1
    This has been a topic on my mind for a very long time now and I thought I would share my ideas here in hope for some feedback. (Note: I'm not sure if this is in the correct section, please move, if necessery!) I am not jumping to any conclusions here but just wanted to express an idea!

    Everyone must of had that feeling of Deja Vu before? The feeling where you think you have seen a certain scenario before (I have had it once that I could even finish what the person speaking to me was saying just because of this "Deja Vu" feeling.
    This all depends on my understanding of higher dimensions, but I think if you live in 5 dimensions (we live in 4) then you can freely move through time and what I am getting at is if Deja Vu experiences may simply be leaks from higher dimensions? Could you somehow be absorbing this information leak from a higher dimension subcontiously and then when it comes to that time that is the reason for this Deja Vu feeling?

    I really have no idea how this would work but I was wondering if anyone knew anything more about this or has any comments. It has been on my mind for a while now!

    Thanks, Rich
  2. jcsd
  3. Sep 7, 2006 #2


    User Avatar
    Gold Member

    I'd always assumed deja vu was just a sense of familiarity of the characteristics of the situation, and not so much an actual sharing of two different times.

    That is, It's largely a psychological phenomena, rather than one of time or space.
  4. Sep 7, 2006 #3
    Hmmm...yes. But what about them times where you just know its been exactly the same before? Surely thats a little more than familiar with the situation. But then, I guess, that can be down to personal experience.
  5. Sep 7, 2006 #4


    User Avatar
    Gold Member

    People tend to think they 'know' things a lot. The people that 'knew' everything over the ages have asseted that: the earth was flat, Earth was the center of the universe, flight was impossible, and a thing like TV could never be invented.

    That's one of the major issues of science. Seperating what you 'know' from what you can observe and measure repeatedly.

    I've never had the experience, and I'd have to admit I'm skeptical. It sounds like something I would have came up after smoking a joint in high school.
  6. Sep 7, 2006 #5


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    I think this thread should be on the Skepticism and Debunking board, so I am going to transfer it there.
  7. Sep 7, 2006 #6

    Math Is Hard

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I'd categorize it as a neurological phenomenon. There was a discussion about it here:
  8. Sep 7, 2006 #7
    I used to have deja-vu alot especially in my teen years. I was absolutely convinced I had a vision couple seconds into the future. But as much as I'd like to believe, this phenomena is actually a glitch in the brain caused by mini-seizures.

    Well that's the current psychological explanaton.
  9. Sep 7, 2006 #8

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I realize that Zooby is well read on the subject of simple partial seizures, but the supporting evidence for the statements in the linked thread is pretty thin. A few references beyond a drug site would be nice.

    Also, does this account for all experiences? If I walk into a room and have a sense of deja vu, and later I remember that I was once there as a small child, have I experienced a simple partial seizure? Clearly there are other reasons why one might have a feeling like this. And here is another problem with this sort of thing: If I feel a breeze on my arm or hear a buzzing sound, it may be a breeze or a buzzer, or it may be a simple partial seizure, but the existence of simple partial seizures does not exclude the existence of wind or buzzers.
    Last edited: Sep 7, 2006
  10. Sep 7, 2006 #9

    Math Is Hard

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Most of what I read about it links it to the temporal lobe region near the hippocampal formations. I definitely am not that knowledgeable about it since I am more interested in parietal lobe functions and focus most of my studying there. Would I say that a mini-seizure in this region explains all experiences? Probably not. But there does seem to be some evidence of at least a single dissociation for the phenomenom:
  11. Sep 7, 2006 #10


    User Avatar
    Science Advisor

    I've identified that i get the feeling of Deja Vu, for example, in the following scenario:
    - at one point i see an object, like a toothbrush, and i think of something, or the toothbrush reminds me of something.
    - later on, if i see the same object and think the exact same thing, i get the feeling of Deja Vu,.

    I think the reason sometimes the feeling is hard to explain is because either the first or, more likely, the second thought might happen unconsciously, as a reflex, so you might not be aware of what triggered the feeling.
    For example, have you ever, while flipping through the pages of a book, have a word pop into your head without you ever actually seeing (or remembering seeing) the word? Whenever this happens to me i always scan the page for what might have triggered the word to get into my head. If i closely study the path my eyes followed when they moved across the page i always either find the word or some syllables, maybe in different lines, that form the word.
    Similarly, in the same way the word got into my head when i was flipping through the pages, sometimes, unconsciously, maybe from seeing an object from the corner of my eye, something may trigger a thought to get into my head. If this has happened before i will get the feeling of Deja Vu. If i'm unable to identify what triggered this then i won't be able to explain it, which is common.
    I'm pretty confident that this is what deja vu is, i usually pay close attention whenever i get the feeling, and i find that this explanation works for me.
    Last edited: Sep 7, 2006
  12. Sep 8, 2006 #11
    It's kinda weird when you get deja vu, in your dreams!

    When it happens in real life, it's kinda weird. When it happens to me, I usually feel that it happened once only slightly before it actually happens (giving me no time to think)...
  13. Sep 8, 2006 #12
    You should have read the whole thread:

    In addition, in another thread on the subject I linked to this abstract:


    The sensory and emotional experiences of simple partial seizures call attention to themselves for being inexplicable in normal terms. The hyperfamiliarity of a deja vu is so striking because the person can't account for it. It doesn't strike you as a memory of childhood, or anything you can point to in your past. It is weird and noteworthy for seeming like nothing but a memory of the present.

    Likewise, if a simple partial causes a loud buzzing sound or feeling of a breeze, it is remarkable because there is nothing around to account for it.

    Of course authentic memories, sounds, and buzzers aren't simple partial seizures.
  14. Sep 9, 2006 #13
    What interests you about the parietal lobes? Most people seem to get interested in the frontal or temporal lobes.
  15. Sep 9, 2006 #14
    Job, I'm not sure that what you're describing is the experience refered to as a deja vu. It sounds more like you are actually remembering something, actually being reminded of something that you can't quite recall, but maybe could if you tried.

    A deja vu is an extremely mysterious and powerful experience where your current situation suddenly seems remarkably familiar when you concurrently know it cannot be familiar. Not everyone has had a deja vu and I think that people who haven't are somewhat confused about what it's like, and maybe think they have had one. It isn't a matter of something seeming vaguely familiar, it's an overwhelming, stop-you-in-your-tracks, flood of familiarity attached to a situation you intellectually know is not one you've ever been in before. The strength of this feeling is unbelievable. It seems 20 times more familiar than anything that actually is familiar. It's distinctly unnatural feeling: the present seems like an exact repeat of itself down to the smallest detail, as if your mind had skipped back in time and was reliving a moment all over again.

    Your description of being reminded of what you were thinking about the previous time you were looking at a toothbrush doesn't sound like an authentic deja vu to me.
  16. Sep 9, 2006 #15

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I looked it over and only saw one link. The other references can't easily be verified.

    Of course.

    If there is such a thing as a genuine precognitive or similar experience, then it might also be mistaken for what you describe as deja vu.

    I was struck recently by a story from a woman who, due to what was described as precognition, insisted that her husband not take one of the doomed AA flights on 911. It saved his life.

    The question is not whether clinical observations and explanations for deja vu are correct. The question is whether or not there could be more to the story.
    Last edited: Sep 9, 2006
  17. Sep 9, 2006 #16

    Math Is Hard

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I am interested in dyscalculia and acalculia and how the symptoms can arise after left parietal lobe damage.
  18. Sep 9, 2006 #17
    If you google simple partial seizures symptoms you'll find that deja vu's are mentioned in just about all lists. For the sake of ease of reading I generally just provide one link when explaining that deja vu's are simple partials. If the questioner seems naive about neurology I try to find a simpler link geared toward the layman with the least medical jargon to slog through.

    Here's a link to a serious medical paper for you with all the jargon:


    From that link, here's a relatively comprehensive list of simple partial symptoms:
    Notice the section labeled "psychic" symptoms. Here you'll find the deja vu mentioned. (Note that the use of the word "psychic" here, means of, or pertaining to, the psyche, i.e. the mind, and shouldn't be construed to refer to anything paranormal.)

    Once again it seems you're arguing against me without having even read what I said. I discussed this in the thread linked to by Math Is Hard with a member named Seraphim. Please read that exchange. If a person has a precognitive feeling about the future that authentically comes to pass then it is some kind of authentic precognition, and not the illusion of precognition that sometimes accompanies a deja vu. The illusion of precognition that arises from a deja vu is quite noteworthy for being innaccurate.

    Back when I was having a couple hundred deja vu's a day I started making a point of noting what I was certain was going to happen next and found out I was wrong about 99% of the time despite the fact I was always completely certain I knew, the feeling I had lived through this moment already was so intensly strong.

    On the other hand, and in contrast to that, I once had an anomalous experience where the situation I was in caused me to "remember" that I had literally seen this situation before, projected in front of my eyes like a movie at some point in the past. I could remember when and where that projection had taken place. This was a distinctly different experience than a deja vu. This may have been an instance of authentic precognition, I'm not sure. The regular deja vu's I used to have all the time were definitely not.
  19. Sep 9, 2006 #18
    In that case you may be interested in a rare genetic disorder called William's Syndrome. Oliver Sacks did an hour long special on TV about it as part of a four part series on rare syndromes a few years back. People with William's Syndrome are born without the gene for elastin. In addition to the way this affects their skin, it also produces four other remarkable results. The most amazing of these is that they have superhearing and can hear a whisper a hundred feet away. Another, a deficit, is that they have no sense of the passage of time. The third is that they all seem to be extremely attracted to music and seem to experience an almost synaesthetic feeling of physical pleasure when listening to it. Alot of them learn to play musical instruments and sing, though not particularly well. The fourth, the one that would interest you, is that they are completely unable to handle numbers and math and spatial relations.

    At the time this show aired they didn't know much about this syndrome and the neurologists interviewed seemed to be in the beginning stages of just sorting out the spatial and math problems trying to determine the exact extent of these. I don't know what they've found out in the meantime, but it seems a fair guess that the parietal lobes are implicated.
  20. Sep 9, 2006 #19

    Math Is Hard

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Thanks for the tip. I would not have thought about looking at William's syndrome in relationship to this. I remember reading about children with WS in a biology class and I was struck by their similar physical appearance (they look like pixies). I do remember reading that they had severe learning and developmental disabilities, but didn't know much about the nature of them. So your hunch may be right. I found this article:
    Evidence for superior parietal impairment in Williams syndrome.
    Unfortunately I wasn't able to read the entire article and find out if there were any significant differences found in the inferior parietal lobule which is supposed to very important for manipulation of numbers.

    I've also read about a peculiar disorder called Gerstmann Syndrome.
    It's really odd because one of the symptoms is inability to recognize one's own fingers, but it goes along with dyscalculia, dysgraphia, and left-right orientation. One of the theories about the finger agnosia/dyscalculia connection is that early learning of math concepts is strongly tied to finger-counting.

    What I have found really compelling are cases where adults lose different math abilities due to stroke or brain injury, and it seems to be consistently occurring with left parietal lobe damage. I was thinking about starting a thread on this topic, but I don't know how many people would be interested.

    But back to Deja Vu...
  21. Sep 9, 2006 #20
    Dr. Bellugi, one of the authors of the WS article you linked to, was the main neurologist Sacks interviewed in his TV special about it. She did alot of tests on a little girl named Heidi. In one, Heidi was asked to copy the arrangement of 5 or 6 wood blocks. They were a mix of cubes and rectangular ones. Heidi seemed completely unable to grasp the original arrangement, and couldn't reproduce it with the second identical set they gave her. In another scene they showed Heidi a dozen cinammon buns on a plate and asked her to count them. This she could do by pointing to each one and counting aloud as she went along. Then they covered all but three of the buns with a cloth and asked her how many there were on the plate. She counted three. They reminded her that the ones under the cloth were still there. Still, she insisted there were only three buns on the plate.

    I was personally confused about what kind of deficit this latter demonstration indicated, but it was clear that the covered buns somehow ceased to exist for her when she couldn't see them.

    The inability to recognize the fingers in Gerstmann Syndrome sounds like a proprioceptive deficit, which I've always read to be associated with parietal problems. My brother-in-law who has MS cannot sense the position of his feet. He has to watch them when he walks to know where they are. Some people have simple partials where their proprioceptive "knowledge" of various body parts shuts off, and they are startled by the sight of their own limbs, the limbs don't feel like they belong to them.

    The theory that agnosia for the fingers could lead to math deficits sounds pretty logical to me. I still count on my fingers.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Deja Vu
  1. Déjà Vu (Replies: 3)

  2. Déja Vu? (Replies: 12)

  3. Deja vu (Replies: 2)

  4. Deja Vu (Replies: 1)

  5. Deja Vu (Replies: 5)