What is déjà vu? Psychologists are exploring this creepy feeling of having already lived through an experience before

By Anne Cleary, Colorado State University, via The Conversation

Have you ever had that weird feeling that you’ve experienced the same exact situation before, even though that’s impossible? Sometimes it can even seem like you’re reliving something that already happened. This phenomenon, known as déjà vu, has puzzled philosophers, neurologists and writers for a very long time.

Starting in the late 1800s, many theories began to emerge regarding what might cause déjà vu, which means “already seen” in French. People thought maybe it stemmed from mental dysfunction or perhaps a type of brain problem. Or maybe it was a temporary hiccup in the otherwise normal operation of human memory. But the topic did not reach the realm of science until quite recently.

Moving from the paranormal to the scientific

Early in this millennium, a scientist named Alan Brown decided to conduct a review of everything researchers had written about déjà vu until that point. Much of what he could find had a paranormal flavor, having to do with the supernatural – things like past lives or psychic abilities. But he also found studies that surveyed regular people about their déjà vu experiences. From all these papers, Brown was able to glean some basic findings on the déjà vu phenomenon.

For example, Brown determined that roughly two thirds of people experience déjà vu at some point in their lives. He determined that the most common trigger of déjà vu is a scene or place, and the next most common trigger is a conversation. He also reported on hints throughout a century or so of medical literature of a possible association between déjà vu and some types of seizure activity in the brain.

Brown’s review brought the topic of déjà vu into the realm of more mainstream science, because it appeared in both a scientific journal that scientists who study cognition tend to read, and also in a book aimed at scientists. His work served as a catalyst for scientists to design experiments to investigate déjà vu.

Testing déjà vu in the psychology lab

Prompted by Brown’s work, my own research team began conducting experiments aimed at testing hypotheses about possible mechanisms of déjà vu. We investigated a near century-old hypothesis that suggested déjà vu can happen when there’s a spatial resemblance between a current scene and an unrecalled scene in your memory. Psychologists called this the Gestalt familiarity hypothesis.

For example, imagine you’re passing the nursing station in a hospital unit on your way to visit a sick friend. Although you’ve never been to this hospital before, you are struck with a feeling that you have. The underlying cause for this experience of déjà vu could be that the layout of the scene, including the placement of the furniture and the particular objects within the space, have the same layout as a different scene that you did experience in the past.

Maybe the way the nursing station is situated – the furniture, the items on the counter, the way it connects to the corners of the hallway – is the same as how a set of welcome tables was arranged relative to signs and furniture in a hallway at the entrance to a school event you attended a year earlier. According to the Gestalt familiarity hypothesis, if that previous situation with a similar layout to the current one doesn’t come to mind, you might be left only with a strong feeling of familiarity for the current one.

To investigate this idea in the laboratory, my team used virtual reality to place people within scenes. That way we could manipulate the environments people found themselves in – some scenes shared the same spatial layout while otherwise being distinct. As predicted, déjà vu was more likely to happen when people were in a scene that contained the same spatial arrangement of elements as an earlier scene they viewed but didn’t recall.

This research suggests that one contributing factor to déjà vu can be spatial resemblance of a new scene to one in memory that fails to be consciously called to mind at the moment. However, it does not mean that spatial resemblance is the only cause of déjà vu. Very likely, many factors can contribute to what makes a scene or a situation feel familiar. More research is underway to investigate additional possible factors at play in this mysterious phenomenon.The Conversation

Anne Cleary is a Professor of Cognitive Psychology at Colorado State University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Comments

  1. I would assume he got paid for this study? When I have a deja vu experience I know what the person is going to say verbatim even though I have never ever met them before. ,Also about familiar settings, that does not pan out.

  2. These researchers did not study real deja vu. Deju vu is when you already remember everything that is happening or about to happen down to the smallest detail. Even your own internal dialogue is exactly the same. It not merely a “feeling” of “familiarity”.

  3. Could it be sometimes the mind is recording and remembering at the same time? And, at other times it seems as if the exact situation happening at a moment in our lifetime is something we might have dreamed about before it actually happens in our for real time life situation?

  4. dejavu gives me a sense of comfort yet strange that it’s happening. The situations weren’t traumatic which I am so thankful for. If I’m around someone at the time it’s happening, I always call it out to the person(s) I am with. They acknowledge at the time it’s not happened before with them. Also, I think sometimes it is associated with a dream I had while sleeping. I can’t count how many times I have had dejavu but I am in the 2/3 persons that have it. I often wondered what causes it. It seems to me to be spatial I am not talking about the same thing I’ve talked about to someone else. It would be the same people I am talking to about the same subject matter. Waiting patiently for truth. Thank you Mr. Brown.

  5. Doesn’t explain when you have foresight of someone dying in a car crash or seeing a obituary about someone days or even weeks before it happens.

  6. Like 99.9% of studies throughout history, it’s the nonsensical type.

    Most of this garbage gets put out a few times, then never heard about again. Some studies will make a run every ten years & a hundred years later still mean nothing. Then, there will be that one real study that amounts to something like Special Theory.

    One more for the trash today.

  7. Dude fractal geometry as above as below the same above as below…. so life in time you will bound to become part of the start over as when zooming in on a fractal…. god has problems and humans too have problems as above as below…. so when you experience da ja vu , like the
    Mandolbrot you have come to the exact spot when you left … history repeates as above as below
    Everything obeys the laws of Physics… but most people their physics is mystical rythems that have no logic/…. Physics explains de ja v u through Fractal Geometry ./

    1. Wow , I’ve come to the same sort of conclusion just I differ in that I believe we have died and it wasn’t our “time” so we are brought back to the latest “safe” moment before we prematurely died … I like your take as well and will meditate on that one

  8. Bull crap. Most of my experiences are in areas or scenes I’ve never been In. Yet I know I have seen that moment before. Not because I remember the previous, but because I am being shown my path in life is correct.

  9. The times I have experienced deja vu, have left me dizzy and nauseous. It’s like I am seeing or saying two of the same experiences or conversations at the same time.

    1. Hey,

      Its not impossible for everything to happen again. There’s a lot of space and time out there, baby brain.

        1. Yeah same here, I was pulling onto an busy hwy and remembered my truck was about to lose the drive shaft, even stranger was I knew the only spot on the side of the road I could pull off safely (tall grass, fences and a ditch). My wife must have thought I was crazy as I drove off the road but the drive shaft went out just as I left the road. It was a trip out of state.

      1. Same. Every time I’ve had deja vu it’s because I’m sure I’ve seen or experienced this exact moment in time in a dream. Sometimes years prior to it actually happening. And it’s never anything of consequence, just a random conversation or being on a street corner, innocuous stuff like that. Not sure what to make of it but it’s always unnerving.

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