Déjà vu—that uncanny feeling of having experienced a situation before—has eluded explanation for centuries. Now the first study to use virtual reality to model the phenomenon in the laboratory is helping demystify the spooky illusion, revealing that the layout of a scene can trigger it.

Previous studies of déjà vu suggested the bizarre feeling most commonly concerns places. As such, cognitive psychologist Anne Cleary at Colorado State University in Fort Collins and her colleagues wanted to see if spaces modeled in virtual reality could experimentally replicate the striking experience.

The scientists had college students wear head-mounted video displays that immersed them in a 3-D virtual-reality depiction of a village of structures they called "Deja ville," which Cleary devised. The locale, created with the game The Sims 2 incorporated 128 scenes that were divided into pairs that secretly had objects such as chairs and artwork in the same places on a grid to create identical layouts in space.

The researchers found déjà vu most often occurred when new scenes were very similar to previously experienced scenes in terms of their spatial layout but not similar enough that people consciously recognized the resemblance. For instance, a virtual-reality museum scene might seem familiar because it had the same configuration as an earlier courtyard scene—the location of the central statue relative to the benches and rugs in the museum was the same as the location of the central potted plant relative to bushes and plants in the courtyard.

"One reason for the jarring sense that accompanies déjà vu may be the contrast between the sense of newness and the simultaneous sense of oldness—something unfamiliar should not also feel familiar," Cleary says. "A situation that resembles one in memory may be a particularly good candidate for producing that simultaneous recognition of newness alongside a sense of familiarity." Cleary and her colleagues detailed their findings in the June issue of Consciousness and Cognition.

There are many other theories about the origins of déjà vu, none of which are mutually exclusive, Cleary notes. For example, instead of a scene's layout sparking déjà vu, perhaps a single familiar element within an otherwise novel scene might produce the feeling. "We in fact have another virtual-reality study going on right now where we are investigating and finding support for this hypothesis," she says. Another possibility could lie in whether a person was distracted when they first experienced a scene, making it more difficult to recall with any detail. Such circumstances could increase the likelihood of later déjà vu because a greater variety of scenes could match that vague memory.

"Déjà vu has been an elusive phenomenon—something we have all experienced, but has been very difficult to isolate in the lab. Cleary's method provides for a way of consistently eliciting déjà vu in the lab so that we can uncover the mechanisms behind it," says cognitive psychologist Bennett Schwartz of Florida International University in Miami, who did not take part in this research.

As to whether or not the feeling that Cleary and her colleagues analyzed is the real feeling of déjà vu, "it's an amazing analogue," Schwartz observes. For example, he was on vacation for the first time in Scotland and experienced déjà vu while touring a castle. At the end of the tour he saw photographs from a movie he had seen five years earlier that had been shot in part at the castle. "Thus, I had seen the castle in the movie but I could not recall the specifics that would have allowed me to resolve the déjà vu until I saw the photos in the gift shop," Schwartz recollects. "I have heard many similar stories from others. So yes, I think Dr. Cleary's methodology captures something very real about déjà vu and is immediately applicable to any sensible explanation of déjà vu—that is, those explanations that do not involve a 'glitch in the Matrix.'"

6 Comments

1. 1. promytius 08:33 AM 6/6/12

   Mildly tangential idea, but since déjà vu is a non-predictable event, how can you possibly reproduce it in a prepared environment? This is more money-sci than actual investigation. The "jarring" experience is the leading indicator - the mind is so upset or interrupted by the experience that it is usually unprepared to "take good notes" during the feeling, and yet,after there is often a great deal of matching "experiences" - my strongest déjà vu was when I was eight years old in the playground, on a new teacher's first day - the bell rang to go in, and from that moment, through lining up, going upthe ramp and passing back into the school through the double doors, I KNEW everything that was going to happen, speech, order, position, everything was a repeat performance in front of me, led by a person I had never seen before that day; it was intensely marvelous and led to years and years of reality-confusion,and hope for another déjà vu.
   Any constructs designed to somehow "capture" déjà vu will only succeed in a placebo effect for results, it cannot be a valid test or production or reproduction of déjà vu; have I said that before???

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2. 2. Shortie 11:36 AM 6/6/12

   I am severely geographucally challenged and can only drive to known locations through habit or on-board GPS. Occasionally, I will drive through a place - location, city, street, town -- and think I have been here before, it looks so familiar...
   But this is NOT what dejavu feels like. When I experience dejavu, it is like my mind is falling into a vortex, the air is sucked out of my lungs and I am drawn forward to some place that I know I have been to before, yet, know that I haven't.
   Familiarity - being reminded of something/someplace -- is qualitatively different from dejavu. It would appear that the VR testing matched the former, but not the latter.

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3. 3. Lurker 04:31 PM 6/6/12

   I'm convinced earlier comments were made by people who have true deja vu experiences, because they each have stated an important difference between the hazy feeling described in the article and the actual deja vu. In a deja vu experience, every detail of the scene, including people, words, clothes, scenery, etc. is exactly the same as the, "memory." The memory is extremely sharp; it is not just, "similar."
   
   I've had deja vu experiences all my life, and there is absolutely no hazy memory at all.
   
   I have read a lot of articles about deja vu experiments, but none have discussed what actually seems to be happening to me. In short, my brain seems to be confusing short term memory with long term memory. Rather than consciously experiencing an event in real time, my brain seems to push the event into a long-term memory pattern before actually allowing me to consciously realize the event. Therefore, when I consciously experience the event, I also remember this new long-term memory pattern. It seems like I have had the experience at some time in the long-ago past, although I didn't.
   
   In fact, there have been times that I would remember that I remembered the event before. The whole process goes into a loop, so that I will, "remember," it previously happening multiple times.
   
   I first thought of this possible explanation while I was studying BASIC programming in the 1970's. Just as programming code can include a loop back to a previous line in the code, my brain seems to do the same thing during a deja vu. That would explain why every detail of the memory is exceptionally clear and identical to the actual event. The event only just happened, so it would obviously be easy to remember. It would also explain why I often, "know," what is about to happen. Obviously, I had the experience first; but, my brain quickly exchanges the order of the real-time memory and the long-term pattern, making it seem like I knew what was going to happen before it actually happened. Of course, this happens so quickly (and in the wrong order), that I can't tell anyone else that I know what is about to happen.
   
   This is certainly not some kind of supernatural event. There is no such thing. This is something that is happening in my brain that cannot be explained by a hazy memory of being in a similar scene at some time in the past.
   
   I do not have the expertise or equipment needed to test my hypothesis. However, I believe that approaching the subject from this angle would be more productive than the many studies I have read which assumed that deja vu is a memory of a similar scene and designed experiments based on that assumption. (Hint: scientific experiments should not automatically assume the truth of the thing being tested.)
   
   I will agree with the author about this: if my hypotheses turns out to be correct, the study of true deja vu could open a lot of avenues for the study of memory.

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4. 4. mggordon 07:28 PM 6/6/12

   Three comments all agree about this -- Deja vu is very sharp. The times I have experienced it have been so abrupt that I nearly stumble at a bad time upon realizing that I have done it before but I couldn't have.
   
   I disagree with Lurker's assertion "This is certainly not some kind of supernatural event. There is no such thing."
   
   That's not for him to say or to know. No one can know with certainty the non-existence of a thing, especially if you don't bother to define the thing you believe does not exist. He can only say that for HIM there is no supernatural. For me, there is, but like this deja vu thing, isn't really amenable to testing.
   
   However I think Lurker is more likely correct that the visual cortex has already processed the image and placed it in storage before conscious perception takes place, such that when conscious perception DOES take place it feels like you have done this exact same thing before and yet not really *before*, it is more like a peek into an alternate universe in real time.
   
   

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5. 5. mggordon 07:37 PM 6/6/12

   I am surprised not more association is made between deja vu and supernatural, other than Lurker's assertion there is no such thing.
   
   When I was stationed in Iceland about to go on an adventure to Gulfoss, I had a vision of my roommate suddenly turning and walking toward the waterfall, but slipping on ice and falling in. On a grey day the slope of the ice is impossible to discern. I insisted as a condition of him going, that when the time came that I told him to stop, that he would instantly and unquestioningly obey for his life would depend on it.
   
   Sure enough, after some time at the waterfall, on the flat area on the west side of the river, out of the corner of my eye I saw him suddenly turn like a robot and start to walk closer to the edge. Now to explain; this is in winter, water spray freezes to the lava cliffs and wet ice is incredibly slippery and being also very smooth and featureless, impossible to discern slope. I said "stop", he did, and I walked in front of him. I was wearing crampons so it was relatively safer for me. I turned around from about ten feet in front of him and was looking at about his kneecaps. Then another 30 feet or so of level ice, then it drops down into the mid-atlantic rift which is what Gulfoss actually falls into. One more step and he would have started sliding toward his death with no way to stop it.
   
   This is a fact, not deja vu, he knows it and I know it and maybe so do some others because I didn't care what people thought of me then and not a lot right now. It is arrogant for the blind to assert that others cannot see.

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6. 6. jtdwyer 08:08 PM 6/6/12

   I generally agree with the earlier commentators - that the sensations were very clear. I've not had any such experiences in many years, but those I most clearly recall from my teenage years had no visual or even audible component (in terms of specific frequencies or patterns, etc.): it was solely the sensation of having a premonition of a dialog among several people; the feeling that I knew in advance exactly what would be said next by whom (deja entendu?).

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