Have you ever felt like you’ve been somewhere before, even though you know you haven’t? That’s déjà vu! It’s that strange feeling when a situation seems oddly familiar. Imagine you’re at a restaurant, and everything feels like a scene you’ve already experienced, even though it’s your first time there. So, what’s happening?
Unfortunately, there’s no single explanation for déjà vu. It’s a quick and unexpected feeling, making it tough for scientists to study. They can’t just wait around for it to happen because it might take years. Since it doesn’t have any physical signs, it’s mostly described as a sensation. Because of this, there have been many guesses about what causes it. Since the term déjà vu, meaning “already seen” in French, was introduced by Emile Boirac, over 40 theories have tried to explain it. However, with new technology and research in brain science, we’re getting closer to understanding it.
Let’s explore three popular theories about déjà vu, using a restaurant scene as an example.
Imagine a waiter drops a tray of dishes. Your brain quickly processes everything: the waiter’s movements, his shout, and the smell of food. Usually, your brain records all this information at the same time. But according to this theory, déjà vu happens when there’s a tiny delay in processing. If one piece of information arrives late, your brain might think it’s a separate event. When it overlaps with the moment you just experienced, it feels like it happened before because, in a way, it did.
Now, look at the tablecloth. As you notice its pattern, a distant memory might pop up. This theory suggests that memories are stored like holograms, where a small piece can bring back the whole picture. Your brain might connect the tablecloth to one from your past, like at your grandmother’s house. Instead of remembering where you’ve seen it, your brain just gives you a sense of familiarity without the details. So, even though you’ve never been to this restaurant, the tablecloth feels familiar.
Focus on a fork for a moment. This theory says that déjà vu happens when your brain takes in the surroundings while you’re distracted by something specific. When you shift your attention back, it feels like you’ve been there before. For example, while you were focused on the fork, your brain was still recording everything else, like the tablecloth and the waiter. When you finally notice them, it seems familiar because your brain already took it all in without you realizing it.
While these theories share some ideas about déjà vu, none of them fully explain it. As researchers continue to study this mysterious feeling, you can explore it yourself. The next time you experience déjà vu, take a moment to think about it. Were you distracted? Did something seem familiar? Was your brain just processing slowly? Or is it something else entirely?
Keep a journal for a week and note down any instances of déjà vu you experience. Describe the situation, your surroundings, and any familiar elements. Reflect on which theory might explain your experience. This will help you understand how déjà vu might occur in your daily life.
In groups, create short skits that illustrate each of the three theories of déjà vu. Act out a scene where someone experiences déjà vu and explain which theory is being demonstrated. This activity will help you visualize and better understand the different explanations for déjà vu.
Conduct a simple experiment where you focus on a specific object in a room for a minute, then close your eyes and try to recall other details in the room. Discuss how divided attention might lead to a sense of familiarity, similar to the Divided Attention Theory. This will give you insight into how your brain processes information.
Choose one of the 40 theories about déjà vu not covered in the article. Research it and prepare a short presentation for the class. Explain the theory and how it attempts to explain déjà vu. This will broaden your understanding of the various scientific perspectives on déjà vu.
Write a short story where the main character experiences déjà vu. Use one of the theories to explain their experience within the story. This will allow you to creatively apply your understanding of déjà vu and its theories.
Have you experienced déjà vu? It’s that peculiar feeling you get when a situation seems familiar. A scene in a restaurant plays out exactly as you remember, but the sequence can’t be based on a past experience because you’ve never eaten here before. This is the first time you’ve had clams, so what’s going on?
Unfortunately, there isn’t one single explanation for déjà vu. The experience is brief and occurs without notice, making it nearly impossible for scientists to record and study it. Scientists can’t simply wait for it to happen to them — this could take years. It has no physical manifestations, and in studies, it’s described by the subject as a sensation or feeling. Because of this lack of hard evidence, there’s been a surplus of speculation over the years. Since Emile Boirac introduced déjà vu as a French term meaning “already seen,” more than 40 theories have attempted to explain this phenomenon. However, recent advancements in neuroimaging and cognitive psychology have narrowed down the field of prospects.
Let’s walk through three of today’s more prevalent theories, using the same restaurant setting for each.
First up is dual processing. We’ll need an action — let’s go with a waiter dropping a tray of dishes. As the scene unfolds, your brain’s hemispheres process a flurry of information: the waiter’s flailing arms, his cry for help, the smell of pasta. Within milliseconds, this information zips through pathways and is processed into a single moment. Most of the time, everything is recorded in sync. However, this theory asserts that déjà vu occurs when there’s a slight delay in information from one of these pathways. The difference in arrival times causes the brain to interpret the late information as a separate event. When it plays over the already-recorded moment, it feels as if it’s happened before because, in a sense, it has.
Our next theory deals with a confusion of the past rather than a mistake in the present. This is the hologram theory, and we’ll use that tablecloth to examine it. As you scan its squares, a distant memory surfaces from deep within your brain. According to the theory, this is because memories are stored in the form of holograms, and in holograms, you only need one fragment to see the whole picture. Your brain has identified the tablecloth with one from the past, maybe from your grandmother’s house. However, instead of remembering that you’ve seen it at your grandmother’s, your brain has summoned up the old memory without identifying it. This leaves you with a sense of familiarity, but no clear recollection. Although you’ve never been in this restaurant, you’ve seen that tablecloth but are just failing to identify it.
Now, look at this fork. Are you paying attention? Our last theory is divided attention, which states that déjà vu occurs when our brain subliminally takes in an environment while we’re distracted by one particular object. When our attention returns, we feel as if we’ve been here before. For example, just now you focused on the fork and didn’t observe the tablecloth or the falling waiter. Although your brain has been recording everything in your peripheral vision, it’s been doing so below conscious awareness. When you finally pull yourself away from the fork, you think you’ve been here before because you have; you just weren’t paying attention.
While all three of these theories share common features of déjà vu, none of them propose to be the conclusive source of the phenomenon. Still, while we wait for researchers and inventors to come up with new ways to capture this fleeting moment, we can study the moment ourselves. After all, most studies of déjà vu are based on first-hand accounts, so why can’t one be yours? The next time you experience déjà vu, take a moment to think about it. Have you been distracted? Is there a familiar object somewhere? Is your brain just acting slowly? Or is it something else?
Déjà vu – A feeling that you have already experienced something that is actually happening for the first time. – During the science experiment, I had a strong sense of déjà vu, as if I had already been in that exact situation before.
Sensation – The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. – The sensation of the cold wind on my face reminded me of the winter days spent studying in the library.
Theory – A well-substantiated explanation of some aspect of the natural world that is based on a body of evidence and that can be tested and verified. – In psychology class, we learned about the theory of cognitive development proposed by Jean Piaget.
Memory – The faculty by which the mind stores and remembers information. – My memory of the science fair project helped me explain the experiment to my classmates.
Brain – The organ inside the skull that controls thought, memory, feelings, and activity. – The brain is responsible for processing all the information we receive from our senses.
Processing – The act of taking in information, analyzing it, and making sense of it. – The brain’s processing of visual information allows us to recognize familiar faces quickly.
Familiar – Well-known from long or close association. – The familiar sound of the school bell signaled the end of the psychology class.
Attention – The act of concentrating on a particular object, task, or activity. – Paying attention in science class helped me understand the complex concepts better.
Experience – The knowledge or skill acquired by observing, encountering, or undergoing something. – My experience in the biology lab taught me how to conduct experiments safely and accurately.
Research – The systematic investigation into and study of materials and sources in order to establish facts and reach new conclusions. – The research conducted by the students revealed new insights into the effects of sleep on memory retention.
