In A Nutshell
Scientists have been wondering since at least the 19th century: What’s the deal with deja vu? Research now suggests that it’s the result of a miscommunication in the brain, occurring when you see something that has a familiar pattern that you can’t quite place, or a location you might have seen in a book, online, or in a movie. Other theorists say that deja vu happens when parallel universes temporarily sync, and that it’s an indication that you’re experiencing the same thing somewhere else.
The Whole Bushel
It’s that strange, unnerving feeling that we’ve lived through something before, been somewhere before, even had the same conversation before. It happens to most people rarely, but sometimes, it comes with such a powerful, overwhelming feeling that we’ve been in a certain place before, heard certain things before, and smelled certain smells before that it can make a person believe that they actually have been through an event before, whether it was in this life or another.
And it’s one of those weird brain hiccups that science still can’t explain entirely, although there have been some pretty neat theories.
Researchers at Colorado State University have found that they can actually cause people to have feelings of deja vu under carefully controlled circumstances, and they did it using video games.
Using The Sims as a layout editor, the researchers created a town of structures that they had volunteer students view. The rooms and buildings weren’t random, they had been carefully designed to share certain elements like layout, patterns, graphics, and artwork.
Results were interesting. If they layouts were too similar, the students could recognize them as having the same features as another room they had already looked at. But if they were only vaguely similar, with a more carefully disguised pattern, they would create a feeling of deja vu.
This suggests that deja vu actually involves a memory malfunction, and it’s triggered when you’re looking at something similar to something you’ve seen before, but you just can’t place it. It’s thought that deja vu that happens when you’re visiting a place means that you might have seen it before, but you don’t remember it; it may have been the setting of a movie, a set of pictures you saw online. There’s a sense of familiarity, but it’s not familiar enough that your brain can make the connection between the place and where you’ve seen it before.
A similar theory suggests that it’s caused by glitches in the way our brains process information, specifically information that passes through perception and memory. This one is supported by the number of people who suffer from epilepsy reporting higher-than-average occurrences of deja vu. Once the epilepsy and the seizures are managed, the occurrences of deja vu decrease, suggesting there’s a connection between the way the brain interprets images and what it thinks it remembers.
And, of course, there are always the fringe theories.
One fringe theory says that deja vu happens when two universes, normally separate, are temporarily in sync.
Theoretical physicist Dr. Micho Kaku explains the idea that multiple universes coexisting and—briefly–coming together to create the feeling of deja vu is complicated, highly unproven, but perhaps, occasionally, possible but doubtful. The idea of multiple universes is an accepted one; we’re surrounded by them all the time. We’re made up of waves, and waves vibrate on different frequencies—we can only see and experience those that are on the same frequency as we are.
The example he gives is that occasionally, your radio might pick up two stations at once. It’s rare, but it does happen. And the multiverse explanation of deja vu suggests that when this happens on a larger scale, it results in two normally separate universe falling in sync.
Possible, perhaps . . . but Dr. Kaku also says that deja vu is more likely a misfiring, misremembering brain picking out bits and pieces of knowledge and memories that it’s not sure where it found.
Sorry, fringe theorists.
Show Me The Proof
Smithsonian: Wait, Have I Been Here Before? The Curious Case of Déjà Vu
Scientifici American: Been There, Done That—or Did I?: Déjà Vu Found to Originate in Similar Scenes
What is Deja Vu? Dr. Kaku’s Universe—Big Think