You've probably had déjà vu at some point, that feeling that you've already experienced a situation you are living through right now before this point in time.
Of course (as with pretty much anything), there are people who have put this weird feeling down to a supernatural explanation. Nope, sorry, experiencing déjà vu does not mean that you have predictive powers. In fact, scientists have already tested that out just for the hell of it.
In that experiment, the researchers used virtual maps made in the video game The Sims, allowing participants to explore them. Some of the models had the same basic layout (see below) but with different skins, such as a junkyard or a regular back yard.
When the participants went around environments that they'd been through before (albeit under a different skin), they were more likely to report a sense of déjà vu. The study, published in Psychological Science, looked at whether this sense of déjà vu would actually help participants to navigate their way around a maze.
It did not.
The phenomenon of déjà vu is very much in your brain. In a very succinct video, popular TikTok doctor Dr Karan Raj explained one of the theories as to what the phenomenon is: essentially "sloppy admin" as performed by your brain.
"It's a glitch in your brain," he explains in the video. "It's when a new short term memory gets accidentally stored in the long term memory, so it feels like it's happened before because our brain is telling us it's an old memory."
There are several other theories about what déjà vu is, though most involve memory. As the Sims experiment implied, it could be that déjà vu is a memory problem, where we encounter a situation that is similar to a previous memory that we can't quite recall, causing a strange sense of familiarity.
As Dr Raj explains, it's also possible that it's caused by new information being "misfiled" into long-term memory rather than short-term, making us feel like it's a memory from further back rather than what's happening now.
For now, more study is needed before we can say for sure what the phenomenon actually is. Though whatever it is, Dr Raj is right to say it's a glitch in your brain.