You’ve probably experienced déjà vu at least a few times in your life and wondered, “What just happened to me?” Déjà Vu’s meaning comes from the phrase “already seen” in French, and occurs when we feel like a person, place, or thing is familiar to us without actually having experienced them before.

This strange phenomenon happens to as much as seventy percent of the population. However, 15 to 25-year-olds experience it more than any other age group.

Maybe you’ve driven down a road in a foreign country before, and it just felt very familiar to you. That is deja vu. Indeed, it’s the knowledge of “I’ve been in this place before”.

Logically, however, you know you haven’t. But while that is the term’s literal meaning, that doesn’t explain what it is or why it happens.

So, what does deja vu mean? We’ll get into all the details so you’ll have a deeper understanding of it the next time it happens to you.


signs of deja vu

While different people experience it differently, the phenomenon’s meaning remains universal. Scientists have even begun researching the sensation because so many people experience it. So, they wanted to gain more insight into what causes it.

One study by Akira O’Connor and his team at the University of St. Andrews, UK, found that deja vu occurs so that we can ‘check’ our memories. To test the phenomenon, O’Connor and his team found a way to trigger the feeling of deja vu in the lab.

To conduct the study, O’Connor and his team first found a way to trigger ‘false’ memories. They would tell the participants a list of related words – such as bed, pillow, night, and dream – but leave out the one word linking them together; in this example, sleep. When the team quizzed the participants later about the words, many believed they heard “sleep,” which would be a false memory.

To recreate the feeling of deja vu, O’Connor’s team asked the participants if they had heard any words beginning with the letter ‘s.’ They said they hadn’t. Later, when asked if they had heard the word “sleep,” they remembered that they couldn’t have. Still, the word still felt familiar. “They report having this strange experience of déjà vu,” says O’Connor.

The team used fMRI to do brain scans on the 21 volunteers while they experienced the sensation. You might have expected that area of the brain that sorts memories, like the hippocampus, would become active during this phenomenon. But this surprisingly didn’t happen. O’Connor’s team discovered that frontal areas of the brain involved in decision-making became activated instead.

He believes this occurs because the brain’s frontal regions are likely sorting through our memories and sending signals if there’s a memory error. This would create a conflict between what we’ve experienced and what we BELIEVE we’ve experienced.

“It suggests there may be some conflict resolution going on in the brain during déjà vu,” says Stefan Köhler at the University of Western Ontario in Canada.


The study suggests that deja vu is just a part of having a healthy memory-checking system. In fact, people who experience deja vu more often are less likely to forget the details of important events.

This would explain why more young people experience this phenomenon since memory tends to decline as we age. “It may be that the general checking system is in decline, that you’re less likely to spot memory mistakes,” says O’Connor.

Christopher Moulin at Pierre Mendès-France University in Grenoble says the study results don’t look too promising for people who have never experienced deja vu. “Without being unkind, they don’t reflect on their memory systems,” he says.

On the other hand, people who don’t experience this feeling may have a better memory in the first place, says O’Connor. He says that if they aren’t misremembering events, deja vu won’t become triggered.

Köhler says they still don’t know if deja vu benefits the brain. He says this:

“It could be that déjà vu experiences make people cautious, because they might not trust their memory as much. But we don’t have any evidence for that yet.”

deja vu

While some people believe that deja vu’s meaning is related to past life experiences, no one can really confirm this. However, it is still an interesting idea nonetheless. And if it proves true, it could allow us to learn about ourselves much deeper.

Have you ever had deja vu? Let us know in the comments!