Have you ever experienced a wave of familiarity that washes over you like a cold shower? A feeling that’s known yet unknown all at the same time? Those strange and usually rare instances when the present moment feels like the past. That abrupt and acute sense of familiarity – however improbable – is a phenomenon known as déjà vu.

It’s a fleeting sensation that can be unsettling and overwhelming all at once. It happens when you suddenly feel like you’ve been somewhere before, even though you know that you haven’t. The eerie feeling of déjà vu, French for “already seen,” is very common – approximately two thirds of people report that they have experienced this sensation. Déjà vu is especially prevalent in younger people, particularly between ages 15-25. 

How can this make sense? Logically you know that you haven’t had this specific experience before… but your brain is telling you otherwise! This makes déjà vu hard to interpret, and even more difficult to analyze. This peculiar awareness is what makes déjà vu as fascinating as it is bizarre. 

Why Does Déjà Vu Occur? 

There has been speculation that déjà vu is the product of remembering a past life or experiencing the remnant of an intense dream. 

Some people have precognitive dreams, having the present moment feel like a repeat of the past, and mistake this as déjà vu. However, precognitive dreams are defined as dreams that include knowledge about the future – so essentially where dreams can seemingly predict the future. Most of us experience déjà vu without any relation to a dream. 

Déjà vu is also different from a vision. A vision is when something seems familiar because you remember having seen or experienced it before. But with déjà vu, you have no idea why something seems familiar because you don’t remember seeing or experiencing it at all.

People in ancient times believed déjà vu to be of mystical nature – a kind of premonition. However, a premonition differs from déjà vu as it involves an emotional response that predicts a future event. Unlike a premonition, the feeling of déjà vu occurs much too commonly to dismiss it as pseudoscience. 

Whatever this ‘glitch’ in our brains might be, there are a few theories and studies conducted in attempts to explain why this anomaly happens. Psychiatrists, neuroscientists, and psychologists have been interested for centuries in studying déjà vu. Modern day scientists believe déjà vu to simply be our minds playing a trick on us. 

The Science Behind Déjà Vu… 

The human brain is strange and unpredictable – which makes experiences such as déjà vu hard to study! Scientists explain the concept of déjà vu through subtle disparities between certain memory processes in our brain. 

Let’s dive a little deeper into the basics of neuroscience on memory, and how this relates to déjà vu. All of our memories are stored in an area of the brain called the temporal lobe. Especially our long-term memories, events, and facts that we know occupy this area of the brain. Certain parts of our temporal lobe also play a role in recognizing something as familiar. 

While it’s not completely proven that there is an association between déjà vu and the temporal lobe, due to a lack of research, there has been some headway leading scientists to draw a connection.

This connection was found from people who suffer with temporal lobe epilepsy – a condition where the nerve cell activity is distributed, causing a seizure – and reports of déjà vu being experienced right before this seizure. Since the temporal lobe controls memory, the discrepancy of déjà vu has indicated to researchers that there is a link between the temporal lobe and this mishap in our memory. 

So why do others experience déjà vu then? Well, it was found that people who are tired and stressed may be more prone to déjà vu, as both of those factors cloud short and long-term memory. When your memory is impacted, this happens in the temporal lobe, which could possibly lead to a feeling of déjà vu.

What Does Déjà Vu Signify? 

In all of its ambiguity, déjà vu is still a perplexing phenomenon that has not yet been fully explained. This sixth sense is often described as “familiarity without awareness.” Generally, déjà vu is left unexplained and is described in a vague sense, often as simply as “Wow, I just got the strangest feeling of déjà vu.” Because it is so difficult to research and seems to have no deleterious effects on daily and long-term nervous system functioning, déjà vu is left up for interpretation. 

Megan Binder (B.A. Psychology)  

References

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Johnson, J. (2008, March 01). I could swear i’ve been here before… Retrieved March 06, 2021, from https://serendipstudio.org/exchange/llamprou/i-could-swear-ive-been-here

Kate Stanton, U. (2021, February 24). What is déjà vu? What is déjà vu? Retrieved March 06, 2021, from https://pursuit.unimelb.edu.au/articles/what-is-deja-vu-what-is-deja-vu

Murphy, T. (n.d.). Spirituality and the brain. Retrieved March 06, 2021, from https://www.god-helmet.com/wp/dejavu.htm

Schredl, M. (2009). Apapsycnet. Retrieved March 06, 2021, from https://psycnet.apa.org/record/2009-10466-00