The Science Behind Deja Vu
Person Holding A Photograph Of Himself

The Science Behind Deja Vu

Becky Milligan June 18, 2022

At some point in our lives, we’ve all had that sensation during a certain moment where we remember being in that exact situation before. This phenomenon is named ‘deja vu’; a French term that translates to ‘already seen’. During an episode of deja vu, your surroundings will seem oddly familiar, including the conversations you’re having, the people you are with, and where you are. It may feel like you’ve had the exact same conversation twice with the exact same people. It’s a strange, yet interesting, and common phenomenon.

Who gets deja vu?

Research suggests that approximately 66% of healthy people have experienced deja vu at some point. There are factors that can make you more likely to experience it, including being between the ages of 15-25, travelling more, having more education, and being able to remember most of your dreams. There are also suggestions that deja vu is more common amongst students, with stress or tiredness being among the factors that increase the likelihood of experiencing deja vu.

Generally, deja vu is harmless to most. It should, however, be taken more seriously in people with temporal lobe epilepsy, as many of these patients report experiencing deja vu right before an epileptic seizure occurs.

The science behind deja vu

Most of the scientific evidence, including epilepsy patients, points towards the key involvement of memory. The temporal lobes, located behind the ears on both sides of the head, are largely responsible for encoding memories.

Illustration of human head profile and graphic brain

Research suggests that deja vu occurs due to split attention during a situation. This results in incomplete storage of the environmental information in your memory. So, when you encounter a similar situation, your brain reminds you about the previous situation. However, since fragments of the information are missing, it tricks you into believing the whole situation is familiar. Therefore, it feels as though you have been in the exact same situation before when it is really just the consequence of improper memory encoding.

The conspiracy theory alternatives

The science behind deja vu is not the only cause that people believe. Many people have shared their conspiracy theories on the internet as to why we experience deja vu. One of my favourite deja vu conspiracy theories is that we are experiencing a situation that our grandparents experienced. Another popular one is that we are remembering a situation that we have experienced in a past life already. There are many more conspiracy theories of deja vu, and they’re all pretty interesting to think about.

The takeaway message

Deja vu is common and occurs more frequently in younger people. It is a harmless psychological phenomenon that is the result of improper memory encoding in the temporal lobe, supported by people’s experiences of deja vu in relation to temporal lobe epilepsy. If science isn’t your thing, the conspiracy theories of deja vu suggest perhaps more compelling reasons for its occurrence. Researchers are still studying deja vu and its causes, so it is nice to have some theoretical causes behind it too.

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Becky Milligan is a Freelance Writer for Freshered and a Lead Generator for PROP by GRV Media. The main focus of her articles is mental health, as she strongly believes in reducing the stigma surrounding mental health for university students through education. She also shares stories about her personal university experiences and gives advice for university living. She currently studies Psychology at the University of Sussex and volunteers for Shout 85258. She is an avid animal lover, with two rescue cats called Smudge and Oreo, and she loves to dance and sing in her free time.