Scientists are coming closer to understanding the mystery that is déjà vu, an experience that is often hard to explain, making it feel almost supernatural. Although roughly two-thirds of people have experienced déjà vu at some point in their life, the paranormal concept was not explored until the late 1800s and has left philosophers and neurologists completely stumped until now...
Déjà vu, meaning "already seen" in French, is when you feel like you have experienced a situation before it already happened, almost like you are reliving an exact situation. This paranormal feeling prompted many theories on what it could mean and how it could happen, but back in the 19th century, people equated déjà vu to some sort of a brain problem or mental dysfunction. Scientists only more recently began exploring the topic, specifically Alan Brown, who reviewed everything related to the topic from previous researchers. From the material, Brown was able to determine that déjà vu is most commonly triggered by a specific place or a scene and, after that, a conversation.
Due to Brown's findings, many scientists began further exploring the virtually untouched subject. Researcher Anne Cleary began conducting various experiments to identify the width of different déjà vu hypotheses but focused on the Gestalt familiar hypothesis. This suggested déjà vu can happen when there is a spatial resemblance in someone's memory and a person's current environment. Cleary provides the example of visiting a hospital you've never been to before and passing by the nursing station; when you get the sudden déjà vu feeling. The experience could come from the scene's layout, like the placement of the objects and furniture in the nursing station and the associated feeling with it. The Gestalt familiarity hypothesis indicates that if the previous situation with a close layout to the current one doesn't come to mind initially, one may develop the intense feeling of familiarity with the current one.
Cleary's team decided to investigate this theory by using virtual reality to place people within scenes in order to control their environment. Some scenes showed the same spatial layout, while others were different, but the outcome indicated déjà vu was more likely to happen when people were in scenes with the same spatial scenarios they saw but did not recall.