Have you wondered if this moment has happened already? You are standing at a particular spot, feeling like you have previously been here. Do you feel like it is not your first time experiencing a situation? Don’t worry. This spooky sensation is called ‘déjà vu.’ It is a French phrase that means ‘already seen.’ Sounds creepy right? But can there be a scientific explanation behind déjà vu?
Déjà vu feels paranormal and creepy, to say the least. This perplexing phenomenon is short-lived but we can recall it vividly, it is odd. Déjà vu is common as 60% of the population have experienced it. The term was coined in 1876 by a French philosopher and investigator, Emile Boirac. Sigmund Freud even came up with a theory that déjà vu could be prompted by our repressed desires.
Scientists Try To Decode Déjà Vu
There is no perfect explanation to determine how it is caused. Some scientists thought the event had occurred and we forgot about it but suddenly remembered it later. Others thought there could be a processing error in our brain where two elements have been operating simultaneously so there is a step missing in between.
The theory of ‘attentional explanation’ suggested that we might not pay attention to what is happening around us so the moment we are distracted for a split-second; the focus on what is happening disappears. So when we re-focus, it may feel oddly familiar but it happened in the past.
A study in 2017 on Memory found that déjà vu shows activity in the anterior cingulate cortex, medial prefrontal cortex, and parietal cortex which all deal with memory conflicts. Another study in 2013 on Epilepsy & Behaviour Case Reports suggests that EEG patterns of people with and without epilepsy experience déjà vu differently which makes us even more curious.
More Experiments, Fewer Answers
Scientists tried long and hard to understand the phenomenon and suspected it to be a memory phenomenon. They assumed that we encounter a situation that is similar to our memory but we cannot fully recall it. Our brain is scrambled between memory and reality and we are left with a feeling of familiarity. There a lot of theories on why we feel this way- some have blamed it on the rhinal cortex which sends the signals to the brain when we feel something familiar. It could have gotten triggered by not letting the memories back up.
Another theory by scientists is that there is a circuit of the brain leading to long-term to short-term memory and the new information without being processed goes to long-term without making a stop at short-term.
Déjà vu is often associated with false memories. Researchers have thought that déjà vu could be a feeling when you cannot differentiate between a dream and reality. One study used Magnetic Resonance Imaging (fMRI) to scan 21 patients to put them in a lab-induced déjà vu. Did it work? Not really. The hippocampus of the brain did not detect the feeling of false memory. They found the affected area of the brain was the decision-making. So, they came up with a theory that déjà vu would occur when we face a conflict over whether an experience happened or not.
Déjà What- Pop culture and Spooky Experiments!
Scientists have been intrigued with this phenomenon and even tried using hypnosis and virtual reality to get a sense of it. In 2006, the Leeds Memory Group conducted a study trying to create a memory for the subjects under hypnosis. The patients were asked to remember a colour or a word, nothing too hard. They could either forget or remember it but it would trigger a sense of déjà vu with the word.
Scientists even tried using virtual reality- where they created a scene on purpose where it would spatially end up on the Sims Video game. The study reported that the patients experienced a déjà vu while playing it as the layouts were the same but the objects in it were replaced.
Déjà vu is often suggested as something that gives a glimpse of the future which makes us feel like we can predict what will happen next. There is a possibility that there are different kinds of déjà vu depending on the situation.
This eerily feeling strikes mostly young people between the ages of 15 to 25. In the UK, scientists found a man in his 20s who suffered ‘chronic déjà vu.’ He felt he was reliving the experience for minutes at a time. He felt more trapped than those movies where a person keeps reliving the same day again and again.
However, there is still no specific scientific understanding of this phenomenon. In The Matrix Trilogy, Carrie-Anne Moss defines it as part of a simulated reality to keep humanity unaware of intelligent machines. Spooky much? Do you think Deja Vu is real?