Déjà vu is one of the oddest sensations we often experience is the feeling when we are in a complete new environment but get an intense feeling of familiarity. We feel like we have been reliving a past experience without any apparent reasons. In French, déjà vu is called as “already seen”. This experience is really hard to explain as it makes us remember something that slips away before we fully get a hold of it. This is a feeling that has puzzled researchers as how to replicate it in a laboratory environment. A few theories have come forward over the time on explaining how the human brain acts in an extremely strange manner.

Accidental trigger in the brain:

In 2006, researchers recruited 18 volunteers who were asked to look at 24 common words. The sensation was recreated in a lab by hypnotizing them and telling them when they were presented with a word in a red frame, it would make them feel familiar to it. The word was though to belong to original list of 24 presented in a green frame. Once the subjects were taken out of hypnosis, they were presented with a series of words in frames of different colors. These frames also included the ones that didn’t appear in the digital list. Among the participants of the group, ten felt a particular sensation by looking at the new words in red frames whereas only five approved of having the feeling of déjà vu.

Malfunctioning memory:

Another different theory for déjà vu explained by the psychologists is that there can be some sort of malfunctioning between the long term and short term circuits in the brain. It means that the new information my take a shortcut directly to the long-term memory. In this process, the mechanism that brain usually uses to store all the information, is skipped and makes us feel we are experiencing something from the past.

The researchers also explained that it might have to do something with the rhinal cortex that is an area of the brain that makes us feel the familiarity. It can be triggered in any way and explains the déjà vu is feeling of vague familiarity not specific to any person or object.

A memory mismatch:

According to psychology researcher Akira O’ Connor, the false memory could be a sign that the brain is checking its memory. The researcher along with the team scanned the brains of 21 volunteers and performed a common test for triggering the false memories. Every person was given a list of related words like bed, nap, snooze, etc. Then they were asked about the words afterwards and in this case it was “sleep”. The researchers presented the findings as the frontal regions of the brain could be flipping through the memories. It then sends signals when there is a mismatch between our thoughts and experiences and what we have actually experienced. The regions of the brain that are associated with memory conflict are considered to be driving the déjà vu experience.

Via: Business Insider