What causes déjà vu? The quirky neuroscience behind the memory illusion

According to extensive research, the younger population experiences more déjà vu, and as one gets older, the noticing of errors becomes less frequent. This is a natural part of ageing.

There are cases where people are persistently experiencing the feeling of Déjà Vu. The cause can be taking a mixture of medications that can have unpredictable side effects, as in some documented cases.

A lesser-known feeling is Jamais Vu or ‘never seen’. It is essentially failing to recognize or remember a situation that should be familiar to us. This is different from standard forgetting, like amnesia, but is a momentary lapse of awareness of the familiar.

What’s intriguing is that it has the same characteristics:

1. It is a disorienting feeling.
2. It happens more to young people.
3. It is more likely to happen when one is tired.

An experiment to prompt the feeling of Jamais Vu involved writing a familiar word like apple or door, constantly on a piece of paper for a few minutes. 70 percent of the participants began to doubt the spelling or the authenticity of the word.