Moments where the current situation seems to be happened before but somehow we don’t have a clue that where has that event occurred before. Scientifically it is difficult to study déjà vu’s cause because there is no reliable way which may cause it in people’s minds to happen but hypnotism may help in examination and study of déjà vu
Apparently déjà vu is somehow related to brain development because it was noted that déjà vu is firstly experienced by kids in the age of 8-10 years and it is increased substantially in the teens and reduces in the later age.
Déjà vu may be caused to a slight disconnect or unsynchronized parts of brain handling the conscious part and the unconscious part. When the body is in an environment and perceiving information regarding the surroundings, the brain unconsciously collects information and sends it to part of brain which stores that data. Meanwhile the conscious part collects the same information leading to duplicate information which might occur to us like we have already been in this current situation thus leading to déjà vu.
Presque vu (tip of the tongue)
It’s the phenomenon when sometimes when we try to recollect a very familiar thing, but somehow unable to recall it. One possible explanation is that, when we try to recall the target word, other words similar to it are remembered, but your brain blocks out these words to help you out, and in this case the required word is also blocked along. This leads to the inability to recall that word or piece of information, despite being very common and familiar to you.
This is when something you already know about suddenly seems to be brand new and bizarre. Most of the people have already experienced jamias vu. For instance when you a certain activity like speaking or writing a word over and over again, that word seems to lose it meaning and you think how this be even be a word. It is believed that continuously exciting neurons responsible for that word make them inhibited and the further use is less intense.
Image Credits: Anonymous