Question: What is déjâ vu?

Alex Reid answered on 15 Nov 2018:

Déjà vu is a feeling of familiarity and translated from French roughly means ‘the feeling of having “already lived through” something’. Basically it is a feeling of recollection but in quite a specific way. Déjà vu is also very difficult for us to study as psychologists. As a science we need things to measure, and as you can image it is hard to pin this sensation down. People might only experience it naturally a handful of times in their lives! There are a few educated guesses as to why it happens though. For example the most likely reason may be due to a slight delay in coordination between the two hemispheres (halves) of your brain. As such you experience things ever so slightly twice, which then leads to this eerie sense of recollection. This is speculation though, and I am not sure how you might actually measure déjà vu it under controlled circumstances (i.e. in a laboratory).