Question: what is the scientific explanation for de ja vu

Wilhelmiina Toivo answered on 12 Mar 2017:

This is a very interesting question! 🙂 There are two types of déjà vu: the pathological type (in this case, it usually happens to people who have epilepsy), and the type of déjà vu healthy people get. It has been estimated that about 60% of people have experienced deja vu.

Psychologists still haven’t found a clear answer to why déjà vu happens – there are many possible explanations. According to a review paper of a lot of previous studies on déjà vu, there are 4 categories of explanations for it: dual processing (this means two brain processes are out of synchrony for a moment creating a feeling of déjà vu), neurological (it can happen because of a seizure, or a problem in how your neurons communicate to each other), memory (the thing causing deja vu is really similar to something you have seen before, but you cannot correctly remember what it is and this is why you get a feeling of familiarity), and attentional (this happens when you first don’t pay attention to something properly, and once you do, it feels familiar because your perception has already registered it, even though you did not pay attention to it consciously). In addition to this, some scientist think there is a dream explanation to déjà vu – you feel something is really familiar to you because you have dreamt about it. There has also been some evidence that déjà vu can be linked to stress and tiredness.