KnowHow team explains: Déjà vu (French for “already seen”) describes the experience of feeling that one has been through a particular situation previously. The term was coined by French psychic researcher, Émile Boirac, in his book L’Avenir des sciences psychiques (The Future of Psychic Sciences).

An absolute sense of familiarity and eeriness accompany déjà vu. The “previous” experience is most frequently attributed to a dream, although in some cases there is a firm sense that the experience “genuinely happened” in the past. Déjà vu has been described by some as “remembering the future”.

Experiencing déjà vu is a very common phenomenon. Studies indicate that most people have experienced this phenomenon at least once in their lifetime. However, it has been extremely difficult to invoke the déjà vu experience in laboratory settings, therefore making it a subject of few empirical studies. Recently, researchers have found ways to recreate this sensation using hypnosis.

In recent years, déjà vu has been subject to serious psychological and neurophysiological research. Based on these researches, the most likely explanation of déjà vu is that it is not an act of prophecy, but rather an anomaly of memory. This explanation is substantiated by the fact that the sense of recollection at the time is strong in most cases, but that the circumstances of the previous experience (when, where and how the earlier experience occurred) are quite uncertain. The phenomenon occurs perhaps due to an overlap between the neurological systems responsible for short-term memory (events which are perceived as being in the present) and those responsible for long-term memory (events which are perceived as being in the past).

However, those believing in reincarnation theorise that déjà vu is caused by fragments of past-life memories being jarred to the surface of the mind by familiar surroundings or people.