The term “déjà vu” is French and translates to the phrase “already seen”. When we have a “déjà vu” experience it seems like the whole event, even the smallest details, has happened before even though we know that the event is unique and is happening at the moment. This experience is usually frustrating and often accompanied by a feeling of unreality. Most people experience a “déjà vu” at some point of their lives and many of them have had it more than once.
According to a certain research, patients with epilepsy repeatedly experience “déjà vu” as opposed to people who do not have the disease. According to other research, in such moments, something new in the situation triggers memories of a similar event in the past, but our brain fails to remember. The “déjà vu” feeling itself is very unusual and strange. You feel as if you did the same thing before, but for some reason you cannot think what it was. The feeling is neither negative nor pleasant. This effect usually occurs between the ages of 15 and 25 years, although it occurs in people of all ages.
Sigmund Freud, the father of psychoanalysis, claimed that when “déjà vu” occurs, the person experiencing it is spontaneously reminded of every unconscious fantasy. While according to Herman Sno, one of the leading experts on the subject, “déjà vu” experiences occur when a current situation coincides with hazy image of a past event. It is as if you convince yourself that you know a person you have seen on a vague image recorded by a security camera. Another possible theory is that the brain is confused with the situation in reality, at the expense of a certain experienced in a dream. Also, “déjà vu” can be explained in terms of global patterns of overlapping memory. According to these models the situation may seem familiar because one of the following two reasons. The first reason is that the situation is very similar to a certain event in our memory. However, a situation may seem familiar if it is moderately similar to many other situations of our memories. That is the second reason.
There are many different theories that attempt to explain the “déjà vu” effect, but there is still no definitive answer to the question which of these theories is correct. This is an area that is still suitable for explanations and further research.