What is Deja Vu?

On seeing something you had never seen before, have you felt to have seen it? Have you sensed of knowing something that is yet to happen? It was Deja vu. What is Deja vu? Deja vu is the phenomenon wherein one feels sure to have experienced a new situation previously. While facing an entirely new situation, one feels a familiarity with something experienced in the past. One feels to have been through the same thing in recent past or to have seen it in a dream. Emile Boirac, a French researcher in psychology, coined the term, 'Deja vu' in an essay about this interesting phenomenon. Most of those who get the Deja vu feeling claim to have seen something in their dreams or are pretty sure to have seen it some time ago.

Types of Deja vu

Deja Senti: This feeling refers to something 'already felt'. It is a mental phenomenon and researchers believe that something felt in the past is very similar to that felt in the present. This similarity in the two experiences makes a person feel that he/she has felt the same way in the past.

Deja Vecu: A feeling that everything that is happening currently is identical to what had happened before and a strange idea about what is going to happen next, is termed as Deja Vecu. A person experiencing a Deja vecu feeling claims to know what is going to happen in near future and often feels to have remembered it.

Deja Visite: This form of Deja vu is a feeling of having visited a completely new place. A person experiencing this form of Deja vu claims to have knowledge of an unvisited place. One claims to be well aware of the geography of a place, when the person has never been there in reality. Deja Visite is characterized by a weird know-how of a spot one has never ever visited.

Researchers have long sought the reasons behind the Deja vu. They have attributed psychological diseases like schizophrenia, anxiety or other neurological disorders. Researchers have not achieved much success in establishing the relationship between these diseases and Deja vu.

However, the researchers have discovered that Deja vu can be the result of the mal-functioning of the electrical system of the brain. Deja vu is believed as being an incorrect sensation of memory. Certain medicines are also believed as being one of the factors responsible for Deja vu. Medicinal drugs such as amantadine and phenylpropanolamine have been observed to cause the feelings of Deja vu. Certain medical drugs can cause hyperdopaminergic action in the mesial temporal areas of the brain, resulting in Deja vu.

The human brain is a highly complex and a wonderful organ. It is the tendency of the brain to derive associations between different situations. The brain often tries to experimentally reproduce a situation that it has never faced before. Thus one's own anticipation of a certain incident may make the person think he/she has already encountered a similar experience in the past.

Interestingly, it may so happen that one of the human eyes perceives a certain thing before the other. One eye records the incident earlier. The other eye, which records the same incident milliseconds later, makes the brain get a feeling of recollection. One eye perceives something and the brain interprets it. The other eye that lags in time by a few milliseconds perceives the same thing and sends the image to the brain. As the brain perceives the same thing milliseconds later, the person senses it as having seen it before. This idea cannot be an exact reason behind Deja vu, as people with only one eye, also claim to be experiencing Deja vu.

Not everyone believes that everything has a science to it! Some theories attribute Deja vu to certain psychic abilities that some human beings possess while others say that Deja vu feelings are a result of past life experiences. Indeed, Deja vu has something mysterious about it!