Defining Déjà vu And Its Causes

There are times when one gets a feeling of familiarity upon walking into a room. He or she starts to envision himself or herself as though he or she has walked into the future. This may signal that the person is in the situation known to be as déjà vu.

Science Daily reports that déjà vu is experienced by approximately 60 to 80 percent of the people at least once in their lifetime. It is a phenomenon of having an intense sensation that a situation in life is presently being experienced has already been felt in the past.

Michelle Hook, Ph.D., assistant professor from the Texas A&M University explained that déjà vu has no clear and recognizable stimulus that elicits the experience, and it's very difficult to study it in the laboratory. Some people explained it as a premonition or foresight. On the other hand, scientific methods reject these explanations. The researchers contemplate that déjà vu is possibly caused by an improper electrical discharge in the brain resulting in an erroneous sensation of memory.

There are two types of déjà vu that may exist. The first type is related to epilepsy and another one is the psychological phenomenon.

"Clinical reports show that some patients who suffer from temporal lobe epilepsy report experiencing déjà vu, almost a sort of warning, before an epileptic seizure event," said Hook. On the other hand, healthy people who are experiencing déjà vu may be presented as a "glitch" in the brain. This happens when the neurons for recognition and the familiarity occurs, allowing the brain to err the present for the past.

The epileptic seizures are described by dysfunctional nerve cell across the brain. This disrupts the electrical impulses that "fire" neurons. The abnormal electrical impulses that may experience by epileptic may also be present in healthy people when déjà vu occurs.

Déjà vu could also be associated to inconsistencies in the memory system of the brain. This leads to sensory information to sidestep short-term memory and instead grasp for long-term memory. This may create an unsettling feeling of experiencing a new moment before.