What is deja vu?
Deja vu is the strange feeling that “exactly the same thing happened before,” even in a place you are visiting for the first time or during an experience that is new to you. It means “already seen” in French. The term is said to have been first used by the 19th-century French researcher Emile Boirac.
Deja vu is by no means rare; depending on the survey, about 60–70% of people are said to have experienced it at least once. It is especially common among people in their teens and twenties and tends to become less frequent with age.
Rumors of past lives and precognition
Because the sensation can be so vivid, mystical explanations are sometimes told: “I had the same experience in a past life,” “I foresaw the future in a dream,” “a memory from a parallel world resurfaced.” There is also a rumor that people who often have deja vu have strong psychic sensitivity.
What causes deja vu?
Deja vu is studied in many ways in psychology and neuroscience. One theory says that the atmosphere or layout of the current place closely resembles another place seen in the past, so only the feeling of “knowing it” arises without a clear memory. Another says that a slight glitch occurs as the brain processes the information in front of it, causing the current experience to be mistaken for “something already stored in memory.”
It is known that deja vu often occurs before epileptic seizures involving the part of the brain responsible for memory. Like the doppelganger, in which one sees another self, it is a phenomenon produced by the brain’s mysterious workings.
