ABSTRACT
Deja vu is the subjective experience of familiarity combined with the knowledge that this experience is false. It is a relatively striking but infrequent experience. In large-scale questionnaire studies it is estimated to be experienced by at least two-thirds of the population, and people generally report experiencing it less than ten times a year. For the person experiencing it, it is a somewhat mysterious and difficult-to-define feeling, although scientists are now beginning to offer some concrete suggestions about what causes the sensation and how it is produced in the human memory system. While it is experienced more in some conditions, such as certain forms of epilepsy, it is not thought to be particularly diagnostic of any type of cognitive problem or disorder. It is experienced by people with neurological and psychological disorders and healthy populations alike.
