DÉJÀ VU

déjà vu: translation

Also known asfalse memory. The termdéjà vuis French for 'already seen'. As pointed out by the South Africandéjà vuexpert Vernon M. Neppe, the term is used in a broad sense to denote "any subjectively inappropriate impression of familiarity of a present experience with an undefined past" (i.e. as a synonym of the generic term "déjàexperience), and in a narrow sense to denote a "déjàexperience occurring in the visual modality. As used in the latter sense, the termdéjà vuis used in opposition to more than 20 related terms, such asdéjà arrivé(already happened),déjà connu(already personally known), anddéjà entendu(already heard). As used in the broad as well as the narrow sense,déjà vuis considered the obverse of "jamais vu. The origin of the termdéjà vuis unclear, but it is sometimes attributed to the French philosopher and psychologist Emile Boirac (1851-1917), who reportedly mentioned it in 1876 in a letter to the French journalRevue Philosophique de la France et de l'Étranger.Theconcomitant concept, however, would seem to be much older. It has been suggested that the Church Father St. Augustine (354-430) referred to this phenomenon when he used the termfalsae memoriaein his workDe Trinitate. Although the termdéjà vumay seem to suggest otherwise, this symptom is not conceptualized as a perceptual phenomenon but as a false, but compelling sense of familiarity or recognition (i.e. a mnestic event) that may accompany a regular perceptual experience or event. For example, one may walk into a restaurant, and observe the other guests sitting at their dinner tables, and have the feeling that one has witnessed that exact scene before. Pseudo-presentiments like these would seem to be fairly common in healthy individuals of all ages. They typically last for various seconds to minutes, without affecting the subjects' judgment of their present situation.The subject's feeling is rather characterized by the cognitive dissonance between the feeling of re-experiencing a given situation, and the simultaneous awareness of its impossibility. Epidemiological surveys indicate that the lifetime prevalence ofdéjà vuexperiences in the non-institutionalized population lies between 30 and 96%. This broad range of prevalence figures is probably due to differences in the operational criteria ofdéjà vu, and to population biases. The literature also suggests that the incidence ofdéjà vumay be higher in young and imaginative individuals, and that its incidence tends to increase in the context of conditions such as fatigue and heightened perceptual sensitivity. Some studies also suggest thatdéjà vumay be more prevalent among individuals with a psychiatric disorder, such as anxiety disorder, dissociative identity disorder, mood disorder, personality disorder, or "schizophrenia. In addition, a heightened incidence ofdéjà vuis associated with the organic brain syndrome, temporal lobe epilepsy, Alzheimer's disease, and other types of dementia. Whendéjà vuis attributed to an organic cause, it is referred to as endogenousdéjà vu. In the case of a specific association with epilepsy, the phenomenon is sometimes referred to as epileptic " aura or epilepticdéjà vu. Epilepticdéjà vutypically presents as adéjà vuphenomenon with a prolonged or recurrent course. It can be complicated by hallucinatory phenomena such as " abdominal aura and olfactory hallucinations, and by subjective phenomena such as derealization, depersonalization, and strong affective states. As to the pathophysi-ology ofdéjà vu, various competing models exist. Most of these revolve around the notion of a dissociated activation of the familiarity/remember-centres of the brain, as may occur in dysfunctional activation of the mesial temporal lobe. In the literature this dysfunctional activity is conceptualized as epileptic in origin or not. Alternatively, the dual pathway hypothesis suggests that perceptual information from the senses does not always converge on sensory cortical areas in a coordinated fashion, thereby luring the cortex into labelling a single percept as a duplicated (i.e. re-experienced) one. As the alleged delay in neurotransmission is thought to originate from the optic nerve, the concomitant model is referred to as the optical pathway delay hypothesis. A third hypothesis suggests thatdéjà vumay arise from an instance of unattended perception, followed by an instance of attended perception. In parapsychology,déjà vuand otherdéjàexperiences are sometimes regarded as telepathic phenomena, or as veridical memories of an alleged past life.

Berrios, G.E. (1995). Déjà vu in France during the 19th century: A conceptual history.Comprehensive Psychiatry, 36, 123-129.

Brown, A.S. (2003). A review of the déjà vu experience.Psychological Bulletin, 129, 394-413.

Neppe, V.M. (1983).The psychology ofdéjà vu. Have I been here before? Johannesburg: Witwa-tersrand University Press.

Sno, H.N., Linszen, D.H. (1990). The déjà vu experience: Remembrance of things past?American Journal of Psychiatry, 147, 1587-1595.