Scientific Approach to Deja

This article constitutes a summary of the empirical findings and scientific speculation concerning the dejavu experience. The review is divided into four sections: (a) techniques used to study the dejavu experience, (b) summary of empirical findings, (c) possible scientific explanations from cognitive and neuropsychological perspectives, and (d) directions for future research.

Although the dejavu phenomenon is widely experienced by the general public and is oft-cited in the popular literature (Sno, Linszen, & de Jonghe, 1992), the dejavu experience has been relatively neglected by memory researchers.

The dejavu experience lacks any clearly identifiable eliciting stimulus or verifiable behavioral response, and these lacunae have presented impediments to systematic research efforts. Much of the published literature on dejavu is from the psychodynamic or parapsychological perspectives, and although psychodynamic interpretations may have some explanatory value, these remain generally complex and cumbersome in light of possibly simpler scientific explanations.

Recently, a number of cognitive researchers have begun to relate empirical work to the dejavu phenomenon in an effort to elucidate the mechanisms underlying the experience (Hoffman, 1997; Jacoby, 1988; Jacoby, Allan, Collins, & Larwill, 1988; Jacoby & Whitehouse, 1989; Roediger, 1996; Schacter, 1996; Seamon, Brody, & Kauff, 1983).

A goal of the present review is to provide sufficient information on the phenomenon to stimulate constructive ideas from researchers in the clinical, neuropsychological, and cognitive areas and to bring clarity and focus to an extensive but fragmented literature.

Although much of the prior research on the dejavu experience has been published in journals and books that do not connect with mainstream scientific research, there is sufficient data and speculation available to formulate a nascent picture of the dejavu experience.