Converging on an Understanding of the Déjà vu Experience

Abstract

Andrews"For a few precarious seconds, the chaplain tingled with a weird occult sensation of having experienced the identical situation in some prior time or existence… déjà vu. The subtle, recurring confusion between illusion and reality that was characteristic of paramnesia fascinated the chaplain." (Heller, 1955, p. 235). The chaplain's experience in Catch 22 provides a vivid illustration of a memory quirk that has fascinated creatives for centuries. The scientific study of déjà vu arrived with Boirac's (1876) description and Arnaud's single case study (Arnaud, 1896; see Bertrand, Martinon, Souchay, & Moulin, 2017 for a translation into English) but by then a significant body of literature describing the experience, from Saint Augustine (400AD, XII.xv.24), to Dickens (1850) and Hawthorne (1863), had already amassed.Fundamental to references to déjà vu in popular literature, extended today into song, cinema and online media, is the phenomenologically uncanny, highly idiosyncratic nature of the experience. Without any unique observable markers, the only way those experiencing it can understand that déjà vu is not unique to them, is to describe it in all its subjectivity. In turn, those observing the occurrence of déjà vu rely on these descriptions and their own interpretations of them being accurate. The processes of introspecting and communicating this information to one another is not unique to déjà vu-it could be argued that communicating the occurrence of any cognitive process shares the same challenges-but what makes déjà vu unique (alongside related memory quirks, such as jamais vu and presque vu) is that it cannot be identified solely by its behavioural outcomes. Here, we will describe key features of the déjà vu experience, ultimately concluding that subjective experience lies at its core, in spite of disagreement about its behavioural consequences. We will then outline how three strands of déjà vu research have sought to investigate the experience, which each bring with them attendant challenges. Finally, we propose a single, convergent, prospective approach by which these collective challenges can be overcome. Déjà vu as a Subjective ExperienceDefinitions of déjà vu have either concentrated solely on the feeling of uncanny familiarity, or introduced an additional conflict with an awareness that the familiarity is incorrect. Brown ( 2004) provided a table of 53 definitions from the scientific literature, within which the majority (40) focused solely on the feeling of familiarity, typically noting that déjà vu was experienced in the context of a situation that was novel (see Table 1). The familiarity in