Déjà Vu fra fransk betyr "allerede sett"
What causes a déjà vu episode? There are several possible explanations for what is occurring during a déjà vu experience. One possibility is simply the occasional mismatch made by the brain in its continuous attempt to create whole sensical pictures out of very small pieces of information. Looking at memory as a hologram, only bits of sensory information are needed for the brain to reconstruct entire three-dimensional images. When the brain receives a small sensory input (a sight, a smell, a sound) that is strikingly similar to such a detail experienced in the past, the entire memory image is brought forward. The brain has taken the past to be the present by virtue of one tiny bit of sensory information. It is this mismatch of past and present sensory information that causes the sense of disconcertment and unease associated with a passing déjà vu [The above from (2) and (3)]. This theory provides a satisfactory explanation for the physical effects of déjà vu. These appear to be similar to the effects of mismatch between sensory input and corollary discharge signal information to the brain. It does not, however, seem to provide sufficient answers to individual (even my own) accounts of déjà vu, where the memory image pulled up is not necessarily from a true past event.
Another explanation for déjà vu is that there is a slight malfunctioning between the long and short-term memory circuits of the brain. Somehow, specific information shortcuts its way from short to long-term memory storage, bypassing the usual mechanisms used for storage transfer. The details concerning this shortcut are not yet well understood. When this new, recent piece of information is drawn upon, the person thinks that the piece is coming from long-term storage and so must have come from the distant past (6). A similar theory says that the error is in the timing of the perceptive and cognitive processes. Sensory information is rerouted on its way to memory storage and, so, is not immediately perceived. This short delay causes the sensation of experiencing and remembering something at the same time, a very unsettling feeling (2). One other explanation is that déjà vu is actually the process of remembering memory connections, of following the impulses and synapses (4). All of these neurobiologically based explanations for déjà vu seem plausible and intriguing and perhaps there is some overlap or combination that accounts for the different experiences we call déjà vu.
Other explanations for déjà vu have been given by psychoanalysts, such as the manifestation of wish fulfillment. Here, déjà vu is the subconscious repetition of a past experience, but with a more positive ending (2). The realm of parapsychology proposes that déjà vu is a chance for reincarnates to get a sneak peak into a past life. Most scientists scoff at these "magical" explanations for neurological events, citing that they break many of the laws of nature (6). Some, however, point to more recent findings in physics, such as the possibility of particles that can travel backwards in time (tachyons), time loops and multiple universes. They say that these may give cause for more non-traditional ways of seeing causality and for the possibility of neurological "time travel" (1). This means that, maybe, just maybe, understanding déjà vu as a means of seeing into the past or future cannot be so immediately dismissed. It is certainly food for thought for the rising debate, anyway.
Begynte og skulle oversette, men kom ca til 1\3 del og da giddet jeg rett og slett ikke mer :D
