Déjà Vu: the strange feeling of living something already lived before
Have you ever lived something that you think you have lived at another time? Have you been to a place that is familiar but without remembering why you are familiar?
If you have felt something similar, it is very likely that you have experienced a Deja vu .
What does Déjà Vu mean?
Deja vu is a French term coined by the psychic researcher Émile Boirac which means "already seen" and implies a sensation of being living a situation identical to another previously lived of which, however, we are not able to remember when or why we are familiar . Its duration, normally, is a few seconds and is characterized by the feeling of living again a moment already lived, as if the same story was repeated.
Through a collection of data by Millon and his team it has been observed that, approximately, 60% of people experience it and it turns out to be a more frequent phenomenon under stress and fatigue situations (Brown, 2003). It usually arises between the ages of 8-9, because for a Dèjá Vu to occur, a certain level of brain development is required, but once we experience it, it becomes more frequent between 10-20 years (Ratliff, 2006).
When we speak of Dèjá Vu, we are not talking about a new term, since Dèjá vu's experiences have already been described in works by great writers such as Dickens, Tolstoy , Proust and Hardy (Sno, Linszen & Jonghe, 1992).
Why is Déjà Vu produced?
This question is still uncertain. Numerous fields offer diverse explanations to this phenomenon, some of the most known theories are those that relate Dèjá Vu as a symptom of paranormal experiences (past lives, premonitions, etc.) and even in the field of psychoanalysis, Freud (1936) postulated that this sensation was caused by the similarity of the present situation with a repressed fantasy of an unconscious dream, however, he declared the phenomenon as something confusing to investigate.
What does neuroscience tell us about the Déjà Vu phenomenon?
Focusing on a neurocognitive analysis, Alan Brown (2004), psychologist at Southern Methodist University and author of "The Déjà vu Experience", shows us a classification of the various scientific explanations in relation to Déjà Vu through four theories:
1. Double processing
The central idea is the affirmation of Déjà Vu as result of two synchronized parallel cognitive processes that momentarily lose synchronization .
This asynchrony may be due to the absence of one process when the other is activated or the brain is coding the information and recovering it at the same time, meaning that two related pathways that are normally separate are merging. The fact that you are observing an image and that you are remembering at the same time gives us a feeling of having lived this situation before.
2. Neurological
Déjà Vu is produced because of a brief dysfunction / interruption in a temporal lobe circuit , involved in the experience of remembering lived situations, this fact generates a "false memory" of the situation. This theory is justified with the study of patients with epilepsy of the temporal lobe, who often experience Déjà Vu just before suffering one of their attacks.
By measuring neuronal discharges in the brain of these patients, scientists have been able to identify the regions of the brain where Déjà Vu signals begin and how stimulating those same regions it is possible to produce that sensation.
3. Mnics
Define Déjà Vu as a experience generated by the similarities and overlaps between past and present experiences . The psychologist Anne M. Cleary (2008), researcher of the neural bases underlying Déjà Vu, postulates this phenomenon as a normal metacognitive mechanism that occurs when a past experience bears a resemblance to the present and, consequently, makes us believe that we have already been there.
Through various studies and investigations it has shown that the mind stores fragments of information, that is, it does not store the complete information and that, therefore, when we observe, for example, a street that looks like another street or that has identical elements or similar, this feeling may arise.
4. Double perception or attention
It is postulated that the phenomenon is produced as a consequence of a momentary distraction of the brain just after part of the scene has been captured (non-explicit recall) and, when this attention is retaken (fractions of a second) and a complete capture is made , we attributed to that scene a strong sense of familiarity without being aware of its origin giving a feeling of "false memory", since part of that scene had been recorded implicitly and unconsciously.
The fact that there are various theories shows that such a phenomenon is not due to a single cause. Likewise, it is true that not all Déjà Vu is the result of a normal mnesic process, since there seems to be a type of Déjà Vu related to a mnesic alteration observed in pathologies such as schizophrenia or, as mentioned above, in the lobe epilepsy. temporary in which the phenomenon can last a few minutes or even hours (Thompson, Moulin, Conway & Jones, 2004).
For the moment, there is no clear and definitive explanation that determines the anatomical and functional bases for this phenomenon to occur , but advances in neuroimaging techniques and current research can help to better understand the topic from a neurocognitive perspective.
Bibliographic references:
- Brown, A. (2003). A review of the déjà vu experience. Psychological bulletin, 129 (3), 394.
- Brown, A. (2004). The Dèjá vu experience. England: Psychology Press.
- Cleary, A. M. (2008). Recognition memory, familiarity, and déjà vu experiences. Current Directions in Psychological Science, 17 (5), 353-357.
- Freud, S. (1964). A disturbance of memory on the Acropolis. In The Standard Edition of the Complete Psychological Works of Sigmund Freud, Volume XXII (1932-1936): New Introductory Lectures on Psycho-Analysis and Other Works (pp. 237-248).
- Ratliff, E. (2006). Déjà vu, again and again. New York Times Magazine, 2, 38-43.
- Sno, H., Linszen, D., & Jonghe, F. (1992). Art imitates life: Leave vu experiences in prose and poetry. The British Journal of Psychiatry, 160 (4), 511-518.
- Thompson, R., Moulin, J., Conway, M. & Jones, R. (2004). Persistent Déjà vu: A disorder of memory. International journal of geriatric psychiatry, 19 (9), 906-907.
