It must have happened to you before:you are doing something when suddenly you stop, convinced that you have already experienced this scene. And yet, no, it is impossible. Until then, different theories tried to explain paramnesia (the scientific name of deja vu):recently, experts claimed that it is a malfunction of the brain that imprints the current scene in the brain. But the phenomenon remained very difficult to explain, since as déjà vu is unpredictable, it was almost impossible to study it. A researcher has yet succeeded in this feat.
Akira O'Connor, a researcher at St Andrews University (Scotland), studied the behavior of the brain during a deja vu experience. For this, he mobilized 21 volunteers, whose brains were analyzed via an MRI. To "force" the feeling of deja-vu, researchers read to volunteers words belonging to a specific lexical field, without ever saying the keyword that connects them (here the terms bed, pillow, night, dream, but never the word sleep). Following this, the volunteers were asked if they had heard a word beginning with the letter S, to which they replied no. But when, afterwards, they were asked if the word “sleep” had been uttered, they knew very well that it had not, but nevertheless, it was familiar to them… presto! Deja vu feeling.
This is where the experience became exciting:the MRI images showed that during deja vu, it is not the area of the brain linked to memory (the hippocampus) that was activating, but rather the region related to decision-making (the frontal zone). Which means ? The brain is not looking for memories, but rather checking if there is not an error between what we live and what we think we have lived. Clearly, this is a very good sign, because it means that the brain is checking and correcting memories. Moreover, déjà vu is generally experienced by young people, mainly between the ages of 15 and 25, which seems logical in view of this explanation:as you age, the brain is less reactive and less able to check memories. What if we have never felt this sensation (this still concerns about 30% of the population)? Do not panic ! For Akira O'Connor, this would be the sign of a very efficient memory and which has nothing to correct.
Of course, the results of the study still need to be confirmed before we can say once and for all that deja vu is no longer a mystery. But hey, it's quite reassuring to think that our brain is just very efficient... isn't it?
