“Why do some scenes arouse thoughts that seem to belong to dreams of early and obscure memories, as my old Brahmin Moonshie would have attributed to a former state of existence? Are it the visions of our dreams that float confusedly in our memory and are evoked? by the appearance of real objects that, in some respect, correspond to the phantoms that they presented to our imagination?
It was like that, in such a beautiful way, that the Scottish novelist Walter Scott described, in 1815, in the book Guy Mannering, or The Astrologer, what is now known as déjà vu, an experience through which it is estimated that the 97 percent of people.
The writer was almost right in supposing that the phenomenon defined by the sensation of having already experienced in the past a situation that occurs in the present is linked to concrete situations. The ethereal and the magical, somehow, were left, in his description, to one side. And according to scientific studies, the sensation of living again something already lived has a rational explanation where supposed past lives and paranormal phenomena have no place.
Neither does the explanation Carrie-Anne MossWhat Trinity in The Matrix trilogy, when she says very confidently that déjà vu is a “glitch in the Matrix”, the simulated reality that keeps humanity unaware that intelligent machines have taken over the world. Beautiful image for a science fiction dystopia, but with little real and concrete scientific support.
hypotheses
According to the latest scientific consensus, the feeling of déjà vu is actually the result of a instantaneous comparison that the brain makes between a previous experience and the one that occurs in the present momentwhose trigger -here is the novelty- is the similarity of the spatial arrangement of furniture, objects and people.
Walter Scott, that Scottish writer, was somewhat right in thinking of objects as pieces capable of provoking sensations. Although in the times in which he lived it was not yet possible to imagine that the distribution of things, furniture, curtains, decoration, within the environment in which that sensation of experience already lived was produced was decisive.
“We still don’t know everything about déjà vu, but the similarity of the spatial distribution between the two situations, the past and the present, contributes to its emergence,” he explains. Anne Clearyof the Colorado State University in the United States, author of the most recent work on the subject.
“My team used virtual reality to locate the people within the scenes,” explains the scientist in an article published in “The Conversation”-. That way, we could manipulate the environments people were in: some scenes shared the same spatial layout and otherwise they were different. As predicted, déjà vu was more likely to occur when people were in a scene that contained the same spatial arrangement of elements as a previous scene that they viewed but did not remember.
An everyday example. A person walks into a restaurant that he has never been to and, for a moment, has the impression that he has once been there. It is an illusion. In fact, what his brain did was recover the sensations that he had stored from some other occasion in which that same person was in a place where the tables, chairs, and people in the environment were located in similar positions.
At first glance, the information may seem like just a curiosity about a peculiar event that occurs at least once in the lifetime of virtually every human being. However, it adds relevant knowledge about memory by explaining how spatial data captured by the brain is intertwined with sensory data and can be activated if needed.
Knowing these mechanisms in depth is one of the most urgent efforts in science, which is under pressure to find solutions to growing diseases characterized by damage to the ability to store memories, such as Alzheimer’s disease.
groundhog day
Until the mid-nineteenth century, the phenomenon of “I already lived through this” remained restricted to philosophical and religious discussions: it is attributed to San Agustinin fact, the first description of the event, considered by the theologian as the outbreak of false memories.
The advancement of new fields of medicine, especially in the area of neurology, expanded the research possibilities, which began to search for answers within the brain itself.
One of the first findings came from studies on the epilepsy, whose seizures are caused by disturbances in the transmission of electrical signals in the brain. Teams of scientists managed to verify that people in whom the imbalance occurs in the temporal lobe have more episodes of déjà vu. From there came the hypothesis: the region is responsible for processing visual, auditory and sensory information and also for organizing memories.
But also, There are people who experience repetitive episodes of déjà vou. It is in those situations that the feeling of having been there before becomes persistent. Like living in a kind of “Groundhog Day”. Psychologists at the Leeds Memory Laboratory (Leeds Memory Groupin Great Britain) published their first study on the subject in 2006.
Chris Moulin of the lab first encountered chronic déjà vu patients at a memory clinic. “We had a peculiar reference from a man who said there was no point in visiting the clinic because he had already been there, even though this would have been impossible.” The man not only genuinely believed that he had met Moulin before, but gave specific details about the times and locations of those alleged sessions which, to him, were reliable memories.
That man had episodes of “I’ve already experienced this” so constant that he had stopped watching television, watching the news, because everything seemed like a repetition. And he was not the only patient who came to specialists in Leeds, because the feeling of déjà vu can be chronic. And then, the romantic idea of past lives can lead to a real loss of quality of life and health.
At the same center in Leeds they treated a blind man with episodes of déjà vou. “This is the first time this has been reported in the scientific literature,” O’Connor said. “This is a specific case study that contradicts the optic pathway delay theory,” he explained at the time O’Connor, who published his work in the specialized journal “Brain and Cognition”.
Traditionally it was thought that images from one eye were delayed and reached the brain microseconds after images from the other eye, causing the sensation that something was being seen a second time.
But the blind patient who went to Leeds was experiencing episodes of déjà vu through smell, hearing and touch. Thus, lowering or raising the zipper of a jacket while he listened to a certain piece of music; hearing a snippet of conversation while he was holding a plate in a packed restaurant triggered bouts of déjà vou in the man that he couldn’t see.
Hypnosis
One of the options of the specialists from the Leeds Memory Group to study their patients was to create a memory in people, under hypnosis. That memory used to be something simple like playing a game or looking at a word printed on a certain color. The participants in the different groups were then suggested to forget or relive the memory, which could later trigger the feeling of déjà vu when they encountered the game or the word.
Other researchers chose to provoke a déjà vu through the use of the virtual reality. One study found that participants reported experiencing déjà vu when moving through the virtual reality video game “Sims.” This happened when one scene was purposefully created to spatially map another. For example, all the bushes in a virtual garden were replaced with piles of garbage to create a junkyard with the same design.
Most of the leading scientific hypotheses about the phenomenon share one idea: déjà vu occurs when areas of the brain (such as the temporal lobe) feed into the frontal regions of the mind and signal that a past experience is recurring. In other words, it would be an experience linked to memory. People are faced with a situation that is similar to a real memory, but they cannot fully remember what has already happened. The brain then recognizes the similarities between the current experience and one in the past. There remains a feeling of familiarity that seems to have no explanation.
