What is the déjà vu and why it happens?

Déjà Vu is a French term that means "already seen". This term describes the feeling we have at any given time that We have seen or experienced something previously, when we know we have not done it.

There are some variations from the same term that are: déjà vécu "already experienced", Déjà Senti, "already thought" and Déjà visited, "already visited". French scientist Emile Boira was one of the first to study this strange phenomenon and who gave him his name in 1876.

Content

• What is the déjà vu?
• Memory systems
• Theories to explain why the dejà vu happens
  • Scientific theories
  • Paracientific theories

What is the déjà vu?

Many times the term déjà vu is used to define certain preocognitive experiences, in which someone feels exactly what will happen next, and does so. But an important characteristic of this phenomenon is that The déjà vu is experienced while an event happens, not before. Precognitive experiences instead, if they are real, show things that will happen in the future, not things that we have already experienced.

It is said that the dejà vu occurs occasionally in 60-80% of people. It is an experience that is almost always fleeting and brief, which occurs without prior notice and is randomized.

The majority of researchers claim that this phenomenon is an experience based on memory, so that the centers of memory of the brain would actually be responsible for it.

Memory systems

Temporary lobes are the main ones involved in the retention of long -term memories, both events and facts. Certain regions of medial temporal lobes are also very important in the detection of familiarity and recognition, unlike the detailed memory of specific events.

The detection of familiarity is said depending on the function of the entorrinal cortex, while the detailed memory is linked to the hippocampus.

Unfortunately, the randomness of the experiences of the Déjà Vu in healthy individuals, hinders the empirical study of this phenomenon, since any research on the subject depends on the subjective information of the people involved. This means that to reach the root of the cause of the Déjà Vu depends on the perceptions of each individual, which causes it to be very difficult to understand this strange and mysterious event.

But as with many phenomena that we still fail to understand, there are different theories that surround the origin of the Déjà vu. Here are the main.

Theories to explain why the dejà vu happens

Scientific theories

Some researchers propose that the Déjà Vu occurs due to a discrepancy in memory systems that generates a detailed but incorrect memory of a new sensory experience. That is to say, The déjà vu is evoked by a mismatch between sensory entry and memory output. The information overlooks our short -term memory and goes directly to our long -term memory, causing a mismatch between sensory entry (hearing, vision, touch) and working memory. This causes a new experience to seem familiar, although this experience is not really strong enough to be true.

Another theory suggests that the activation of the neuroentorrinal system, involved in the detection of familiarity, arises without Activation of the memory system within the hippocampus. This leads us to have a sense of recognition, but without specific details.

It has also been proposed that Déjà vu is a Reaction of brain memory systems to a family experience. This experience is known for being novel, but it has many recognizable elements, although in a slightly different environment. For example, find ourselves in a bar or restaurant away from our place of residence, but that has the same design or very similar to that we are regularly in our city.

It has also been observed that a subset of Patients with epilepsy constantly experience Déjà vu at the beginning of a seizure, that is, when convulsions begin in the medial temporal lobe. This has given researchers some of the main clues for the empirical study of the Déjà Vu.

Apparently epileptic seizures are caused by alterations in electrical activity in neurons within the focal regions of the brain. This dysfunctional neuronal activity can spread throughout the brain as shock waves generated by an earthquake. The brain regions in which this electrical activation can occur include medial temporal lobes.

The electrical disturbance of this neural system generates an aura (a type of warning) in the form of Déjà Vu before the epileptic event.

On the other hand, the experience experienced before an epileptic attack can be quite durable, and not a fleeting feeling as it happens in those people who do not have epileptic seizures.

Paracientific theories

There are many more theories about the cause of the déjà vu. These cover from the paranormal how to say that they come from memories of past lives, through precognitive dreams and even alien abductions.

Some justify this experience as The proof of the existence of a parallel universe. According to the physicist Michio Kaku, quantum physics shows that there is a possibility that the déjà vu be caused by the ability of the human brain to "walk between several universes". Michio explains these "parallel universes" making a simile with radio waves; We cannot see them, but there are hundreds or even thousands that fill our space. However, as a result of the laws of gravity, the radio can only be tuned in one station at the same time. In the same way, our mind is tuned in a single frequency of reality, and when we feel this reality as too familiar to be new, it could mean that we are "vibrating in unison" with a parallel universe.

Another theory within the paranormal states that The déjà vu is generated by our spirit, not the memory of our brain. It would be like a nebulous memory or a forgotten dream. Therefore, it is believed that this can only make sense if it originates from the spiritual ether. Apparently this experience is the way in which our spirit rootes us in now, and allows us to know that it is in this place of time and space where we are destined to exist. It is like a small reminder of consciousness.