Nov 43 min read

Been There, but Haven't Done That?

Déjà Vu: A Brief Overview
Déjà Vu: Origins
Implications of the Déjà Vu Experience
Fun Facts
Sources & Works Cited

Déjà Vu: A Brief Overview

Ever heard of Déjà Vu? Nope- not the song. Déjà vu- a French term for “already seen” is a feeling that a new situation one finds oneself in has already happened before. It is an expected resultant pattern from the fusion of map and path, which implies that your mind has likely felt it before but cannot be trusted. According to neuroscientists, déjà vu occurs when the frontal regions of the brain are trying to correct a memory error – acting like a fact-checking device. But the good news is that what used to be thought to indicate disruptions in the brain could show that your brain’s memory-checking system works really well. [1][2]

Nevertheless, the reason behind it remains buried in mystery, enough to make a detective's head spin. Some theories go as far as suggesting paranormal roots while others delve into time-keeping functions in the brain. Although there might not be any accepted theoretical model responsible for such occurrence, the majority of explanations label this phenomenon as short-lived malfunctioning sensory input during which our minds misjudge something familiar from history. This strange feeling only lasts for a moment and gives us an incredible insight into how baffling and complicated human memory works. [1][4]

Déjà Vu: Origins

Déjà vu is evoked from many factors related to brain function and thought activity. One big culprit? Being stuck between being stressed out and so tired you could sleep through a notification from your BFF. When a brain is fatigued or under a lot of pressure, its neuronal systems might not act optimally, which might result in irregular firing patterns. That would make the brain signal wrongly that the experience being had at that moment is familiar, causing déjà vu.

Another important component of experiences of déjà vu is dopamine, a neurotransmitter that excites. High levels of dopaminergic activity in regions of the brain that resolve familiarity can cause the déjà vu experience. This is one reason that such a sensation sometimes occurs with drug use or misuse in which dopamine levels are affected. Another reason younger people experience déjà vu more commonly is their higher brain activity and more developed frontal cortex, the part of the brain that is responsible for fact-checking and reasoning. Their brains are like that friend who somehow remembers every single embarrassing moment of you.

The neural mechanisms of this phenomenon have been related to the interplay between the medial temporal lobe, which is responsible for the proper formation and recognition of memories, and the frontal cortex, which primarily plays a role in higher cognitive processes. Thus, déjà vu might be experienced because the medial temporal lobe mistakenly signals to feel familiar, while the frontal cortex cannot check this against real past experiences. Hence, the desynchronization of memory from cognition would produce the illusion of familiarity.

Experimental research has also implicated spatial resemblance in déjà vu. Virtual reality studies have indicated that people are more likely to experience déjà vu when placed in environments that resemble those they have been to but cannot consciously remember. It’s like seeing an old crush and thinking, “Wait, why did I ever like them?” This spatial similarity, combined with the failure of the brain to recognize it, will most likely lead to the uncanny sensation of familiarity.

Implications of the Déjà Vu Experience

Déjà vu can be an indicator of good brain health. It suggests that the brain’s fact-checking mechanism is functioning well, aiding accurate memory recall. In contrast, jamais vu—an experience where something familiar feels strange or unfamiliar—is the opposite of déjà vu. This phenomenon is often experienced with overexposure to familiar words, can be induced easily, and highlights a different quirk of memory. Both déjà vu and jamais vu are interesting aspects of how our brains process familiarity and memory. Usually, more educated people are more likely to experience déjà vu. [2][6]

Fun Facts

The term dates all the way back to 1876 when it was considered paranormal to have experienced.
Though it is usually experienced in only 5 seconds, others may have day-long déjà vu.
On average, people experiencing déjà vu get it about once per year.
Though it could be a sign or symptom of some mental issues, déjà vu is often common among people and is not considered dangerous.
Two-thirds of people experience it at least once in their lifetime. [2][7]