Déjà Vu—What Is It?

The Sixth Sense?

Throughout my life, this odd “sixth sense” was something that happened often enough to make me ponder it from a scientific perspective, but also infrequently enough that I hoped knew I wasn’t losing my marbles. I’ve never been one to disregard my personal encounters but I often found myself asking people if they’ve ever experienced this elusive phenomenon. Growing up, this sometimes cast me as a weirdo when trying to explain it to people, but other times close friends would be excited to say they had had similar sensations or just showed interest in my pseudoscience-tinged ramblings on the matter.

Déjà vu is French for “already seen” and I would say could more literally be defined as “already experienced”. Nearly all of my experiences with déjà vu have lasted anywhere from 10-30 seconds and it seems as if I already know what is happening as it happens. It is an unusual feeling, which you almost cannot describe without having felt it before… Sounds like a paradox, right? Sigmund Freud is right to have called this strange experience “the uncanny”, a term which may be the most precise description I’ve come across. My best attempt to describe the feeling would be to imagine you’re re-watching of a movie you haven’t seen for a very long time—you kind of know what happens next, but you can’t quite put it forward before it takes place before your eyes.

Sigmund Freud is right to have called this strange experience ‘the uncanny’…

Various studies have shown as much as 70% of the population have experienced déjà vu-like episodes—so certainly not a rare by any measure. A majority of them proved to be younger people in the age range of 15-25 years old, although other significant polls have shown much more dynamic age ranges that prove that it isn’t a phenomenon that only occurs in younger generations who are over-saturated in media and other stimuli.

This is further supported when taking into account that déjà vu was being discussed as early as the 1800’s—even if historically speaking, it did not seem to be very significant until scientists began discussing the subliminal mind in greater depth. The lack of discussion prior to that time should not discount the possibility of occurrence before then either, as further back in human history odd and/or paranormal experiences were often just attributed to decrepit memories from ghosts of ancestors past or even memories of past lives for those who believe in reincarnation. No one knows for certain what sort of experiences they were actually focused on, but it’s probably not too forward to make some assumptions.

So what are some of the possible explanations for this strange feeling that is so common?

The Theories

I have discussed the phenomenon in detail with close friends and family from time to time, as well as doing light research on the subject in books and online. My older brother and I have always enjoyed discussing (pseudo) scientific concepts, mind-storming extraordinary answers—regardless of how involved with actual scientific research we actually are in our daily lives. These discussions often became an amalgam of concepts ranging from things we have experienced, to much more creative concepts,
and (most times) some actual science.

Here are some of the theories that often present themselves from my personal discussions as well as others’, ranked by my perceived plausibility of the explanation.

• Highly Unlikely: There is a group of people who say they have all the answers to the experience. This group of spiritual people seems to either claim that déjà vu is the result of past life experiences or say it could be the result of “ghosts” of ancestors long past returning for a brief visit. The sensation is described as if it is the actual inheritance of a ghost’s consciousness due to the frequencies of your mind matching up to their frequency. I never suspected that this could be the answer to the déjà vu question, but who knows!
• Highly Unlikely (but cool): The idea that déjà vu is, of course, actual precognition or foreknowledge of the world. No matter how thought-provoking and exciting this prospect is to me, I must say that I personally do not believe déjà vu is some sort of foresight into the future, as much as it seems to be, but would, of course, be quite interested if this could be tested more thoroughly…
• Unlikely: The subconscious mind perceiving a previous set of thoughts or dream as a memory due to overlapping details in events or emotions. This is an interesting theory, as I assume we have all had a recurring dream at some point in our life, and from my experience, little things change and evolve in them as they happen again and again. Not to discount simple everyday thoughts as well, your brain processes and organizes massive amounts of data per second, per hour, per day! I would not be surprised if some information streams were crossed unintentionally. (We all know what happens when you cross the streams…)
• Unlikely Possibility: A glitch in the Matrix. I kid… or at least I thought! Physicist Silas Beane of the University of Bonn, Germany recently submitted a paper called “Constraints on the Universe as a Numerical Simulation” in which he says it’s possible to test whether our universe is simply a simulation or not.
• Possible: Another theory similar to the previous, about overlapping memories and dreams, is the idea that the brain is simply mislabeling short term memories as long term memory. It’s a well-established fact that the brain stores memories in this way, so this idea plays on the concept that the brain is trying to categorize a short term memory that is currently happening as a long term memory, which does not actually exist there. Perhaps this simple mismatching of information coming in—confusing past with present—is what causes us to feel déjà vu as we all know it. Other scientists have theorized that it is simply dream-to-memory fulfillment that takes place in a conscious state.
• Plausible: Another common theory involves latency that exists between when the eyes see something and when it is received and processed by each hemisphere of the brain itself. This basically says that one hemisphere of the brain will register an experience via the eyes a few millionths of a second sooner than the second half, therefore creating that odd feeling of “this happened before…” This, however, can be expanded from not only sight but theoretically any of the other senses, as many blind people have described the same feelings without vision.
• Most Plausible: Déjà vu is known to be linked to temporal lobe epilepsy, and the experience seems to happen during a seizure of the lobe in test patients. Researchers know that many people experience small epileptic seizures from time to time as a normal process of the body: called hypnagogic jerks—or the small “jolts” experienced sometimes before falling asleep. They believe déjà vu could be a similar but slightly altered form of these jerks, that their theory formulates is simply a neurological anomaly resulting in sensations of memory formation, recall, and familiarity. The temporal lobes are critically important for both memory and recognition and neuroscientists found that after implanting electrodes on the temporal lobes, they could elicit a dream-like state in participants causing them to find nearly everything around them familiar. Thus supporting their hypothesis that déjà vu is just the faulty actuation of the temporal lobes, which causes the present to seem like a long past memory.

In Summary

No matter the cause of this strange phenomenon, it seems to happen often for me and I remain ever curious to find the answers to life’s little secrets. It is truly something you must experience for yourself to try and understand the extraordinary sensation that accompanies it.

I plan to try and create a déjà vu journal—much like a dream journal—to try and find some commonalities in my personal experiences if any seem to exist. Feel free to share your thoughts, experiences, and theories as well, as I’d love to hear them.