What is Déjà Vu + Why Does It Happen?
Sometimes, we find ourselves encountering new experiences that don't actually seem so new. What is that? The feeling of familiarity runs through our veins. Our mind's neurons fire away, feeling as if time and space have warped, and like, well... like we've been exactly here before. This fleeting, totally random, and unquantifiable sensation is known as déjà vu; a French phrase translated as "already seen". But where do these feelings come from and why do we feel them? The truth is... no one really knows, but we're all itching to find out.
Scientific researchers suggest that deja vu is a memory-based experience, coming to us via the brain's sudden recollection of cerebrally stored information on the more surreal ways in which a previous experience occurred. Though, other researchers (scientific still!) suggest that déjà vu comes to us via the workings of the universe - something that we can't tangibly explain.
Though sensibly, there are specific parts of the brain that deal with memory, such as the medial temporal lobes. This neural region consists of the hippocampus and the entorhinal, perirhinal, and parahippocampal cortices. Hello again, 10th grade anatomy. These lobes are vital for the retention of long-term memories of events and facts. Certain regions of the medial temporal lobes are important in the detection of familiarity, or recognition. Recognizing something as familiar is a function that's dictated by the rhinal cortex, whereas recollection of specific events and experiences is linked to the hippocampus. Aka - the hippocampus is quite essential for a happy, healthy, memory filed life.
Here’s the thing though: deja vu is totally random in mentally-healthy individuals, and getting down to the root cause of the experience is reliant on an individual’s own perceptions. Which in turn, makes the entire thing just that much more difficult to understand. But as is with many things we have yet to understand, there are different theories surrounding déjà vu, suggesting different origins of the feeling...
- Theory #1: Information bypasses your short-term memory and goes straight to your long-term memory, causing a mismatch between sensory input (hearing, sight, touching) and memory-recalling output. This leads to a new experience that maybe seems not so new, but the overall experience isn't strong enough to be entirely true.
- Theory #2: The activation of the rhinal neural system (which is the stunner involved in your detection of all things familiar) occurs without previous activation of the recollection system within the hippocampus. This leads to a feeling of recognition without specific details.
- Theory #3: Déjà vu is the brain-memory-system's reaction to a familiar, been-there-done-that, experience. So in short, you encounter one experience that is new, but has many familiar aspects to it, yet is ultimately different. For example, you walk into a friend’s living room that has the same layout, the same color scheme, and the same energy as your sister’s apartment, but is - in reality - an entirely new experience in an entirely new space.
- Theory #4: Your experience may be proof of a parallel universe (seriously). According to physicist Michio Kaku, quantum physics proves that there is a possibility that déjà vu is caused by the human brain's miraculous ability to "flip between universes." He relates these "parallel universes" to the like of radio waves; you can't see them, but when in the car, there are hundreds if not thousands of radio wave frequencies filling the space. Yet as a result of the laws of gravity, the radio can only be tuned into one station at a time. Likewise, your mind is tuned into just one frequency of reality, and when that reality feels all too familiar to be new, it could mean that you are "vibrating in unison" with a parallel universe.
- Theory #5: Déjà vu comes from your spirit, not the physical matter of your brain. Put it this way - if you try to focus on a specific memory, you can recollect the elements of it fairly easily, though when you try to focus on the elements of your déjà vu sensation, well, you just can't. It's like a foggy memory, or a forgotten dream. Therefore, some believe that it can only make sense for déjà vu to originate from the ether, thus memory functions of the mind do not apply. It is believed that this experience is your spirit's way of rooting you in the Now, and letting you know that this place in time + space is where you're meant to be. It's a little reminder of awareness, if you will.
And the theories don’t stop there... Others believe that deja vu can be linked to past lives and precognitive dreams. The ultimate consensus? The "already seen" is something that we may never quite understand - which makes the experience just that more captivating.
Where do you believe that déjà vu comes from? What does it feel like in your world, and how often do you experience it?