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What Exactly Is Happening In Your Brain When You Get Déjà Vu?

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Even had that dizzying feeling that you've been somewhere before, not just somewhere, but in that exact spot, doing the exact same thing, with the same people—even though you know there's no way that could be true?

Déjà vu, that sometimes magical, sometimes disconcerting feeling of already having lived the present moment, has been part of the human experience forever. We've explained it as a futuristic vision, a glimpse into a former life, a warning from beyond or some other kind of mystical experience. But now science has a biological explanation: It's a brain glitch. Sorry.

Researchers from Texas A&M University were researching epilepsy, a disease that causes repeated seizures, and found something interesting: Epileptics often have a moment of déjà vu right before a seizure hits, almost like an early warning system. The scientists used brain scans to examine the link between déjà vu and seizures and they found that both events appear to be caused by the same neurological hiccup in our brains. (Did you know leg workouts could be key to better brain health?)

But déjà vu is super common, with over two-thirds of people saying they've experienced it, while epilepsy is relatively rare, affecting just one percent of the population. So how exactly are they connected? It all comes down to how we store our memories, lead researcher Michelle Hook, Ph.D., an assistant professor in the Department of Neuroscience and Experimental Therapeutics, said in a press release. The temporal lobe is where the nerve cell activity in the brain is disrupted in patients with temporal lobe epilepsy, and it's also the place where we make and store our memories. (Find out how technology messes with your memory.)

Hook explained that this part of our brain is responsible for the detection of familiarity and the recognition of certain events, so when there is a neurological misfire there, it can lead us to mistake the present for the past. For people with epilepsy, the neurological disruption continues on to cause a full-blown seizure, but in healthy patients, it just causes that all-too-familiar feeling of déjà vu.

Another factor, according to the study, is that our brains are constantly trying to create a whole picture of the world based on our limited sensory input. They do this by filling in the gaps with what we know from past experience—for instance, a honking horn tells us there's a car and there's danger, even if we can't see it. Most of the time this works seamlessly, but every once in awhile our brains fill in the blank with the wrong piece of information, leading to a strange "memory" happening in the present moment. (Stock up on the 11 Best Foods for Brain Health.)

Lastly, the different speeds at which we process all that incoming sensory data may also spark déjà vu. For instance, we may process what we see slightly before we process what we hear and that difference may make us think we're having two experiences at the same time.

"Some suggest that when a difference in processing occurs along these [incoming sensory] pathways, the perception is disrupted and is experienced as two separate messages. The brain interprets the second version, through the slowed secondary pathway, as a separate perceptual experience, and thus the inappropriate feeling of familiarity (déjà vu) occurs," Hook explained.

So now that we know why it happens, the real question is if déjà vu moments are basically just pre-seizures does that mean The Matrix is a true story after all??

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