The memory phenomenon of déjà vu (pronounced day-zhaa voo, French meaning “already seen”) has puzzled researchers, psychologists, philosophers, and physicians for centuries. Various types of experiments have been conducted in an attempt to uncover the details, but déjà vu has largely remained a mystery. The phenomenon is unpredictable with no obvious signs of onset, difficult to reproduce, making it nearly impossible to study within the context of an experimental study. Those who investigate the science behind déjà vu would likely make better cat herders.

As there have been various experiments conducted, there have been even more variable hypotheses put forth about where, how, and why déjà vu originates in the human mind. Ideas like evidence for previous lives and epileptic and psychiatric disorders have been proposed, none of which have been the decidedly supreme explanation. Dr. Vernon Neppe is revered as the expert on déjà vu and a pioneer in the fields of Behavioral Neurology and Neuropsychiatry. Dr. Neppe so eloquently defined the déjà vu phenomenon as, “any subjectively inappropriate impression of familiarity of the present experience with an undefined past.” Basically, the fleeting feeling of an inhuman-like super power, the quick and unfortunate realization you’re just like the rest of us average apes, then disappointment as the out-of-body experience wears off. That’s my own eloquent definition. An 8-second sensory roller-coaster while you curse it as it floats away, you wish it would come back again soon. Unfortunately, some research claims after the age of 25, you will likely experience the lovely sensation of déjà vu less often. It appears approximately 70 percent of the population report having experienced déjà vu, mostly from those aged 15-25. If you’re lucky enough to still be clutching to your early years, then hold on to your hats because you may still be in for a few more rollercoaster rides. If your younger years are slipping away from you, then you might as well say sayonara to your déjà vu trips as well.

A few of the more developed theories behind the déjà vu phenomenon include errors in memory processing and temporal lobe epilepsy, though Dr. Neppe’s research supports there is no single cause of déjà vu that scientifically explains the variety of clinical manifestations he has studied. All I know is as soon as scientists find a way to trigger déjà vu, I’ll be one of the first to sign up as a test subject.

Another curious grey matter subject is dreaming. Why can they seem so real, so specific, so vivid? Why are some more memorable than others? While the activity of dreaming has a bit more contextual research behind it (seeing as it’s much more predictable and trigger-happy), there still exists multiple theories behind the purpose and functionality of dreaming. For nail-biting, edge-of-your-seat real-time information on dream research, visit It will exceed all your wildest dreams and make all your dreams come true. Insert more dream puns here…


Have you experienced the crazy phenomenon of déjà vu? Had any exceptionally vivid dreams?

 Additional Images: Allan Ajifo/Flickr



Eli Stewart
Eli Stewart
When she's not writing, she's baking...or traveling the world with a pack on her back and a camera 'round her neck. She's got a wild imagination and an insatiable fernweh. Try to keep up. Follow her on the Tweeter at @TheWritingBaker.