How Does Déjà Vu Work? There's A Scientific Explanation For This Bizarre Phenomenon

If you've experienced a flicker of puzzling recognition as you do something —pet a cat, watch a film, enter a house you know you've never been in before — you've experienced the puzzling psychological phenomenon that is déjà vu. It's a sudden sensation, often short-lived, that implies that you've experienced your current situation before, and are recalling it vividly, even when you haven't. However, déjà vu doesn't happen all the time: If we experienced the feeling every time we retraced our steps or went through our routine, it'd cease to be an anomaly. Instead, it's seen as a bit of a psychiatric oddity that's extremely common, occurring in about 60 percent of the population. And understanding how déjà vu works might shed light on the functions of human memory and our complex brains.

The déjà vu sensation has always been associated with a slight air of strangeness and mystery. It first entered scientific circles in 1876, when the French philosopher and investigator of the paranormal Émile Boirac coined the term in a letter. It's fascinated psychologists, scientists and artists ever since; Freud thought it was prompted by repressed desires (because of course he did), Marcel Proust based the most famous segment in his masterpiece In Search Of Lost Time on déjà vu sparked by a madeleine cookie, and the makers of the Matrix trilogy made the feeling a sign of a "glitch" in the artificial world. As it happens, the truth might actually not be much less bizarre.