Déjà vu (French for “already seen”): you find yourself in a situation that feels very familiar, but you can’t quite put a finger on why. It’s a frustrating feeling, and even scientists are still perplexed over what causes it. But new research of epileptic patients shows some correlation between a misfiring of neurons that causes déjà vu and the misfiring that causes seizures.
Additional research showed that, when given two completely different scenes with the same layout, people were likely to feel déjà vu with the second image without knowing why. Learn more from Smithsonian‘s Surprising Science Blog.