Cleary worked off the idea that memory is often stored in our brain as individual elements, like a jigsaw puzzle. When you fit all the pieces together correctly, your brain produces a complete, coherent memory. Oftentimes though, if certain elements of a new situation match certain elements of a previously stored memory, your brain will mix up the puzzle and convince you that you have actually experienced the present situation before. The more the elements overlap, the bigger the sense of déjà vu.
The second prong in the study was to find out what these trigger elements are. Cleary designed an experiment in which she gave volunteers a list of words to study. Afterward, they were given a word-recognition test. Some of the words had been on the list, some not, and some simply resembled words on the list (for example "lady" in place of "eighty"). When confronted with a new, similar-sounding word, subjects identified a sense of familiarity with it, even when they could not remember what the original, similar word on the list was. A parallel experiment using geometric shapes instead of words led to similar results. Cleary's conclusion is that visual and audio fragments are able to create the sensation that an entire scene has been viewed before, even though it is actually brand new.
"Many parallels between explanations of déjà vu and theories of human recognition memory exist," Cleary concludes. "Theories of familiarity-based recognition and the laboratory methods used to study it may be especially useful for elucidating the processes underlying déjà vu experiences."
Maybe science is catching up, after all. But don't worry. Have another martini and you won't remember a thing.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.