One of the Cognitive ghosts discussed in the The Rest Is Science episode “Cognitive Ghosts”.

What it is

Jamais vu (French for “never seen”) is the eerie opposite of Déjà vu: something completely familiar — a word, a face, your own front door — suddenly feels alien, strange, or unreal, as if you were seeing it for the first time. The most relatable version is staring at an ordinary word until it briefly stops looking like a real word at all (semantic satiation).

What’s happening in the brain

Repetition temporarily exhausts the representation. When you over-expose your brain to a familiar stimulus, the normal automatic sense of “yes, this is meaningful and known” fatigues and drops out — leaving the raw stimulus stripped of its usual feeling of familiarity. One evolutionary reading from the episode: jamais vu may be a circuit-breaker for repetitive loops — when you’ve been doing the same thing too long, the jolt of strangeness nudges you to stop, re-check, and seek novelty.

References from the show

  • Chris Moulin (Université Grenoble Alpes) and Akira O’Connor (University of St Andrews) — “The Induction of Jamais Vu in the Laboratory”. They had volunteers write a single word ~30 times (the show says ~30; the published figure is around 33), and roughly 70% reported a peculiar feeling of strangeness, loss of meaning, or even that the word “wasn’t real”.
  • This work won the 2023 Ig Nobel Prize in Literature.
  • Try it yourself: write “door” thirty-odd times in a row.