Why Does Deja Vu Feel Like You have Lived This Exact Moment Before?

You have stood somewhere new and felt, with total certainty, that you have lived this before. It lasts about ten seconds and it leaves nothing behind. No memory, no date, no story you can point at. For a century that feeling was filed as a glitch - evidence that your memory is unreliable. It is the opposite. Your brain stores an experience as two separate things: the picture of what happened, drawn deep in the temporal lobe, and a tag stapled onto the outside of it that says this is old. Deja vu is the tag firing with no picture attached. In the middle of the last century a neurosurgeon operating on awake patients could produce that exact feeling with a thin electrode, move it two centimetres, and switch it off again. But you do not have an electrode in your skull. Most deja vu appears to come from the shape of the room - psychologists reproduced it in virtual reality by building scenes made of completely different objects arranged in exactly the same layout. And the reason it feels so deeply weird is not the false familiarity. It is the argument about the false familiarity. Some part of you is refusing to accept the signal, and that refusal is the sensation. Which is why deja vu fades as you get older, and why the people who have lost that check entirely do not find it strange at all. Further reading: Wilder Penfield's awake cortical stimulation work and the experiential responses of the temporal lobe Temporal lobe epilepsy and deja vu as a seizure aura Cleary et al., on familiarity driven by spatial configuration, tested in virtual reality environments The dual-process account of recognition: recollection in the hippocampus, familiarity in the rhinal cortex Conflict-detection accounts of deja vu, and the age-related decline of frontal monitoring Chapters: 0:00 Ten seconds of impossible certainty 1:10 The two things a memory is made of 2:00 A song you have not heard in twenty years 2:40 The picture and the stamp 3:20 Fire the stamp without the picture 4:00 The surgeon who could switch it on 4:50 The people who get it as a warning 5:20 It is the shape of the room 6:20 Your brain compares arrangements, not objects 7:00 The part everyone gets backwards 7:50 Why the feeling is the argument, not the signal 8:20 What happens when the check stops running #psychology #neuroscience #dejavu #brain