Explains Andrew Sullivan. Greek food to blame.
The brain cranks out memories near its center, in a looped wishbone of tissue called the hippocampus. But a new study suggests only a small chunk of it, called the dentate gyrus, is responsible for “episodic†memoriesâ€â€information that allows us to tell similar places and situations apart.
The finding helps explain where déjàvu originates in the brain, and why it happens more frequently with increasing age and with brain-disease patients, said MIT neuroscientist Susumu Tonegawa. The study is detailed today in the online version of the journal Science.
Like a computer logging its programs’ activities, the dentate gyrus notes a situation’s patternâ€â€it’s visual, audio, smell, time and other cues for the body’s future reference. So what happens when its abilities are jammed?
When Tonegawa and his team bred mice without a fully-functional dentate gyrus, the rodents struggled to tell the difference between two similar but different situations.
“These animals normally have a distinct ability to distinguish between situations,†Tonegawa said, like humans. “But without the dentate gyrus they were very mixed up.â€Â
Déjàvu is a memory problem, Tonegawa explained, occurring when our brains struggle to tell the difference between two extremely similar situations. As people age, Tonegawa said déjà-vu-like confusion happens more oftenâ€â€and it also happens in people suffering from brain diseases like Alzheimer’s. “It’s not surprising,†he said, “when you consider the fact that there’s a loss of or damage to cells in the dentate gyrus.â€Â
I know I read this somewhere before…!
Hmmm, I disagree. I distinctly remember having had feelings of deja vu in situations that resembled no previous actual experience in my life.
The explanation I’ve read that fits these is that the process of committing realtime experiences to memory sometimes multithreads, creating the illusion of remembering the event even as it happens. Not the same thing at all.
Isn’t it easier to explain St. Andy, the patron Saint of the perpetually annoying, without all of the scientific mumbo jumbo. Just call it what it is … a gob-smackingly hysterical butt dart?
McGehee
There is also Jamais Vu (never seen) and Presque Vu(almost seen).
Deja vu is when, while walking on the street, a hairy mongolian man smacks you in the face with a huge dildo, and you know it feels so familiar.
Jamais vu is when, even though a hairy mongolian follows you around constantly whacking you with a huge dildo, this time it just seems utterly bizarre.
Presque vu is when the mongolian almost whacks you across the head with the huge dildo.
What, you never read Catch-22?
So I’m not the only one that damn Mongolian keeps bothering……
No, you’re definitely not the only one.
What hairy Mongolian guy?
<thwack!>
What hairy Mongolian guy?
<thwack!>
Towana…wanoa