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Deja Vu as a Brain Event

Déjà vu is a common prodrome, and it is a brain event that is experienced frequently by non-epileptic people. Déjà vu is an eerie feeling of "having been here before." In one classroom survey I conducted, 95% of introductory students reported having occasional déjà vu sensations.

John Hughlings Jackson (1835-1911) was a London neurologist who pioneered in the study of epilepsy. He noticed that déjà vu and similar sensations were common in epileptics.

The state is often like that occasionally experienced by healthy people as a feeling of "reminiscence"... It is sometimes called "dreamy feelings" or is described as "dreams mixed up with present thoughts," "double consciousness," "feeling of being somewhere else," "as if I went back to all that occurred in my childhood"... (Jackson, quoted in Penfield, 1959)

What feelings commonly accompany limbic "storms"?

The déjà vu sensation is probably caused by a small discharge of neural activity in the temporal lobe and the limbic system, areas joined by dense fiber tracts. As Swartz (1982) puts it, limbic epileptic storms can make the mind light up with "vivid feelings, including convictions of what is real and true." Déjà vu sensations, in particular, can be triggered by direct stimulation on the top surface of the temporal lobe, during surgery.

How do people commonly interpret a déjà vu sensation?

Déjà vu means, literally, "already seen." A variation of déjà vu called déjà penseé (already thought) occurs when one has a feeling that every detail of a current situation is familiar or that one has predicted the events of the present moment. This prediction is felt to be "real and true." Some people interpret such sensations as a memory of a recent dream that foretold the exact details of the present moment. The feeling is an illusion- it is not a dream coming true-but the illusion is very powerful. It can be difficult to convince someone in the grip of a déjà vu episode that this is an illusion, a brain stimulation event, not an episode of psychic power.

My boyfriend and I were sitting eating lunch last week, having a small conversation. I remarked that I couldn't wait for cold weather to come so we could go skiing in North Carolina. "Yeah," he said, "And I'll clobber you in a snowball fight if you give me any hassle about not knowing how to ski." I laughed and told him that I once had to learn, too, and that Beach Mountain Ski Slope had a special place for teaching beginners.

Suddenly my boyfriend's face went white, and his eyes grew wide open. "What's the matter?" I said. "This has happened before!" he remarked. "We have had this whole conversation before and it seems like we were right at this table and everything, everything's the same." I knew good and well that we hadn't talked about us going skiing before, but I smiled and became excited because I knew why it seemed that we had this conversation before. I said, "Hey, that's déjà vu. We talked about it in psychology. You really didn't have this conversation with me before, it only seems like it because déjà vu is what happens. It's only a little feedback going on in your brain..." I proceeded to explain it to him in a proud scientific way (because I was proud of myself for knowing) but he interrupted me and said, "Forget it. I don't want to hear about all that psychology stuff, 'cause I know I'm psychic !"

I smiled and said to myself, "Sure, that's what they all say!" [Author's files]

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