Deja vu Center located in brain

[SteveGrenard]

Neuroscientists from the US and the UK publish their discovery in Science:


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" memories — information that allows us to tell similar places and situations apart.

The finding helps explain where déjà vu originates in the brain, and why it happens more frequently with increasing age and with brain-disease patients, said MIT neuroscientist Susumu Tonegawa.

http://www.foxnews.com/story/0,2933,279496,00.html


More at:

http://www.sciam.com/article.cfm?articleID=0D7230B5-E7F2-99DF-33A3DA38AE4500AC&chanID=sa007



http://news.bbc.co.uk/1/hi/health/6727727.stm

[kellyb]

I didn't really find the animal study very impressive regarding a tie to deja vu.
Haven't neuroscientists applied electrical stimulation to parts people's brains before and induced deja vu in humans?

[Jeff Corey]

I didn't really find the animal study very impressive regarding a tie to deja vu...
I found it very unsophisticated, because they just changed cages. First, you don't need to use shock. Second, changing cages is crude. Why not use a discrimination task where some precisely controlled stimuli are associated with performing an operant response for food and others aren't? Then you could test for stimulus generalization.
Where I work, any biologists interested in such questions would come down and consult with the behaviorists.

It's true.

[Dragon]

Haven't we seen all this stuff before?








Sorry, I'll get my coat .....

[Jeff Corey]

I haven't. Where was it?
Here's you coat, I'll get your hat.
Leave your worries on the doorstep.

[Corpse Cruncher]

Isn't Deja Vu a brain fart or something like that?

[kellyb]

My opinion on what actually qualifies as deja vu might be skewed because I'm epileptic, and when I have deja vu, it's probably a small seizure...but for me, deja vu is much more than just feeling as though I've been somewhere before. It's more like reliving an entire experience. I'm doing the exact same thing, and someone I'm talking to might be saying the exact same thing, or I'm reading the exact same thing and having the same thoughts about it.
But that intensity of "the deja vu experience" might be unique to temporal lobe epilepsy for all I know.
Out of curiosity, I've brought this subject up on epilepsy forums and other forums to compare people's experiences, and they seem to all be very similar to mine.

[Yuri Nalyssus]

Haven't we seen all this stuff before?Deja vu is a sign of a disturbance in the matrix. :cool:

Yuri (finding Nemo)

[Brattus]

Haven't we seen all this stuff before?








Sorry, I'll get my coat .....

Now THAT is funny!!!!!!!! LOL!!!!

[Myriad]

My opinion on what actually qualifies as deja vu might be skewed because I'm epileptic, and when I have deja vu, it's probably a small seizure...but for me, deja vu is much more than just feeling as though I've been somewhere before. It's more like reliving an entire experience. I'm doing the exact same thing, and someone I'm talking to might be saying the exact same thing, or I'm reading the exact same thing and having the same thoughts about it.
But that intensity of "the deja vu experience" might be unique to temporal lobe epilepsy for all I know.
Out of curiosity, I've brought this subject up on epilepsy forums and other forums to compare people's experiences, and they seem to all be very similar to mine.

As far as I know, I don't have TLE or any other epilepsy, but I experience deja vu like this also. It feels like reliving the entire experience, including the deja vu itself. ("I've done/heard/read this before, and I had deja vu then too!") I think that's an aspect of normal deja vu, or at least not unique to epileptics.

Respectfully,
Myriad

[Kariboo]

and when I have deja vu, it's probably a small seizure...but for me, deja vu is much more than just feeling as though I've been somewhere before. It's more like reliving an entire experience. I'm doing the exact same thing, and someone I'm talking to might be saying the exact same thing, or I'm reading the exact same thing and having the same thoughts about it.

what you describe is exactly how I experience my deja vus as well, however I don't have epilepsy. Interesting.

Funny there are simultaneously 2 thread popping up about deja vus
It's almost like having a deja vu

[Roboramma]

My opinion on what actually qualifies as deja vu might be skewed because I'm epileptic, and when I have deja vu, it's probably a small seizure...but for me, deja vu is much more than just feeling as though I've been somewhere before. It's more like reliving an entire experience. I'm doing the exact same thing, and someone I'm talking to might be saying the exact same thing, or I'm reading the exact same thing and having the same thoughts about it.
But that intensity of "the deja vu experience" might be unique to temporal lobe epilepsy for all I know.
Out of curiosity, I've brought this subject up on epilepsy forums and other forums to compare people's experiences, and they seem to all be very similar to mine.
Yes!

And, moreover, as I think "he said that the last time this happened" it doesn't take me out of the feeling that the experience is being played out a second time. The next thing that happens, even the next thought that comes in to my head, feels like it too happened before.
The only way to get myself out of it (other than just waiting) is to try to predict what's going to happen next - obviously it doesn't work. Maybe I just have bad memory :P

[billydkid]

For it is worth, I experienced deja vu much more frequently when I was younger. I almost never have it now.

[ImaginalDisc]

My opinion on what actually qualifies as deja vu might be skewed because I'm epileptic, and when I have deja vu, it's probably a small seizure...but for me, deja vu is much more than just feeling as though I've been somewhere before. It's more like reliving an entire experience. I'm doing the exact same thing, and someone I'm talking to might be saying the exact same thing, or I'm reading the exact same thing and having the same thoughts about it.
But that intensity of "the deja vu experience" might be unique to temporal lobe epilepsy for all I know.
Out of curiosity, I've brought this subject up on epilepsy forums and other forums to compare people's experiences, and they seem to all be very similar to mine.

I experience the same thing, and I don't have epilepsy. I usually have the overwhelmingly strong feeling that I knew exactly what was about to happen right before it happened, and I get that feeling right afterwards. It's always retrospective. Like, "Gosh, I know we he was going to say that and then a ball was going to flew by the window."

[kellyb]

This is kind of interesting. (it's just some dude's opinion, but it's in line with my own pet theory).

http://www.sciencemaster.com/columns/archives/gamon_4_01.php

DÉJÀ VU — A TOUCH OF TEMPORAL LOBE EPILEPSY?

There are certain run-of-the-mill experiences that give all of us a little taste of what it might be like to have a brain disorder. Dreams are one example. Another is what is called déjà vu (literally, "already seen") — a short-lived, overwhelming, but false sense of having already lived through the present moment, and of being able to predict what is about to happen next.


Other more recent experiments using EEG recordings show that stimulating the temporal lobe, hippocampus, or amygdala can trigger a déjà vu experience involving all three regions. Imaging studies also show that this is the same network of brain areas involved in a temporal lobe epileptic seizure. The hippocampus and amygdala are brain structures crucially involved in memory and emotion. The involvement of the hippocampus and amygdala in déjà vu may explain the mélange of memory-like sensations and emotional components that déjà vu combines.

This evidence indicates that the déjà vu experience is, in a sense, like a small, brief epileptic attack that fails to spread to as many regions of the brain, and thus fails to trigger a full-blown epileptic seizure.

[kellyb]

Ok...and I found the study where neurologists induced deja vu by electrically stimulating different parts of people's brains...

http://www.neurology.org/cgi/content/abstract/63/5/858

Methods: The authors studied the symptoms evoked by direct electrical stimulations of PC and EC in comparison with those obtained after stimulation of the amygdala and hippocampus. Stimulations were performed in a group of 24 patients with epilepsy, during stereoelectroencephalographic (SEEG) recordings in the setting of presurgical evaluation. All patients had electrodes that sampled the rhinal cortices, amygdala, and hippocampus.

Results: A total of 280 stimulations were analyzed. Entorhinal and perirhinal stimulations induced classic mesial temporal lobe responses (emotional, dysautonomic) but also more specific responses, particularly the déjà vu phenomenon and reminiscence of scenes. Such déjà vu or déjà vécu type responses were produced proportionately more often by stimulation of the EC than by stimulation of the amygdala and hippocampus. In particular, déjà vu was associated with stimulation of the EC and reminiscence of memories with PC stimulation.

I find that a lot more interesting and relevant than the mouse study that's been making headlines all week.