Brain Cells Observed Summoning a Memory 381
Anti-Globalism writes "Scientists have for the first time recorded individual brain cells in the act of summoning a spontaneous memory, revealing not only where a remembered experience is registered but also, in part, how the brain is able to recreate it."
What the article actually says... (Score:5, Informative)
Article Text (Score:5, Informative)
September 5, 2008
For the Brain, Remembering Is Like Reliving
By BENEDICT CAREY
Scientists have for the first time recorded individual brain cells in the act of summoning a spontaneous memory, revealing not only where a remembered experience is registered but also, in part, how the brain is able to recreate it.
The recordings, taken from the brains of epilepsy patients being prepared for surgery, demonstrate that these spontaneous memories reside in some of the same neurons that fired most furiously when the recalled event had been experienced. Researchers had long theorized as much but until now had only indirect evidence.
Experts said the study had all but closed the case: For the brain, remembering is a lot like doing (at least in the short term, as the research says nothing about more distant memories).
The experiment, being reported Friday in the journal Science, is likely to open a new avenue in the investigation of Alzheimer's disease and other forms of dementia, some experts said, as well as help explain how some memories seemingly come out of nowhere. The researchers were even able to identify specific memories in subjects a second or two before the people themselves reported having them.
"This is what I would call a foundational finding," said Michael J. Kahana, a professor of psychology at the University of Pennsylvania, who was not involved in the research. "I cannot think of any recent study that's comparable.
"It's a really central piece of the memory puzzle and an important step in helping us fill in the detail of what exactly is happening when the brain performs this mental time travel" of summoning past experiences.
The new study moved beyond most previous memory research in that it focused not on recognition or recollection of specific symbols but on free recall â" whatever popped into people's heads when, in this case, they were asked to remember short film clips they had just seen.
This ability to richly reconstitute past experience often quickly deteriorates in people with Alzheimer's and other forms of dementia, and it is fundamental to so-called episodic memory â" the catalog of vignettes that together form our remembered past.
In the study, a team of American and Israeli researchers threaded tiny electrodes into the brains of 13 people with severe epilepsy. The electrode implants are standard procedure in such cases, allowing doctors to pinpoint the location of the mini-storms of brain activity that cause epileptic seizures.
The patients watched a series of 5- to 10-second film clips, some from popular television shows like "Seinfeld" and others depicting animals or landmarks like the Eiffel Tower. The researchers recorded the firing activity of about 100 neurons per person; the recorded neurons were concentrated in and around the hippocampus, a sliver of tissue deep in the brain known to be critical to forming memories.
In each person, the researchers identified single cells that became highly active during some videos and quiet during others. More than half the recorded cells hummed with activity in response to at least one film clip; many of them also responded weakly to others.
After briefly distracting the patients, the researchers then asked them to think about the clips for a minute and to report "what comes to mind." The patients remembered almost all of the clips. And when they recalled a specific one â" say, a clip of Homer Simpson â" the same cells that had been active during the Homer clip reignited. In fact, the cells became active a second or two before people were conscious of the memory, which signaled to researchers the memory to come.
"It's astounding to see this in a single trial; the phenomenon is strong, and we were listening in the right place," said the senior author, Dr. Itzhak Fried, a professor of neurosurgery at the University of California, Los Angeles, and the University of Tel Aviv.
His co-authors were Hagar Gelbard-Sagiv, Michal Harel and Rafael Malach of
Re:Self portriat (Score:3, Informative)
Sometimes it causes me to recall events which may not have happened. I am literally processing garbage data.
Everyone remembers events that never happened. "False memory" they call it, and according to trusty old Wikipedia there's no way to distinguish between a false memory and a true one.
Um, we've known this for well over 10 years!!!! (Score:4, Informative)
Re:Um, we've known this for well over 10 years!!!! (Score:2, Informative)
Re:Wow (Score:3, Informative)
That's quite fascinating! (I hope the condition isn't too serious, of course.) The idea of a brain processing garbage data is certainly thought-provoking. Do you have any buffer overflow vulnerabilities that could lead to an exploit?
Possibly. When I was a teenager I would sometimes be terrified of small things. I don't have a fear of heights except a small height like standing on a curb could generate strange fears.
I took medication for my condition between the ages of 19 and 25. It is mostly under control now, possibly because of the medication but also possibly because I have learnt what states to avoid.
I am very much aware that the brain is not a stored program computer. Memory, behaviour and (to some extent illness) are all hard wired. If an anomoly is caused by a particular state in my brean then I can avoid the problem by avoiding that state.
Over time I have become much more relaxed. I avoid the stressful conditions which I associated with having seizures. Maybe I have learnt around the problem. Maybe the drugs changed my brain. Maybe this is a natural change which everybody experiences.
Re:Wow (Score:4, Informative)
A few years back a /.er told of recovering from a seizure like their brain rebooting, senses coming online one-by-one. I wish I could find the link now.
That might be a good way to describe it, but it is probably not close to what actually happens. Long term memory is one of the most vulnerable brain functions. It is the first to be lost when anything goes wrong and the last to come back.
My recollection of recovering from a grand mal seizure is that of vague memories early on and better memories later. That is consistent with long term memory starting to come back. But the spotty early memories include myself apparently behaving normally: talking to people, etc. So simple functions may come back quote quickly.
Re:I just summoned some 'memories' (Score:5, Informative)
Yes, muscle memory is stored in the cerebellum, not the cerebrum. That's why you don't have to "think" about it to do it.
Most of the martial arts training is about moving the information from the latter to the former.
The original study (Score:2, Informative)
Re:I just summoned some 'memories' (Score:5, Informative)
Yes, a couple of grams. Of the exhaled air...
Yeah, kind of like when you take a photo. After a little while, the eyes start drying out too, removing any sparks left.
Now hold on there, sheriff. There's no way to prove that they didn't have the information long before they told you. Hoaxes like that gain the involved lots of publicity and possibly money. Don't you think some people are willing to do it?
If you want to see, you will see.
Re:Give me a practical use... (Score:3, Informative)
All I could find was this article: http://www.damninteresting.com/?p=229 [damninteresting.com]
It's related - it also discusses a man that they did the same thing to...he "vigorously protested" when they wanted to stop the experiment.
Re:Um, we've known this for well over 10 years!!!! (Score:1, Informative)
This is interesting and I don't mean to be cynical, but cognitive science and psychology are at least 200 years behind philosophy. I can't wait until they use their pseudoscience and poorly executed statistical models to tell us something that Kant didn't pull out his ass in the late 18th century. http://en.wikipedia.org/wiki/The_Critique_of_Pure_Reason
Seriously, neuroscience is actually science, in the sense that it explores the functionality of the brain in a manner that is testable and repeatable, and so provable. Psych/cogsci had a theory about how the brain worked (one which, as I noted, had been deduced from common sense 200 years ago, so, you know, good job guys). This is step one toward actually proving that theory.
Re:Careful! (Score:4, Informative)
Re:Um, we've known this for well over 10 years!!!! (Score:1, Informative)
Great, except all of those are not even scientific theories - they are merely philosophical theories (at best, scientific hypotheses, although the falsifiability of some of these is questionable).
Having actual science to demonstrate the working of the brain is significantly more useful than any philosophical musing on how the brain works (and I would argue perhaps even still more useful than psychological theories, although there's significantly more scientific foundation in psychology these days).