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The Unforgettable Amnesiac
Posted by
kdawson
on Sat Dec 06, 2008 11:14 PM
from the every-20-seconds-a-new-day dept.
from the every-20-seconds-a-new-day dept.
jamie found an account in the NYTimes of the life and death of one of the most important figures in modern neuroscience, Henry Gustav Molaison — a man who could not form memories. Molaison became an amnesiac after a brain operation in 1953. Known worldwide as H.M., Molaison was studied intensively for 55 years. Dr. Brenda Milner, a psychologist from Montreal, was the first researcher to visit Molaison. In 1962 she authored a landmark study demonstrating that a part of Molaison's memory was fully intact. "The implications were enormous. Scientists saw that there were at least two systems in the brain for creating new memories. One, known as declarative memory, records names, faces and new experiences and stores them until they are consciously retrieved. ... Another system, commonly known as motor learning, is subconscious and depends on other brain systems. This explains why people can jump on a bike after years away from one and take the thing for a ride, or why they can pick up a guitar that they have not played in years and still remember how to strum it. Soon 'everyone wanted an amnesic to study,' Dr. Milner said..."
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What was I going to post? (Score:5, Funny)
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Re:What was I going to post? (Score:5, Informative)
New Topic:
H.M. learned how to solve the Tower of Hanoi (documented by decreasing time to solve) but denied ever seeing the Tower of Hanoi before.
This is an example of some evidence that distinguished between semantic(facts) and episodic(event) memory systems.
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Re:What was I going to post? (Score:5, Interesting)
A scientist would tape a tack onto his palm. Then he would walk into the room with H.M. He would first ask him, "Have you ever seen me before?" H.M. would deny ever seeing the scientist before. Then they would shake hands. OUCH!! The scientist leaves the room, and comes back in two minutes. Rinse. Repeat. H.M. over and over would get poked by the tack.
Then one day: Scientist asks, "Have you ever seen me before?" H.M. denies seeing the scientist before. The scientist offers a hand to shake. H.M. refuses to shake hands. When asked why, H.M. responds,
"Sometimes scientists tape tacks on their palms."
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Does make me wonder about our "gut feel" stuff and how accurate it is, and how it might be subverted. A lot of our decisions are not based on the "declarative" stuff.
Whether you choose chocolate or vanilla, fried chicken or something else. You might make up the reasons later (justify your decisions), but maybe your gut has already chosen. Of course if you see something gross, your gut gets informed about it
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Without disputing the Doctor's main conclusion, which goes well with the current mainstream understanding in psychology, and without having read the primary source of his study (the google sholar link only showed a summarized secondary source), I'd like to dispute the Doctor's particular line of thinking in this example (at least, the reasoning that I could glean from the secondary source, perhaps his actua
Re:What was I going to post? (Score:5, Funny)
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Interesting case (Score:4, Interesting)
Re:Interesting case (Score:5, Informative)
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Re:Interesting case (Score:5, Interesting)
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Re:Interesting case (Score:5, Funny)
...and his wife has of course visibly aged, he's not surprised by her current appearance.
Well of course not, he hasn't seen her in years!
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There was this one guy a few years ago who, whenever he bumped his head (not a big bump, either), he'd forget what he was doing.
He sat in a van for 2 days in the middle of winter, engine idling, trying to figure out what to do next. The Montreal police finally found him and called his wife.
Memory is a strange beast at times.
I believe this was part of the inspiration (Score:5, Informative)
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...and 50 First Dates.
Re:I believe this was part of the inspiration (Score:5, Funny)
Just when you thought it was safe to form new memories...
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Offered his brain for further scientific study (Score:5, Interesting)
I am sure that this man's misfortune has provided the rest of us a great opportunity to benefit form the research that has been performed on him to date, and possible further gains with his brian now (or soon to be) directly accessible to scientific research.
But I do wonder how a man who was unable to create new memories (or at least had great difficulty in this area) would be able to take in what is going on around him and give informed consent to offer his brain for further study after his passing.
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Re:Offered his brain for further scientific study (Score:5, Interesting)
This may well be, but the NPR piece on this seem to make a big point about HM himself wanting his brain to be available for further research.
In my mind this would seem to imply that he had an understanding that he was an unusual case. The story seemed to imply that with great effort he was able to remember items beyond the 30 seconds of short term memory, but given the complexities of this case I wonder how much he himself understood of it as his life drew to a close.
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Re:Offered his brain for further scientific study (Score:5, Informative)
One of the quotes from H.M. I always read in my neuroscience classes:
"Right now I'm wondering, have I done or said anything amiss? You see, at this moment everything looks clear to me, but what happened just before? That's what worries me. It's like waking from a dream; I just don't remember.... Every day is alone in itself, whatever enjoyment I've had, whatever sorrow."
RIP, Henry.
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So sub consciously he knew he was helping. So when asked to consent to giving his brain up, it was probably that sub conscious that gave him the feeling to say "Yes, I'll do that."
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You only have to get his signature on some paper ONCE ;)
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Evil Mad Nazi Scientists?
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Generally speaking,
consent to treatment isn't predicated on memory per se. Here is the link to a PDF file written by one the noted experts on competence to consent to treatment:
http://content.nejm.org/cgi/reprint/357/18/1834.pdf [nejm.org]
The Grisso and Applebaum book "Assessing Competence to Consent for Treatment: A Guide for Physicians and Other Health Care Providers" is the defacto book for health care providers to understand and assess competence as it relates to medical decision making.
hth,
jeff
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thanks for the memories (Score:5, Funny)
So when we see this article duped next week, now we'll know why?
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Re:thanks for the memories (Score:5, Funny)
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Authored???? (Score:2, Funny)
Verbing weirds language :-(
Re:Authored???? (Score:5, Informative)
Author has been a verb (and a noun) since at least 1596 (oed) [oed.com].
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Re:Authored???? (Score:5, Informative)
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I've noticed that (at least in my generation, I'm 19 (*)) people don't think the generation before them knew many of the stuff they knew. Like swear words, expressions, jokes and other similar things. Maybe a generation is like a new day in the life of a species and that species doesn't remember the previous 'day' properly. You don't remember everything you did yesterday and feel weird when something similar happens again.
(*) notice how I have the same problem, did people
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You've really never heard the word "authored" before? It's not that uncommon.
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Re:Authored???? (Score:5, Interesting)
It's been a valid use of the word for 400 years.
"The problem with defending the purity of the English language is that English is about as pure as a cribhouse whore. We don't just borrow
words; on occasion, English has pursued other languages down alleyways to beat them unconscious and rifle their pockets for new vocabulary."
--James D. Nicoll
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Hmm... (Score:4, Funny)
Looking down from Heaven, Gustav Molaison was surprised to learn people remembered him.
H.M. Is the Father of my Field (Score:5, Informative)
The most important contribution of H.M. is helping pin down the fact that for Episodic memory, the Medial Temporal Lobe is critical. From there a whole lot of work has been done pinning down the sub regions of the Medial Temporal Lobe with memory function:
The hippocampus: CA1 CA3 and dentate gyrus, is important for associating memory traces with contexts. The surrounding cortices important for making global assessments of the familiarity of a memory trace. Look up Professor Andrew Yonelinas at his UC Davis website for some current reviews of Recollection and Familiarity processes.
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When I see slashdot stories like this, I'm always hopeful that someone will post links to relevant and insightful research information that I might use to glean more insight into how intelligence works. I do realize that this last sentence might not have been overly intelligent, but I do have a notion that the human brain (in fact all mammalian brains) function as several highly integrated processors might. I've tried finding discussions and research along these lines, but it would seem non-existent or not
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FSM Google Search [google.com]
Not the first results surely?
Explain.
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mea culpa - Yes, I did mean finite state machine. Though a complex cascade of flying spaghetti monsters has a certain ring to it.
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Link to another interesting article (Score:5, Informative)
I find this stuff fascinating. Oliver Sacks [wikipedia.org], who has researched this condition, wrote a lengthy article about Clive Wearing [newyorker.com], who is another person with the same condition as H.M.
One of the best ways to explore motor control (Score:3, Interesting)
This is obvious if you have experienced it (Score:3, Interesting)
3 Case Studies (Score:3, Informative)
Due to an accidental needle stick while working in surgery, I contracted hepatitis C. I didn't know it until my liver almost stopped working. The way I found out about it was being told that I'd totaled my van the day before as well as having two other accidents. In all 3 cases the police came and didn't detect any evidence of intoxication. And I wasn't intoxicated. But I was anesthetized. I was taking prescribed amounts of Ativan and Benadryl. My liver wasn't clearing them out of me, and they built up to a level that made me a fully functional zombie. I've since had another episode of amnesia caused by medication, and my liver is running at 100% now. I took Ambien, and ended up 2 days later finding out that I'd spent the previous 2 days eating all 30 days worth of the stuff, forgetting that I'd taken any previously. The first dose caused it. And it's even listed as a side effect: "can cause sleep walking with no memory of the event". It's not sleepwalking, but it's a good description anyway.
The most distressing case of amnesia I ever saw was an educational movie about a man who had been an orchestra conductor, had been in an accident, and due to the whiplash effect of the brain inside the skull, sustained brain damage in the hippocampus, where memories are formed. The best (or worst, you decide) example of what a person goes through was shown in the movie as he wrote in his journal "I have just woken up. I have only just this moment become aware." Over, and over, and over, day after day.
I once visited a man in a nursing home who had amnesia. He was due to all the thiamine (vitamin B-1) being washed out of his hippocampus by alcohol. Commonly called "wet brain", its clinical name is Wernicke-Korsakoff syndrome. It appears almost exactly like Alzheimer's. You can tell the difference by giving the person a list of words to remember. Later, ask them to recall the words, and neither can. But give the first two letters of the words, and the W-K patients can recall the words. They have implicit memory -- they can remember, but they don't know they remember. The Alzheimer's patients can't recall even having been given the list if shown the complete list later. As I spoke with this man, he frequently interrupted and asked me my name, what I do for a living, and similar questions, and asked these same questions again every couple minutes. He never once caught on to the fact that I was his son, and I didn't bother to tell him, because he wouldn't have remembered it just a few minutes later.