8 ms·

What Happens When a Neurosurgeon Removes Your Hippocampus

111 points by ghosh 13y ago

icantthinkofone 13y ago
They subscribe to reddit.
JoeAltmaier 13y ago
I wonder how this man with no memory could have been considered competent to consent to the preservation of his brain. That part seemed a little like a circus.
- Ihmahr 13y ago
  Just ask him? He wasn't retarded, he just didn't have a working memory. You can also ask him multiple times.
  - JoeAltmaier 13y ago
    You can just ask a child too. What experience did he draw on to make an informed decision? I feel he was definitely taken advantage of.
    - Dylan16807 13y ago
      The experience of the decades of life he could remember? I don't see how postmortem brain scanning is any worse than doing memory tests on him when he's alive. And children can agree to things just fine through their guardians.
      - JoeAltmaier 13y ago
        He was 20-something when he lost his memory. So barely an adult. And memory tests are not quite the same as dissecting his brain on television, then putting it on permanent display in grotesque life-sized cross-sections. Further, he was institutionalized. So the guardians were - who? the doctors doing the dissecting?
        nitrogen 13y ago
        You say "grotesque" in several of your comments, but this is a value judgment that is not shared by all. After death, what could be more poetic than using the instrument of one's intellect, the brain, to uplift the intellects of others?
        JoeAltmaier 13y ago
        And you, as an educated 21st-century world citizen can make judgements like that for yourself. This guy arguably can't. That's the whole issue, ignoring semantic arguments about word choice.
        Dylan16807 13y ago
        And a permanent-twentysomething with an IQ of 117 can't make such a decision? Even though it barely affects him?
    - DanBC 13y ago
      The UK has the Mental Capacity Act. It's important to recognise tjat lack of capacity is limited - a person may not have capacity to look after their own money but you should not assume that they lack capacity to decide where to live for example. Informed consent is mostly not that informed. Clinicians don't understand risk, cannot communicate risk to patients, and patients can't understamd that communication.
    - dennisgorelik 13y ago
      What exactly did he loose by having his brain dissected postmortem?
  - mcguire 13y ago
    And if he gives different answers?
- patio11 13y ago
  He's an adult with many normal reasoning capabilities. Clearly if you were to ask him with regards to other preferences about the disposition of his mortal remains, like "Would you prefer to be buried or cremated? At what cemetery? What type, if any, of funeral service would you prefer?", he'd be capable of giving answers and they'd necessarily be the right ones. If he's capable of answering all of those questions, he's capable of making the decision to donate his brain to science. (After all, there is no conceivable way in which this harms his medical interests. It's not like they're asking him to consent to e.g. limited palliative care options with an eye towards getting his organs in the most usable possible state.)
  - jessriedel 13y ago
    > he'd be capable of giving answers and they'd necessarily be the right ones. > (After all, there is no conceivable way in which this harms his medical interests. It's not like they're asking him to consent to e.g. limited palliative care options with an eye towards getting his organs in the most usable possible state.) Your comment seems to assume that medical or hedonic interests are obviously more important than interests in dignity, aesthetics, or tradition. That's a popular view, but the proper way to handle these sorts of cases does not rest on it. It's very reasonable to think that one could get a legitimate answer to the question "HM, are you in pain?" without being able to get a legitimate answer to the question "HM, do you want your body used for scientific study?" The "true" HM, which we generally approximate as the man before the accident, might very well consider his dignity (as personally conceived) to be more important than pain. That's why the correct answer to this, as already pointed out by others, is to rely on his gaurdian as our best guess as to HM's true preferences.
    - JoeAltmaier 13y ago
      And his parents were dead. He was institutionalized. So who were his guardians? The doctors perhaps? The conflict of interest would then be clear.
      - ceejayoz 13y ago
- jerf 13y ago
  He probably wasn't, so I would assume he had some sort of court-appointed guardian or something (not sure which term is most applicable, but under the circumstances "guardian" may not be that far off...). That would not have been the first decision the guardian would have had to make, after all.
  - JoeAltmaier 13y ago
    At the time apparently the doctors Were his guardians? He was institutionalized without relatives. So conflict of interest is clear.
    - jerf 13y ago
      There's really no solution to this problem. It's obvious you disagree with the outcome, but equally obviously many would agree... he certainly didn't have the agency to give a solid answer by most of our standards (apparently some here disagree). There's no good solution, nor would I even agree there's a "default answer" here per se that we can fall back to. In the end all you can possibly end up with is a power struggle over whose personal preferences are going to be followed.
      - JoeAltmaier 13y ago
        Sure there's a good solution! Don't saw his head open on TV! Anybody can see that is a very dodgy move by anybody's standards.
        phkahler 13y ago
        I have to agree here. The default would be to dispose of his body in a traditional way. There could be arguments about burial or cremation or maybe some other tradition I don't know about, but no one thinks of thin-slicing the head as any kind of default in todays (or yesterdays) world. I find the question of how this got approved almost as interesting as the original story. I can only think of 3 ways to decide: 1) prior consent from a parent 2) just ask him even though his brain is not normal 3) politics. Debating the legitimacy of #2 is really just going with option #3.
sjclemmy 13y ago
Those two kinds of memory mentioned must be concious memory and unconscious memory. I'd be interested to know about how memory affects ones sense of identity. I'd also like to know if there has been any work that pinpoints the part of the brain that might give insight into self-awareness / consciousness.
- amirmc 13y ago
  The types of memory you're referring to are (more formally) declarative and implicit [1]. Please be wary of 'pinpointing' any regions involved in higher-level functions. It borders on phrenology and despite the vast interest in consciousness, no-one had claimed to have identified regions. If you haven't come across it before, I'd recommend The Man Who Mistook his Wife for a Hat by Oliver Sacks. Following that, Descartes Error by Antonio Damasio might also be interesting (if you're interested in emotion and reason). [1] http://en.m.wikipedia.org/wiki/Memory http://en.m.wikipedia.org/wiki/Memory
- Sharlin 13y ago
  "Conscious memory" and "unconscious memory" aren't really well-defined concepts; the actual classification is as follows: Explicit (declarative) memory - Semantic memory: knowledge of facts and meanings - Episodic memory: autobiographic memory of past events Implicit memory - Procedural memory: motor skills, implicit attitudes
- vacri 13y ago
  Procedural memory isn't really best termed as 'unconscious' memory. It's memory laid down through practise of a task. There's a lot of different flavours of memory, though most people think of memory as 'recall of factoids'. In terms of 'unconscious' memory, there's a semantic but salient difference between reacting automatically/unconsciously to something (being fearful of dogs because you were bitten once), and voluntarily doing an action but performing it better because of practice (playing a musical instrument). Regarding anatomy, there's no one part of the brain that is responsible for self-awareness or consciousness (both of which a philosophically difficult to define in the first place), though the frontal lobes (just behind the forehead) are usually implicated in complex thought, concentration, or expressions of personality. There's a lot of overlap in functionality in the brain, when you look at it from a viewpoint of "what bit does this task?" - broken down into its constituent bits, most tasks require a variety of functions to be handled. "What bit of the brain is involved in waving hello to a friend when we meet them?" would touch on most of the parts, for example - pure perception, pattern recognition, emotion, motor control, decision making, and a few others. The task sounds simple, but it's really quite complex once it's broken down.
klapinat0r 13y ago
Oh, this is a conflicted comment I'm posting. I've recently read a very interesting and, while intuitive, very indepth book on the subject of brains, and brain evolution/commonalities. It covers reactions, active choices, responsibilities, creativity, memory, sleeping patterns, learning and much more. It's written by a famous Danish brain surgeon, and unfortunately written in Danish. It's called "Dr. Zukaroffs Testamente" (an intertwined story following the books 500 pages explanations, making it easier to digest), by Peter Lund Madsen. Why am I commenting even though it's in danish? Because it truly is an amazing book, and one I would've loved to read back when I was deciding which path to choose in life (medschool or other), and in the hope that we may be able to push for an English translation. If you have any means of reading a Danish book, it's genuinely worth it. EDIT: Link: https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.gyldendal.dk%2Fdr-zukaroffs-testamente-id16656&edit-text= https://translate.google.com/translate?sl=auto&tl=en&js=y&pr...
- Filligree 13y ago
  Well, since I'm Norwegian and can probably read it, I'll thank you for the tip. :-)
- jnbiche 13y ago
  We have a neurologist author who writes kind of similar books: Oliver Sacks. If you've never read any of his books, he's worth checking out.
  - klapinat0r 13y ago
    Thanks, I'll check him out.
  - paulojreis 13y ago
    António Damásio (portuguese, but based in USC) is also worth checking out. Descartes' Error is a must read.
  - septerr 13y ago
    Another author (and neuroscientist) is David Eagleman. His book - Incognito: The Secret Lives of the Brain, is fantastic.
vacri 13y ago
As an aside, a way to perform well on the 'tracing-the-star-in-the-mirror' exercise: stop watching what your hand is doing, and instead feel what your hand is doing. Your vision keeps you inside the lines for the most part; where people screw up is making a decision at the vertices. If you look, you'll screw it up, but if you were drawing the star with your eyes closed, you'd know which way the pencil should go.
kevinwang 13y ago
Weird, I was just thinking about the difference between "muscle memory" (procedural), and declarative memory. Except I was thinking about people on the opposite end of the spectrum: Hyperthymesia. I was wondering if those with the condition also have superior procedural memory, but if the two forms of memory don't share the same neurological underpinnings, hyperthymesiacs shouldn't have perfect procedural memory, correct? edit: and as a corollary, I wonder if there is a condition for procedural memory parallel to hyperthymesia for declarative memory. It seems very possible, since hyperthymesia wasn't even recorded until 2006, and a superior procedural memory would be less salient.
robg 13y ago
Thanks to Henry we know far more than we ever would have about human memory. He literally gave the memories of his life to science. In return, he got none. RIP: http://en.wikipedia.org/wiki/Henry_Molaison http://en.wikipedia.org/wiki/Henry_Molaison
brightsize 13y ago
Another bio + photos at Find A Grave: http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=45095010 http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=450950...
milliams 13y ago
I wonder what taking a digital photo "at 20x magnification" actually means. Magnification implies a conversion factor between two comparable objects. There's no sensible comparison between an object 8 inches across and a digital image of that object 5000 pixels across.
- Retric 13y ago
  It's more obvious at the extremes. At 20,000x magnification your going to show a lot of details normally missed. A high resolution close up shot will often have less detail and than the same number of pixels using some magnification.
  - Retric 13y ago
    I guess I did not get my point across aka not all pixels are equivalent. A camera such as a cellphone camera is designed to take a fairly wide angle picture. It also has a minimum distance it needs to be from an object so moving your finger closer to the sensor stops providing more detail at some point and just provides a blurry mess. Adding a magnifying lens between the camera and the subject allows you to get more details at the same distance by sacrificing that wide field of view. With the right setup it also allows for higher detailed pictures of the same object aka more details than you would get at the minimum distance for a clear picture. So that 20x zoom refers to the physical optical zoom. You can try this by comparing the highest detailed picture of your hand from your cellphone with and without a magnifing glass.
- twic 13y ago
  The digital photo is captured using a physical sensor. It is meaningful to talk about the ratio of the size of the object, and the size of the image formed on the sensor - this is called the reproduction ratio. It's as relevant now as it was back when images were captured on film and then blown up onto prints. It is the combination of the reproduction ratio and the resolution of the sensor (in pixels per unit distance on the sensor) which determines the resolution of the image (in pixels per unit distance on the object). That said, it's not clear that this is what is meant here.
- 13y ago
andyjohnson0 13y ago
"It was like early retirement, except for the days a Ph.D student named Brenda Milner arrived to test him." Brenda Milner went on to become a founder of the field of neuropsychology. She's now in her nineties and, according to wikipedia, is still active in research and teaching [1]. [1] http://en.wikipedia.org/wiki/Brenda_Milner#Current_life.2Fresearch http://en.wikipedia.org/wiki/Brenda_Milner#Current_life.2Fre...
joveian 13y ago
"Given how deeply all these structures are embedded in the brain, only a neurosurgeon could have destroyed them with such precision." This is just false to the extent it isn't nonsensical. The surgeon claimed that the destruction was precise, but the autopsy actually determined that damage was much more widespread than expected. This has resulted in reconsideration of theories that were based on assumptions that the damage was more limited. In general, when reading anything that mentions H.M. without mentioning this fact it is important to keep that in mind. This article should have taken the new knowledge into account, but continues to present false information. This is the type of jounalism that helps make it very difficult for popular but incorrect scientific information to be corrected. Another example of this I know of is how REM sleep is commonly referred to as "dream sleep" (including, unfortunately, on Wikipedia last I checked) although the idea that dreaming happens only or even primarily in REM sleep has been considered disproven for multiple decades now and was based on flawed early studies that continue to be described uncritically long after the serious flaws are well known. On the topic of books: one really excelent (although old now, mostly written in the early 90s and maybe late 80s IIRC) technical book on brain organization is Pierre Gloor's _The Temporal Lobe and Limbic System_. I haven't looked again recently, but I don't know of a comparable work where a neroscientist tries to lay out in depth (it is a neruoscience text) almost everything known about how the brain works together (it is easy to see why; it is a huge amount of work!).
- slazaro 13y ago
  > including, unfortunately, on Wikipedia last I checked I'm gonna be that guy: did you try editing it to make it more accurate?
  - enraged_camel 13y ago
    To be fair, last time I tried to make an edit on Wikipedia, it resulted in a huge argument that spanned literally several days, at the end of which I gave up. Note that this was a tiny edit, changing the word order in a sentence or something like that on a rather niche topic. I haven't bothered trying to edit anything since then.
todd8 13y ago
I heard about this back in 1971 or 1972 as an undergraduate student. In order to satisfy a general humanities requirement I took a class, 9.01 to be precise (or roughly Intro to Psychology). It turned out to be nothing like I expected. There was only one lecture (two hours) per week on thursday nights. Right away I realized that they were going to be different. The largest lecture hall at MIT (capable of holding half of the entire Freshman class) was packed. People would sit on the stairs and aisles between the fully occupied seats and the head and creator of the Psychology department Professor Hans-Lukas Teuber[1] lectured. It was like listening to the most fascinating episode of Discovery every week. He was an amazing intellect, and he lectured on brain science. During the lecture on memory, he discussed this very case and his experience of meeting this patient. He said that every time he entered the room he had to be re-introduced to the patient. But he said there were hints of the mystery of memory. He showed the patient a half-dollar with an image John F. Kennedy on it and the patient said something that indicated an awareness of JFK (assassinated in 63). He published a few papers with Brenda Milner. As the semester passed the lecture hall filled more and more until there was finally standing room only, and the final lecture was followed by a standing ovation. It was an absolutely masterful introduction to brain science, delivered in a series of two hour lectures, without ever using notes. Professor Teuber spoke of the need to study the brain scientifically, to treat subjects and patients humanely, and the need for appropriate ethical guidelines in the field. He made me realize that everything we do, from recognizing our grandmother, scratching our back, or recalling an early romance involves fantastic processes in our brain. After that course, I decided that I would change majors. I went to the Psychology department where (fortunately) they told me that MIT didn't offer an undergrad degree in Psychology. Math and EE/CS was where I stayed. [1] http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/teuber-hans-lukas.pdf http://www.nasonline.org/publications/biographical-memoirs/m...
skizm 13y ago
> For or good measure, Scoville removed H.M.’s amygdalae and other nearby structures as well. How do they separate the effects of these two? The amygdalae plays a large part in emotion, which probably accounted more for H.M.'s mood changes than the hippocampus. Also memories tied to emotion are more strongly remembered. How do they know they didn't destroy another path to creating memories via the amygdalae? Maybe there are three or more types of memory storage systems. I do agree that the "muscle memory" test was fairly conclusive but the other conclusions drawn are not.
tom_jones 13y ago
As phenomenally complex, finely tuned, and resilient as the mind is, there are those with otherwise excellent minds who not only believe such minds were created by random chance, but scoff at the idea that the mind was designed.

111 points by ghosh 13y ago

They subscribe to reddit.

I wonder how this man with no memory could have been considered competent to consent to the preservation of his brain. That part seemed a little like a circus.

Ihmahr 13y ago
Just ask him? He wasn't retarded, he just didn't have a working memory. You can also ask him multiple times.
- JoeAltmaier 13y ago
  You can just ask a child too. What experience did he draw on to make an informed decision? I feel he was definitely taken advantage of.
  - Dylan16807 13y ago
    The experience of the decades of life he could remember? I don't see how postmortem brain scanning is any worse than doing memory tests on him when he's alive. And children can agree to things just fine through their guardians.
    - JoeAltmaier 13y ago
      He was 20-something when he lost his memory. So barely an adult. And memory tests are not quite the same as dissecting his brain on television, then putting it on permanent display in grotesque life-sized cross-sections. Further, he was institutionalized. So the guardians were - who? the doctors doing the dissecting?
      - nitrogen 13y ago
        You say "grotesque" in several of your comments, but this is a value judgment that is not shared by all. After death, what could be more poetic than using the instrument of one's intellect, the brain, to uplift the intellects of others?
        JoeAltmaier 13y ago
        And you, as an educated 21st-century world citizen can make judgements like that for yourself. This guy arguably can't. That's the whole issue, ignoring semantic arguments about word choice.
        Dylan16807 13y ago
        And a permanent-twentysomething with an IQ of 117 can't make such a decision? Even though it barely affects him?
  - DanBC 13y ago
    The UK has the Mental Capacity Act. It's important to recognise tjat lack of capacity is limited - a person may not have capacity to look after their own money but you should not assume that they lack capacity to decide where to live for example. Informed consent is mostly not that informed. Clinicians don't understand risk, cannot communicate risk to patients, and patients can't understamd that communication.
  - dennisgorelik 13y ago
    What exactly did he loose by having his brain dissected postmortem?
- mcguire 13y ago
  And if he gives different answers?
patio11 13y ago
He's an adult with many normal reasoning capabilities. Clearly if you were to ask him with regards to other preferences about the disposition of his mortal remains, like "Would you prefer to be buried or cremated? At what cemetery? What type, if any, of funeral service would you prefer?", he'd be capable of giving answers and they'd necessarily be the right ones. If he's capable of answering all of those questions, he's capable of making the decision to donate his brain to science. (After all, there is no conceivable way in which this harms his medical interests. It's not like they're asking him to consent to e.g. limited palliative care options with an eye towards getting his organs in the most usable possible state.)
- jessriedel 13y ago
  > he'd be capable of giving answers and they'd necessarily be the right ones. > (After all, there is no conceivable way in which this harms his medical interests. It's not like they're asking him to consent to e.g. limited palliative care options with an eye towards getting his organs in the most usable possible state.) Your comment seems to assume that medical or hedonic interests are obviously more important than interests in dignity, aesthetics, or tradition. That's a popular view, but the proper way to handle these sorts of cases does not rest on it. It's very reasonable to think that one could get a legitimate answer to the question "HM, are you in pain?" without being able to get a legitimate answer to the question "HM, do you want your body used for scientific study?" The "true" HM, which we generally approximate as the man before the accident, might very well consider his dignity (as personally conceived) to be more important than pain. That's why the correct answer to this, as already pointed out by others, is to rely on his gaurdian as our best guess as to HM's true preferences.
  - JoeAltmaier 13y ago
    And his parents were dead. He was institutionalized. So who were his guardians? The doctors perhaps? The conflict of interest would then be clear.
    - ceejayoz 13y ago
jerf 13y ago
He probably wasn't, so I would assume he had some sort of court-appointed guardian or something (not sure which term is most applicable, but under the circumstances "guardian" may not be that far off...). That would not have been the first decision the guardian would have had to make, after all.
- JoeAltmaier 13y ago
  At the time apparently the doctors Were his guardians? He was institutionalized without relatives. So conflict of interest is clear.
  - jerf 13y ago
    There's really no solution to this problem. It's obvious you disagree with the outcome, but equally obviously many would agree... he certainly didn't have the agency to give a solid answer by most of our standards (apparently some here disagree). There's no good solution, nor would I even agree there's a "default answer" here per se that we can fall back to. In the end all you can possibly end up with is a power struggle over whose personal preferences are going to be followed.
    - JoeAltmaier 13y ago
      Sure there's a good solution! Don't saw his head open on TV! Anybody can see that is a very dodgy move by anybody's standards.
      - phkahler 13y ago
        I have to agree here. The default would be to dispose of his body in a traditional way. There could be arguments about burial or cremation or maybe some other tradition I don't know about, but no one thinks of thin-slicing the head as any kind of default in todays (or yesterdays) world. I find the question of how this got approved almost as interesting as the original story. I can only think of 3 ways to decide: 1) prior consent from a parent 2) just ask him even though his brain is not normal 3) politics. Debating the legitimacy of #2 is really just going with option #3.

sjclemmy 13y ago

Those two kinds of memory mentioned must be concious memory and unconscious memory. I'd be interested to know about how memory affects ones sense of identity. I'd also like to know if there has been any work that pinpoints the part of the brain that might give insight into self-awareness / consciousness.

amirmc 13y ago
The types of memory you're referring to are (more formally) declarative and implicit [1]. Please be wary of 'pinpointing' any regions involved in higher-level functions. It borders on phrenology and despite the vast interest in consciousness, no-one had claimed to have identified regions. If you haven't come across it before, I'd recommend The Man Who Mistook his Wife for a Hat by Oliver Sacks. Following that, Descartes Error by Antonio Damasio might also be interesting (if you're interested in emotion and reason). [1] http://en.m.wikipedia.org/wiki/Memory http://en.m.wikipedia.org/wiki/Memory
Sharlin 13y ago
"Conscious memory" and "unconscious memory" aren't really well-defined concepts; the actual classification is as follows: Explicit (declarative) memory - Semantic memory: knowledge of facts and meanings - Episodic memory: autobiographic memory of past events Implicit memory - Procedural memory: motor skills, implicit attitudes
vacri 13y ago
Procedural memory isn't really best termed as 'unconscious' memory. It's memory laid down through practise of a task. There's a lot of different flavours of memory, though most people think of memory as 'recall of factoids'. In terms of 'unconscious' memory, there's a semantic but salient difference between reacting automatically/unconsciously to something (being fearful of dogs because you were bitten once), and voluntarily doing an action but performing it better because of practice (playing a musical instrument). Regarding anatomy, there's no one part of the brain that is responsible for self-awareness or consciousness (both of which a philosophically difficult to define in the first place), though the frontal lobes (just behind the forehead) are usually implicated in complex thought, concentration, or expressions of personality. There's a lot of overlap in functionality in the brain, when you look at it from a viewpoint of "what bit does this task?" - broken down into its constituent bits, most tasks require a variety of functions to be handled. "What bit of the brain is involved in waving hello to a friend when we meet them?" would touch on most of the parts, for example - pure perception, pattern recognition, emotion, motor control, decision making, and a few others. The task sounds simple, but it's really quite complex once it's broken down.

klapinat0r 13y ago

Oh, this is a conflicted comment I'm posting. I've recently read a very interesting and, while intuitive, very indepth book on the subject of brains, and brain evolution/commonalities. It covers reactions, active choices, responsibilities, creativity, memory, sleeping patterns, learning and much more. It's written by a famous Danish brain surgeon, and unfortunately written in Danish. It's called "Dr. Zukaroffs Testamente" (an intertwined story following the books 500 pages explanations, making it easier to digest), by Peter Lund Madsen. Why am I commenting even though it's in danish? Because it truly is an amazing book, and one I would've loved to read back when I was deciding which path to choose in life (medschool or other), and in the hope that we may be able to push for an English translation. If you have any means of reading a Danish book, it's genuinely worth it. EDIT: Link: https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.gyldendal.dk%2Fdr-zukaroffs-testamente-id16656&edit-text= https://translate.google.com/translate?sl=auto&tl=en&js=y&pr...

Filligree 13y ago
Well, since I'm Norwegian and can probably read it, I'll thank you for the tip. :-)
jnbiche 13y ago
We have a neurologist author who writes kind of similar books: Oliver Sacks. If you've never read any of his books, he's worth checking out.
- klapinat0r 13y ago
  Thanks, I'll check him out.
- paulojreis 13y ago
  António Damásio (portuguese, but based in USC) is also worth checking out. Descartes' Error is a must read.
- septerr 13y ago
  Another author (and neuroscientist) is David Eagleman. His book - Incognito: The Secret Lives of the Brain, is fantastic.

vacri 13y ago

As an aside, a way to perform well on the 'tracing-the-star-in-the-mirror' exercise: stop watching what your hand is doing, and instead feel what your hand is doing. Your vision keeps you inside the lines for the most part; where people screw up is making a decision at the vertices. If you look, you'll screw it up, but if you were drawing the star with your eyes closed, you'd know which way the pencil should go.

kevinwang 13y ago

Weird, I was just thinking about the difference between "muscle memory" (procedural), and declarative memory. Except I was thinking about people on the opposite end of the spectrum: Hyperthymesia. I was wondering if those with the condition also have superior procedural memory, but if the two forms of memory don't share the same neurological underpinnings, hyperthymesiacs shouldn't have perfect procedural memory, correct? edit: and as a corollary, I wonder if there is a condition for procedural memory parallel to hyperthymesia for declarative memory. It seems very possible, since hyperthymesia wasn't even recorded until 2006, and a superior procedural memory would be less salient.

robg 13y ago

Thanks to Henry we know far more than we ever would have about human memory. He literally gave the memories of his life to science. In return, he got none. RIP: http://en.wikipedia.org/wiki/Henry_Molaison http://en.wikipedia.org/wiki/Henry_Molaison

brightsize 13y ago

Another bio + photos at Find A Grave: http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=45095010 http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=450950...

milliams 13y ago

I wonder what taking a digital photo "at 20x magnification" actually means. Magnification implies a conversion factor between two comparable objects. There's no sensible comparison between an object 8 inches across and a digital image of that object 5000 pixels across.

Retric 13y ago
It's more obvious at the extremes. At 20,000x magnification your going to show a lot of details normally missed. A high resolution close up shot will often have less detail and than the same number of pixels using some magnification.
- Retric 13y ago
  I guess I did not get my point across aka not all pixels are equivalent. A camera such as a cellphone camera is designed to take a fairly wide angle picture. It also has a minimum distance it needs to be from an object so moving your finger closer to the sensor stops providing more detail at some point and just provides a blurry mess. Adding a magnifying lens between the camera and the subject allows you to get more details at the same distance by sacrificing that wide field of view. With the right setup it also allows for higher detailed pictures of the same object aka more details than you would get at the minimum distance for a clear picture. So that 20x zoom refers to the physical optical zoom. You can try this by comparing the highest detailed picture of your hand from your cellphone with and without a magnifing glass.
twic 13y ago
The digital photo is captured using a physical sensor. It is meaningful to talk about the ratio of the size of the object, and the size of the image formed on the sensor - this is called the reproduction ratio. It's as relevant now as it was back when images were captured on film and then blown up onto prints. It is the combination of the reproduction ratio and the resolution of the sensor (in pixels per unit distance on the sensor) which determines the resolution of the image (in pixels per unit distance on the object). That said, it's not clear that this is what is meant here.
13y ago

andyjohnson0 13y ago

"It was like early retirement, except for the days a Ph.D student named Brenda Milner arrived to test him." Brenda Milner went on to become a founder of the field of neuropsychology. She's now in her nineties and, according to wikipedia, is still active in research and teaching [1]. [1] http://en.wikipedia.org/wiki/Brenda_Milner#Current_life.2Fresearch http://en.wikipedia.org/wiki/Brenda_Milner#Current_life.2Fre...

joveian 13y ago

"Given how deeply all these structures are embedded in the brain, only a neurosurgeon could have destroyed them with such precision." This is just false to the extent it isn't nonsensical. The surgeon claimed that the destruction was precise, but the autopsy actually determined that damage was much more widespread than expected. This has resulted in reconsideration of theories that were based on assumptions that the damage was more limited. In general, when reading anything that mentions H.M. without mentioning this fact it is important to keep that in mind. This article should have taken the new knowledge into account, but continues to present false information. This is the type of jounalism that helps make it very difficult for popular but incorrect scientific information to be corrected. Another example of this I know of is how REM sleep is commonly referred to as "dream sleep" (including, unfortunately, on Wikipedia last I checked) although the idea that dreaming happens only or even primarily in REM sleep has been considered disproven for multiple decades now and was based on flawed early studies that continue to be described uncritically long after the serious flaws are well known. On the topic of books: one really excelent (although old now, mostly written in the early 90s and maybe late 80s IIRC) technical book on brain organization is Pierre Gloor's _The Temporal Lobe and Limbic System_. I haven't looked again recently, but I don't know of a comparable work where a neroscientist tries to lay out in depth (it is a neruoscience text) almost everything known about how the brain works together (it is easy to see why; it is a huge amount of work!).

slazaro 13y ago
> including, unfortunately, on Wikipedia last I checked I'm gonna be that guy: did you try editing it to make it more accurate?
- enraged_camel 13y ago
  To be fair, last time I tried to make an edit on Wikipedia, it resulted in a huge argument that spanned literally several days, at the end of which I gave up. Note that this was a tiny edit, changing the word order in a sentence or something like that on a rather niche topic. I haven't bothered trying to edit anything since then.

todd8 13y ago

I heard about this back in 1971 or 1972 as an undergraduate student. In order to satisfy a general humanities requirement I took a class, 9.01 to be precise (or roughly Intro to Psychology). It turned out to be nothing like I expected. There was only one lecture (two hours) per week on thursday nights. Right away I realized that they were going to be different. The largest lecture hall at MIT (capable of holding half of the entire Freshman class) was packed. People would sit on the stairs and aisles between the fully occupied seats and the head and creator of the Psychology department Professor Hans-Lukas Teuber[1] lectured. It was like listening to the most fascinating episode of Discovery every week. He was an amazing intellect, and he lectured on brain science. During the lecture on memory, he discussed this very case and his experience of meeting this patient. He said that every time he entered the room he had to be re-introduced to the patient. But he said there were hints of the mystery of memory. He showed the patient a half-dollar with an image John F. Kennedy on it and the patient said something that indicated an awareness of JFK (assassinated in 63). He published a few papers with Brenda Milner. As the semester passed the lecture hall filled more and more until there was finally standing room only, and the final lecture was followed by a standing ovation. It was an absolutely masterful introduction to brain science, delivered in a series of two hour lectures, without ever using notes. Professor Teuber spoke of the need to study the brain scientifically, to treat subjects and patients humanely, and the need for appropriate ethical guidelines in the field. He made me realize that everything we do, from recognizing our grandmother, scratching our back, or recalling an early romance involves fantastic processes in our brain. After that course, I decided that I would change majors. I went to the Psychology department where (fortunately) they told me that MIT didn't offer an undergrad degree in Psychology. Math and EE/CS was where I stayed. [1] http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/teuber-hans-lukas.pdf http://www.nasonline.org/publications/biographical-memoirs/m...

skizm 13y ago

> For or good measure, Scoville removed H.M.’s amygdalae and other nearby structures as well. How do they separate the effects of these two? The amygdalae plays a large part in emotion, which probably accounted more for H.M.'s mood changes than the hippocampus. Also memories tied to emotion are more strongly remembered. How do they know they didn't destroy another path to creating memories via the amygdalae? Maybe there are three or more types of memory storage systems. I do agree that the "muscle memory" test was fairly conclusive but the other conclusions drawn are not.

tom_jones 13y ago

As phenomenally complex, finely tuned, and resilient as the mind is, there are those with otherwise excellent minds who not only believe such minds were created by random chance, but scoff at the idea that the mind was designed.