What Happens When a Neurosurgeon Removes Your Hippocampus
wired.com
wired.com
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!).
I'm gonna be that guy: did you try editing it to make it more accurate?
I haven't bothered trying to edit anything since then.
For all our sake, I hope you choose to make appropriate edits where you see they are needed. Don't be deterred by that one experience.
I routinely make changes to wikipedia, once you have a decent reputation and have demonstrated competency in an area it's a very fluid process. Obviously if I tried changing one of the contention pages (political, religious etc) that would be a different matter, but for the areas that I am knowledgeable, CS and art history, changes are accepted and stick.
Right, so once you have dedicated many hours of your life, editing becomes easier. I imagine that's why most consider it "not worth the effort." If I can't get a good edit with supporting evidence to stick without first spending a large amount of time in the system, I'll probably pass.
And while you might have had a good experience plenty of people get embroiled in kafkesque bureaucratic policy stuff after attempting to make small uncontroversial edits to uncontroversial articles.
They'll change some spelling and punctuation without being logged in. Someone using rollback or twinkle will rapidly revert, and leave a vandalism warning on the IP page. The IP editor will remove that warning, revert the edit, and say something like "what? This isn't vandalism, read what I changed". At that point a bunch of people descend and there is little hope of getting the edits to stick. Someone will suggest creating an account to look more legit (even though most useful edits are made by anon accounts). The IP will create an account and log in to continue the discussion. Even though their name passes the strict software-enforced requirements they might find someone taking them to one of the noticeboards for usernames (the fact that WP has more than one admin area for usernames, on top of software enforced policy, is an elegant example of how out of control bureaucracy is.). Assuming they get through this someone back at the talk page will accuse them of sock-puppeting and will template their page.
Someone will slap up a welcome template. So the new users sends them a message asking for help. The other user will maybe say "I can't actually help you; i don't really know that much about policy; I'm just doing this on my way to get admin rights". Or they will agree to help, at which point the new user is accused of forum shopping.
I'd love to see some decent research on the experience of new editors at WP. I know several people who attempted to make good quality edits to uncontroversial articles who had a horrible experience. WP is, for some people, thoroughly toxic.
This is flat wrong. Based on structural neuroimaging evidence, Corkin et al. (1997) showed that HM's resection was less extensive than Scoville's notes suggested, not more extensive. The more recent post-mortem analysis of HM's brain (Annese et al., 2014) concurs, and in fact gives an even more conservative estimate of the resection.
As a researcher who studies memory and works with severely amnesic patients, I think that it's important to point out that the precision of HM's lesion was unique in our field because every other bilateral hippocampal amnesic patient has a naturally-occurring lesion. Etiologies vary (herpes simplex encephalitis, anoxia, and, historically, Korsakoff's), but common to each etiology is the potential for widespread damage beyond the hippocampus and medial temporal lobe (MTL). Given that HM's surgery predated sophisticated neuroimaging methods, his case provided researchers of the era the very best possibility of isolating the cognitive processes that depended on the MTL. There have been many methodological and theoretical improvements over the intervening decades, but the work that Brenda Milner, Sue Corkin, and many others carried out with HM was seminal for the field.
Annese, J., Schenker-Ahmed, N. M., Bartsch, H., Maechler, P., Sheh, C., Thomas, N., … Corkin, S. (2014). Postmortem examination of patient H.M.’s brain based on histological sectioning and digital 3D reconstruction. Nature Communications, 5, 3122. doi:10.1038/ncomms4122
Corkin, S., Amaral, D. G., Gonzalez, R. G., Johnson, K. A., & Hyman, B. T. (1997). H.M.’s medial temporal lobe lesion: findings from magnetic resonance imaging. J. Neurosci., 17, 3964–3979.
I think part of what I was thinking of was from this previous wired article on the study you mention: http://www.wired.com/2014/01/hm-brain-closeup
Particularly Suzane Corkin's quote about shifting the emphasis from the hippocampus to the entorhinal cortex.
The wider damage I was misremembering the extent and cause of looks like it was the combination of the left orbitofrontal legion (possibly but not necessarily connected to the accident or surgery) and the cerebellar atrophy (attributed to anticonvulsant medication). The most recent paper suggest that the cerebellar atrophy was likely to do lifelong medication, but I'm not sure if the higher does of whatever medication he took prior to sugery could have caused that as well. In any case, little if any of the additional damage was likely related to the sugery so as you say that point I made is wrong.
Apologies to all for the misinformation and thanks for the correction and references.
Edit: Also, I suspect I was partly thinking of this article as well and others along these lines (rather than what I actually said): http://hargreaves.swong.webfactional.com/HM.htm
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&pr...
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/m...
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.2Fre...
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.
That said, it's not clear that this is what is meant here.
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.
And children can agree to things just fine through their guardians.
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?
Informed consent is mostly not that informed. Clinicians don't understand risk, cannot communicate risk to patients, and patients can't understamd that communication.
> (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.
Because in this case it wasn't the whole story that he 'happens to have a major medical condition'. The condition speaks directly to his ability to think and decide. Similarly to a child, or a senile person, at least in some degree.
The man literally cannot form new memories. How could we say that he could change his mind about something in a meaningful way? All the life experiences, reasoned arguments, etc. that are supposed to lead to people rationally changing their minds do not work on H.M.
Look, people end up mentally crippled in all sorts of ways, and we are forced all the time to ask the question "Is he so crippled that we cannot trust this new version? Or is the impairment minor enough that this new version is better representation than a third party mental model?" This question is unavoidable because there are extremes that make it clearly "yes" in some circumstances and clearly "no" in others. We have the "real, actual, living patient" in front of us all the time, and often they are profoundly disabled.
But what they did was, saw his brain out on TV, then slice it into grotesque slides that they preserved on permanent display. Lots of people would have a problem with that.
Its questionable if he could be considered an adult. Certainly not an adult like you and me. Not able to 'think about it for a while' for instance. Perhaps the only answers he could give were impulsive ones. It would be childs-play to get him into a frame of mind where he was anxious to be agreeable, then pop the question.
Lots of people don't.
If he was the type of person to object to that sort of thing, he would say so. They can do that to my brain, I don't care, I don't need to 'think about it for a while'.
And it's easy to verify if he was tricked. Ask him again later. But someone trusted should have been doing the asking in the first place, making this a non-issue. Not that I agree with your patronizing assertion of how easy it would be.
I agree with your conclusion, that if there were a conflict of interest, then it's an outrage. But please don't assume something then draw conclusions from it.
It seems that you have strong emotions about the issue. I guess you would not have consented to this treatment. That's okay. But strong emotions doesn't make circular reasoning right.
Please let me know if you find, or have found already, anything more about the court-appointed guardian.
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.
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.
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).
Explicit (declarative) memory
- Semantic memory: knowledge of facts and meanings
- Episodic memory: autobiographic memory of past events
Implicit memory
- Procedural memory: motor skills, implicit attitudesRegarding 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.
Not exactly answering your question, but one neuroscientist (who got a Nobel Prize... if I remember correctly) who worked on phantom limbs, did a lot of work on damaged brains and one of his patients could not recognize his mother when meeting her face to face, but instantly recognized her when talking with her over the phone. The "wiring" between different parts of the brains was involved to link the memory of the person with the sensory signals, and for that patient the "link" between the visual stimulus and memory was somehow broken while the auditory one was intact. Very interesting.
At this point her husband sang his own name in the manner in which she had during their entire name - this 'got through' and she recognised him again, simply because he sang his name her way, instead of just saying it.