Link - total body transplant
post by Dr_Manhattan · 2011-01-14T04:41:04.177Z · LW · GW · Legacy · 16 commentsContents
16 comments
Amazing video. This is really "out there" medical research that actually worked, and not surprisingly, was closed down.
http://www.vbs.tv/newsroom/dr-white-s-total-body-transplant-2-of-2--2
16 comments
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comment by Randaly · 2011-01-14T09:44:51.428Z · LW(p) · GW(p)
The linked video seems to be a little misleading. The actual procedure doesn't add on a second identically connected brain to a body, and it doesn't allow for 'body transplants.' What is does is allow a brain to survive without its own body's blood flow, and there are other, artificial ways to do so (or cryonics, as well).
"It's entirely misleading to suggest that a head transplant or a brain transplant is actually really still connected in anything except in terms of blood stream to the body to which it has been transplanted. It's not controlling or relating to that body in any other sort of way." ~Dr. Steven Rose
Replies from: TheOtherDave, Vladimir_Nesov↑ comment by TheOtherDave · 2011-01-14T13:48:56.334Z · LW(p) · GW(p)
What is does is allow a brain to survive without its own body's blood flow, and there are other, artificial ways to do so (or cryonics, as well).
Cryonics doesn't allow a brain to survive without its own body's blood flow.
Cryonics doesn't allow a brain to survive, period.
Cryonics involves killing a brain (or preparing a dead brain) in such a way as to maximize the chances that some future technology can extract its instantiated mind.
A worthy goal, but a different one.
Replies from: icebrand↑ comment by icebrand · 2011-01-14T19:45:35.080Z · LW(p) · GW(p)
Cryonics involves killing a brain (or preparing a dead brain) in such a way as to maximize the chances that some future technology can extract its instantiated mind.
[edit to take away the quibble about definitions]
Cryonics keeps open the possibilities both of uploading and robust repair scenarios. Assuming that it will play out one way or the other is unnecessarily specific for a belief about the future. There may be e.g. cultural or contractual reasons to repair people instead of extracting the information to instantiate on a digital substrate.
Replies from: TheOtherDave, orthonormal↑ comment by TheOtherDave · 2011-01-14T20:36:16.596Z · LW(p) · GW(p)
I haven't claimed that the person dies; I've claimed the brain does.
Sure, perhaps future technology will include the ability to reconstruct the person from the dead cells of the person's brain, in which case the person survives... no argument. And in that case cryonics is, as you say, a form of survival.
But the cells remain dead, as does the organ they comprise. And the comment I was responding to was talking about ways to allow a brain to survive without the body's blood flow, not about people.
And, sure, it's possible that future technology will include the ability to reconstruct a living brain from the brain's dead cells. Actually, I suspect that will be much easier than reconstructing the person. And it's possible that it will include the ability to repair the cells themselves and restore them to their former state.
Personally, I would say it's still a dead brain, much as my ability to reforge a broken sword doesn't prevent the sword from breaking. But that's a purely semantic question... the reality is the same whether we call the brain "dead" or not.
So, OK, what term would you prefer I use? (Resting? Stunned? Pining for the fjords? Passed on? This brain is no more! It has ceased to be! It is an ex-brain!)
Or do you object to using any terminology to differentiate a post-cryonics brain from a pre-the-event-that-ordinarily-entails-a-funeral brain?
Replies from: icebrand↑ comment by icebrand · 2011-01-14T21:16:01.461Z · LW(p) · GW(p)
But the cells remain dead, as does the organ they comprise.
In the case of vitrification under ideal conditions this is not true of most of the cells. There is a spectrum of cryonics cases, and many of them do have a high rate of cell death, but the goal of cryonics is to prevent cell death to the greatest degree possible.
Death is a process, not an all or nothing proposition. You don't really need to assign a category "dead" or "not dead" to understand what's going on. The brain is broken beyond simple repair and ceases to be animate. Maybe a more useful term would be one that connotes brokenness rather than irreparability.
Most cells survive for several hours after clinical death. Ten minutes or so without oxygen (blood flow) initiates an ischemic cascade that current technology cannot halt, but this cascade takes a lot of time before most of the cells actually die.
ETA: It is a good point that cell death isn't the same problem as information loss. A really powerful AI with high grade molecular nanotech could probably recover more information by analyzing non-viable cells than a more minimalistic rejuvenation technology that simply rescues the remaining viable cells and replaces missing ones.
Replies from: TheOtherDave↑ comment by TheOtherDave · 2011-01-14T21:25:19.674Z · LW(p) · GW(p)
My problem with "broken" in this context is that it fails to distinguish between a brain that fails to function as intended in some important capacity -- for example, one that is incapable of identifying its person's wife -- and one that fails to function as intended in any capacity at all.
I guess I can go with "inanimate," if you want (since you say "ceases to be animate"). It seems weird to fail to distinguish between a corpse and a statue, but not unbearably weird.
Replies from: icebrand↑ comment by orthonormal · 2011-01-16T21:33:56.069Z · LW(p) · GW(p)
Incidentally, I suspect that this was downvoted for starting an argument over definitions. (The downvotes weren't mine, FYI.)
Replies from: icebrand↑ comment by icebrand · 2011-02-05T15:42:28.001Z · LW(p) · GW(p)
Thanks for the information. Edited out. The main issue I had with the original comment was that it seemed to assume everyone would agree with a specific, vastly oversimplified definition of organic death. In reality organic death is a process that happens over a long period of time and has not happened completely by the time the brain reaches LN2 temperatures in ideal circumstances. It could easily be reversible via biological means.
↑ comment by Vladimir_Nesov · 2011-01-14T11:20:17.038Z · LW(p) · GW(p)
"It's entirely misleading to suggest that a head transplant or a brain transplant is actually really still connected in anything except in terms of blood stream to the body to which it has been transplanted. It's not controlling or relating to that body in any other sort of way." ~Dr. Steven Rose
If we attach adequate brain-computer interface to the brain, a person can continue living, even without having control over the brain-sustaining contraption (human body or something else). (Assuming the brain can be made conscious/awake.)
Replies from: Document↑ comment by Document · 2011-01-14T16:00:46.026Z · LW(p) · GW(p)
Are there BCIs that can pass signals to the brain as well as reading them from it?
Replies from: JenniferRM↑ comment by JenniferRM · 2011-01-15T00:40:29.069Z · LW(p) · GW(p)
There exist implants that interface with nervous tissue for input purposes either via nerves or sometimes lately as "cortical implants". This stuff comes up around visual prosthetics and cochlear implants.
My understanding is that this is an area of active research for helping people with sensory disabilities, and that the issues that tend to come up have to do with input resolution that its "good enough" to get along, and (especially with vision) the decrease in expected lifespan of individual neurons and nervous tissue after being put in close proximity to electronics.
Sharp, hot, electrical stuff is frequently "ouchy"...
comment by JoshuaZ · 2011-01-14T04:57:03.223Z · LW(p) · GW(p)
and not surprisingly, was closed down.
I'm not sure what you are implying here. Can you be more explicit?
Replies from: Dr_Manhattan↑ comment by Dr_Manhattan · 2011-01-14T14:28:32.924Z · LW(p) · GW(p)
I suspect emotional aversion to the idea contributed to the shut down; whatever your stand on the goal of head transplant, this seems like cutting surgical medicine, and at the very least useful because of all the techniques you'd learn on the way to a goal you don't care for (like the moon landing).