I don’t think anybody has hard evidence of answers to any of those questions yet (though I’d be fascinated to learn otherwise) but I can offer some conjectures:
Possible in principle?
Yes. I see no evidence that sentience and identity are anything other than information stored in the nervous system, and in theory the cognitive portion of a nervous system an organ and could be transplanted like any other.
Preserving anatomical integrity?
Not with anything like current science. We can take non-intrusive brain scans, but they’re pretty low-resolution and (so far as I know) strictly read-only. Even simply stimulating parts of the brain isn’t enough to basically re-write it in such a way that it becomes another person’s brain.
Need to kill donors?
To the best of my knowledge, it’s theoretically possible to basically mature a human body including a potentially-functional brain, while keeping that brain in a vegetative state the entire time. Of course, that’s still a potential human—the vegetativeness needs to be reversible for this to be useful—so the ethics are still highly questionable. It’s probably possible to do it without a full brain at all, which seems less evil if you can somehow do it my some mechanism other than what amounts to a pre-natal full lobotomy, but would require the physical brain transplant option for transference.
Nerves connecting and healing?
Nerves can repair themselves, though it’s usually extremely slow. Stem cell therapies have potential here, though. Connecting the brain to the rest of the body is a lot of nerves, but they’re pretty much all sensory and motor nerves so far as I know; the brain itself is fairly self-contained
Personality change?
That depends on how different the new body is from the old, I would guess. The obviously-preferable body is a clone, for many reasons including avoiding the need to avoid immune system rejection of the new brain. Personality is always going to be somewhat externally-driven, so I wouldn’t expect somebody transferred from a 90-year-old body to a 20-year-old one to have the same personality regardless of any other information because the body will just be younger. On the other hand, if you use a clone body that’s the same age as the transferee, it wouldn’t shock me if the personality didn’t actually change significantly; it should basically feel like going under for surgery and then coming out again with nothing changed.
Now, mind you, I’m no brain surgeon (or medical professional of any sort), nor have I studied any significant amount of psychology. Nor am I a philosopher (see my question above). However, I don’t really see how the mind could be anything except a characteristic of the body. Altering (intentionally or otherwise) the part of the body responsible for thought alters the mind. Our current attempted maps of the mind don’t come close to fully representing the territory, but I firmly believe it is mappable. Whether an existing one is re-mappable I can’t say, but the idea of transplanting a brain has been explored in science fiction for decades, and in theory I see ne logical reason why it couldn’t work.
To the best of my knowledge, it’s theoretically possible to basically mature a human body including a potentially-functional brain, while keeping that brain in a vegetative state the entire time.
I don’t think this is currently possible. The body just wouldn’t work. A large part of the ‘wiring’ during infant and childhood is connecting body parts and functions with higher and higher level concepts. Think about toilet training. You aren’t even aware of how it works but it nonetheless somehow connects large scale planning (how urgent is it, when and where are toilets) to the actual control of the organs. Considering how differnt minds (including the connection to the body) are I think the minimum requirement (short of signularity-level interventions) is an identical twin.
That said I think the existing techniques for transferring motion from one brain to another combined with advanced hypnosis and drugs could conceivably developed to a point where it is possible to transfer noticable parts of your identity over to another body—at least over an extended period of time where the new brain ‘learn’ to be you. To also transfer memory is camparably easy. Whether the result can be called ‘you’ or is sufficiently alike to you is another question.
Need to kill donors? To the best of my knowledge, it’s theoretically possible to basically mature a human body including a potentially-functional brain, while keeping that brain in a vegetative state the entire time. Of course, that’s still a potential human—the vegetativeness needs to be reversible for this to be useful—so the ethics are still highly questionable.
That’s how I pictured it, yes. At this point I wouldn’t concern myself with the ethics of it, because, if our technology advances this much, then simply the fact that humanity can perform such a feat is an extremely positive thing, and probably the end of death as we know it. What worries me more is that this wouldn’t result in a functional mature individual. For instance: in order to develop the muscular system, the body’s skeletal muscles would have to experience some sort of stress, i.e. be used. If you grow the organism in a jar from birth to consciousness transfer (as is probably most ethical), it wouldn’t have moved at all its entire life up to that point, and would therefore have extremely weak musculature. What to do in the meantime, electrically stimulate the muscles? Maybe, but it probably wouldn’t have results comparable to natural usage. Besides, there are probably many other body subsystems that would suffer similarly without much you could do about it. See Gunnar Zarncke’s comment below.
On the other hand, if you use a clone body that’s the same age as the transferee, it wouldn’t shock me if the personality didn’t actually change significantly; it should basically feel like going under for surgery and then coming out again with nothing changed.
Yes, but I imagine most uses to be related to rejuvenation. It would mean that the genetic info required for cloning would have to be gathered basically at birth (and the cloning process begun shortly thereafter), and there would still be a 9-month age difference. There’s little point in growing a backup clone for an organism so soon after birth. An age difference of 20 years between person and clone seems more reasonable.
I don’t think anybody has hard evidence of answers to any of those questions yet (though I’d be fascinated to learn otherwise) but I can offer some conjectures:
Possible in principle? Yes. I see no evidence that sentience and identity are anything other than information stored in the nervous system, and in theory the cognitive portion of a nervous system an organ and could be transplanted like any other.
Preserving anatomical integrity? Not with anything like current science. We can take non-intrusive brain scans, but they’re pretty low-resolution and (so far as I know) strictly read-only. Even simply stimulating parts of the brain isn’t enough to basically re-write it in such a way that it becomes another person’s brain.
Need to kill donors? To the best of my knowledge, it’s theoretically possible to basically mature a human body including a potentially-functional brain, while keeping that brain in a vegetative state the entire time. Of course, that’s still a potential human—the vegetativeness needs to be reversible for this to be useful—so the ethics are still highly questionable. It’s probably possible to do it without a full brain at all, which seems less evil if you can somehow do it my some mechanism other than what amounts to a pre-natal full lobotomy, but would require the physical brain transplant option for transference.
Nerves connecting and healing? Nerves can repair themselves, though it’s usually extremely slow. Stem cell therapies have potential here, though. Connecting the brain to the rest of the body is a lot of nerves, but they’re pretty much all sensory and motor nerves so far as I know; the brain itself is fairly self-contained
Personality change? That depends on how different the new body is from the old, I would guess. The obviously-preferable body is a clone, for many reasons including avoiding the need to avoid immune system rejection of the new brain. Personality is always going to be somewhat externally-driven, so I wouldn’t expect somebody transferred from a 90-year-old body to a 20-year-old one to have the same personality regardless of any other information because the body will just be younger. On the other hand, if you use a clone body that’s the same age as the transferee, it wouldn’t shock me if the personality didn’t actually change significantly; it should basically feel like going under for surgery and then coming out again with nothing changed.
Now, mind you, I’m no brain surgeon (or medical professional of any sort), nor have I studied any significant amount of psychology. Nor am I a philosopher (see my question above). However, I don’t really see how the mind could be anything except a characteristic of the body. Altering (intentionally or otherwise) the part of the body responsible for thought alters the mind. Our current attempted maps of the mind don’t come close to fully representing the territory, but I firmly believe it is mappable. Whether an existing one is re-mappable I can’t say, but the idea of transplanting a brain has been explored in science fiction for decades, and in theory I see ne logical reason why it couldn’t work.
I don’t think this is currently possible. The body just wouldn’t work. A large part of the ‘wiring’ during infant and childhood is connecting body parts and functions with higher and higher level concepts. Think about toilet training. You aren’t even aware of how it works but it nonetheless somehow connects large scale planning (how urgent is it, when and where are toilets) to the actual control of the organs. Considering how differnt minds (including the connection to the body) are I think the minimum requirement (short of signularity-level interventions) is an identical twin.
That said I think the existing techniques for transferring motion from one brain to another combined with advanced hypnosis and drugs could conceivably developed to a point where it is possible to transfer noticable parts of your identity over to another body—at least over an extended period of time where the new brain ‘learn’ to be you. To also transfer memory is camparably easy. Whether the result can be called ‘you’ or is sufficiently alike to you is another question.
That’s how I pictured it, yes. At this point I wouldn’t concern myself with the ethics of it, because, if our technology advances this much, then simply the fact that humanity can perform such a feat is an extremely positive thing, and probably the end of death as we know it. What worries me more is that this wouldn’t result in a functional mature individual. For instance: in order to develop the muscular system, the body’s skeletal muscles would have to experience some sort of stress, i.e. be used. If you grow the organism in a jar from birth to consciousness transfer (as is probably most ethical), it wouldn’t have moved at all its entire life up to that point, and would therefore have extremely weak musculature. What to do in the meantime, electrically stimulate the muscles? Maybe, but it probably wouldn’t have results comparable to natural usage. Besides, there are probably many other body subsystems that would suffer similarly without much you could do about it. See Gunnar Zarncke’s comment below.
Yes, but I imagine most uses to be related to rejuvenation. It would mean that the genetic info required for cloning would have to be gathered basically at birth (and the cloning process begun shortly thereafter), and there would still be a 9-month age difference. There’s little point in growing a backup clone for an organism so soon after birth. An age difference of 20 years between person and clone seems more reasonable.