Cryonics and the importance of body to cognition

post by lukeprog · 2011-03-12T05:21:40.902Z · score: 5 (8 votes) · LW · GW · Legacy · 23 comments

Many approaches to cryonics assume that a detailed map of the neural patterns in a brain (via brain scanning technology) may be sufficient, using future technology, to bring that person "back to life." But cognition is greatly shaped by more than just the neural pattern: it is shaped by biology - by the body. (See Noe 2009; Pfeifer et al. 2006; Lakoff & Johnson 1999.)

I admit I'm pretty unfamiliar with the cryonics literature. I assume this is a standard objection, and has standard responses. Where can I find those responses?



Comments sorted by top scores.

comment by TheOtherDave · 2011-03-12T15:28:19.480Z · score: 9 (11 votes) · LW(p) · GW(p)

No idea about what's raised in the standard literature.

For practical purposes, the key question here is not how important the non-brain body is to cognition, but how much of the variation among individuals is explained by differences in bodies vs. differences in brains.

If the variation due to body differences is sufficiently negligible, then the "personality extraction" process can be done with just the brain, and uploaded into a standard body (whether biological or mechanical or digital or energetic or what-have-you), and the resulting person will be a "close enough" match to the original.

If not, then the resulting person won't be a close enough match.

Personally, I suspect that most people vastly overestimate the precision-of-duplication required to be a close enough match for practical purposes. I suspect the differences in cognition caused by the loss of original somatic context will be swamped by, for example, the differences caused by the original social context.

Of course, if one wants to drop the practical stance and instead ask metaphysical questions about whether it's "really the same person" without the original body, then different issues are salient... of course, that's true even with the original body. I have trouble seeing the point of that, though.

comment by TheOtherDave · 2011-03-12T15:39:55.808Z · score: 5 (7 votes) · LW(p) · GW(p)

Incidentally, it seems to follow from this line of reasoning that quite a lot of the brain is unnecessary, also. Though the state of the art in neuroscience is nowhere near up to being able to freeze just the necessary bits.

It leads to an interesting thought experiment, though... if I can only preserve enough information to allow an N%-match copy of me to be constructed at the other end, at what point does my intuition that "I" have been "brought back to life" (or teleported, depending on the particular intuition pump being used) collapse? What tests would I want to have the terminal point use before certifying that the constructed person was Dave, and what would I want them to do with people who failed the test?

My own intuition is that this is really no different than the question of whether I'm the same person I was 20 years ago, all we're doing is playing with how strongly privileged the default answer is. The more exotic the process, the less confident we are in preservation of identity... that's all.

If that's true, then if reconstituting people from frozen brains becomes commonplace, we will quickly develop just as much confidence that we really are the people we were as modern-day septagenarians have about their adolescent selves.

comment by Wei_Dai · 2011-03-12T07:48:28.992Z · score: 8 (10 votes) · LW(p) · GW(p)

I'm not an expert on cryonics, but it seems obvious to me that simulating the body (to the level of detail needed to support cognition) is orders of magnitude easier than simulating the brain. Do you think a more substantial response than this is needed?

comment by khafra · 2011-03-13T00:22:23.855Z · score: 2 (2 votes) · LW(p) · GW(p)

I think his objection is more about what body in particular is being simulated. As two examples, I've been doing martial arts for years, and massage for decades. I'm not sure how much of my somatic ability and characteristics is completely within my brain, and how much is in my peripheral nervous system, muscles, etc.

I don't know of any conclusive studies showing one way or the other whether Alcoring my entire body is worth twice as much as just doing my head.

comment by TheOtherDave · 2011-03-13T01:30:25.082Z · score: 2 (2 votes) · LW(p) · GW(p)

One question worth thinking about is how much you value your specific martial arts and massage experience, vs. some other experience in a similar space.

That is, if you lost all of that stuff upon being rebooted, but I installed off-the-shelf martial arts and massage modules that were not quite identical, how much would you care?

By way of comparison -- I would care a lot if this were done for, say, my memories of or feelings about my marriage, my birth family, my social circle, my abstract thoughts about life, my stroke and recovery. If you told me that on reboot you'd replace those with some standard package of family relations, social history, etc., I'd look for another vendor... though, admittedly, I'd still choose that over simple oblivion.

I would care significantly less, though still quite a bit, if it were done for my memories of work or school. A standard memory package set to "successful computer industy knowledge worker, mediocre MIT student, smartest kid in a suburban high school, etc." is something I would tolerate, though still be sort of twitchy about... probably more due to chagrin at being forced to face my non-special-snowflakeness than anything else.

But if you replaced my memories of living in this body with a standard package configured for "male, average health, marginally below-average fitness, male pattern baldness onset mid-20s, etc." I doubt I would even notice the difference.

comment by AngryParsley · 2011-03-12T11:02:20.103Z · score: 5 (5 votes) · LW(p) · GW(p)

I agree that the state of one's body changes cognition quite a bit. Still, if someone becomes a quadriplegic or acquires locked-in syndrome, we don't consider them to be dead or a different person. And compared to extracting a mind from a cryopreserved brain, rebuilding a (simulated or real) body from memories and DNA isn't that hard.

comment by David_Gerard · 2011-03-12T11:37:29.902Z · score: 2 (2 votes) · LW(p) · GW(p)

Definitely. But some people really, really like being a body - it's a major part of who they consider themselves. Cryonics may have trouble reaching them if it doesn't address this. (Which may be minor to all the other marketing deficiencies it seems to have.)

comment by [deleted] · 2011-10-27T23:52:54.531Z · score: 2 (2 votes) · LW(p) · GW(p)

Definitely. But some people really, really like being a body - it's a major part of who they consider themselves.

To be fair to them, demonstrable alternatives are pretty thin on the ground.

comment by Risto_Saarelma · 2011-03-12T17:16:35.660Z · score: 4 (4 votes) · LW(p) · GW(p)

If people are given a chance of either dying or having an arm amputated and replaced with a high-quality prosthetic limb, I'm having a great deal of trouble imagining people who will choose death, all else being equal.

If the question is between losing all four limbs and death, it becomes a bit trickier. Being a quadruple amputee is a big drop in quality of life with current prosthetic technology, and if no prosthetics whatsoever are going to be available, people might justifiably choose death instead. But we already have good enough prosthetics for the below the knee/elbow case that I wouldn't hesitate to take the amputation then, and it shouldn't take unimaginable technology to provide reasonably good complete limb prostheses.

I imagine most people haven't worked through such an extrapolation into the case of a brain in an entire prosthetic body. Will they still keep the aversive intuition if they do?

comment by lesslimits · 2011-03-13T18:34:02.982Z · score: 2 (2 votes) · LW(p) · GW(p)

I think the DNA of the neurons is very important. The production of hormones e.g. is of course very relevant for character of a person. This is definitely not stored in the connectome. Hormones are created in the brain and different organs of the body.

The production of neurotransmitter depends on genes too and is therefore not represented by the connectome alone.

We should assume that the character of a person would change a lot if the body is exchanged. On the other hand, memory and knowledge could still be very similar.

comment by vallinder · 2011-03-14T11:59:51.605Z · score: 0 (0 votes) · LW(p) · GW(p)

I recall thinking about this as a possible objection to whole brain emulation in general – specifically in the context of a Hansonian singularity.

Strangely, I've never seen a response. It seems as if transhumanist folks and embodied cognition folks don't interact much with each other.

comment by TheOtherDave · 2011-03-14T14:40:13.288Z · score: -1 (1 votes) · LW(p) · GW(p)

Can you summarize why it's a significant objection in that context?

From my novice perspective, the fact that in practice "whole-brain emulation" will also require the emulation of various sensory and motor and endocrine systems to achieve anything we'd recognize as intelligent seems like mere "haggling over the price," not a significant objection. If we can emulate cortical functions, it seems likely that we figured out how to emulate the other stuff generations back.

comment by Nick_Tarleton · 2011-03-12T23:27:08.565Z · score: 0 (0 votes) · LW(p) · GW(p)

I would be very surprised if information in the brain were insufficient to reconstruct a (simulation of a) subjectively indistinguishable body. (You also have genetic information, but the brain should be sufficient.)

I thought the point of Lakoff et al. was that cognition is shaped by genetically encoded and/or learned physiological metaphors, not that the body plays much of an active role in cognition, let alone that it stores enough long-term state that its loss would be a severe problem for cryonics. The existence of mentally normal quadruplegics falsifies strong forms of the latter claim, though I have heard claims that paralysis dulls emotion.

comment by Sniffnoy · 2011-03-12T22:47:45.554Z · score: 0 (0 votes) · LW(p) · GW(p)

Oh, here I thought this was going to be about glial cells. But I suppose if you freeze the head, and can already do neural reconstruction, that shouldn't be a much harder problem. This also possibly falls under TheOtherDave's point.

comment by David_Gerard · 2011-03-12T07:17:20.315Z · score: 0 (2 votes) · LW(p) · GW(p)

I haven't seen it raised as a "standard" objection, but it has occurred to me quite a few times as a problem with the head-only approach.

comment by lsparrish · 2011-03-12T19:16:40.837Z · score: 1 (1 votes) · LW(p) · GW(p)

What is interesting about this is that some people can't even imagine this being an issue whereas others can't imagine it not being an issue. To me it seems like a simple extrapolation from stem cell research and organ printing to regenerating the whole body.

comment by David_Gerard · 2011-03-12T20:35:09.124Z · score: 2 (2 votes) · LW(p) · GW(p)

I've mentioned recently reading Tim Ferriss' Four Hour Body before. He's a very intelligent man, but he lives for doing body stuff - "Decades of full-contact abuse and overconfidence in all sports ending in '-boarding' ..." The book makes it clear how much of his self-image is his entire body, every bit of it, and really brought it home to me how much sporty people will feel this way.

Even given cryonics as only "the second-worst thing that can happen to you" - addressing the body issue strikes me as a non-futile idea, e.g. preserving the enteric nervous system, which may not be the 100 billion cells of the brain in the head, but at 100 million is still pretty sizable as neural networks go.

That said, the cryogenic preservation of organs in general is going great guns, because there's buckets of cash in transplant research. This suggests we'll find out soon enough what happens when someone gets someone else's gut. Or even just a clone of their own gut.

comment by MartinB · 2011-03-12T07:12:38.650Z · score: 0 (0 votes) · LW(p) · GW(p)

If you change the sensory equipment you change the person. Blinding, othe handicaps do that, but you can also tack on new sensory. Like a compass. But is not that still better than not being?

It would be awesome to stay alive, even if the body needs a make over.

comment by h-H · 2011-03-12T13:50:54.814Z · score: -1 (1 votes) · LW(p) · GW(p)

without a body the brain won't 'work', the brain is very much linked to the rest of the body, the fiction that we only need the head to 'reanimate' a person back to normal is just that, fiction.

wei Dai:"rebuilding/simulating the body to the level of detail needed to support cognition" yes,but how complex is the nervous system? which wire connects to which, or is that not important? seems to me that you're oversimplifying..

comment by lsparrish · 2011-03-12T15:18:50.967Z · score: 3 (3 votes) · LW(p) · GW(p)

A significant data point here is that organ transplants -- including those of entire limbs -- have been made to work already. This indicates that the wiring in general cannot be so specific as to be impossible to replicate or regrow without originals.

comment by lukeprog · 2011-03-12T16:14:06.543Z · score: 3 (3 votes) · LW(p) · GW(p)

Also, we've transplanted animal heads.

comment by JoshuaZ · 2011-03-12T22:29:19.058Z · score: 1 (1 votes) · LW(p) · GW(p)

Yes, but we don't have any good data on whether the animals had the same personality so that doesn't provide the same sort of data that organ and limb transplants do. But the overarching point seems correct.

comment by AlephNeil · 2011-03-12T15:10:00.197Z · score: 2 (2 votes) · LW(p) · GW(p)

the fiction that we only need the head to 'reanimate' a person back to normal is just that, fiction.

Well, it might be a fiction in the sense that we never actually do it. (Personally, I doubt there will ever be star-trek style teleportation for macroscopic objects, even though it seems 'possible in principle'.)

But I think the OP is asking about the possibility in principle of restoring a dead person such that their memories, personality and intellect remain intact. If a frozen body has 'enough information' then so does a frozen head, right? Seems pretty uncontroversial, but as the OP points out, there are people who disagree.