Teleportation. It isn't you that comes out the other side. Or is it?

demagogue on 24/9/2012 at 09:05

Yeah I agree to that first part, but the whole issue of the thread (re: Star Trek style teleportation) is that we are killing off the leaving agent and bringing a new agent to life that shares all his memories and experiences & everything you mentioned and asking if it's the "same person"... If we want to say it is, then I think we'd want to say all the personality management & narrative of self just seamlessly moves into the new mind, nevermind an intervening "death". All the things you mentioned aren't essential to the wetware itself, so it's okay for it to move from one instantiation to another and still maintain its identity.

Edit: I mean that was the point of bringing up the issue of death vs just being unconscious to begin with. If we say "death" can't be like "being unconscious" because "identity can't survive" the death of a brain, even if we made an exact replica, then that's like admitting the person coming out of the transporter has to be a different person -- but then that tosses out all those things you (I think rightly) said should be what's important, "identity & narrative of self" management by a mind module over itself as a whole, etc.

DDL on 24/9/2012 at 09:21

Quote Posted by Subjective Effect

Nope. The conciousness doesn't switch off, it's still there and if it wasn't you'd wake up knowing nothing. It's just certain input/output centres that are temporarily turned off.

Is there a reference for "if it wasn't you'd wake up knowing nothing"? I mean, you do anaesthetics, right? So presumably there are various depths of anaesthesia you can put someone into that suppress increasing levels of brain function (I know you can do it with mice), and I'm assuming these all usually result in full recovery of brain function and self-awareness upon recovery (admittedly...less easy to compare with mice :p)....which then suggests that the whole "you'd wake up knowing nothing" is a totally binary hypothesis: a sliding scale of "full recovery, full recovery, full recovery, NO RECOVERY".

Also, since I'm unaware of any process by which one can anaesthetise someone so deeply that they wake up a blank slate (brain damage notwithstanding), I'm lead to conclude that this is an untestable hypothesis, too.

Please feel free to correct me, though.

Quote Posted by Subjective Effect

I just want to highlight one error in your statement; some of the particles are not swapped out, ever. The DNA for example. The nucleotides in cell 415 are made of the same particles now as they were when cell 415 came into existence however many years ago. There will be other structures that have remained constant. This is true of many but not all tissues.

Also not entirely true: DNA gets turned over quite a lot, individual bits are swapped out and replaced an estimated (http://en.wikipedia.org/wiki/DNA_repair) 1 million times a day, per cell. And there's also homologous recombination for long deletions/mutations: a given DNA molecule is almost never a static entity. Yes, you could say "it's the same molecule, only some of the atoms have changed", but then we're back to the "my grandfather's axe" arguments, which you could also apply to the cell (same cell, only some of the enzymes etc have changed), or to the body (same body, only some of the cells have changed).

The key message here is that we're not static entities. I am not the same person I was this morning, neither are you, neither is anybody: we're in a constant state of reinvention at the molecular, cellular, and consciousness level. You can see this happening in trivial ways all the time: "I really feel like X for dinner tonight.." *gets home* "Actually, you know what, I'm just not feeling it anymore. I'll have Y instead."

If you like, our consciousness could be thought of as the sum of our memories, and given that our memories are not static (new memories laid down constantly, old memories lost constantly), we're never the same person for any real length of time.

If you were suddenly created, utterly de novo, in my handy deus ex-ian universal constructor, complete with the brain architecture that holds your current set of memories and the exact positions and states of all the different glutamate receptors and so on in your brain, what is really the difference between that you and a you that's actually lived those memories? Neither of you can revist them, neither of you can genuinely confirm that those things happened to YOU, and not the other incarnation.

Hell, most of the time your brain is fudging things left right and centre just to make you think life isn't utterly mental. The fact you can only focus on a TINY area at any time (like, size of your thumbnail at arm's length), the fact that your brain (http://en.wikipedia.org/wiki/Chronostasis) slows and speeds up time based on how fast your eyes are moving (and where they're moving), just so you don't get shakingcam headache from being an actual shakycam.

So really, the question here could be "living: it isn't really you that continues doing so. Or is it?" :)

Which leads us to the whole "if you reassemble somone at the teleport destination, but also keep the original, which one is the real person", to which the answer would be neither. Or indeed, both.

Though there is always the (http://www.smbc-comics.com/index.php?db=comics&id=1879#comic) engineering approach.

Also, (http://www.smbc-comics.com/index.php?db=comics&id=1677) this one seems appropriate.

SubJeff on 24/9/2012 at 10:26

Quote Posted by DDL

There is no reference, it's my hypothesis. But I've been thinking and it depends on one assumption - that the electrical pattern has to exist in some form at all times. We are not like computers so turning us off destroys the pattern and rebooting doesn't re-establish all the connections in the same was as rebooting a computer.

I realise that this hypothesis is totally dependant upon the pattern having some quality that somehow supersedes the cellular architecture alone. I think I must have been imagining what you might consider a soul, or at least some "magical" property of the brain, a ripple in that water flow if you will.

Yes, I was thinking of a binary hypothesis. There are depths of anaesthesia but it is a continuum with a few arbitrarily defined points such as the difference between "not anaesthetised" and "anaesthetised". People talk about light and deep anaesthesia but there is so much debate about the whole thing; it's never ending. It's not a science, it's an art with scientific components that you use to achieve the desired result.

In the absence of brain damage there is no depth you can take someone to that will "wipe" them. The limiting factor isn't how deeply anaesthetised the brain is but rather how the rest of the body reacts; more anaesthetic tends to mean lower blood pressure and so on so you can't go too far.

As to DNA changes; I know that occurs in cells that need to replicate but I thought that the CNS, being a relatively static system, maintained most of it's core in a static manner.

faetal on 24/9/2012 at 10:30

Quote Posted by Subjective Effect

See, it's this kind of opinion that makes me think people don't get the Star Trek teleporters. You realise it kills you, right? The copy is a copy, it's not you. It may act like you and have all your memories, even be you for all other purposes. It may even lead the exact same life that you would have but you are dead and it has taken your place.

Definition of me is the identity which exists as part of my brain function. Create a duplicate me and there are 2 of me, bothof which diverge from that moment with every experience. If the me that steps into the teleporter is sedated and destroyed, the me which steps out at the other side will notice no more difference than a person sleeping for the duration of a plane journey. You'd have all of the same memories and experiences from before the trip and you'd be carrying on with new ones afterwards. You'd be as much you as the one that stepped into the teleporter, as the pattern of experience would be identical prior (assuming a perfect replication, this is after all a thought experiment).

SubJeff on 24/9/2012 at 10:35

That is your definition of "me" and I disagree.

faetal on 24/9/2012 at 10:40

Explain why.

DDL on 24/9/2012 at 10:44

Quote Posted by Subjective Effect

As to DNA changes; I know that occurs in cells that need to replicate but I thought that the CNS, being a relatively static system, maintained most of it's core in a static manner.

DNA is always subject to damage, be it UV, chemical or just plain ol' bad luck. And there are 6 billion DNA bases in each cell's genome, spread between 46 molecules (good ol' haploid sperm aside), so even if 'damage' is incredibly rare, it's still going to happen a decent number of times per DNA molecule per day.

Now you're right that post-mitotic cells have lower 'DNA turnover' (and yes, without need for replication, it's lower by a huge factor), but even with that caveat (and with the fact that many post-mitotic cells bundle up much of their unused DNA regions into more compact, marginally more damage-resistant bundles) you're still looking at a steady process of turnover on a base-by-base basis (hah: awful phrase, that one) even in nominally quiescent cells. Cells really don't like tolerating DNA damage.

faetal on 24/9/2012 at 11:00

The main point of ponderance for me is that electrical activity in the brain it the result of membrane potentials set up by transport gradients of free ions along nerve fibres. When the copy is finished, assuming all ions and molecules are in exactly the same position and state as when you step in the machine, it should carry on as normal and there would be no scientific way of determining if one of these yous is you or not. Any distinction is entirely on principle and IMO is not material in any way. SO as well as assuming a perfect copy, I'd want to assume an instantaneous copy also. And by instantaneous, I don't even mean 1 ns, I mean nominal time passed. Unless there was some way to create perfect stasis while the copy occurred, but there is another assumption to consider.

SubJeff on 24/9/2012 at 11:14

So we're back to the ship theory then, or rather the pipes and water theory, but without any static parts to the pipe then.

Quote Posted by faetal

Explain why.

What makes me me is inherent to me. The copy is just that, a copy. It doesn't matter if it is identical to me in every way, I am still as separate being.

You say that the difference between the two is not material in any way and yet if you were copied and told you would be killed but the copy would live on you wouldn't be happy about that, would you?

DDL on 24/9/2012 at 11:14

And then of course you'd have to consider how much the 'rapid timescale' temporal dynamics of action potentials and so on governs consciousness, vs the (comparatively vastly slower timescale) dynamics of long term potentiation, synapic rearrangement etc. Would an alteration in membrane potential dynamics totally reset your brain, or would it be more like a "huh, what was I thinking about just now? Oh well" experience, since all the structural information that (presumably) governs memory would still be intact?

And that's without even considering quantum effects, which may or may not be relevant. :p