Consciousness and Sleep

post by casebash · 2016-01-07T12:04:32.572Z · LW · GW · Legacy · 36 comments

This will be a short article. I've been seeing a lot of dubious reasoning about consciousness and sleep. One famous problem is the problem of personal identity with a destructive teleporter. In this problem, we imagine that you are cloned perfectly in an alternate location and then your body is destroyed. The question asked is whether this clone is the same person as you.

One really bad argument that I've seen around this is the notion that the fact that we sleep every night means that we experience this teleporter every day.

The reason why this is a very bad argument is that it equivocates with two different meanings of consciousness:

You can still have experiences while you are asleep, these are internal experiences and they are called dreams. Your sensory system is still running, but in a kind of reduced power mode. If someone shouts or prods you or it gets too hot, then you wake up. You aren't like a rock.

Perhaps some people would like to talk about what kind of waves we do or do not see while you are asleep. What I would like to point out is that we still have very little understanding of the brain. Just because we don't see one particular wave or another doesn't mean much given our incredibly limited understanding of what consciousness is. Perhaps in the future, we will have this knowledge, but anything at the moment is merely speculation.

I'm not arguing either way on personal identity. I haven't done enough reading yet to comment. But this is one particularly bad argument that needs to be done away with.



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comment by gjm · 2016-01-07T13:44:12.733Z · LW(p) · GW(p)

You still have experiences while you are asleep

During some periods of sleep. So far as I am aware, in deep sleep there's no reason to think you are having any experiences at all.

Anyway, for those who don't object to thought experiments: imagine that there's some machine that completely suspends all your brain activity for five minutes, after which it continues from exactly its previous state. Are you the same person after as before? If you answer yes to this -- which I bet almost everyone does -- then the implications are the same as those you'd get from sleep involving a complete cessation of consciousness.

Replies from: None, Gunnar_Zarncke, casebash, Kyre, kithpendragon, None, TezlaKoil
comment by [deleted] · 2016-01-07T17:19:31.100Z · LW(p) · GW(p)

During some periods of sleep. So far as I am aware, in deep sleep there's no reason to think you are having any experiences at all.

Your brain keeps doing stuff however. Your lungs keep breathing, and your heart keeps beating. There is no normal phase of sleep where someone shaking you and yelling in your ear won't wake you up, but normal noises and the hum of machinery or cool breeze does not. So something is processing and filtering inputs for relevance.

imagine that there's some machine that completely suspends all your brain activity for five minutes, after which it continues from exactly its previous state. Are you the same person after as before?

The only honest answer I can give to this is "I don't know."

Replies from: Brillyant
comment by Brillyant · 2016-01-08T19:51:03.086Z · LW(p) · GW(p)

imagine that there's some machine that completely suspends all your brain activity for five minutes, after which it continues from exactly its previous state. Are you the same person after as before?

If a tree falls in a forest and no one is around to hear it, does it make a sound?

Replies from: polymathwannabe
comment by polymathwannabe · 2016-01-08T20:04:01.672Z · LW(p) · GW(p)

Addressed before. TL;DR: it's not really a question about the existence of sound, but about the definition of sound.

Replies from: Brillyant
comment by Brillyant · 2016-01-08T21:11:21.470Z · LW(p) · GW(p)

This is what I was referring to.

comment by Gunnar_Zarncke · 2016-01-07T17:34:52.610Z · LW(p) · GW(p)

imagine that there's some machine that completely suspends all your brain activity for five minutes, after which it continues from exactly its previous state. Are you the same person after as before?

And the obligatory poll:


Replies from: RichardKennaway, philh
comment by RichardKennaway · 2016-01-07T22:42:05.398Z · LW(p) · GW(p)

I am the same parson afterwards

The Rev. Bayes would be.

comment by philh · 2016-01-08T18:24:19.800Z · LW(p) · GW(p)

I'd like to tick both 'I am' and 'the question makes no sense'.

comment by casebash · 2016-01-07T14:33:33.412Z · LW(p) · GW(p)

"So far as I am aware, in deep sleep there's no reason to think you are having any experiences at all." - No reason to think you are having experiences != Reason to believe that you are having no experiences. How would we know?

I think that is a very interesting thought experiment and I have no objections to it. The reason I am objecting to the sleep argument is that it is based upon uncertain science and an equivocation between two words.

Replies from: None
comment by [deleted] · 2016-01-07T18:15:29.997Z · LW(p) · GW(p)

Somehow people are able to throw covers off or burrow into them without waking up. I would say this is evidence of both having experiences and reacting to them.

comment by Kyre · 2016-01-12T07:47:48.745Z · LW(p) · GW(p)

For 5 minutes suspension versus dreamless deep sleep - almost exactly the same person. For 3 hours dreamless deep sleep I'm not so sure. I think my brain does something to change state while I'm deep asleep, even if I don't consciously experience or remember anything. Have you ever woken up feeling different about something, or with a solution to a problem you were thinking about as you dropped off ? If that's not all due to dreaming, then you must be evolving at least slightly while completely unconscious.

comment by kithpendragon · 2016-01-08T10:16:48.518Z · LW(p) · GW(p)

Are you the same person as before?

I expect I will do the same things for the same reasons as before. Or, to put it another way, I do not expect a brief interruption in my input/output patterns to significantly affect my input/output patterns in the future. Even less so than if they had not been interrupted and I had been allowed to have an experience of the same duration, now that I think about it.

I choose not to comment on the concept of "sameness" as it applies to "person", however, without some rigorous definitions. Ship of Theseus and all that.

comment by [deleted] · 2016-01-07T18:12:12.360Z · LW(p) · GW(p)

What do you understand as brain? Neocortex? Because if the evolutionary old parts of your brain stop doing anything for five minutes, you will likely die. If you mean 'whole body is put into stasis', that's a different matter.

Replies from: gjm
comment by gjm · 2016-01-07T22:20:12.600Z · LW(p) · GW(p)

Fair point. I think whole-body stasis for 5 minutes works about as well for the thought experiment, or else "everything in the brain except what's needed to keep you alive".

comment by TezlaKoil · 2016-01-07T14:36:42.668Z · LW(p) · GW(p)

I bet if you phrase the question as "your brain is destroyed and recreated 5 minutes later", most people outside LW answer no. I guess this might be another instance of brain functions inactive vs lack of ability to have experiences.

Replies from: gjm, CAE_Jones
comment by gjm · 2016-01-07T15:38:25.870Z · LW(p) · GW(p)

Yes, I agree (except that I'm not sure whether most people outside LW would really answer no; for sure a lot would, but I don't have a strong intuition about whether it would be a majority). My point is just that even if sleep never turns off experiences altogether, the intuition people appeal to when saying "experience stops every night when you sleep" isn't actually dependent on that.

comment by CAE_Jones · 2016-01-07T19:27:45.335Z · LW(p) · GW(p)

What do "destroy" and "recreate" mean?

I interpret them as meaning something like "disassemble" and "reassemble in the same configuration as before, with the same component parts"

That's not how I interpret the descriptions of the destructive teleportation, uploading, and forking scenarios.

The only arguments I can presently think of that really make me doubt my response to the "do you survive destructive uploading/teleportation/copying?" questions are more on the lines of the Ship of Theseus. My computer remains my computer if I turn it off and on again. "My files" can refer to specific instances, versions, copies, whatever, whether they're on "my computer" or copied to an external device. If my computer falls apart and is put back together again, it's still my computer. If my computer is taken apart, and an identical computer with my files on its hard drive is built (with different parts), it's a different computer. If my computer slowly has all its parts replaced, one at a time, I don't really know what I'd think; I want to say it's no longer the same computer at some point, but I don't know which point. Maybe when the hard drive is replaced, but that's a bad example because replacing individual chunks of atoms in the hard drive is a weird concept. Actually, I'd probably think of the new chunks as "the new chunks", and more or less treat it as portions of two separate disks acting as one. (And if files are modified, deleted, copied, etc, then they are modified, deleted, copied, etc, and this does not make it stop being "my computer".)

So what does that mean for the brain? The brain changes a lot; does its component parts get replaced all that often? A huge portion of the cells in the body get replaced at varying rates; do they play into this at all? How would my conclusions change if the brain replaces its cells frequently and I was just that bad at understanding neurology? I'm not really sure about the answers to these. It's possible that the answers could change my mind. It's possible that I would just stay in the same boat and remain existentially horrified forever or something.

But flipping the switch from on to off to on is more or less irrelevant. I feel like we are using the same words to describe completely different phenomena, then debating as though everyone is using the words in the same way. (Compare "Congress" to "the 75th congress" to "the 76th congress". The first is defined by an enduring pattern with interchangeable components, such that it describes the both of the other two; the second refers to a specific configuration of components and behaviors; the third is as specific as the second, but it's entirely possible that only a few members from the 75th congress were replaced for the 76th. If someone was particularly attached to the 75th congress, and by the 80th congress, the last member from the 75th was replaced, what would we take from such a person's reaction? Keeping in mind that people tend to write dramatic articles whenever an enduring group loses or replaces all of its original members, or all of the members present for particularly charished events, etc. What if a band breaks up, then most of its members form a new band?)

comment by Dagon · 2016-01-07T18:56:06.793Z · LW(p) · GW(p)

You need to more formally define consciousness and "continuity of consciousness" in order for this to be a worthwhile topic.

Whether it's a period of deep/no-dream sleep, a freeze and thaw cycle, emulation, or a copy operation, you're trying to answer the question of "what relationship do these two distinct-but-very-similar configurations of data (brain or electronic model) have to each other". Your brain at 2016-01-07T18:54:26,922604088 is different from your brain at 2016-01-07T18:54:55,035292477, but in many ways, you want to treat them as "the same".

Define the critera for identity, and this question will dissolve.

Replies from: Brillyant
comment by Brillyant · 2016-01-07T19:30:53.061Z · LW(p) · GW(p)

This is the answer.

comment by buybuydandavis · 2016-01-09T01:35:08.255Z · LW(p) · GW(p)

"The question asked is whether this clone is the same person as you."

Depends on what you mean by "the same".

I say that these identity discussions always revolve around "the same" mistake - mistaking an issue about values for an issue about facts.

If you want to treat them the same, you will, and if you don't, you won't.

comment by Pacificmaelstrom · 2018-09-14T21:36:54.131Z · LW(p) · GW(p)

You are fully sentient (having experiences) during all phases of sleep. It is the brain processes related to MEMORY that shut down causing you not to remember it.

How do we know this? Myself and many people I've talked to have had the experience of almost falling asleep and then waking back up and realizing we were just thinking about a bunch on nonsense thoughts strung together in a stream of consciousness manner. For example:

"I am thinking about to go to the dog is up there is a good view of my office manager isnt really such a big potato chips are the lights on...."

It is clear that this kind of thought pattern reflects a lack of memory engagement. In the deepest sleep (or coma) this lack likely becomes so pronounced that not even single words or images are possible, but the sentient experience remains.

For another example, during dreams (REM) the memory processes turn partially back on, but not all the way, which is why dreams seem so illogical when you wake up and remember everything you couldn't in the dream.

Our sentience always experiences only the present moment, but the complex memory hardware of our advanced brains allows our sentience to re-experience the past as well, making coherent thinking possible. Without memory there is only pure experience of the now. This is the most elementary state of mind and the definition of sentience.

From the time your neurons first start firing in the womb until they stop at death, they propagate your sentience continuously like a wave moving over the ocean. Through waking, sleeping, and even the deepest of comas this wave continues unbroken.

But when a wave crashes on the beach it is gone and nothing can bring it back. You can create a new wave of course, but you cannot get the original back. Like waves, the IDENTITY of a particular instance of sentience ("you" or "me" for example) arises from continuity and nothing else. And yes, it certianly does not arise from memory.

Silly ideas about teleported copies and clones being "you" come from basing identity on memories not continuity. Thats why it is important to understand that when you sleep it isnt your sentient awareness that shuts down... just your memory of it!

comment by kilobug · 2016-01-08T14:18:45.288Z · LW(p) · GW(p)

Regular sleep may not suspend consciousness (although it can very well be argued in some phases of sleep it does), but anesthesia, deep hypothermia, coma, ... definitely do, and are very valid examples to bring forward in the "teleport" debate.

I've yet to see a definition of consciousness that doesn't have problems with all those states of "deep sleep" (which most people don't have any trouble with), while saying it's not "the same person" for the teleporter.

Replies from: casebash
comment by casebash · 2016-01-08T23:00:13.753Z · LW(p) · GW(p)

"Anesthesia, deep hypothermia, coma, ... definitely do" - don't people have dreams or at least some thoughts occur during these?

Replies from: DanArmak
comment by DanArmak · 2016-01-26T14:54:26.062Z · LW(p) · GW(p)

How would you distinguish between no experiences occurring, and no memories being formed or retained?

Replies from: casebash
comment by casebash · 2016-01-27T19:44:54.877Z · LW(p) · GW(p)

Just because we can't observe things doesn't mean they don't exist

Replies from: DanArmak
comment by DanArmak · 2016-01-29T00:31:01.621Z · LW(p) · GW(p)

But what's your reason for thinking they exist?

comment by Lightwave · 2016-01-12T11:48:41.271Z · LW(p) · GW(p)

Your sensory system is still running

There are brain subsystems that are still running, but they are not necessarily ones "you" identify with. If you replaced the parts/networks of the brain that control your heart and lungs (through some molecular nanotechnology), would "you" still be you? My intuition says yes. The fact that "something is running" doesn't mean that something is you.

I know the computer metaphor doesn't work well for the brain, but imagine the system in the brain that wakes you up when you hear some sound could be sort of like when a sleeping computer that gets woken up by a signal in the computer network.

Also as others have mentioned, I'm pretty sure during anesthesia/coma there can be periods where you are completely lacking any experience.

comment by [deleted] · 2016-01-07T22:56:14.038Z · LW(p) · GW(p)

I believe this thought experiment raises the following question : is one consciousness (sentience) unique ?

One answer could be that there can't be two identical consciousnesses, ie if you have two identical clones experimenting the exact same life, then they share only one sentience. If there were more than one, they would be different in some way. If consciousness is what is, in some way, computed by their brains, then this output can be produced in different brains, but it only exists once. It is quite similar to the "conceptual differenciation" proof for the unicity of god.

In this case, the one who wakes up after I went to sleep or taken the teleporter is still me, since the brain hasn't changed significatively. Weirder is the fact that your consciousness may not be dependent on time itself : if someone has built a brain in the 19th century that is identical to yours the moment you die, maybe you would just "wake up" there.

And falling asleep wouldn't be so frightening (SMBC is a great web-comic I recommend).

comment by Brillyant · 2016-01-07T17:00:31.035Z · LW(p) · GW(p)

Sleep or the destructive teleporter (in your example) don't do away with a brain's memories. In my view, this is a key component to what makes up "identity" for people.

Replies from: Usul, Gunnar_Zarncke
comment by Usul · 2016-01-08T06:04:24.567Z · LW(p) · GW(p)

If retention of memory is a key component of identity, then what are the implications for identity:

When decades of new memories have been made (if loss of memory=loss of identity does gain of memory also=change of identity)? When old memories have changed beyond all recognition (unaware to the current rememberer he doesn't recall Suzy Smith from 1995 in 2015 the same way he recalled her in 2000)? When senile dementia causes gradual loss of memory? When mild brain injury causes sudden loss of large areas of memory while personality remains unchanged post injury? When said memory returns?

Tricky stuff, identity. Without a clear continuity to hang it on why should I care about what happens to me in five minutes, much less five years? Why do I work to benefit me tomorrow more than I do to benefit you next week? That's why I like hanging it on passive conscious awareness (assuming that thing exists), but damned if I know.

Replies from: cousin_it, Brillyant
comment by cousin_it · 2016-01-08T16:17:09.521Z · LW(p) · GW(p)

Without a clear continuity to hang it on why should I care about what happens to me in five minutes, much less five years?

You care because your brain was created by evolution, which relies on physical continuity of your body. Whether you "should" care depends on your meaning of "should".

comment by Brillyant · 2016-01-08T17:30:02.393Z · LW(p) · GW(p)

Identity is tricky, but only if you want to devise questions to be tricked by it. I'd suggest it can be deconstructed to a point where these sorts of questions disappear.

comment by Gunnar_Zarncke · 2016-01-07T17:32:24.622Z · LW(p) · GW(p)

And I guess that there are animals that retain memories across periods of being frozen or without measurable brain activity. Not conscious animals probably but that means little in this context.

comment by EphemeralNight · 2016-01-09T05:02:02.643Z · LW(p) · GW(p)

In this problem, we imagine that you are cloned perfectly in an alternate location and then your body is destroyed.

In which case, "you" have a 50% chance of dying, because your self-continuity forks and one fork is then destroyed. The obvious answer to this dilemma isn't a metaphysical one. It's that this is a stupid way to design a teleporter.

If we instead imagine that you are destroyed and then duplicated perfectly in an alternate location, there is no longer an extra self-continuity branch that terminates. Correct order of operations in the engineering solution is all it takes to solve this problem.

Replies from: Dagon
comment by Dagon · 2016-01-10T16:47:39.962Z · LW(p) · GW(p)

In which case, "you" have a 50% chance of dying

Actually, you have 100% chance of dying. You will also live. The teleporter creates a new branch of you, and the old branch dies. The fact that a copy exists doesn't stop the old one being you too.

Replies from: EphemeralNight
comment by EphemeralNight · 2016-01-15T05:01:40.258Z · LW(p) · GW(p)

That is actually what I meant. But the way you're phasing it re-introduces confusion on the word "you".

What this means is, neither branch is privileged, neither branch takes precedence, there is no soul that only goes to one or the other, the subjective "you" prior to duplication does have a 50% chance of experiencing either branch. After duplication, there are two people, who are both, objectively, "you", but neither subjectively experiences being in two places at once.

One experiences the destination and subsequent existence, the other experiences a split second of dawning horror and then oblivion. Each time a "you" steps into the badly designed dupli-teleporter, that "you" has a 50% chance of either experience.