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Comment by txrx0000 | Hacker News Reader

The article's definition of consciousness is precise, but it's not what people are referring to in most cases where the word "consciousness" is used. Of course, a word can have multiple definitions. But colloquially, when people say consciousness, we usually mean the thing that goes away when we sleep or are anesthetized. I don't think there's a much better way to define that. The contrast between the wakeful and non-wakeful state as oneself experiences from the inside is precisely what defines consciousness in the colloquial sense. It seems to be a self-defining concept because I can't even define what "experiences" means without thinking about the wakeful/non-wakeful contrast phenomena that is consciousness, and "experiences" was supposed to be a part of the definition of "consciousness" one sentence ago.

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I am unsure as to what you are trying to say here. It reads to me as “the word the article discusses has a more popular homonym, but they are clearly not talking about that”.

I'm thinking out loud and pointing out the difference to avoid confusion, and also trying to invite discussion around the colloquial def, because I think the colloquial def is the most important/useful one.

Anesthesia is a rather different state than sleep.

I had some serious surgery a few years ago and paid attention when I went under to see if I could recall anything.

Nope. You don’t exist for that time. Anesthesiologist counts down 10, 9, 8, 7, and then I was teleported to the recovery bed.

I consider it incredibly weird and very unlike sleep. Consciousness is off, instantly, then back.

Well... memory is off at least.

Ahh, yes, the cosmic horror hypothesis about how anesthesia works. You can't move and experience everything but remember nothing.

But hey, I don't have cancer anymore. So if I had to endure four hours of agony that I don't remember, I'll take it.

Well we do know you can't feel pain, because we've actually done the MRI studies to confirm. Which makes me feel a lot better personally.

But I also have a doctor friend who tells me how removing my appendix actually worked: I go under. Then they take out the appendix. Then they wake me so that I can, with help, move from the operating table to the wheeled bed. This part is not a part of my memory, but people can talk to me and I can get down from the table and onto the bed (again, with help).

So I'd say there's some middle ground here.

When observed by a different conscious being, yes. But from the inside observed by oneself, it feels quite similar, besides the fact that sleep is initiated by oneself, and the wakeful state transition for sleep is more gradual than for anesthesia.

I think that distinction matters because strictly speaking, oneself only has access to one's own consciousness, and that defines one's own understanding of the word "consciousness". It's not possible for me to be you after all, and whatever inferences I make about other people being conscious is based on the fact that I experience my consciousness, and you are similar to me in some specific way (such as being, presumably, a human), therefore you must be conscious. Of course, I'm taking a materialist stance here but that's what's practical to talk about anyway.

> But from the inside observed by oneself, it feels quite similar

Having been under general anesthesia once the feeling of just completely not existing for the time period I was under felt very different than sleep does to me.

Perhaps it's because I almost never dream. Sleep feels almost just as dead to me.

Case in point, I think we're probably talking about slightly different phenomena even when we talk about the same linguistic definition of consciousness. Kind of like how my idea of an "apple" is based on all of the apples I've seen in the past and instances where I've used the word or saw it being used by others, whereas your idea of "apple" is based on your experiences. They must be mostly similar in information content or we wouldn't be able to communicate at all, but the self-or-other distinction is important.

> But from the inside observed by oneself, it feels quite similar, besides the fact that sleep is initiated by oneself, and the wakeful state transition for sleep is more gradual than for anesthesia.

Have you been anesthetized before? Different forms are very different, but none of them feel like sleep, at all. General anesthesia feels like a time simply skipped forward. Like a chunk of your memory tape was cut out completely. Twilight sedation feels like you temporarily inhabited someone else's body but the experience was so strange that you blocked out almost all of the memory.

Sleeping and dreaming is totally different.

I've been under general anesthesia, but it does not feel too different. I'm dead when sleeping, and basically never dream. I should have said "dreamless sleep" in the earlier comment to be more precise because dreaming is obviously different, but it happens so rarely I forget it exists.

> basically never dream

I’m open to correction but my understanding is everyone dreams when they have REM sleep and everyone has some REM sleep every night unless there are rare medical conditions which would be unhealthy if there is a long period of no REM sleep.

People who believe they never dream (including myself before I learned this) simply don’t remember it. If you were woken artificially during REM you might remember fragments.

The last time I dreamt was in April. I'd make a note about it in my day log txt file when it happens. It's not the same as a normal night's sleep, and I would remember it. But I assume not having REM sleep for the past 4 months would mean reduced cognitive functioning, which is obviously not the case, so maybe I simply cannot remember my dreams most of the time.

Perhaps memory and consciousness are closely related or even the same process, as there is no way to tell them apart from the inside.

I misread that as "the first time I dreamt...".

Anyway yes, as I understand it this should be the last time you _remember_ having dreamt. https://en.wikipedia.org/wiki/Rapid_eye_movement_sleep says we hit REM multiple times per night normally.

... Also this Wikipedia says we have non-REM dreams. This whole article is interesting, thank you for indirectly prompting me to read up a bit :)

This is fascinating to me. Your experience is so different from mine.

When I wake from sleeping, I have a distinct sense of time passing and can usually tell you what time it is when I first wake up. But under anesthesia, absolutely no sense of any time passing at all.

Feels like sleep to me every time. Dreams and all.

Ok, then let's revise the definition to dreamless sleep or anesthesia.

Sleep is very subjectively different from anesthesia, in my personal experience. Sleep still carries a feeling of the passage of time, and in fact dreams can feel "more real than real" (I remember my dreams to varying degrees, most often when I drink alcohol, although I don't like to use that as a specific method to remember dreams on demand). Anesthesia, for me, resulted in the absolute cessation of time experience during the process. From my perspective, I went out in the OR and was immediately in the recovery room, even though it had in reality been about an hour.

The more interesting aspect of that is that there's an element of recall implicit in that though: if someone was active, moving around and interacting according to observers then whether they were conscious during that time is heavily informed by whether they remember it later.

Quite where that line exists then is very fuzzy because while for example I feel conscious while I'm typing this, it's also clearly possible I could but then have no memory of it.

> But colloquially, when people say consciousness, we usually mean

And by "we", you mean "you".

If I read an article about the nature of "consciousness", I assume it means "as opposed to being a rock or a twig".

N=2; two definitions.

> But colloquially, when people say consciousness, we usually mean the thing that goes away when we sleep or are anesthetized.

Sounds like attention rather than consciousness. You lose your attention.

Why only as oneself experiences? I can easily tell if a horse is conscious or not. The whole matter is rather simple IMO.

Let's say it's variability (number of distinct if you prefer discrete) of stable responses to external stimuli.

> when people say consciousness, we usually mean the thing that goes away when we sleep or are anesthetized.

How is dreaming during sleep different from consciousness when awake?

It feels very different to me. I have a dream perhaps once a year, and it's nowhere near as vivid as real experiences. Dreams don't have much color, shape, or audio, just a blurry mess where I could barely make out things resembling objects or people. There is no way to mistake that with reality.

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