The brain is the most complicated structure in the known universe. The probes currently available to science- fMRI and GSR - are both gross measures of cortical electrical activity. They're enough to start to explore apparent structural and (gross) electrical correlation between brain areas and (gross) alterations in "consciousness", in this case unconsciousness invoked via propofol and ketamine. Fair enough.
However, it irritates me when I hear scientists loosely throw the word "consciousness" into these studies and here's why.
In these studies, consciousness is always implicitly defined operationally as the electrical activity in some identified networks- DAT and DSM and front-parietal and sensory motor etc.. But the concept of consciousness has another life in philosophy where in works by people like Patricia Churchland and others, it references something more subtle- the mystery of why there should be anything we call experience at all.
Experience itself doesn't seem to be necessary to the working of any machine, including our brains. We don't think our TVs have any experiences despite (being capable of) accurately representing all human visual experiences. The reason we don't think they experience what they're displaying is because we know how they work and we know there's no ghost in the machine. Adding on "experiences" to an explanation of how TVs work is gratuitous and unnecessary.
But that's not the case with humans-just the opposite. Experience is absolutely foundational.
Descartes tried to boil his world down to what he could know with absolute certainty and arrived at his famous "Cogito ergo sum" formulation, but actually, he skipped a step; that step is simply- "There is experience".
Experience is perfectly gratuitous to any explanation of brain activity since all that activity, like an electrical storm, could take place in exactly the same way without it. We (our brains) could be, and most scientists believe are, very complicated, but purely mechanical machines. They could be exactly as they are with no more awareness- not to say feedback loops- than a blender.
But that account leaves the problem of experience or consciousness completely untouched. That would be O.K. except we know we have it.
The mystery of consciousness is not totally defined by questions like of "can I make you unconscious or conscious?" or "can I cause you to have this or that illusory experience by stimulating your brain?". The mystery of consciousness is why is there anything like experience at all ?
So whenever I read a paper that makes some confident assertion about consciousness, it gets under my skin. It's electrical activity and perhaps human behavior and speech they are actually examining, not consciousness. I hear these papers gratingly assuming the consequent with respect to the biggest mystery there is. They are implicitly saying "this is consciousness, this pattern of electrical activity in the brain and here is what we have discovered about consciousness". That's one perspective, but to philosophers, both academic and non-academic, it's a form of punting on the real question.
Consciousness is to brain science what AGI is to AI. Researchers just love to make assertions and grand predictions.
Actually the correlation between the two is closer than that since strong AI claims that consciousness can be captured in a computer; Kurtzweil and his Singularity concept is in this school of thought.
He and people like him claim that not only does experience arise as a direct result of brain activity but any substrate- including general purpose computer platforms- will similarly give rise to the same experiences if only they are programmed in a particular way, specifically, if the computations are functionally equivalent to the brain's computations.
Are badly programmed computers therefore experiencing chaos? Well, why not? Are simpler computers, like a thermostat which "experiences" temperature changes, also somehow dimly conscious? If that seems like a straw man argument to you, you should know Marvin Minsky bought it and so do a lot of other scientists whether they realize it or not.
All of this is just a non-starer to people like me. You don't get to skip a step because it keeps your theory neat or provides you the promise of immortality because you uploaded your "you" to a machine.
Consciousness, understood in this way, is a genuine mystery which for now at least I don't think we have the conceptual tools to even define much less make pronouncements about.
I think we're a long way from a good understanding of how consciousness works, but I also think a lot of people are going to subscribe to a sort of consciousness-of-the-gaps idea no matter how much progress is made in understanding the actual mechanisms. Even if we fully understood and and could reproduce it, there would be scores of people who would flat out refuse to see the evidence and would simply assert that the ineffable "experience" does not exist within beings for which they don't want to acknowledge it. The very concept of p-zombies illustrates this a priori refusal to admit any possible evidence whatsoever of consciousness. Another person could simply decide that I am in fact a p-zombie and lock themselves in a closed system of thought out of which there is no path to demonstrating that I "experience" anything at all.
I think if you want to put forth a hypothesis that there is some ghostly ineffable part of consciousness called "experience" that cannot ever be touched or measured by scientific means, then you have a self-defeating argument that cannot be supported. You might as well go full solipsism. There's nothing stopping you.
Consciousness is a genuine mystery at this point, but I think some people will still see it that way even if we solve it, and this is clearer to me every time I see people trash any kind of effort or progress made by science in understanding the brain, claiming that it is not in fact progress at all.
On the other hand, I think that many people are emotionally invested in believing that science must be capable of solving the hard problem of consciousness even though there is no reason to assume that science is.
It is perfectly possible that the hard problem of consciousness is in principle and forever beyond the reach of scientific investigation.
Just to toss off one more worthwhile idea to you since it seems like you're interested in this topic. p-zombies is not the most challenging scenario strong-AI deniers are likely to face. Brain cell replacement is.
With p-zombies you have two observers outside the system arguing about the system's inner life. With brain cell replacement, you have the subject directly and quite authoritatively experiencing the system in question and reporting back.
It seems many times more likely some of us will live to see this, but you just never know. Newtonian mechanics had it all locked up save for a few details and look what those details held.
Every brain science / cog-sci paper it seems has some alternative amputating conclusions to pronounce about consciouness.
They sort of have to do that because of the funding model they live under. Positive results only ! It's not the researcher's fault; I don't fault them. I just adopt a highly skeptical, wait and see, there's-probably-more-to-the-story attitude generally in science, that, and the more concrete counter-arguments I mentioned in my other comments make me a very highly dissident observer of this field.
"The very concept of p-zombies illustrates this a priori refusal to admit any possible evidence whatsoever of consciousness. Another person could simply decide that I am in fact a p-zombie and lock themselves in a closed system of thought out of which there is no path to demonstrating that I "experience" anything at all."
This is a good point and makes the problem interesting in an additional way. We (I) assume something like p-zombies exist in non-human consciousness, dogs and cats for example. It's like something to be a dog. How far down do we want to go ? Frogs? I'll bite; it's like something to be a frog:
But here's a counter to the p-zombies argument, OK?
The p-zombies argument is usually taken to mean there comes a point where what has been created is so indistinguishable from "real" people, ala Ex Machina, that arguing over it is a form of ideologically motivated perversion.
Let me turn that round and say that the p-zombie argument is (accidentally) making the following strong claim- it is impossible to build a machine which in every way acts human but has no experience.
That's a very very strong claim on this universe. I wouldn't take the bet, because someone's going to do it.
But if someone is going to do it, how can we tell when they have or they haven't? The Turing Test is outdated (as I see it) and anyway already passed for some judges ( re: ELIZA).
To me, this circles back to the original problem. We can't distinguish between the high probability that someone can eventually create an actual zombie and "real" experience-having artificial intelligence, and why is that ?
The issue is just another form of the basic problem- we don't have the conceptual framework to get our minds around what experience is.
Our basic assumptions may be off. Instead of quarks et.al. being the basic building blocks of matter and matter of brains and brains of consciouness, some people take experience to be the most basic building block of the universe.
This was my conclusion and I thought it would just brand me as an eccentric so I never pushed it, but now I see it's being kicked around by people with careers.
Another assumption is that experience/consciousness is comprehensible to the level of scientific causality/reality we're aiming at, (let's just shorthand it to "ultimate reality"), because there are separate, distinct things in the first place.
But what if separate things is not a fact about ultimate reality? What if they're more like a hardwired perceptual compulsion we can't escape? Then we might very well find truly insoluable mysteries on the foundational tier of our conceptual scaffolding, because none of the "things" we think about are real in the first place. Things which don't exist, don't have to "add up".
So this would mean our minds and ultimate reality are just not made for each other, even as that reality directly impinges on our personal daily lives in ways we can and do readily experience and talk about.
It seems like the most far fetched and deflating hypothesis possible, but consider we'd merely be joining the rest of the animal kingdom in this regards.
The thing is, if you're an atheist (and I write from one of the non-USA countries in which being an atheist is entirely unremarkable) then experience (or qualia) and consciousness itself are still very mysterious, but it's hard to avoid the conclusion that it must all be a side effect of processing or information somehow.
Daniel Dennett has some good stuff on this (see Consciousness Explained, etc). Its not that he knows the answers, but his point is that consciousness might not be exactly what we think it is, there are lots of thought-traps around it, so we have to carefully unpick some of our assumptions about it to get anywhere - e.g. what he calls the cartesian theatre is one very powerful misconception (too long to explain here).
Also I always like to drop this Iain Banks quote in these kinds of discussions (from A Few Notes About The Culture)
Certainly there are arguments against the possibility of [strong] Artificial Intelligence, but they tend to boil down to one of three assertions: one, that there is some vital field or other presently intangible influence exclusive to biological life - perhaps even carbon-based biological life - which may eventually fall within the remit of scientific understanding but which cannot be emulated in any other form (all of which is neither impossible nor likely); two, that self-awareness resides in a supernatural soul - presumably linked to a broad-based occult system involving gods or a god, reincarnation or whatever - and which one assumes can never be understood scientifically (equally improbable, though I do write as an atheist); and, three, that matter cannot become self-aware (or more precisely that it cannot support any informational formulation which might be said to be self-aware or taken together with its material substrate exhibit the signs of self-awareness). ...I leave all the more than nominally self-aware readers to spot the logical problem with that argument.
Edit: changed 'cant really avoid the conclusion' to 'its hard to ...'
Never take the arguments of a side from their opponent's mouths.
The arguments I offered have nothing to do with any of the three he claims they all boil down to.
If you think I made one of these three, please tell me which one so I can clarify the argument.
Assuming it's a side effect of processing- known as an epiphenomena- immediately commits you to answering the question- does a badly programmed computer have a form of consciouness? Does a thermostat have a primitive form? Is it specifically impossible to create AI which emulates human thinking to the last detail, but has no consciouness, i.e. really is just an empty machine with zero experience? Is that an impossible task which could not be achieved by anyone by any means?
Suppose I debate with someone who has a computer programmed to be conscious. Here's what I'm going to do. I'm going to very very slightly change the programming so whatever output it's producing which is proving, my opponent claims, the computer is conscience, starts to degrade.
I'm going to do that then ask my opponent- still conscious? I'm going to do this and I'll guess my opponent will say "less so perhaps" , which would be his best reply.
Then I'm going to repeat until I get a "probably not" and then a "no" from him, which by his own hypothesis has to happen.
Then I'm going to diff the conscious program and the unconscious program and ask him if he really thinks those slightly altered lines of code are the difference between consciousness and a humdrum computer.
Because that's where this goes, this idea that a certain type of computation is consciousness.
It also goes to consciousness being granted to a machine like a Turing Tape. You may not think that squishy biological matter should be bequeathed with a "magical" property which hosts consciousness, but tell me, how do you feel about a Turning Tape?
I'm going to very very slightly change the programming so whatever output it's producing which is proving, my opponent claims, the computer is conscience, starts to degrade.
[...]
Then I'm going to diff the conscious program and the unconscious program and ask him if he really thinks those slightly altered lines of code are the difference between consciousness and a humdrum computer.
Is that not equivalent to giving a human being alcohol, observing that they become progressively less conscious, and asking if you really think that a few centiliters of alcohol is the key to consciousness?
Doesn't that kind of reasoning lead you down a path towards panpsychism or panexperientialism?
Either there is a phase transition of consciousness or there is not. If there is, we have no idea where it is because we can't prove that another being has subjective experience the way we can ourselves. If there isn't, then something roughly panexperientialist follows and even, say, a gas cloud has (very occasionally and very limited) experience. But which is it?
The problem to science itself seems to be that we can't make any comparison of the "what it is like to be" sense of experience. I experience things right now. I can't tell you what it's like with the kind of certainty that is usually associated with science. I can't even tell my future self with that certainty, because memory is a sense in itself and when I recall something, I'm just experiencing something with the sense of memory.
If whatever experience is can't be "frozen", then science has nothing to work on, apart from trying to get at it from the objective side of things. But it seems like it's very easy to get sidetracked, hence the argument that Dennett just redefines consciousness as executive function and then proceeds to explain the latter in a materialist framework.
panpsychism or panexperientialism can't be right because they're not weird enough- to paraphrase Bohr. Would it surprise anyone to find out that, in our exploration of the brain we come across something as weird and upsetting to standard theory as QM is to physics ?
__________
If we do a gradual, over a long time, brain cell by brain cell replacement of a living human's brain, that human's self-report is our best bet to get around the impenetrability of the subjective experience of other minds.
It is also the biggest challenge to people like me and could point strongly to consciousness as a thing supportable by machines.
__________
I agree that this is a problem that science, as it is right now, can't deal with. But that doesn't mean it's not real. The Big Scientific Inquiry, the spirit of science, seeks to explain and understand everything. Many really dramatic upheavals come out of corner cases in science; the things that are slighly off or not accounted for in an otherwise productive theory.
_______________
It's not important to anyone's brain research, but it is important to society because making a mistake about what is and is not conscious has the potential for huge negative repercussions.
When Dennett dismisses the issue and effectively assumes the consequent of the argument he's supposedly engaged with, not only is he making an error but the consequences of that error are far-reaching into how we act towards one another.
What I am arguing, to the extent I am arguing for anything, is that people like Pat Chruchland have a point and it's not an "academic" one; it's substantive. We are making a mistake if we ignore it.
>if you're an atheist [...] you can't really avoid the conclusion that it must all be a side effect of processing or information somehow
Why? I'm an atheist-leaning agnostic, but I think that the hard problem of consciousness might well turn out to be impossible for scientific investigation to tackle.
I cannot think of any valid logic that would show that "there are no gods" implies "consciousness is a side effect of processing or information somehow".
Well yes OK. I guess I'm jumping from 'being an atheist' to 'general distrust of the so called supernatural'.
Do you mean 'impossible for scientific investigation to tackle' because its just too complex (in the same way we can't predict the weather very accurately) or do you mean more like: because you suspect there is some outside-of-known-physics involvement that we wont ever be able to get a grip on?
Not because it is too complex, but because I suspect that there may be something to consciousness that is outside of knowable physics. There is no reason to assume that scientific investigation is in principle capable of getting a grip on all of reality. That does not mean that consciousness is some mystic woo-woo, it just means that scientific investigation may in principle be limited. Consciousness might well turn out to be impossible in principle to tackle using mathematical modeling, reproducible experiment, theories of physical mechanisms, etc. - but that would not mean that consciousness is not real. It does not require scientific inquiry to show that consciousness is real. Subjective experience is immediately obviously real, as subjective experience.
I agree that what you say is possible, but it's also possible that consciousness does lie inside known physics, so I reckon it's worth people investigating that angle, as formidable as it seems.
I've edited my comment above to be a bit less absolutist
I wouldn't say it's impossible, although honestly I cannot even begin to imagine how consciousness could lie inside known or even knowable physics. But if people want to try, more power to them. I'm open to my suspicion being wrong.
All true enough, and I think any honest scientist would say that the most we can hope for is to notice a few patterns in the wallpaper on Plato's Cave. There's no reason to think that any real insight beyond that is possible.
However, it irritates me when I hear scientists loosely throw the word "consciousness" into these studies and here's why.
In these studies, consciousness is always implicitly defined operationally as the electrical activity in some identified networks- DAT and DSM and front-parietal and sensory motor etc.. But the concept of consciousness has another life in philosophy where in works by people like Patricia Churchland and others, it references something more subtle- the mystery of why there should be anything we call experience at all.
Experience itself doesn't seem to be necessary to the working of any machine, including our brains. We don't think our TVs have any experiences despite (being capable of) accurately representing all human visual experiences. The reason we don't think they experience what they're displaying is because we know how they work and we know there's no ghost in the machine. Adding on "experiences" to an explanation of how TVs work is gratuitous and unnecessary.
But that's not the case with humans-just the opposite. Experience is absolutely foundational.
Descartes tried to boil his world down to what he could know with absolute certainty and arrived at his famous "Cogito ergo sum" formulation, but actually, he skipped a step; that step is simply- "There is experience".
Experience is perfectly gratuitous to any explanation of brain activity since all that activity, like an electrical storm, could take place in exactly the same way without it. We (our brains) could be, and most scientists believe are, very complicated, but purely mechanical machines. They could be exactly as they are with no more awareness- not to say feedback loops- than a blender.
But that account leaves the problem of experience or consciousness completely untouched. That would be O.K. except we know we have it.
The mystery of consciousness is not totally defined by questions like of "can I make you unconscious or conscious?" or "can I cause you to have this or that illusory experience by stimulating your brain?". The mystery of consciousness is why is there anything like experience at all ?
So whenever I read a paper that makes some confident assertion about consciousness, it gets under my skin. It's electrical activity and perhaps human behavior and speech they are actually examining, not consciousness. I hear these papers gratingly assuming the consequent with respect to the biggest mystery there is. They are implicitly saying "this is consciousness, this pattern of electrical activity in the brain and here is what we have discovered about consciousness". That's one perspective, but to philosophers, both academic and non-academic, it's a form of punting on the real question.
Consciousness is to brain science what AGI is to AI. Researchers just love to make assertions and grand predictions.
Actually the correlation between the two is closer than that since strong AI claims that consciousness can be captured in a computer; Kurtzweil and his Singularity concept is in this school of thought.
He and people like him claim that not only does experience arise as a direct result of brain activity but any substrate- including general purpose computer platforms- will similarly give rise to the same experiences if only they are programmed in a particular way, specifically, if the computations are functionally equivalent to the brain's computations.
Are badly programmed computers therefore experiencing chaos? Well, why not? Are simpler computers, like a thermostat which "experiences" temperature changes, also somehow dimly conscious? If that seems like a straw man argument to you, you should know Marvin Minsky bought it and so do a lot of other scientists whether they realize it or not.
All of this is just a non-starer to people like me. You don't get to skip a step because it keeps your theory neat or provides you the promise of immortality because you uploaded your "you" to a machine.
Consciousness, understood in this way, is a genuine mystery which for now at least I don't think we have the conceptual tools to even define much less make pronouncements about.