Dirty Secrets of Consciousness by David Chalmers

[Music] at least have the standards of physics the science of consciousness is you know somewhere where physics was maybe a few hundred years ago so about maybe making this clean secrets instead I thought actually maybe I'll do dirty secrets but so we'll get the dirty secrets and we'll get Thea will get the but so okay number one do any secret we can't define there's no good definition of consciousness simple totally convey the phenomena someone hasn't experienced it for themselves we're quite fond of that fond of this one not just is that that annoying time between naps but we have to have been there to know what we be that said we do have some useful distinction at least in the air in the area from different things you might mean by consciousness but one thing is just the distinction between what we might call intelligence objective behavior doing sophisticated things performing sophisticated functions and consciousness in the sense of experience subjective experience what it feels like from the inside for example to see to hear to feel emotions and to think and the really central questions of consciousness are all tied to subjective experience which is where I'll be focusing here there are distinctions between consciousness in the sense of access to an objective mechanistic sense access to information reflective consciousness access to internal states that can then be deployed in behavior and what philosophers called phenomenal consciousness which again is the experiential sense on which I'll be concentrating here a system is phenomenally conscious this useful definition which about as good as any definition you'll find due to Tom Nagel in his paper what it's like to be in that same system is conscious in the phenomenal sense if there's something it's like to be that system so my thought is ok this something is like to be me right now experiencing presumably there's think it's like to be this microphone the who knows and a state is phenomenally conscious this something is like to be in that state there's something it's like for me to see right now to have a visual experience there's nothing it's like for example for my kidneys to be doing some particular thing right now so that's at least ER and we're getting a grip on the phenomena for those who have ever has been there now next problem next dirty secret we can't measure it consciousness by its nature is private and subjective directly observable from the first person point of view introspectively I know perfectly well that I'm conscious and a fair amount about what I'm conscious of not directly observable from the third person point of view I can't just you know look at the system and immediately read off what it's conscious of but in practice we have a way around this at least in humans we measure consciousness in humans by the use of verbal reports you basically take it as a principle that if someone says they're consciously experiencing say a Red Cross in their visual field then they are at least unless there's some reason to think something's going wrong the summary unless there's some reason to believe otherwise and this practice of relying on verbal introspective reports in humans at least has come to ground the robust science of consciousness in humans where for example we can start to ascertain the neural correlates of consciousness the brain area is there active when people report states of consciousness and so on this is of course a very limited measure it requires that systems have the ability to report their state and there is no uncontroversial measure of consciousness in non-human systems that don't have the ability to report if I want to figure out whether a mouse or a fly is conscious verbal report is useless and there's nothing which is even remotely as useful of course there are controversial measures kind of post theoretical measures like say information integration or whatever but these are all post Cerreta chol and none of them are close to consensus or controversial or uncontroversial measures okay dirty secret number three we can't explain it standard methods at least of explanation in the mind and brain sciences are very much designed to explain behavior and objective functions leading up to to behavior and explaining to learning or memory or language that I mean in the case of consciousness that works fine for you know explaining things like access and rapport but these are the easy problems when it comes to consciousness the basic challenge of the field is it seems that explaining all that behavior at best explains the phenomena we were associating with intelligence and doesn't on the face of it explain subjective experience you can explain all those behavioral functional things that would still leave the open question why is all that accompanied by subjective experience why does it feel like something from the inside that's what we call the hard problem so it starts to look as if standard methods wonderful for the easy problems don't explain phenomenal consciousness the hard problem ok so that's dirty not-so-secret point here stronger claim is that no explanation wholly in terms of physical processes will explain consciousness roughly because all you're going to get from an explanation in terms of physical processes is the explanation of behaviors really useful for explaining a whole lot of things throughout nature from life on up explaining various behavioral phenomena in psychology but if I was going to go into this more length I'd argue this in a sense that's all you're going to get from standard explanation in terms of physics again great for the easy problems not so great for the hard problems if you accept that I can't defend the claim here then it starts to look as if although putting together the fundamentals of physics whatever they are space and time and mass and charge is great for explaining life and great for even explaining behavior doesn't explain consciousness if you want to bring consciousness in you need something more in the picture and various people have suggested maybe we need to take consciousness itself as a fundamental in our theories and that's the way I want to go can't exactly fully defend that claim here but I do think it's where you're led to by taking this hard problem of consciousness seriously now but okay so yeah that's extremely dirty very bad news because that means no reductionist theory of consciousness is possible when in purely physical terms but non reductionist theories are still possible non reduction a series of consciousness that basically ones that don't try to reduce consciousness just acknowledge it in its own terms try to ascertain some of its properties and to connect it to everything else we know about for example physical processes in the brain and perhaps ultimately to physics oh we might have some psycho physical principles connecting the mental and the physical by way of certain sets of laws and that's actually the way that the science of consciousness if you look at the science of consciousness one really cool thing is over the last twenty years a very robust science of consciousness has started to be developed in neuroscience in psychology and so on most of it is not reductionist in the way I've been talking about that's not to say it's not necessarily non reductionist maybe it's just neutral on the question of reductionism but what it does is doesn't try and fully explain consciousness in terms of say underlying neural processes it assumes consciousness and tries to connect it to neural processes say by finding neural correlates of consciousness that is somewhat more general and universal level Giulio Tononi who's here is a develop the integrated information theory of consciousness which I think is a nice example of a a-- of a non reductive theory of consciousness makes a connection between consciousness and certain computational or informational processes Giulio be talking about this later he's got his measure fie of integrated information and authorities the amount of consciousness goes along with the degree of fie integrated information Giulio is quite explicit this is not in ended as a reduction of consciousness he takes the existence of consciousness as a starting point but he assumes it nice exactly what can we connect it to that we understand that the information processing level he's got this bold hypothesis about how it works of course it's still very early days and any proposal that right now is out there is probably going to turn out to be wrong but it's nice to have proposals like this on the table okay next dirty secret we don't know what it does just about you know what is consciousness full what does it cause just about any behavior that we think consciousness might explain can be explained it seems without invoking consciousness do you say consciousness is for planning or for decision-making or responding or for withdrawing your hand from the flame or or something what starts to look as if there's a story about what explains that in terms of brain processes that never needs to mention subjective experience anywhere so pretty well right now no one knows what the function of consciousness is many proposals nothing like a consensus that's said this does I think connect to some of the issues here at the conference about possible roles for observation in physics at least some possible roles for observers and observation in physics might suggest some possible roles for a consciousness not just leave that hanging for now and return to that in a few minutes towards the the end of the talk when I start to speculate wildly um okay so those are for dirty secrets but dirty secret number five is despite all these problems we can't explain it and we can't measure it and we can't define it we don't know what it does nevertheless we can't ignore it you might you might say okay well screw consciousness then but but we can't ignore it consciousness is a datum it's arguably the central datum of our existence they can't so this is the one thing about the world that we know more certainly than any other now I do think it's a respect it's a respectable approach to the problems of consciousness to deny that claim and try to argue in fact this datum is a kind of an illusion and people like Dan Dennett have tried to take that approach it hasn't proved very popular hasn't general proved terribly plausible it's really hard to work out that view I think if you if you want to oppose the kind of non reductionist view that I take is probably best to try and deny the datum and try to take a view of consciousness as an illusion but if you don't take that approach which most people don't you've got to take this as a data we've got to accommodate it in your theories somewhat and we won't have a theory of everything without a theory of consciousness so physics has this ambition to build this great chain of explanation for physics chemistry biology psychology whatever consciousness is going to have to get in there somewhere and right now I'm kind of standing outside like a sore thumb so we have to bring it in somewhere it's great to see that you know some people in this group we're taking these questions of our consciousness seriously furthermore for our local purposes here in understanding observers and the role of the observer say in physical theories kind to think that we can't really understand observers without understanding consciousness is it's high between the notion of observation or at least certain key notions of observation and consciousness it's pretty crucial for some local purposes here so I'll get to that theme next then the question of what is an observer you want in one sense of observer of observation is kind of trivial you might the observation is just registration of one physical system on another you get an observation whenever one entity has some reliable effect on another one particle affects another in a reliable way this one can be said to make an observation or a registration of the state of another in that sense you're even a classical particle will be or can be and observer well maybe that's one sense of observation I'm inclined to think that for many purposes within physics this is not the relevant sense I mean one thing I think is going to come out is that in different domains of physics different notions different notions of observer an observation or relevant maybe in relativity something like this sense is all you need I think in quantum mechanics and cosmology something more robust is a is needed then then the question is what distinguishes observation from registration that's kind of a challenge for anyone who wants a robust notion of observation that doesn't just collapse into registration and the obvious suggestion I think is that what marks the difference is something mental observers are people who perceive or who know or who are conscious and that means that you know once you start talking about observation you're up to your your ears in the philosophy of mind whether you you like it or not maybe people think there's some intermediate sense for Lexia camera gets to be an observer but a but a particle does not then I think the challenge is try to articulate that sense without drawing very arbitrary lines since - then since I'm interested in this observation equals conscious perception there there's a very non arbitrary line observation is something really pretty special certainly the observations that we make as human observers all involve conscious perception consciously observing the state of a system and experiencing it in that sense observers are conscious perceivers and that's the sense that I'm interested to focus on another question very relevant for this conference I think is what is the theoretical role of observation in physical theories and I think one thing is going to come out is there are many such roles for observation we can't reduce it to one such roles there's probably different roles for observation and cosmology in quantum mechanics in relativity some roles I think are epistemological observation is a guide to the correct physical cosmological theory not part of the theory itself it's to the logical means this is about knowledge so for example we can throw poq reasoning and cosmology might take our existence as observers as a data point that helps constrain the correct cosmological theory without observers playing any fundamental role within those theories I mean there are strong anthropic principles that go for something stronger I take it that approach is much less popular in cosmology but maybe some rules are on too large this is the much more radical suggestion that observation is somehow part of a physical or cosmological theory playing a role somehow in their dynamics or the basic principles now suppose in cosmology strong anthropic reasoning would give you an essence of that but the obvious other physical theory where you might look for this kind of phenomenon is traditional quantum mechanics which at least prima facie gives a central role to this notion of measurement or observation in the dynamics here I mean that traditional thing you learn in some textbooks with Schrodinger evolution and then this other special thing that happens upon measurement that seems to involve some special dynamics of collapse this is at least one of the many things that sometimes get called the Copenhagen interpretation that I'm inclined to agree to I think that term is somewhat useless now because it means so many different things so if you're interested in possible rules for consciousness and observation within physical theories that's at least a one interesting place to look and you might think the theories of consciousness could help to play at least some clarifying role here so that's going to be my final section it's just thinking a little bit about what theories of consciousness might say about role of observation in traditional quantum mechanics I mean it's fair to say I think that this kind of traditional interpretation of quantum mechanics is extremely unpopular at least among people working on quantum foundations and you know I'm myself quite sympathetic with other interpretations like like Everett plasti coherence and so on that said I'm inclined to think the traditional collapse on measurement interpretations have been somewhat under theorized recently and deserve a little bit more attention they're often rejected because they give an ontological role to observe it and measurement and how could that play a role in the fundamental physical theory and really there's at least two worries here first this whole notion of observational measurement is incredibly vague and imprecise how could something so vague and imprecise play a role in physical dynamics a second somewhat related worry is the notion of observation is on fundamental observation and measurement is very high level seeing and loving consciousness again totally unfit for a role in fundamental physical dynamics those are reasonable reactions still in the context of thinking about fundamental theories of consciousness say of AIT and so on those worries at least become somewhat reduced if we had a rigorous fundamental theory of consciousness with precise psycho physical laws this I think would tend to remove both worries yielding a precise collapse interpretation of quantum mechanics a we'd have something fundamental playing the role be we have precise conditions for collapse so take for example to know an ease integrated information theory which purports to give precise conditions for the existence of consciousness well here's a thought let's do a mash-up of IIT with quantum collapse theories and say okay IIT gives you the condition for consciousness or for or for observation fire above threshold gives you consciousness and then when that happens that's the condition for collapse well now at least we have precise conditions for collapse now I'm not saying this is the correct theory they'll turn out to be a whole range of precise collapse interpretations of quantum mechanics corresponding to different precise theories of consciousness and although imprecision is often put forward as a problem for these theories like you could also almost see it as a feature we've got a whole range of theories now which we can we actually experimentally try to distinguish in principle of course each of these theories can be experimentally distinguished in principle through experiments involving interferometers and the like extremely difficult to do right now but at least in the long term there's the possibility of experimentally distinguishing these different precise consciousness collapse interpretations of quantum mechanics so here's a project i'm just recommending to you as a as a project articulate precise collapsed theories of quantum mechanics of this sort and then experimentally test them now there's any number of obvious obstacles to both of those parts both to articulating the theories and to testing them but I do think it's a it's a it's a project at least we're thinking about a couple of people from Oxford came up with one collapse Terri creme laser and ranch and in the spirit my old student Kelvin McQueen is now a Chapman and I have been thinking about this project too in any case it's a project to be carried out if successful this project would yield an experimentally verified interpretation of quantum mechanics a theory of consciousness a role for consciousness in the physical world and even a way of measuring consciousness that's enabling us to clean up some of those dirty secrets from the start look I think it's a long shot but at least it I think is um it ought to be at least in the space of possible interpretations of quantum mechanics so I'm done I think this is at least a theory a reason for theorists of consciousness to pay some attention to physics because some pay off in thinking about theories of consciousness and for physicists to pay at least some attention to consciousness thanks you

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Keywords: David Chalmers, consciousness, fqxi

Id: Tgc_jvnuyqs

Length: 21min 10sec (1270 seconds)

Published: Thu Dec 15 2016

Reddit Comments

[u/Thelonious_Cube]

I don't know - at about 18 minutes he it seems to me that he starts grasping for straws, trying use a basically obsolete interpretation of quantum physics to bolster his ideas about consciousness being essential and essentially non-physical.

I think he's just too attached to how he originally framed "the hard problem" and he's just not willing to let that go.

Defining consciousness as "what it is to be like something" just seems so hand-wavy and unhelpful to that I was surprised how much he endorsed that "definition"