Donald Hoffman - What is Consciousness?

don 1979 1980 you and i were both at mit getting involved in brains and consciousness yes so after all this time you tell me what you think consciousness is well my views are a bit unusual i think the consciousness is fundamental in the universe i think that it's not a product of space and time or anything inside space and time i think that efforts to derive consciousness from space-time either by identity theories or by causal theories have proven ineffective and i've been forced to take the view that consciousness is actually fundamental in the universe well everybody who we worked with every neuroscientist at mit then and now would believe that consciousness is a product of our brain our brain is an accidental product of evolution and we have emerged to have consciousness for some fitness reason and and that's all it is it may not have been necessary and it we have it and the reason we think it's important is because we have and who are asking the question well i think the evidence for evolution is quite strong so i don't question evolution but no one's been able to give a theory about how consciousness could emerge from brain activity and i i you know have to admit that i've tried myself for a long time to understand how brain activity could cause what is it about consciousness that causes you to make such a radical departure from everyone normal well of course i'm not the only one in the field that thinks the problem's hard so it's quite quite common to think that the problem is very very hard and and my departure from a physicalist attempt is partly there's a couple reasons one is um it's a good search strategy if you're trying to solve a problem and everybody's searching in one part of the search space if 99 of the researchers are in one part of the search space that's not an effective search strategy we need to have at least one or two researchers that are searching in a different part of the search space and so i decided to jump out and and look over in the consciousness fundamental space must have had tenure first i i definitely had this is not something you do before you get 10 years so i was i played it safe on that in that regard but but you know now that i've got tenure that's what tenure is for tenure is for allowing researchers to take serious risks to to try enterprises that may or may not work yeah that's great and you know i readily admit that maybe i'm wrong but i'm willing to explain so what is it about consciousness that forces you to make this radical uh a jump the thing about consciousness is that partly it's first person subjective whereas our descriptions in the physical world are tend to be more third person and what we would call objectives but there's this big gap that's known as a heart problem between say neural activity which you can think of crudely as ions flowing through holes and membranes that's roughly what's going on to a first approximation and that causes the electrical activity which is the what we see in the brain to cause information to flow back and forth between neurons that's right so all that but when i have the experience of a green apple uh if you look at my brain there's nothing green hopefully or i'm in deep trouble there's nothing green in there and if you look at the activity of the brain it doesn't look like a green apple and there's no direct connection that we can make between that activity and the actual experience as an experience of a green apple so that's what's been called the hard problem and by the way the you know the notion that this is a hard problem um has been known for centuries right so thomas huxley in the 19th century talked about this as the very very hard problem he said it's it's it's as mysterious as having a gin pop out of a bottle and john locke talked about this problem in 1690 saying that he had no idea how to make a connection between our conscious experiences and any physical activity of our body yeah but to today to be fair there is a great deal of understanding of what's called the neural correlates of consciousness where you can show and in your field in visual perception there are very specific things that occur in the cortex different parts of the brain when you see visual things you see edges you see lines you see different orientations different cells fire and different frequencies and different ways directly related to what you see in the environment so you see a lot of correlates absolutely and this is data that lock and huxley did not have that we've only gotten in the last couple three decades and it's very impressive what we've found i mean we can find specific neural correlates of color perception motion perception and we know that if you have damage to area mt or v5 you can lose motion perception uh v4 you can lose color perception so we know there are these very very strong neural correlates of of consciousness the question is how do you go from those neural correlates to either a causal theory how does that neural activity cause the experience to happen or some kind of identity theory i mean can we say that conscious experiences of a green apple is identical to neural activity but when you look at it no one has come up with a scientific theory that will make even the most basic prediction that says this kind of neural activity has to be the smell of a rose it could not be the color red for these mathematically precise reasons and if you make this small change in the neural activity you will necessarily change to the taste of chocolate and that could be with one neuron or circus of neurons however you want to do it you're free to choose that's right nobody has any idea not only that but nobody has any idea what would be an idea that that's right there's there's no it's not like you don't know which one is right or how how do we adjudicate between different options you don't even know you don't have any option that could conceivably do that that that's right and there locke is right with us in 1690 he said it's inconceivable even with all the data we've got today it's still inconceivable it's not just that we don't have scientific theories we don't have remotely plausible ideas about how to do it suppose this this is just an idea but it's not the real science suppose that we actually found that you experience a particular color of red say red 31 if and only if this particular neuron and we can name it you know neuron 6 billion 55 fires at 30 hertz and we and it's this amazing discovery that in everybody's brain neuron 1 billion and 55 right when it fires at 30 hertz you experience red 31. well you get your nobel prize that's an amazing discovery but has that solved the problem that we're talking about here about how does neural activity cause the experience of red not at all now the mystery is intensified how could it be that sodium and potassium and calcium ions going through holes in membranes of this particular neuron causes my experience of red 31 now the mystery is even more intensified so the neural correlates of consciousness don't solve the problem they make it more intense why should it be that consciousness seems to be so tightly correlated with activity that is utterly different in nature than conscious experience and where do you go from there well one direction that i go so i i spent a lot of time trying like everybody else to think of physicalist approaches to this or functionalist approaches maybe consciousness isn't identical or arises from neurobiology per se but maybe some kind of functional properties of the neurobiology and and again it's it's tempting my degree was in artificial intelligence at mit i mean we were doing functional models and yet i couldn't and nobody has yet been able to find a way to go from those functional models to a theory that gets conscious coming out without a miracle occurring what i don't want is a miracle at the critical stage right there are these functional properties of neurons then consciousness comes out but i don't want to have a miracle happen right at that key point now scientists have to put their miracles up front right those are our assumptions we just put them on the table these are our miracles our assumptions after that it's no fair it's not fair to put any miracle anywhere else especially not at the key point where consciousness emerges and so it was because i didn't want to put a miracle there and i couldn't think of a way to do it starting with physical or functional primitives assumptions that i said okay let's back off we have mind and body consciousness and the physical brain we've been trying to solve the problem starting with physical or functional and then getting to consciousness what what would happen if we start from the other direction as a purely scientific and rigorous approach so we're not talking about mysticism or anything like that i'm saying can we get a mathematically precise model of consciousness on its own terms where we have to then you know put down mathematical structures um not because they're right but so that we're precise so that we can then find out why we're precisely wrong so the idea is let's put down a mathematical model of consciousness of course it's not going to be right that's what science always does but you get it down there at least it's rigorous now you start to make predictions you get a dynamics of of consciousness the test will be can you derive quantum physics from it can you get the wave equation of a free particle can you get spinners can you get spin networks can you get quantum field theory out of it because if you can then at least you have a mathematically precise solution of the mind body problem starting in the other direction so i don't want a hand wave what i want is a mathematical model of consciousness that any mathematician would recognize is well specified that any empirical you know scientist in the field would say um is not completely implausible as an empirical model you know of the empirical data about consciousness and then the real test of solving the mind-body problem is can i take that model and without any hand waves no miracles get say quantum field theory popping out of it that would then be a a big bridge towards solving the line body problem from the other direction that would be the first pontoon over the over the river you'd then want to then colonize and do lots lots of other we understand all human psychology and how brain science relates to all aspects of human perception and cognition but if we can get the bridge from a basic model of consciousness to um say quantum field theory now we've got something to build on and that that's been my project

Channel: Closer To Truth

Views: 166,101

Keywords: closer to truth, robert lawrence kuhn, Donald Hoffman, What Is Consciousness, consciousness, Philosophy of Mind, don hoffman, Cognitive Science, donald hoffman interview, hoffman consciousness, philosophy of mind, conscious agents

Id: ynTqCFBhRmw

Length: 10min 33sec (633 seconds)

Published: Sun Nov 22 2020