Jeff Hawkins: Thousand Brains Theory of Intelligence | Lex Fridman Podcast #25
-EVqrDlAqYo • 2019-07-01
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Kind: captions Language: en the following is a conversation with Jeff Hawkins he's the founder of the redwood centre for theoretical neuroscience in 2002 and Numenta in 2005 in this 2004 book titled on intelligence and in the research before and after he and his team have worked to reverse-engineer the neocortex and proposed artificial intelligence architectures approaches and ideas that are inspired by the human brain these ideas include hierarchical temporal memory htm' from 2004 and new work the thousands brains theory of intelligence from 2000 17 18 and 19 Jeff's ideas have been an inspiration to many who have looked for progress beyond the current machine learning approaches but they have also received criticism for lacking a body of empirical evidence supporting the models this is always a challenge when seeking more than small incremental steps forward in AI Jeff was a brilliant mind and many of the ideas he has developed and aggregated from your science are worth understanding and thinking about there are limits to deep learning as it is currently defined forward progress in AI is shrouded in mystery my hope is that conversations like this can help provide an inspiring spark for new ideas this is the artificial intelligence podcast if you enjoy it subscribe on youtube itunes or simply connect with me on twitter at lux friedman spelled fri d and now here's my conversation with Jeff Hawkins are you more interested in understanding the human brain or in creating artificial systems that have many of the same qualities but don't necessarily require that you actually understand the underpinning workings of our mind so there's a clear answer to that question my primary interest is understanding the human brain no question about it but I also firmly believe that we will not be able to create fully intelligent machines until we understand how the human brain works so I don't see those as separate problems I think there's limits so what can be done with machine intelligence if you don't understand the principles by which the brain works and so I actually believe that studying the brain is actually the fast the fastest way to get to machine intelligence and within that let me ask the impossible question how do you not define but at least think about what it means to be intelligent so I didn't try to answer that question first we said let's just talk about how the brain works let's figure out how certain parts of the brain mostly the new your cortex but some other parts to the parts of the very most associated intelligence and let's discover the principles about how they work because intelligence isn't just like some mechanism and it's not just some capabilities it's like okay we don't even have know where to begin on this stuff and so now that we've made a lot of progress on this after we've made a lot of progress on how the neocortex works and we can talk about that I now have a very good idea what's going to be required to make intelligent machines I can tell you today you know some of the things are gonna be necessary I believe to create intelligent machines well so we'll get there we'll get to the neocortex and some of the theories of how the whole thing works and you're saying as we understand more and more about the neocortex about our own human mind we'll be able to start to more specifically define what it means to be intelligent it's not useful to really talk about that until I don't know if it's not useful look there's a long history of AI as you know right and there's been different approaches taken to it and who knows maybe they're all useful right so you know the good old fashioned AI the expert systems current convolution neural networks they all have their utility they all have a value in the world but I would think almost everyone agree that none of them are really intelligent in a set of a deep way that that humans are and so it's it's just the question is how do you get from where those systems were or are today to where a lot of people think we're going to go and just big big gap there a huge gap and I think the quickest way of bridging that gap is to figure out how the brain does that and then we can sit back and look and say oh what do these principles that the brain works on are necessary and which ones or not kula we don't have to build this in and telogen machines aren't going to be built out of you know organic living cells but there's a lot of stuff that goes on the brain it's going to be necessary so let me ask me B before we get into the fun details let me ask me to get depressing or a difficult question do you think it's possible that we will never be able to understand how our brain works that maybe there's aspects to the human mind like we ourselves cannot introspectively get to the core that there's a wall you eventually hit yeah I don't believe that's the case I have never believed that's the case there's not have been a single thing we've ever humans have ever put their minds to so we've said oh we reached the wall we can't go any further it just people keep saying that people used to believe that about life you know Ilan's Vittal right there's like what's the difference in living matter and nonliving matter something special you never understand we no longer think that so there's there's no historical evidence to suggest is the case and I just never even considered that's a possibility I would also say today we understand so much about the neocortex we've made tremendous progress in the last few years that I no longer think of it as an open question the answers are very clear to me and the pieces we know we don't know I are clearly me but the framework is all there and it's like oh okay we're gonna be able to do this this is not a problem anymore it just takes time and effort but there's no mystery a big mystery anymore so then let's get it into it for people like myself we're not very well versed in the human brain except my own can you describe to me at the highest level what are the different parts of the human brain and then zooming in on the neocortex the parts of the neocortex and so on a quick overview yeah sure human brain we can divide it roughly into two parts there's the old parts lots of pieces and then there's a new part the new part is the neocortex it's new because it didn't exist before mammals the only mammals have a neocortex and in humans it's in primates it's very large in the human brain the neocortex occupies about seventy to seventy-five percent of the volume of the brain it's huge and the old parts of the brain are there's lots of pieces there there's a spinal cord and there's the brain stem and the cerebellum and the different parts of the basal ganglia and so on in the old parts of the brain you have the autonomic regulation like breathing and heart rate you have basic behaviors so like walking and running or controlled by the old parts of the brain all the emotional centers of the brain are in the old part of the brains when you feel anger or hungry lust with things like that those are all in the old parts of the brain and and we associate with the neocortex all the things we think about as sort of high-level perception and cognitive functions anything from seeing and hearing and touching things to language to mathematics and engineering and science and so on those are all associative the neocortex and they're certainly correlated our abilities in those regards are correlated with the relative size of our neocortex compared to other mammals so that's like the rough division and you obviously can't understand the new your cortex is completely isolated but you can understand a lot of it with just a few interfaces so the all parts of the brain and so it it gives you a system to study the other remarkable thing about the neocortex compared to the old parts of the brain is the neocortex it's extremely uniform it's not visually or anatomically or it's very sucky I always like to say it's like the size of a dinner napkin about two and a half millimeters thick and it looks remarkably the same everywhere everywhere you look and that children have millimeters is this detailed architecture and it looks remarkably the same everywhere and that's a cross species the mouse versus a cat and a dog and a human or if you look at the old parts of the brain there's lots of little pieces do specific things so it's like the old parts of a brain evolved look this is the part that controls heart rate and this is the part that controls this and this is this the kind of thing and that's this kind of thing and he's evolved for eons a long long time and they have their specific functions and all sudden mammals come along and they got this thing called the neocortex and it got large by just replicating the same thing over and over and over again this is like wow this is incredible so all the evidence we have and this is an idea that was first articulated in a very cogent and beautiful argument by a guy named Vernon mal Castle in 1978 was that the neocortex all works on the same principle so language hearing touch vision engineering all these things are basically underlying or all built in the same computational substrate they're really all the same problem all over the building blocks all look similar yeah and they're not even that low-level we're not talking about like like neurons we're talking about this very complex circuit that exists throughout the neocortex is remarkably similar it is it's like yes did you see variations of it here and there more of the cell uh so that's not all so on but what now encruster argued was it says you know if you take a section on your cortex why is one a visual area and one is a auditory area or why 'since and his answer was it's because one is connected to eyes and one is connected ears literally you mean just its most closest in terms of number of connections to listen sir literally if you took the optic nerve and it attached it to a different part of the neocortex that part would become a visual region this actually this experiment was actually done by Mercosur oh boy and uh in in developing I think it was lemurs I can't remember there was some animal and and there's a lot of evidence to this you know if you take a blind person the person is born blind at Birth they they're born with a visual neocortex it doesn't may not get any input from the eyes because of some congenital defect or something and that region become does something else it picks up another task so and it's it's so it's just it's this very complex thing it's not like oh they're all built on neurons no they're all built in this very complex circuit and and somehow that circuit underlies everything and so this is the it it's called the common cortical algorithm if you will some scientists just find it hard to believe and they decide can't really that's true but the evidence is overwhelming in this case and so a large part of what it means to figure out how the brain creates intelligence and what is intelligence in the brain is to understand what that circuit does if you can figure out what that circuit does as amazing as it is then you can then you then you understand what all these other cognitive functions are so a few words to sort of put neural cortex outside of your book on intelligence you look if you wrote a giant tome a textbook on the neocortex and you look maybe a couple centuries from now how much of what we know now would still be two centuries from now so how close are we in terms of understand I have to speak from my own particular experience here so I run a small research lab here it's like yeah it's like I need other research lab I'm the sort of the principal investigator there was actually two of us and there's a bunch of other people and this is what we do we started the neocortex and we published our results and so on so about three years ago we had a real breakthrough in this in this film just tremendous spectrum we started we've now published I think three papers on it and so I have I have a pretty good understanding of all the pieces and what we're missing I would say that almost all the empirical data we've collected about the brain which is enormous if you don't know the neuroscience literature it's just incredibly big and it's it's the most part all correct its facts and and experimental results and measurements and all kinds of stuff but it none none of that has been really assimilated into a theoretical framework it's it's data without it's in the language of Thomas Kuhns a historian it would be a sort of a pre paradigm science lots of data but no way to fit in together I think almost all of that's correct it's gonna be some mistakes in there and for the most part there aren't really good cogent theories about it how to put it together it's not like we have two or three competing good theories which ones are right and which ones are wrong it's like yeah people just like scratching their heads wrong things you know some people given up on trying to like figure out what the whole thing does in fact is very very few labs that we that we do that focus really on theory and all this unassimilated data and trying to explain it so it's not like we have we've got it wrong it's just that we haven't got it at all so it's really I would say pretty early days in terms of understanding the fundamental theories forces of the way our mind works I don't think so that what I would have said that's true five years ago so I we have some really big breakthroughs on this recently and we started publishing papers on this so look it but so I don't think it's I you know I'm an optimist and from where I sit today most people would disagree with this but from where I sit city from what I know uh it's not super early days anymore we are it's it's you know the way these things go is it's not a linear path right you don't just start accumulating and get better and better better no you okay all the stuff you've collected none of it makes sense all these different things we just turn around and then you're gonna have some breaking points or all sudden oh my god now we got it right so that's how it goes and science and I feel like we passed that little thing about a couple years ago all that big thing a couple years ago so we can talk about that time will tell if I'm right but I feel very confident about it that's my moment to say it on tape like this at least very optimistic so let's before those few years ago let's take take step back to HTM the hierarchical temporal memory theory which you first proposed on intelligence and went through a few different generations can you describe what it is how it evolved through the three generations yes you first put it on paper yeah so one of the things that neuroscientists just sort of missed for many many years and ice and especially people were thinking about theory was the nature of time in the brain brains process information through time the information coming into the brain is constantly changing the patterns from my speech right now if you're listening to it at normal speed we'd be changing on IRA's about every 10 milliseconds or so you'd have it change this constant flow when you look at the world your eyes are moving constantly three to five times a second and the inputs complete completely if I were to touch something like a coffee cup as I move my fingers that input changes so this idea that the brain works on time changing patterns is almost completely or was almost completely missing from a lot of the basic theories like fears of vision and so it's like oh no we're going to put this image in front of you and flash it and say what is it a convolutional neural networks work that way today right you know classify this picture but that's not what visions like vision is this sort of crazy time-based pattern that's going all over the place and was touched and so is hearing so the first part of a hierarchal temporal memory was the temporal part it's it's the same you you won't understand the brain orally understand intelligent machines unless you're dealing with time-based patterns the second thing was the memory component of it was is to say that we aren't just processing input we learn a model of the world that's the memory stands for that model we have to the point of the brain part of the New York white chest it learns a model of the world we have to store things that our experience is in a form that leads to a model the world so we can move around the world we can pick things up and do things and navigate know how it's going on so that's that's what the memory referred to and many people just they were thinking about like certain processes without memory at all it just like processing things and finally the hierarchical component was reflection to that the New York or check so though it's just uniform sheet of cells different parts of it project to other parts which project to other parts and there is this sort of rough hierarchy in terms of them so the hyperbole temporal memory is just saying look we should be thinking about the brain as time-based you know model memory based and hierarchical processing and and that was a placeholder for a bunch of components that we would then plug into that we still believe all those things I just said but we now know so much more that I'm stopping to use the word hierarchal thumper memory yeah because it's it's insufficient to capture the stuff we know so again it's not incorrect but it's I now know more and I would rather describe it more accurately yeah so you're basically we can think of HTM as emphasizing that there's three aspects of intelligence that important to think about whatever the whatever the eventual theory it converges to yeah so in terms of time how do you think of nature of time across different time scales so you mentioned things changing a sensory inputs changing every 10 being myself what about it every few minutes every few yeah Montse well if you think about a neuroscience problem the brain problem neurons themselves can stay active for certain perks of time they parts of the brain with this doctor 4-minute you know so you could hold up a certain perception or an activity for a certain period of time but not most of them don't last that long and so if you think about your thoughts are the activity neurons if you're going to want to involve something that happened a long time ago I'm even just this morning for example the neurons haven't been active throughout that time so you have to store that so if I asked you what did you have for breakfast today that is memory that is you've built into your model of the world now you remember that and that memory is in the in the synapses it's basically in the formation of synapses and so it's it you're sliding into what you know is two different time scales there's time scales of which we are like understanding my language and moving about and seeing things rapidly and over time that's the time scales of activities of neurons but if you want to get longer time scales then it's more memory and we have to invoke those memories to say oh yes well now I can remember what I had for breakfast because I stored that someplace I may forget it tomorrow but I'd stored for afor now so this is memory also need to have so the hierarchical aspect of reality is not just about concepts it's also about time do you think of it that way yeah time is infused in everything it's like you really can't separate it out if I ask you what is the what is your you know how's the brain learning a model of this coffee cup here I have a coffee cup and I'm at the coffee cup I said well time is not an inherent property of this of this of the model I have of this cup whether it's a visual model or attack the model I can sense it through time but if the model self doesn't really much time if I asked you if I said well what is the model of my cell phone my brain has learned a model of the cell phone so if you have a smart phone like this and I said well this has time aspects to it I have expectations when I turn it on what's gonna happen what water how long it's going to take to do certain things if I bring up an app what sequences and so I have instant it's all like melodies in the world you know yeah melody has a sense of time so many things in the world move and act and there's a sense of time related to them some don't but most things do really so it's it's sort of infused throughout the models of the world you build a model of the world you're learning the structure of the objects in the world and you're also learning how those things change through time okay so it's it's it really is just a fourth dimension that's infused deeply and they have to make sure that your models have been intelligence incorporated so like you mentioned the state of neuroscience is deeply empirical a lot of data collection it's uh you know that's that's where it is using meshing Thomas Kuhn right yeah and then you're proposing a theory of intelligence and which is really the next step the really important stuff to take but why why is HTM or what we'll talk about soon the right theory so is it more in this it what is it backed by intuition is it backed by evidence is it backed by a mixture of both is it kind of closer to or string theories in physics where this mathematical components would show that you know what it seems that this it fits together too well for not to be true which is what we're string theory is is that where your fix of all those things although definitely where we are right now it's definitely much more on the empirical side than let's say string theory the way this goes about we're theorists right so we look at all this data and we're trying to come up with some sort of model that explains it basically and there's yeah unlike string theory there's this vast more amounts of empirical data here that I think than most physicists deal with and so our challenge is to sort through that and figure out what kind of constructs would explain this and when we have an idea you come up with a theory of some sort you have lots of ways of testing it first of all I am you know there are hundred years of assimilated unassimilated empirical data from neuroscience so we go back and read papers we said oh did someone find this already with you we can predict x y&z and maybe no one's even talked about it since 1972 or something but we go back and find out we say Oh either it can support the theory or it can invalidate the theory and we said okay we have to start over again oh no it's the poor let's keep going with that one so the way I kind of view it when we do our work we come up we we look at all this empirical data and it's it's what I call is a set of constraints we're not interested in something that's biologically inspired we're trying to figure out how the actual brain works so every piece of empirical data is a constraint on a theory in theory if you have the correct theory it needs to explain every pin right so we have this huge number of constraints on the problem which initially makes it very very difficult if you don't have any constraints you can make up stuff all the day you know here's an answer how you can do this you can do that you can do this but if you consider all biology as a set of constraints all neuroscience instead of constraints and even if you're working on one little part of the neocortex for example there are hundreds and hundreds of constraints these are empirical constraints that it's very very difficult initially to come up with a radical framework for that but when you do and it solves all those constraints at once you have a high confidence that you got something close to correct it's just in mathematically almost impossible not to be so it that's the the curse and the advantage of what we have the curse is we have to solve we have to meet all these constraints which is really hard but when you do meet them then you have a great confidence that you discover something in addition then we work with scientific labs so we'll say oh there's something we can't find we can predict something but we can't find it anywhere in the literature so we will then we have people we collaborated with say that sometimes they'll say you know I have some collected data which I didn't publish but we can go back and look in it and see if we can find that which is much easier than designing in your experiment you know new neuroscience experiments take a long time years so although some people are doing that now too so but between all of these things I think it's reasonable it's actually a very very good approach we we are blessed with the fact that we can test our theories out the ying-yang here because there's so much on a similar data and we can also falsify our theories very easily which we do often it's kind of reminiscent to whenever whenever that was with Copernicus you know when you figure out that the sun's at the center of the the solar system as opposed to earth the pieces just fall into place yeah I think that's the general nature of aha moments is in history Copernicus it could be you could say the same thing about Darwin you could say same thing about you know about the double helix that that people have been working on a problem for so long and I have all this data and they can't make sense of it they can't make sense of it but when the answer comes to you and everything falls into place it's like oh my gosh that's it that's got to be right I asked both Jim Watson and Francis Crick about this I asked him you know when you were working on trying to discover the structure of the double helix and when you came up with the the sort of the structure that ended up being correct but it was sort of a guess you know I wasn't really verified yeah I said did you know that it was right and they both said absolutely so we absolutely knew it was right and it doesn't matter if other people didn't believe it or not we knew it was right they get around the thing agree with it eventually anyway and that's the kind of thing you hear a lot with scientists who who really are studying a difficult problem and I feel that way too about our work if you talk to Kirk or Watson about the the problem you're trying to solve the of finding the DNA of the brain yeah in fact Francis Crick was very interested in this in the latter part of his and in fact I got interested in brains by reading an essay he wrote in 1979 called thinking about the brain and that is when I decided I'm gonna leave my profession of computers and engineering and become a neuroscientist just reading that one essay from Francis Crick I got to meet him later in life I got I spoke at the Salk Institute and he was in the audience and then I had a tea with him afterwards you know he was interested in a different problem and he was he was focused on consciousness yeah and the easy problem right well I I think it's the red herring and and so we weren't really overlapping a lot there Jim Watson who's still alive is is also interested in this problem and he was when he was director of the coast of Harbor laboratories he was really sort of behind moving in the direction of neuroscience there and so he had a personal interest in this field and I have met with him numerous times and in fact the last time was a little bit over a year ago I gave a talk close to me Harbor labs about the progress we were making in in our work and it was a lot of fun because he said well you you wouldn't be coming here unless you had something important to say so I'm gonna go change our talk so he sat in the very front row next to most next to him was the director of the lab was Stillman so these guys are in the front row of this auditorium right so nobody else in the auditorium wants to sit in the front row because Jim Watson is detective and and I gave a talk and I had dinner with Jim afterwards but it's I there's a great picture of my colleague sue Battaglia mahad took where I'm up there sort of like screaming the basics of this new framework we have and Jim Watson is on the edge of his chair he's literally on the edge of his chair like intently staring up at the screen and when he discovered the structure of DNA the first public talk he gave was that Cold Spring Harbor labs so and there's a picture those famous picture Jim Watson standing at the whiteboard was where the overrated thing pointing at something was holding a double helix at this point it actually looks a lot like the picture of me so there was funny I got talking about the brain and there's Jim Watson staring intently I didn't course there was you know whatever sixty years earlier he was standing you know pointing at the double helix and it's one of the great discoveries and and all of you know whatever by all the science all science yeah yeah hey so this is the funny that there's echoes of that in your presentation do you think in terms of evolutionary timeline in history the development of the neocortex was a big leap or is it just a small step so like if we ran the whole thing over again from the from the birth of life on Earth how likely develop the mechanism and you okay well those are two separate questions one it was it a big leap and one was how like it is okay they're not necessarily related maybe correlated we don't really have enough data to make a judgment about that I would say definitely was a big league and leap and I can tell you why I think I don't think it was just another incremental step at that moment I don't really have any idea how likely it is if we look at evolution we have one data point which is earth right life formed on earth billions of years ago whether it was introduced here or it created it here or someone introduced it we don't really know but it was here early it took a long long time to get to multicellular life and then from multi to other started life it took a long long time to get his neocortex and we've only had the New York Texas for a few hundred thousand years so that's like nothing okay so is it likely well certainly isn't something that happened right away on earth and there were multiple steps to get there so I would say it's probably not get something what happened instantaneous on other planets that might have life it might take several billion years on average um is it likely I don't know but you'd have to survive for several billion years to find out probably is it a big leap yeah I think it's it is a qualitative difference than all other evolutionary steps I can try to describe that if you'd like sure you know which way uh yeah I can tell you how pretty much I'll start a little press many of the things that humans are able to do do not have obvious survival advantages precedent yeah you know we create music is that is there a really survival advantage to that maybe maybe not what about mathematics is there a real survival advantage to mathematics it's stretchy you can try to figure these things out right but up but mostly evolutionary history everything had immediate survival advantages too right so I'll tell you a story which I like me may not be true but the story goes as follows organisms have been evolving first since the beginning of life here on earth anything this sort of complexity on to that just sort of complexity and the brain itself is evolved this way in fact there's an old parts and older parts and older older parts of the brain that kind of just keeps calling on new things and we keep adding capabilities and we got for the neocortex initially it had a very clear survival advantage and that it produced better vision and better hearing and better thoughts and maybe a new place so on but what what I think happens is that evolution just kept it took it took a mechanism and this is in our recent theories but it took a mechanism evolved a long time ago for navigating in the world for knowing who you are these are the so called grid cells and place cells of an old part of the brain and it took that mechanism for building maps of the world and knowing we are in those maps and how to navigate those maps and turns it into a sort of a slimmed-down idealized version of it mm-hmm and that ideally this version could now apply to building maps of other things maps of coffee cups and maps the phone's maps of these concepts yes and not just almost exactly and and so you and it just started replicating this stuff right you just think more and more more bits so we went from being sort of dedicated purpose neural hardware to solve certain problems that are important to survival to a general purpose neural hardware that could be applied to all problems and now it's just it's the orbit of survival it's we are now able to apply it to things which we find enjoyment you know but aren't really clearly survival characteristics and that it seems to only have happened in humans to the large extent and so that's what's going on where we sort of have we've sort of escape the gravity of evolutionary pressure in some sense in the neocortex and it now does things which but not that are really interesting discovery models of the universe which may not really help us doesn't matter how is it help of surviving knowing that there might be multiple no there might be you know the age of the universe or what how do you know various stellar things occur it doesn't really help us survive at all but we enjoy it and that's what happened or at least not in the obvious way perhaps it is required if you look at the entire universe in an evolutionary way it's required for us to do interplanetary travel and therefore survive past our own Sun but you know let's not get too but you know evolution works at one time frame it's it's survival if you think of a survival of the phenotype survival of the individual it is that what you're talking about there is spans well beyond that so there's no genetic I'm not transferring any genetic traits to my children that are gonna help them survive better on Mars right it's totally different mechanism let's yeah so let's get into the the new as you've mentioned the idea that I don't know if you have a nice name thousand you call it a thousand brain theory often told I like it so can you talk about the this idea of spatial view of concepts and so on yeah so can I just describe sort of the there's an underlying core discovery which then everything comes from that that's a very simple this is really what happened we were deep into problems about understanding how we build models of stuff in the world and how we make predictions about things and I was holding a coffee cup just like this in my hand and I had my finger was touching the side my index finger and I moved it to the top and I was going to feel the the rim at the top of the cover and I asked myself a very simple question I said well first of all I have to say I know that my brain predicts what its gonna feel before it touches it you can just think about it and imagine it and so we know that the brain is making predictions all the time so the question is what does it take to predict that right and there's a very interesting answer that first of all it says the brain has to know it's touching a coffee cup and I said a model or a coffee cup and needs to know where the finger currently is on the cup relative to the cup because when I make a movement and used to know where it's going to be on the cup after the movement is completed relative to the cup and then it can make a prediction about what's going to sense so this told me that Dean your cortex which is making this prediction needs to know that it's sensing it's touching a cup and it needs to know the location of my finger relative to that cup in a reference frame of the cup it doesn't matter where the cup is relative my body it doesn't matter its orientation none of that matters it's where my finger is relative to the cup which tells me then that the neocortex is has a reference frame that's anchored to the cup because otherwise I wouldn't be able to say the location and I wouldn't be able to predict my new location and then we quickly vary installation instantly you can say well every part of my skin could touch this cup and therefore every part of my skin is making predictions and every part my skin must have a reference frame that it's using to make predictions so the the big idea is that throughout the neocortex there are everything as being is being stored and referenced in reference frames you can think of them like XYZ reference things but they're not like that we know a lot about the neural mechanisms for this but the brain thinks in reference frames and it's an engineer if you're an engineer this is not surprising you'd say if I wanted to build a a CAD model of the coffee cup well I would bring it up in some CAD software and I would assign some reference frame and say this features at this locations and so on but the fact that this the idea that this is occurring through out in your cortex everywhere it was a novel idea and and then zillion things fell into place after that it's doing so now we think about the neocortex as processing information quite differently than we used to do it we used to think about the neural cortex is processing sensory data and extracting features from that sensory data and then extracting features from the features very much like a deep Learning Network does today but that's not how the brain works at all the brain works by assigning everything every input everything to reference frames and there are thousands hundreds and thousands of them active at once in your neocortex it's a surprising thing the thing about but once you sort of internalize this you understand that it explains almost every all the almost all the mysteries we've had about this it's about this structure so one of the consequences of that is that every small part of the neocortex so you have a millimeter square and there's a hundred and fifty thousand of those so it's about 150,000 square millimeters if you take every little square millimeter of the cortex it's got some input coming into it and it's going to have reference frames which assign that input to and each square millimeter can learn complete models of objects so what do I mean by that if I'm touching the coffee cup well if I just touch it in one place I can't learn what this coffee cup is because I'm just feeling one part but if I move it around the cup it touched you to different areas I can build up a complete model the cup because I'm now filling in that three dimensional map which is the coffee cup I can say oh what am I feeling in all these different locations that's the basic idea it's more complicated than that but so through time and we talked about time earlier through time even a single column which is only looking at or a single part of the cortex it's only looking at a small part of the world can build up a complete model of an object and so if you think about the part of the brain which is getting input from all my fingers so there's they're spread across the top and here this is the somatosensory cortex there's columns associated all these from areas of my skin and what we believe is happening is that all of them are building models of this cup every one of them or things not do not all building all not every column every part of the cortex builds models of everything but they're all building models of something and and so you have it so when I when I touch this cup with my hand there are multiple models of the cup being invoked if I look at it with my eyes there again many models of the cup being invoked because each part of the visual system and the brain doesn't process an image that's mr. that's a misleading idea it's just like your fingers touching so different parts of my Radnor of looking at different parts of the cup and thousands and thousands of models of the cup are being invoked at once and they're all voting with each other trying to figure out what's going on so that's why we call it the thousand brains theory of intelligence because there isn't one model of a cop there are thousands of models to this Cup there are thousands of models for your cell phone and about cameras and microphones and so on it's a distributed modeling system which is very different than what people have thought about it so this is a really compelling and interesting idea of f2 first questions - one on the ensemble part of everything coming together you have these thousand brains how do you know which one has done the best job of forming the great question let me try Spain there there's a problem that's known in neuroscience called the sensor fusion problem yes and so is the idea of something like oh the image comes from the eye there's a picture on the retina and it gets projected to than your cortex no by now it's all spread out all over the place and it's kind of squirrely and distorted and pieces are all over this you know it doesn't look like a picture anymore when does it all come back together again right or you might say well yes but I also I also have sounds or touches associated with a couple so I'm seeing the cup and touching the cup how do they get combined together again so this it's called the sensor fusion problem is if all these disparate parts have to be brought together into one model someplace that's the wrong idea the right idea is that you get all these guys voting there's auditory models of the cup there's visual models the cup those tactile models of the cup there's one the individual system there might be ones that are more focused on black and white ones fortunate on color it doesn't really matter there's just thousands and thousands of models of this Cup and they vote they don't actually come together in one spot it just literally think of it this way I imagine you have these columns or like about the size of a little piece of spaghetti okay like a two and a half millimeters tall and about a millimeter in mind they're not physical like but you could think of them that way and each one's trying to guess what this thing is they're touching now they can they can do a pretty good job if they're allowed to move over to us so I could reach my hand into a black box and move my finger around an object and if I touch enough spaces like oh okay I don't know what it is but often we don't do that often I can just reach and grab something with my hand all the once and I get it or if I had to look through the world through a straw so long invoking one little column I can only see part of some things I have to move the straw around but if I open my eyes to see the whole thing at once so what we think is going on it's all these little pieces of spaghetti if you know all these little columns in the cortex or all trying to guess what it is that they're sensing they'll do a better guess if they have time and can move over time so if I move my eyes and with my fingers but if they don't they have a they have a poor guest it's a it's a probabilistic s of what they might be touching now imagine they can post their probability at the top of a little piece of spaghetti each one of them says I think and it's not really a probability decision it's more like a set of possibilities in the brain it doesn't work as a probability distribution it works is more like what we call the Union so you could say and one column says I think it could be a coffee cup sort of can or a water bottle and the other column says I think it could be a coffee cup or you know telephone or camera whatever right and and all these guys are saying what they think might be and there's these long range connections in certain layers in the cortex so there's been some layers in some cell types in each column send their projections across the brain and that's the voting occurs and so there's a simple associative memory mechanism we've described this in a recent paper and we've modeled this that says they can all quickly settle on the only or the one best answer for all of them if there is a single best answer they all vote and say yeah it's got to be the coffee cup and at that point they all know it's a coffee go and at that point everyone acts as if it's the coffee cup they yeah we know it's a coffee even though I've only seen one little piece of this world I know it's coffee cup I'm touching or I'm seeing or whatever and so you can think of all these columns are looking at different parts in different places different sensory and put different locations they're all different but this layer that's doing the voting that's it's solidifies it's just like it crystallizes and says oh we all know what we're doing and so you don't bring these models together in one model you just vote and there's a crystallization of the vote great that's a at least a compelling way to think about about the way you form a model of the world now you talk about a coffee cup do you see this as far as I understand you're proposing this as well that this extends to much more than coffee cups it does or at least the physical world it expands to the world of concepts yeah it does and well first the primary face every evidence for that is that the regions of the neocortex that are associated with language or high-level thought or mathematics or things like that they look like the regions of the new your cortex that process vision hearing and touch there they don't look any different or they look only marginally different and so one would say well if Vernon now Castle who proposed it all that come all the parts of New York or trees doing the same thing if he's right then the parts that during language or mathematics or physics are working on the same principle they must be working on the principle of reference frames so that's a little odd flawed hmm but of course we had no eye we had no prior idea how these things happen so that's let's go with that and we in our recent paper we talked a little bit about that I've been working on it more since I have better ideas about it now I'm sitting here very confident that that's what's happening and I can give you some examples to help you think about that it's not we understand it completely but I understand it better than I've described it in any paper so far so but we did put that idea out there says okay this is it's it's it's it's a good place to start you know and the evidence would suggest this how it's happening and then we can start tackling that problem one piece at a time like what does it mean to do high-level thought what it means a new language how would that fit into a reference frame framework yes so there's a if you could tell me if there's a connection but there's an app called Anki that helps you remember different concepts and they they talk about like a memory palace that helps you remember a completely random concepts by so trying to put them in a physical space in your mind yeah and putting them next to each other the method of loci okay yeah for some reason that seems to work really well yeah no that's a very narrow kind of application of just remembering some facts but that's a very very telling one yes exactly so it seems like you're describing a mechanism why this seems yeah so so basically the way what we think is going on is all things you know all concepts all ideas words everything you know are stored in reference frames and so if you want to remember something you have to basically navigate through a reference frame the same way a rat navigates to a Maeve in the same way my finger rat navigates to this coffee cup you are moving through some space and so what you if you have a random list of things you were asked to remember by assigning him to a reference frame you've already know very well to see your house right an idea the method of loci is you can say okay in my lobby I'm going to put this thing and then and then the bedroom I put this one I go down the hall I put this thing and then you want to recall those facts so we call this things you just walk mentally you walk through your house you're mentally moving through a reference frame that you already had and that tells you there's two things are really important about it tells us the brain prefers to store things in reference frames and that the method of recalling things or thinking if you will is to move mentally through those reference frames you could move physically through some reference frames like I could physically move through the reference name of this coffee cup I can also mentally move to the reference time the coffee cup imagining me touching it but I can also mentally move my house and and so now we can ask yourself or are all concepts toward this way there's some recent research using human subjects in fMRI and I'm gonna apologize for not knowing the name of the scientist that did this but what they did is they they put humans in this fMRI machine which was one of these imaging machines and they they gave the humans tasks to think about Birds so they had different types of birds and beverage it looked big and small and long necks and long legs things like that and what they could tell from the fMRI it was a very clever experiment get to tell when humans were thinking about the birds that the birds that the knowledge of birds was arranged in a reference frame similar to the ones that are used when you navigate in a room that these are called grid cells and there are grid cell like patterns of activity in the new your cortex when they do this so that it's a very clever experiment you know and what it basically says that even when you're thinking about something abstract and you're not really thinking about it as a reference frame it tells us the brain is actually using a reference frame and it's using the same neural mechanisms these grid cells are the basic same neural mechanism that we we propose that grid cells
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