0:00:00.800,0:00:03.924 So, I lead a team at Google[br]that works on machine intelligence; 0:00:03.948,0:00:08.598 in other words, the engineering discipline[br]of making computers and devices 0:00:08.622,0:00:11.041 able to do some of the things[br]that brains do. 0:00:11.439,0:00:14.538 And this makes us[br]interested in real brains 0:00:14.562,0:00:15.851 and neuroscience as well, 0:00:15.875,0:00:20.047 and especially interested[br]in the things that our brains do 0:00:20.071,0:00:24.113 that are still far superior[br]to the performance of computers. 0:00:25.209,0:00:28.818 Historically, one of those areas[br]has been perception, 0:00:28.842,0:00:31.881 the process by which things[br]out there in the world -- 0:00:31.905,0:00:33.489 sounds and images -- 0:00:33.513,0:00:35.691 can turn into concepts in the mind. 0:00:36.235,0:00:38.752 This is essential for our own brains, 0:00:38.776,0:00:41.240 and it's also pretty useful on a computer. 0:00:41.636,0:00:44.986 The machine perception algorithms,[br]for example, that our team makes, 0:00:45.010,0:00:48.884 are what enable your pictures[br]on Google Photos to become searchable, 0:00:48.908,0:00:50.305 based on what's in them. 0:00:51.594,0:00:55.087 The flip side of perception is creativity: 0:00:55.111,0:00:58.149 turning a concept into something[br]out there into the world. 0:00:58.173,0:01:01.728 So over the past year,[br]our work on machine perception 0:01:01.752,0:01:06.611 has also unexpectedly connected[br]with the world of machine creativity 0:01:06.635,0:01:07.795 and machine art. 0:01:08.556,0:01:11.840 I think Michelangelo[br]had a penetrating insight 0:01:11.864,0:01:15.520 into to this dual relationship[br]between perception and creativity. 0:01:16.023,0:01:18.029 This is a famous quote of his: 0:01:18.053,0:01:21.376 "Every block of stone[br]has a statue inside of it, 0:01:22.036,0:01:25.038 and the job of the sculptor[br]is to discover it." 0:01:26.029,0:01:29.245 So I think that what[br]Michelangelo was getting at 0:01:29.269,0:01:32.449 is that we create by perceiving, 0:01:32.473,0:01:35.496 and that perception itself[br]is an act of imagination 0:01:35.520,0:01:37.981 and is the stuff of creativity. 0:01:38.691,0:01:42.616 The organ that does all the thinking[br]and perceiving and imagining, 0:01:42.640,0:01:44.228 of course, is the brain. 0:01:45.089,0:01:47.634 And I'd like to begin[br]with a brief bit of history 0:01:47.658,0:01:49.960 about what we know about brains. 0:01:50.496,0:01:52.942 Because unlike, say,[br]the heart or the intestines, 0:01:52.966,0:01:56.110 you really can't say very much[br]about a brain by just looking at it, 0:01:56.134,0:01:57.546 at least with the naked eye. 0:01:57.983,0:02:00.399 The early anatomists who looked at brains 0:02:00.423,0:02:04.230 gave the superficial structures[br]of this thing all kinds of fanciful names, 0:02:04.254,0:02:06.687 like hippocampus, meaning "little shrimp." 0:02:06.711,0:02:09.475 But of course that sort of thing[br]doesn't tell us very much 0:02:09.499,0:02:11.817 about what's actually going on inside. 0:02:12.780,0:02:16.393 The first person who, I think, really[br]developed some kind of insight 0:02:16.417,0:02:18.347 into what was going on in the brain 0:02:18.371,0:02:22.291 was the great Spanish neuroanatomist,[br]Santiago Ramón y Cajal, 0:02:22.315,0:02:23.859 in the 19th century, 0:02:23.883,0:02:27.638 who used microscopy and special stains 0:02:27.662,0:02:31.832 that could selectively fill in[br]or render in very high contrast 0:02:31.856,0:02:33.864 the individual cells in the brain, 0:02:33.888,0:02:37.042 in order to start to understand[br]their morphologies. 0:02:37.972,0:02:40.863 And these are the kinds of drawings[br]that he made of neurons 0:02:40.887,0:02:42.096 in the 19th century. 0:02:42.120,0:02:44.004 This is from a bird brain. 0:02:44.028,0:02:47.085 And you see this incredible variety[br]of different sorts of cells, 0:02:47.109,0:02:50.544 even the cellular theory itself[br]was quite new at this point. 0:02:50.568,0:02:51.846 And these structures, 0:02:51.870,0:02:54.129 these cells that have these arborizations, 0:02:54.153,0:02:56.761 these branches that can go[br]very, very long distances -- 0:02:56.785,0:02:58.401 this was very novel at the time. 0:02:58.779,0:03:01.682 They're reminiscent, of course, of wires. 0:03:01.706,0:03:05.163 That might have been obvious[br]to some people in the 19th century; 0:03:05.187,0:03:09.501 the revolutions of wiring and electricity[br]were just getting underway. 0:03:09.964,0:03:11.142 But in many ways, 0:03:11.166,0:03:14.479 these microanatomical drawings[br]of Ramón y Cajal's, like this one, 0:03:14.503,0:03:16.835 they're still in some ways unsurpassed. 0:03:16.859,0:03:18.713 We're still more than a century later, 0:03:18.737,0:03:21.562 trying to finish the job[br]that Ramón y Cajal started. 0:03:21.586,0:03:24.720 These are raw data from our collaborators 0:03:24.744,0:03:27.625 at the Max Planck Institute[br]of Neuroscience. 0:03:27.649,0:03:29.439 And what our collaborators have done 0:03:29.463,0:03:34.464 is to image little pieces of brain tissue. 0:03:34.488,0:03:37.814 The entire sample here[br]is about one cubic millimeter in size, 0:03:37.838,0:03:40.459 and I'm showing you a very,[br]very small piece of it here. 0:03:40.483,0:03:42.829 That bar on the left is about one micron. 0:03:42.853,0:03:45.262 The structures you see are mitochondria 0:03:45.286,0:03:47.330 that are the size of bacteria. 0:03:47.354,0:03:48.905 And these are consecutive slices 0:03:48.929,0:03:52.077 through this very, very[br]tiny block of tissue. 0:03:52.101,0:03:54.504 Just for comparison's sake, 0:03:54.528,0:03:58.320 the diameter of an average strand[br]of hair is about 100 microns. 0:03:58.344,0:04:00.618 So we're looking at something[br]much, much smaller 0:04:00.642,0:04:02.040 than a single strand of hair. 0:04:02.064,0:04:06.095 And from these kinds of serial[br]electron microscopy slices, 0:04:06.119,0:04:11.127 one can start to make reconstructions[br]in 3D of neurons that look like these. 0:04:11.151,0:04:14.308 So these are sort of in the same[br]style as Ramón y Cajal. 0:04:14.332,0:04:15.824 Only a few neurons lit up, 0:04:15.848,0:04:18.629 because otherwise we wouldn't[br]be able to see anything here. 0:04:18.653,0:04:19.965 It would be so crowded, 0:04:19.989,0:04:21.319 so full of structure, 0:04:21.343,0:04:24.067 of wiring all connecting[br]one neuron to another. 0:04:25.293,0:04:28.097 So Ramón y Cajal was a little bit[br]ahead of his time, 0:04:28.121,0:04:30.676 and progress on understanding the brain 0:04:30.700,0:04:32.971 proceeded slowly[br]over the next few decades. 0:04:33.455,0:04:36.308 But we knew that neurons used electricity, 0:04:36.332,0:04:39.268 and by World War II, our technology[br]was advanced enough 0:04:39.292,0:04:42.098 to start doing real electrical[br]experiments on live neurons 0:04:42.122,0:04:44.228 to better understand how they worked. 0:04:44.631,0:04:48.987 This was the very same time[br]when computers were being invented, 0:04:49.011,0:04:52.111 very much based on the idea[br]of modeling the brain -- 0:04:52.135,0:04:55.220 of "intelligent machinery,"[br]as Alan Turing called it, 0:04:55.244,0:04:57.235 one of the fathers of computer science. 0:04:57.923,0:05:02.555 Warren McCulloch and Walter Pitts[br]looked at Ramón y Cajal's drawing 0:05:02.579,0:05:03.896 of visual cortex, 0:05:03.920,0:05:05.482 which I'm showing here. 0:05:05.506,0:05:09.948 This is the cortex that processes[br]imagery that comes from the eye. 0:05:10.424,0:05:13.932 And for them, this looked[br]like a circuit diagram. 0:05:14.353,0:05:18.188 So there are a lot of details[br]in McCulloch and Pitts's circuit diagram 0:05:18.212,0:05:19.564 that are not quite right. 0:05:19.588,0:05:20.823 But this basic idea 0:05:20.847,0:05:24.839 that visual cortex works like a series[br]of computational elements 0:05:24.863,0:05:27.609 that pass information[br]one to the next in a cascade, 0:05:27.633,0:05:29.235 is essentially correct. 0:05:29.259,0:05:31.609 Let's talk for a moment 0:05:31.633,0:05:35.665 about what a model for processing[br]visual information would need to do. 0:05:36.228,0:05:38.969 The basic task of perception 0:05:38.993,0:05:43.187 is to take an image like this one and say, 0:05:43.211,0:05:44.387 "That's a bird," 0:05:44.411,0:05:47.285 which is a very simple thing[br]for us to do with our brains. 0:05:47.309,0:05:50.730 But you should all understand[br]that for a computer, 0:05:50.754,0:05:53.841 this was pretty much impossible[br]just a few years ago. 0:05:53.865,0:05:55.781 The classical computing paradigm 0:05:55.805,0:05:58.312 is not one in which[br]this task is easy to do. 0:05:59.366,0:06:01.918 So what's going on between the pixels, 0:06:01.942,0:06:05.970 between the image of the bird[br]and the word "bird," 0:06:05.994,0:06:08.808 is essentially a set of neurons[br]connected to each other 0:06:08.832,0:06:09.987 in a neural network, 0:06:10.011,0:06:11.234 as I'm diagramming here. 0:06:11.258,0:06:14.530 This neural network could be biological,[br]inside our visual cortices, 0:06:14.554,0:06:16.716 or, nowadays, we start[br]to have the capability 0:06:16.740,0:06:19.194 to model such neural networks[br]on the computer. 0:06:19.834,0:06:22.187 And I'll show you what[br]that actually looks like. 0:06:22.211,0:06:25.627 So the pixels you can think[br]about as a first layer of neurons, 0:06:25.651,0:06:27.890 and that's, in fact,[br]how it works in the eye -- 0:06:27.914,0:06:29.577 that's the neurons in the retina. 0:06:29.601,0:06:31.101 And those feed forward 0:06:31.125,0:06:34.528 into one layer after another layer,[br]after another layer of neurons, 0:06:34.552,0:06:37.585 all connected by synapses[br]of different weights. 0:06:37.609,0:06:38.944 The behavior of this network 0:06:38.968,0:06:42.252 is characterized by the strengths[br]of all of those synapses. 0:06:42.276,0:06:45.564 Those characterize the computational[br]properties of this network. 0:06:45.588,0:06:47.058 And at the end of the day, 0:06:47.082,0:06:49.529 you have a neuron[br]or a small group of neurons 0:06:49.553,0:06:51.200 that light up, saying, "bird." 0:06:51.824,0:06:54.956 Now I'm going to represent[br]those three things -- 0:06:54.980,0:06:59.676 the input pixels and the synapses[br]in the neural network, 0:06:59.700,0:07:01.285 and bird, the output -- 0:07:01.309,0:07:04.366 by three variables: x, w and y. 0:07:04.853,0:07:06.664 There are maybe a million or so x's -- 0:07:06.688,0:07:08.641 a million pixels in that image. 0:07:08.665,0:07:11.111 There are billions or trillions of w's, 0:07:11.135,0:07:14.556 which represent the weights of all[br]these synapses in the neural network. 0:07:14.580,0:07:16.455 And there's a very small number of y's, 0:07:16.479,0:07:18.337 of outputs that that network has. 0:07:18.361,0:07:20.110 "Bird" is only four letters, right? 0:07:21.088,0:07:24.514 So let's pretend that this[br]is just a simple formula, 0:07:24.538,0:07:26.701 x "x" w = y. 0:07:26.725,0:07:28.761 I'm putting the times in scare quotes 0:07:28.785,0:07:31.065 because what's really[br]going on there, of course, 0:07:31.089,0:07:34.135 is a very complicated series[br]of mathematical operations. 0:07:35.172,0:07:36.393 That's one equation. 0:07:36.417,0:07:38.089 There are three variables. 0:07:38.113,0:07:40.839 And we all know[br]that if you have one equation, 0:07:40.863,0:07:44.505 you can solve one variable[br]by knowing the other two things. 0:07:45.158,0:07:48.538 So the problem of inference, 0:07:48.562,0:07:51.435 that is, figuring out[br]that the picture of a bird is a bird, 0:07:51.459,0:07:52.733 is this one: 0:07:52.757,0:07:56.216 it's where y is the unknown[br]and w and x are known. 0:07:56.240,0:07:58.699 You know the neural network,[br]you know the pixels. 0:07:58.723,0:08:02.050 As you can see, that's actually[br]a relatively straightforward problem. 0:08:02.074,0:08:04.260 You multiply two times three[br]and you're done. 0:08:04.862,0:08:06.985 I'll show you an artificial neural network 0:08:07.009,0:08:09.305 that we've built recently,[br]doing exactly that. 0:08:09.634,0:08:12.494 This is running in real time[br]on a mobile phone, 0:08:12.518,0:08:15.831 and that's, of course,[br]amazing in its own right, 0:08:15.855,0:08:19.323 that mobile phones can do so many[br]billions and trillions of operations 0:08:19.347,0:08:20.595 per second. 0:08:20.619,0:08:22.234 What you're looking at is a phone 0:08:22.258,0:08:25.805 looking at one after another[br]picture of a bird, 0:08:25.829,0:08:28.544 and actually not only saying,[br]"Yes, it's a bird," 0:08:28.568,0:08:31.979 but identifying the species of bird[br]with a network of this sort. 0:08:32.890,0:08:34.716 So in that picture, 0:08:34.740,0:08:38.542 the x and the w are known,[br]and the y is the unknown. 0:08:38.566,0:08:41.074 I'm glossing over the very[br]difficult part, of course, 0:08:41.098,0:08:44.959 which is how on earth[br]do we figure out the w, 0:08:44.983,0:08:47.170 the brain that can do such a thing? 0:08:47.194,0:08:49.028 How would we ever learn such a model? 0:08:49.418,0:08:52.651 So this process of learning,[br]of solving for w, 0:08:52.675,0:08:55.322 if we were doing this[br]with the simple equation 0:08:55.346,0:08:57.346 in which we think about these as numbers, 0:08:57.370,0:09:00.057 we know exactly how to do that: 6 = 2 x w, 0:09:00.081,0:09:03.393 well, we divide by two and we're done. 0:09:04.001,0:09:06.221 The problem is with this operator. 0:09:06.823,0:09:07.974 So, division -- 0:09:07.998,0:09:11.119 we've used division because[br]it's the inverse to multiplication, 0:09:11.143,0:09:12.583 but as I've just said, 0:09:12.607,0:09:15.056 the multiplication is a bit of a lie here. 0:09:15.080,0:09:18.406 This is a very, very complicated,[br]very non-linear operation; 0:09:18.430,0:09:20.134 it has no inverse. 0:09:20.158,0:09:23.308 So we have to figure out a way[br]to solve the equation 0:09:23.332,0:09:25.356 without a division operator. 0:09:25.380,0:09:27.723 And the way to do that[br]is fairly straightforward. 0:09:27.747,0:09:30.418 You just say, let's play[br]a little algebra trick, 0:09:30.442,0:09:33.348 and move the six over[br]to the right-hand side of the equation. 0:09:33.372,0:09:35.198 Now, we're still using multiplication. 0:09:35.675,0:09:39.255 And that zero -- let's think[br]about it as an error. 0:09:39.279,0:09:41.794 In other words, if we've solved[br]for w the right way, 0:09:41.818,0:09:43.474 then the error will be zero. 0:09:43.498,0:09:45.436 And if we haven't gotten it quite right, 0:09:45.460,0:09:47.209 the error will be greater than zero. 0:09:47.233,0:09:50.599 So now we can just take guesses[br]to minimize the error, 0:09:50.623,0:09:53.310 and that's the sort of thing[br]computers are very good at. 0:09:53.334,0:09:54.927 So you've taken an initial guess: 0:09:54.951,0:09:56.107 what if w = 0? 0:09:56.131,0:09:57.371 Well, then the error is 6. 0:09:57.395,0:09:58.841 What if w = 1? The error is 4. 0:09:58.865,0:10:01.232 And then the computer can[br]sort of play Marco Polo, 0:10:01.256,0:10:03.623 and drive down the error close to zero. 0:10:03.647,0:10:07.021 As it does that, it's getting[br]successive approximations to w. 0:10:07.045,0:10:10.701 Typically, it never quite gets there,[br]but after about a dozen steps, 0:10:10.725,0:10:15.349 we're up to w = 2.999,[br]which is close enough. 0:10:16.302,0:10:18.116 And this is the learning process. 0:10:18.140,0:10:20.870 So remember that what's been going on here 0:10:20.894,0:10:25.272 is that we've been taking[br]a lot of known x's and known y's 0:10:25.296,0:10:28.750 and solving for the w in the middle[br]through an iterative process. 0:10:28.774,0:10:32.330 It's exactly the same way[br]that we do our own learning. 0:10:32.354,0:10:34.584 We have many, many images as babies 0:10:34.608,0:10:37.241 and we get told, "This is a bird;[br]this is not a bird." 0:10:37.714,0:10:39.812 And over time, through iteration, 0:10:39.836,0:10:42.764 we solve for w, we solve[br]for those neural connections. 0:10:43.460,0:10:47.546 So now, we've held[br]x and w fixed to solve for y; 0:10:47.570,0:10:49.417 that's everyday, fast perception. 0:10:49.441,0:10:51.204 We figure out how we can solve for w, 0:10:51.228,0:10:53.131 that's learning, which is a lot harder, 0:10:53.155,0:10:55.140 because we need to do error minimization, 0:10:55.164,0:10:56.851 using a lot of training examples. 0:10:56.875,0:11:00.062 And about a year ago,[br]Alex Mordvintsev, on our team, 0:11:00.086,0:11:03.636 decided to experiment[br]with what happens if we try solving for x, 0:11:03.660,0:11:05.697 given a known w and a known y. 0:11:06.124,0:11:07.275 In other words, 0:11:07.299,0:11:08.651 you know that it's a bird, 0:11:08.675,0:11:11.978 and you already have your neural network[br]that you've trained on birds, 0:11:12.002,0:11:14.346 but what is the picture of a bird? 0:11:15.034,0:11:20.058 It turns out that by using exactly[br]the same error-minimization procedure, 0:11:20.082,0:11:23.512 one can do that with the network[br]trained to recognize birds, 0:11:23.536,0:11:26.924 and the result turns out to be ... 0:11:30.400,0:11:31.705 a picture of birds. 0:11:32.814,0:11:36.551 So this is a picture of birds[br]generated entirely by a neural network 0:11:36.575,0:11:38.401 that was trained to recognize birds, 0:11:38.425,0:11:41.963 just by solving for x[br]rather than solving for y, 0:11:41.987,0:11:43.275 and doing that iteratively. 0:11:43.732,0:11:45.579 Here's another fun example. 0:11:45.603,0:11:49.040 This was a work made[br]by Mike Tyka in our group, 0:11:49.064,0:11:51.372 which he calls "Animal Parade." 0:11:51.396,0:11:54.272 It reminds me a little bit[br]of William Kentridge's artworks, 0:11:54.296,0:11:56.785 in which he makes sketches, rubs them out, 0:11:56.809,0:11:58.269 makes sketches, rubs them out, 0:11:58.293,0:11:59.691 and creates a movie this way. 0:11:59.715,0:12:00.866 In this case, 0:12:00.890,0:12:04.167 what Mike is doing is varying y[br]over the space of different animals, 0:12:04.191,0:12:06.573 in a network designed[br]to recognize and distinguish 0:12:06.597,0:12:08.407 different animals from each other. 0:12:08.431,0:12:12.182 And you get this strange, Escher-like[br]morph from one animal to another. 0:12:14.221,0:12:18.835 Here he and Alex together[br]have tried reducing 0:12:18.859,0:12:21.618 the y's to a space of only two dimensions, 0:12:21.642,0:12:25.080 thereby making a map[br]out of the space of all things 0:12:25.104,0:12:26.823 recognized by this network. 0:12:26.847,0:12:28.870 Doing this kind of synthesis 0:12:28.894,0:12:31.276 or generation of imagery[br]over that entire surface, 0:12:31.300,0:12:34.146 varying y over the surface,[br]you make a kind of map -- 0:12:34.170,0:12:37.311 a visual map of all the things[br]the network knows how to recognize. 0:12:37.335,0:12:40.200 The animals are all here;[br]"armadillo" is right in that spot. 0:12:40.919,0:12:43.398 You can do this with other kinds[br]of networks as well. 0:12:43.422,0:12:46.296 This is a network designed[br]to recognize faces, 0:12:46.320,0:12:48.320 to distinguish one face from another. 0:12:48.344,0:12:51.593 And here, we're putting[br]in a y that says, "me," 0:12:51.617,0:12:53.192 my own face parameters. 0:12:53.216,0:12:54.922 And when this thing solves for x, 0:12:54.946,0:12:57.564 it generates this rather crazy, 0:12:57.588,0:13:02.016 kind of cubist, surreal,[br]psychedelic picture of me 0:13:02.040,0:13:03.846 from multiple points of view at once. 0:13:03.870,0:13:06.604 The reason it looks like[br]multiple points of view at once 0:13:06.628,0:13:10.315 is because that network is designed[br]to get rid of the ambiguity 0:13:10.339,0:13:12.815 of a face being in one pose[br]or another pose, 0:13:12.839,0:13:16.215 being looked at with one kind of lighting,[br]another kind of lighting. 0:13:16.239,0:13:18.324 So when you do[br]this sort of reconstruction, 0:13:18.348,0:13:20.652 if you don't use some sort of guide image 0:13:20.676,0:13:21.887 or guide statistics, 0:13:21.911,0:13:25.676 then you'll get a sort of confusion[br]of different points of view, 0:13:25.700,0:13:27.068 because it's ambiguous. 0:13:27.786,0:13:32.009 This is what happens if Alex uses[br]his own face as a guide image 0:13:32.033,0:13:35.354 during that optimization process[br]to reconstruct my own face. 0:13:36.284,0:13:38.612 So you can see it's not perfect. 0:13:38.636,0:13:40.510 There's still quite a lot of work to do 0:13:40.534,0:13:42.987 on how we optimize[br]that optimization process. 0:13:43.011,0:13:45.838 But you start to get something[br]more like a coherent face, 0:13:45.862,0:13:47.876 rendered using my own face as a guide. 0:13:48.892,0:13:51.393 You don't have to start[br]with a blank canvas 0:13:51.417,0:13:52.573 or with white noise. 0:13:52.597,0:13:53.901 When you're solving for x, 0:13:53.925,0:13:57.814 you can begin with an x,[br]that is itself already some other image. 0:13:57.838,0:14:00.394 That's what this little demonstration is. 0:14:00.418,0:14:04.540 This is a network[br]that is designed to categorize 0:14:04.564,0:14:07.683 all sorts of different objects --[br]man-made structures, animals ... 0:14:07.707,0:14:10.300 Here we're starting[br]with just a picture of clouds, 0:14:10.324,0:14:11.995 and as we optimize, 0:14:12.019,0:14:16.505 basically, this network is figuring out[br]what it sees in the clouds. 0:14:16.931,0:14:19.251 And the more time[br]you spend looking at this, 0:14:19.275,0:14:22.028 the more things you also[br]will see in the clouds. 0:14:23.004,0:14:26.379 You could also use the face network[br]to hallucinate into this, 0:14:26.403,0:14:28.215 and you get some pretty crazy stuff. 0:14:28.239,0:14:29.389 (Laughter) 0:14:30.401,0:14:33.145 Or, Mike has done some other experiments 0:14:33.169,0:14:37.074 in which he takes that cloud image, 0:14:37.098,0:14:40.605 hallucinates, zooms, hallucinates,[br]zooms hallucinates, zooms. 0:14:40.629,0:14:41.780 And in this way, 0:14:41.804,0:14:45.479 you can get a sort of fugue state[br]of the network, I suppose, 0:14:45.503,0:14:49.183 or a sort of free association, 0:14:49.207,0:14:51.434 in which the network[br]is eating its own tail. 0:14:51.458,0:14:54.879 So every image is now the basis for, 0:14:54.903,0:14:56.324 "What do I think I see next? 0:14:56.348,0:14:59.151 What do I think I see next?[br]What do I think I see next?" 0:14:59.487,0:15:02.423 I showed this for the first time in public 0:15:02.447,0:15:07.884 to a group at a lecture in Seattle[br]called "Higher Education" -- 0:15:07.908,0:15:10.345 this was right after[br]marijuana was legalized. 0:15:10.369,0:15:12.784 (Laughter) 0:15:14.627,0:15:16.731 So I'd like to finish up quickly 0:15:16.755,0:15:21.010 by just noting that this technology[br]is not constrained. 0:15:21.034,0:15:24.699 I've shown you purely visual examples[br]because they're really fun to look at. 0:15:24.723,0:15:27.174 It's not a purely visual technology. 0:15:27.198,0:15:29.191 Our artist collaborator, Ross Goodwin, 0:15:29.215,0:15:32.886 has done experiments involving[br]a camera that takes a picture, 0:15:32.910,0:15:37.144 and then a computer in his backpack[br]writes a poem using neural networks, 0:15:37.168,0:15:39.112 based on the contents of the image. 0:15:39.136,0:15:42.083 And that poetry neural network[br]has been trained 0:15:42.107,0:15:44.341 on a large corpus of 20th-century poetry. 0:15:44.365,0:15:45.864 And the poetry is, you know, 0:15:45.888,0:15:47.802 I think, kind of not bad, actually. 0:15:47.826,0:15:49.210 (Laughter) 0:15:49.234,0:15:50.393 In closing, 0:15:50.417,0:15:52.549 I think that per Michelangelo, 0:15:52.573,0:15:53.807 I think he was right; 0:15:53.831,0:15:57.267 perception and creativity[br]are very intimately connected. 0:15:57.611,0:16:00.245 What we've just seen are neural networks 0:16:00.269,0:16:02.572 that are entirely trained to discriminate, 0:16:02.596,0:16:04.838 or to recognize different[br]things in the world, 0:16:04.862,0:16:08.023 able to be run in reverse, to generate. 0:16:08.047,0:16:09.830 One of the things that suggests to me 0:16:09.854,0:16:12.252 is not only that[br]Michelangelo really did see 0:16:12.276,0:16:14.728 the sculpture in the blocks of stone, 0:16:14.752,0:16:18.390 but that any creature,[br]any being, any alien 0:16:18.414,0:16:22.071 that is able to do[br]perceptual acts of that sort 0:16:22.095,0:16:23.470 is also able to create 0:16:23.494,0:16:26.718 because it's exactly the same[br]machinery that's used in both cases. 0:16:26.742,0:16:31.274 Also, I think that perception[br]and creativity are by no means 0:16:31.298,0:16:32.508 uniquely human. 0:16:32.532,0:16:36.240 We start to have computer models[br]that can do exactly these sorts of things. 0:16:36.264,0:16:39.592 And that ought to be unsurprising;[br]the brain is computational. 0:16:39.616,0:16:41.273 And finally, 0:16:41.297,0:16:45.965 computing began as an exercise[br]in designing intelligent machinery. 0:16:45.989,0:16:48.451 It was very much modeled after the idea 0:16:48.475,0:16:51.488 of how could we make machines intelligent. 0:16:51.512,0:16:53.674 And we finally are starting to fulfill now 0:16:53.698,0:16:56.104 some of the promises[br]of those early pioneers, 0:16:56.128,0:16:57.841 of Turing and von Neumann 0:16:57.865,0:17:00.130 and McCulloch and Pitts. 0:17:00.154,0:17:04.252 And I think that computing[br]is not just about accounting 0:17:04.276,0:17:06.423 or playing Candy Crush or something. 0:17:06.447,0:17:09.025 From the beginning,[br]we modeled them after our minds. 0:17:09.049,0:17:12.318 And they give us both the ability[br]to understand our own minds better 0:17:12.342,0:17:13.871 and to extend them. 0:17:14.627,0:17:15.794 Thank you very much. 0:17:15.818,0:17:21.757 (Applause)