How computers are learning to be creative | Blaise Agüera y Arcas

452,941 views ・ 2016-07-22

TED


请双击下面的英文字幕来播放视频。

翻译人员: chunhua zhang 校对人员: Chen Zou
00:12
So, I lead a team at Google that works on machine intelligence;
0
12800
3124
我在谷歌领导着一个 机器智能的项目组,
00:15
in other words, the engineering discipline of making computers and devices
1
15948
4650
换句话说,利用工程学原理制造出
00:20
able to do some of the things that brains do.
2
20622
2419
能够像人脑一样 完成某些任务的电脑和设备。
00:23
And this makes us interested in real brains
3
23439
3099
这也使我们对人类的 大脑以及神经科学
00:26
and neuroscience as well,
4
26562
1289
产生了兴趣,
00:27
and especially interested in the things that our brains do
5
27875
4172
尤其在那些大脑的表现
00:32
that are still far superior to the performance of computers.
6
32071
4042
比电脑强太多的领域。
00:37
Historically, one of those areas has been perception,
7
37209
3609
长期以来,我们研究的 其中一个领域便是感知,
00:40
the process by which things out there in the world --
8
40842
3039
一种将外界事物——
00:43
sounds and images --
9
43905
1584
比如图像或声音—
00:45
can turn into concepts in the mind.
10
45513
2178
转化为大脑内概念的过程。
00:48
This is essential for our own brains,
11
48235
2517
这对我们的大脑很重要,
00:50
and it's also pretty useful on a computer.
12
50776
2464
对计算机的作用也非同小可。
00:53
The machine perception algorithms, for example, that our team makes,
13
53636
3350
例如,我们团队开发的机器感知算法
会根据图片的内容 让你在谷歌相册的图片
00:57
are what enable your pictures on Google Photos to become searchable,
14
57010
3874
01:00
based on what's in them.
15
60908
1397
出现在搜索结果中。
01:03
The flip side of perception is creativity:
16
63594
3493
感知的另一方面是创意:
01:07
turning a concept into something out there into the world.
17
67111
3038
将概念变成现实。
01:10
So over the past year, our work on machine perception
18
70173
3555
因此,这些年我们 在机器感知能力方面的工作
01:13
has also unexpectedly connected with the world of machine creativity
19
73752
4859
也意外地跟机器创意以及机器艺术
01:18
and machine art.
20
78635
1160
联系在了一起。
01:20
I think Michelangelo had a penetrating insight
21
80556
3284
我觉得米开朗基罗对感知和创意
01:23
into to this dual relationship between perception and creativity.
22
83864
3656
之间的双重关系有着深刻的见解。
01:28
This is a famous quote of his:
23
88023
2006
他有一句名言:
01:30
"Every block of stone has a statue inside of it,
24
90053
3323
“每一块石头里都藏着一尊雕像,
01:34
and the job of the sculptor is to discover it."
25
94036
3002
而雕塑家的工作就是去发现它。”
01:38
So I think that what Michelangelo was getting at
26
98029
3216
我想米开朗基罗意思是
01:41
is that we create by perceiving,
27
101269
3180
我们通过感知来创造,
01:44
and that perception itself is an act of imagination
28
104473
3023
而感知本身是想象力的表现,
01:47
and is the stuff of creativity.
29
107520
2461
以及创意的来源。
01:50
The organ that does all the thinking and perceiving and imagining,
30
110691
3925
而进行思考、感知和想象的器官,
01:54
of course, is the brain.
31
114640
1588
毫无疑问,就是大脑。
01:57
And I'd like to begin with a brief bit of history
32
117089
2545
我想先简单地谈一谈
01:59
about what we know about brains.
33
119658
2302
我们对大脑的了解。
02:02
Because unlike, say, the heart or the intestines,
34
122496
2446
因为不像心脏或其它内脏,
02:04
you really can't say very much about a brain by just looking at it,
35
124966
3144
你无法仅仅通过观察 就能看出点什么来,
02:08
at least with the naked eye.
36
128134
1412
至少仅凭肉眼看不出来。
02:09
The early anatomists who looked at brains
37
129983
2416
早期的解剖学家看着大脑,
02:12
gave the superficial structures of this thing all kinds of fanciful names,
38
132423
3807
给它的表面结构 取了各种充满想象力的名字。
02:16
like hippocampus, meaning "little shrimp."
39
136254
2433
比如说海马体,意思是“小虾子”。
02:18
But of course that sort of thing doesn't tell us very much
40
138711
2764
但这些并不能告诉我们
02:21
about what's actually going on inside.
41
141499
2318
大脑里面究竟是怎样工作的。
02:24
The first person who, I think, really developed some kind of insight
42
144780
3613
我认为第一个真正对大脑的工作方式
02:28
into what was going on in the brain
43
148417
1930
有所洞悉的人,
02:30
was the great Spanish neuroanatomist, Santiago Ramón y Cajal,
44
150371
3920
是19世纪西班牙 伟大的神经解剖学家
02:34
in the 19th century,
45
154315
1544
圣地亚哥 · 拉蒙 · 卡哈尔 (Santiago Ramón y Cajal),
02:35
who used microscopy and special stains
46
155883
3755
他使用了显微镜以及某种特殊染色剂,
02:39
that could selectively fill in or render in very high contrast
47
159662
4170
有选择性地将大脑中的 单个细胞填充或者渲染上
02:43
the individual cells in the brain,
48
163856
2008
高对比度的颜色,
02:45
in order to start to understand their morphologies.
49
165888
3154
以便了解它们的形态。
02:49
And these are the kinds of drawings that he made of neurons
50
169972
2891
这些就是他在19世纪
02:52
in the 19th century.
51
172887
1209
完成的的神经元手绘图。
02:54
This is from a bird brain.
52
174120
1884
这是一只鸟的大脑。
02:56
And you see this incredible variety of different sorts of cells,
53
176028
3057
能看到这些形态各异的细胞,
02:59
even the cellular theory itself was quite new at this point.
54
179109
3435
甚至在当时对细胞学说 本身还是新鲜事物。
03:02
And these structures,
55
182568
1278
而这些结构,
03:03
these cells that have these arborizations,
56
183870
2259
像树枝一样分岔,
03:06
these branches that can go very, very long distances --
57
186153
2608
能够延伸到很长的距离——
03:08
this was very novel at the time.
58
188785
1616
这些在当时都是闻所未闻。
03:10
They're reminiscent, of course, of wires.
59
190779
2903
他们让人联想到的,当然是电线。
03:13
That might have been obvious to some people in the 19th century;
60
193706
3457
这对于很多19世纪的人 来说是显而易见的,
03:17
the revolutions of wiring and electricity were just getting underway.
61
197187
4314
因为那时电线和电力革命刚刚兴起。
03:21
But in many ways,
62
201964
1178
但是在许多方面
03:23
these microanatomical drawings of Ramón y Cajal's, like this one,
63
203166
3313
拉蒙 · 卡哈尔的神经解剖学 绘画,比如这一张,
03:26
they're still in some ways unsurpassed.
64
206503
2332
从某些方面来说是很卓越的。
03:28
We're still more than a century later,
65
208859
1854
一个多世纪后的我们,仍然在继续
03:30
trying to finish the job that Ramón y Cajal started.
66
210737
2825
尝试完成拉蒙 · 卡哈尔开启的事业。
03:33
These are raw data from our collaborators
67
213586
3134
提供这些原始数据的,是我们来自
03:36
at the Max Planck Institute of Neuroscience.
68
216744
2881
马克斯 · 普朗克 神经科学研究所的合作者。
03:39
And what our collaborators have done
69
219649
1790
他们的工作
03:41
is to image little pieces of brain tissue.
70
221463
5001
是对那些小块的脑组织进行成像。
03:46
The entire sample here is about one cubic millimeter in size,
71
226488
3326
这一整个样品的大小 是1立方毫米左右,
03:49
and I'm showing you a very, very small piece of it here.
72
229838
2621
而我展示的只是它上面 很小很小的一块区域。
03:52
That bar on the left is about one micron.
73
232483
2346
左边那段比例尺的长度是1微米。
03:54
The structures you see are mitochondria
74
234853
2409
你看到的这个结构
03:57
that are the size of bacteria.
75
237286
2044
是一个细菌大小的线粒体。
03:59
And these are consecutive slices
76
239354
1551
这些是利用这个非常微小的组织
04:00
through this very, very tiny block of tissue.
77
240929
3148
所制作成的连续的切片。
04:04
Just for comparison's sake,
78
244101
2403
我们来做个对比。
04:06
the diameter of an average strand of hair is about 100 microns.
79
246528
3792
通常一根头发的直径是 100微米左右。
04:10
So we're looking at something much, much smaller
80
250344
2274
所以我们看到的东西
04:12
than a single strand of hair.
81
252642
1398
比一根头发丝还要细很多。
04:14
And from these kinds of serial electron microscopy slices,
82
254064
4031
通过这些连续的电子显微镜切片,
04:18
one can start to make reconstructions in 3D of neurons that look like these.
83
258119
5008
人们可以重构出类似这样的 神经元三维图像。
04:23
So these are sort of in the same style as Ramón y Cajal.
84
263151
3157
某种程度上,这跟拉蒙 · 卡哈尔 所用的方式是一样的。
04:26
Only a few neurons lit up,
85
266332
1492
我们只对少量的神经元进行了突出显示,
04:27
because otherwise we wouldn't be able to see anything here.
86
267848
2781
否则我们不可能看到任何东西,
04:30
It would be so crowded,
87
270653
1312
因为那样一来画面会很拥挤,
04:31
so full of structure,
88
271989
1330
充满了组织结构,
04:33
of wiring all connecting one neuron to another.
89
273343
2724
充满了各个神经元间 纵横交错的通路。
04:37
So Ramón y Cajal was a little bit ahead of his time,
90
277293
2804
显然,拉蒙 · 卡哈尔 有一点超前于他的时代,
04:40
and progress on understanding the brain
91
280121
2555
接下来的几十年间
04:42
proceeded slowly over the next few decades.
92
282700
2271
人们对大脑的理解进展非常缓慢。
04:45
But we knew that neurons used electricity,
93
285455
2853
但是我们已经知道, 神经元通过电流传导信息,
04:48
and by World War II, our technology was advanced enough
94
288332
2936
而到二战时,我们的技术 已取得了长足的进步,
04:51
to start doing real electrical experiments on live neurons
95
291292
2806
可以开始在活的 神经元细胞上做电流实验,
04:54
to better understand how they worked.
96
294122
2106
以便更好地理解它们的工作原理。
04:56
This was the very same time when computers were being invented,
97
296631
4356
而电脑也正是在 这个时候被发明了出来,
05:01
very much based on the idea of modeling the brain --
98
301011
3100
它的发明是基于对大脑的模拟——
05:04
of "intelligent machinery," as Alan Turing called it,
99
304135
3085
也就是阿兰 · 图灵 所称的“智能机器”理念,
05:07
one of the fathers of computer science.
100
307244
1991
图灵是计算机科学的开创者之一。
05:09
Warren McCulloch and Walter Pitts looked at Ramón y Cajal's drawing
101
309923
4632
沃伦 · 麦卡洛克(Warren McCulloch)和 沃尔特 · 皮兹(Walter Pitts)看到了
05:14
of visual cortex,
102
314579
1317
拉蒙 · 卡哈尔所画的 大脑视觉皮层,
05:15
which I'm showing here.
103
315920
1562
就是我给你们看的这个。
05:17
This is the cortex that processes imagery that comes from the eye.
104
317506
4442
这是负责处理我们视觉信息的大脑皮层。
05:22
And for them, this looked like a circuit diagram.
105
322424
3508
对他们来说,这看起来像一个电路图。
05:26
So there are a lot of details in McCulloch and Pitts's circuit diagram
106
326353
3835
在麦卡洛克和皮兹的电路图上,
05:30
that are not quite right.
107
330212
1352
有许多细节并不是那么正确。
05:31
But this basic idea
108
331588
1235
但基本概念是对的,
05:32
that visual cortex works like a series of computational elements
109
332847
3992
他们认为视觉皮层工作起来 就像一系列计算机元件
05:36
that pass information one to the next in a cascade,
110
336863
2746
在同一个层级中传递信息,
05:39
is essentially correct.
111
339633
1602
这一点是对的。
05:41
Let's talk for a moment
112
341259
2350
我们再聊一聊
05:43
about what a model for processing visual information would need to do.
113
343633
4032
视觉信息处理模型需要做些什么。
05:48
The basic task of perception
114
348228
2741
感知的基本任务就是
05:50
is to take an image like this one and say,
115
350993
4194
抓取这样的图像并且告诉我们
05:55
"That's a bird,"
116
355211
1176
“这是一只鸟”,
05:56
which is a very simple thing for us to do with our brains.
117
356411
2874
这对我们的大脑来说非常简单。
05:59
But you should all understand that for a computer,
118
359309
3421
但对一台电脑来说,
06:02
this was pretty much impossible just a few years ago.
119
362754
3087
在几年前,这还是完全不可能的事。
06:05
The classical computing paradigm
120
365865
1916
传统的计算模式
06:07
is not one in which this task is easy to do.
121
367805
2507
很难完成这个任务。
06:11
So what's going on between the pixels,
122
371366
2552
像素、鸟的图像以及“鸟”这个词,
06:13
between the image of the bird and the word "bird,"
123
373942
4028
这三者之间所产生的联系,
06:17
is essentially a set of neurons connected to each other
124
377994
2814
本质上是在一个神经网络中各神经元
06:20
in a neural network,
125
380832
1155
相互连接的结果,
正如这张图所示。
06:22
as I'm diagramming here.
126
382011
1223
06:23
This neural network could be biological, inside our visual cortices,
127
383258
3272
这种神经网络可能是生物学上的, 存在于我们大脑视觉皮层里,
06:26
or, nowadays, we start to have the capability
128
386554
2162
或者,现如今我们开始有能力
06:28
to model such neural networks on the computer.
129
388740
2454
在电脑上模拟这种神经网络。
06:31
And I'll show you what that actually looks like.
130
391834
2353
我们来看一下它的工作原理。
06:34
So the pixels you can think about as a first layer of neurons,
131
394211
3416
可以将像素想像成第一层的神经元,
06:37
and that's, in fact, how it works in the eye --
132
397651
2239
这实际上就是在 眼睛内部的工作原理——
06:39
that's the neurons in the retina.
133
399914
1663
是视网膜上的神经元。
06:41
And those feed forward
134
401601
1500
然后这些前馈信息
06:43
into one layer after another layer, after another layer of neurons,
135
403125
3403
通过一层层神经元往下传递,
06:46
all connected by synapses of different weights.
136
406552
3033
这些神经元通过突触彼此连接。
06:49
The behavior of this network
137
409609
1335
这个神经网络的行为
06:50
is characterized by the strengths of all of those synapses.
138
410968
3284
是通过所有这些突触的强度来表达的,
06:54
Those characterize the computational properties of this network.
139
414276
3288
也塑造了这个网络的计算性能。
06:57
And at the end of the day,
140
417588
1470
最终,
06:59
you have a neuron or a small group of neurons
141
419082
2447
一个或者一小群神经元
07:01
that light up, saying, "bird."
142
421553
1647
会亮起来,说,“鸟”。
07:03
Now I'm going to represent those three things --
143
423824
3132
接下来我会将这三部分——
07:06
the input pixels and the synapses in the neural network,
144
426980
4696
输入的像素,神经网络中的突触,
07:11
and bird, the output --
145
431700
1585
以及“鸟”,这个输出结果——
07:13
by three variables: x, w and y.
146
433309
3057
用三个变量来表示:x、w和y。
07:16
There are maybe a million or so x's --
147
436853
1811
在那张图片上可能会有一百万个x——
07:18
a million pixels in that image.
148
438688
1953
代表一百万个像素点。
07:20
There are billions or trillions of w's,
149
440665
2446
然后有几十亿或几万亿的w,
07:23
which represent the weights of all these synapses in the neural network.
150
443135
3421
代表着神经网络中所有突触的权重。
07:26
And there's a very small number of y's,
151
446580
1875
只有很少数量的y,
07:28
of outputs that that network has.
152
448479
1858
代表整个网络的输出结果。
07:30
"Bird" is only four letters, right?
153
450361
1749
“Bird(鸟)"这个单词 只有四个字母,对吧?
07:33
So let's pretend that this is just a simple formula,
154
453088
3426
我们假定这只是一个很简单的公式
07:36
x "x" w = y.
155
456538
2163
x 乘以 w 等于 y。
07:38
I'm putting the times in scare quotes
156
458725
2036
我把乘号打上了引号,
07:40
because what's really going on there, of course,
157
460785
2280
因为实际的过程要复杂得多。
07:43
is a very complicated series of mathematical operations.
158
463089
3046
牵涉到一系列非常复杂的数学运算。
07:47
That's one equation.
159
467172
1221
这是一个方程式,
07:48
There are three variables.
160
468417
1672
有三个变量。
07:50
And we all know that if you have one equation,
161
470113
2726
而我们知道在一个方程式中
07:52
you can solve one variable by knowing the other two things.
162
472863
3642
通过两个已知数 你就能算出另一个未知数。
07:57
So the problem of inference,
163
477158
3380
所以这道推论题,
08:00
that is, figuring out that the picture of a bird is a bird,
164
480562
2873
即判断出图中是一只鸟,
08:03
is this one:
165
483459
1274
可以这样来描述:
08:04
it's where y is the unknown and w and x are known.
166
484757
3459
y是未知数,w跟x都是已知数。
08:08
You know the neural network, you know the pixels.
167
488240
2459
也就是神经网络和像素是已知的。
08:10
As you can see, that's actually a relatively straightforward problem.
168
490723
3327
实际上这是一个相当简单的问题。
你只需要用2乘以3,就完事儿了。
08:14
You multiply two times three and you're done.
169
494074
2186
08:16
I'll show you an artificial neural network
170
496862
2123
我会给你们展示我们最近 完成的人工神经网络,
08:19
that we've built recently, doing exactly that.
171
499009
2296
它的工作原理正是如此。
08:21
This is running in real time on a mobile phone,
172
501634
2860
这是在一台在手机上 实时运行的神经网络,
08:24
and that's, of course, amazing in its own right,
173
504518
3313
当然,令人惊叹的是它自身的运算能力,
08:27
that mobile phones can do so many billions and trillions of operations
174
507855
3468
每秒钟可以进行 几十亿甚至几万亿次的
运算。
08:31
per second.
175
511347
1248
08:32
What you're looking at is a phone
176
512619
1615
你所看到的是一台手机的
08:34
looking at one after another picture of a bird,
177
514258
3547
相机对准了一张张含有鸟的图片,
08:37
and actually not only saying, "Yes, it's a bird,"
178
517829
2715
并且它不只能判断出, “是的,这是一只鸟”,
08:40
but identifying the species of bird with a network of this sort.
179
520568
3411
而且还能用这种网络 来判断这些鸟的种类。
08:44
So in that picture,
180
524890
1826
因此在这张图片中,
08:46
the x and the w are known, and the y is the unknown.
181
526740
3802
x和w是已知的,y是未知的。
08:50
I'm glossing over the very difficult part, of course,
182
530566
2508
当然,我省略了非常复杂的那一部分,
08:53
which is how on earth do we figure out the w,
183
533098
3861
也就是我们如何判断出w?
08:56
the brain that can do such a thing?
184
536983
2187
为什么大脑能做出这样的判断?
08:59
How would we ever learn such a model?
185
539194
1834
我们是如何学会这种模式的?
09:01
So this process of learning, of solving for w,
186
541418
3233
在学习以及解出w的过程中,
09:04
if we were doing this with the simple equation
187
544675
2647
如果我们使用简单的等式
09:07
in which we think about these as numbers,
188
547346
2000
将这些都想象成数字,
09:09
we know exactly how to do that: 6 = 2 x w,
189
549370
2687
那这道题就简单了: 6 = 2 x W,
09:12
well, we divide by two and we're done.
190
552081
3312
那么,用6除以2就可以得出答案。
09:16
The problem is with this operator.
191
556001
2220
现在的问题就是这个运算符号。
09:18
So, division --
192
558823
1151
除法——
09:19
we've used division because it's the inverse to multiplication,
193
559998
3121
我们用除法是因为它是乘法的逆运算。
但就像我刚才说的,
09:23
but as I've just said,
194
563143
1440
09:24
the multiplication is a bit of a lie here.
195
564607
2449
乘法表述在这里其实不太准确。
09:27
This is a very, very complicated, very non-linear operation;
196
567080
3326
这是一个非常非常 复杂的非线性运算,
09:30
it has no inverse.
197
570430
1704
它没有逆运算。
09:32
So we have to figure out a way to solve the equation
198
572158
3150
所以我们要找出一个不使用除号
09:35
without a division operator.
199
575332
2024
就能解出这个方程式的方法。
09:37
And the way to do that is fairly straightforward.
200
577380
2343
其实非常简单。
09:39
You just say, let's play a little algebra trick,
201
579747
2671
只需要使用一点代数上的小技巧,
09:42
and move the six over to the right-hand side of the equation.
202
582442
2906
将6移到等式的右边。
09:45
Now, we're still using multiplication.
203
585372
1826
现在我们仍然使用乘法。
09:47
And that zero -- let's think about it as an error.
204
587675
3580
而这个0——我们就当它是一个误差。
09:51
In other words, if we've solved for w the right way,
205
591279
2515
换句话说,如果我们 能用正确的方法解出w,
09:53
then the error will be zero.
206
593818
1656
那么这个误差就为0。
09:55
And if we haven't gotten it quite right,
207
595498
1938
如果我们没有找到正确的答案,
09:57
the error will be greater than zero.
208
597460
1749
那么这个误差就会大于0。
09:59
So now we can just take guesses to minimize the error,
209
599233
3366
所以现在我们可以通过 假设去缩小这个误差,
10:02
and that's the sort of thing computers are very good at.
210
602623
2687
而这正是电脑所擅长的。
比如你最开始假设:
10:05
So you've taken an initial guess:
211
605334
1593
10:06
what if w = 0?
212
606951
1156
如果w = 0呢?
那么误差就为6。
10:08
Well, then the error is 6.
213
608131
1240
如果w = 1呢?误差就变成了4。
10:09
What if w = 1? The error is 4.
214
609395
1446
10:10
And then the computer can sort of play Marco Polo,
215
610865
2367
然后电脑就像玩游戏一样不断测试,
10:13
and drive down the error close to zero.
216
613256
2367
将误差降低到接近于0。
10:15
As it does that, it's getting successive approximations to w.
217
615647
3374
这样就逐步逼近了w的值。
通常来说,它不可能获得完全精确的值, 但是经过很多步运算以后,
10:19
Typically, it never quite gets there, but after about a dozen steps,
218
619045
3656
10:22
we're up to w = 2.999, which is close enough.
219
622725
4624
我们得到了 w = 2.999, 已经足够精确了。
10:28
And this is the learning process.
220
628302
1814
以上就是这个学习过程。
10:30
So remember that what's been going on here
221
630140
2730
大家回想一下刚刚我们所做的,
10:32
is that we've been taking a lot of known x's and known y's
222
632894
4378
我们用了很多已知的x和y的值,
10:37
and solving for the w in the middle through an iterative process.
223
637296
3454
通过迭代法去解出中间的w,
10:40
It's exactly the same way that we do our own learning.
224
640774
3556
这也正是我们自己 在学习时所使用的方法。
10:44
We have many, many images as babies
225
644354
2230
在我们很小的时候, 会看到很多很多图像,
10:46
and we get told, "This is a bird; this is not a bird."
226
646608
2633
然后有人告诉我们: “这个是鸟,这个不是鸟。”
10:49
And over time, through iteration,
227
649714
2098
经过一段时间的重复,
10:51
we solve for w, we solve for those neural connections.
228
651836
2928
我们解出了w,建立起了 神经元之间的连接。
10:55
So now, we've held x and w fixed to solve for y;
229
655460
4086
那么现在,我们有了确定的 x和w。再要去解出Y
10:59
that's everyday, fast perception.
230
659570
1847
就会非常快了。
11:01
We figure out how we can solve for w,
231
661441
1763
我们找到解出w的方法,
11:03
that's learning, which is a lot harder,
232
663228
1903
这是一种学习,要困难得多,
11:05
because we need to do error minimization,
233
665155
1985
因为我们要用很多的训练样本,
去将误差最小化。
11:07
using a lot of training examples.
234
667164
1687
11:08
And about a year ago, Alex Mordvintsev, on our team,
235
668875
3187
一年前,我们团队的 亚历克斯 · 莫尔德温采夫
11:12
decided to experiment with what happens if we try solving for x,
236
672086
3550
决定做一个实验, 看如果给定已知的w和y,
11:15
given a known w and a known y.
237
675660
2037
去解出x,会发生什么。
11:18
In other words,
238
678124
1151
换句话说,
11:19
you know that it's a bird,
239
679299
1352
你已经知道那是一只鸟
11:20
and you already have your neural network that you've trained on birds,
240
680675
3303
并且也有一个接受过 鸟类识别训练的神经网络,
那么一只鸟的图像是怎样的呢?
11:24
but what is the picture of a bird?
241
684002
2344
11:27
It turns out that by using exactly the same error-minimization procedure,
242
687034
5024
我们发现,通过运用相同的 将误差最小化的步骤,
11:32
one can do that with the network trained to recognize birds,
243
692082
3430
加上一个受过鸟类识别 训练的神经网络,
11:35
and the result turns out to be ...
244
695536
3388
我们就可以得到
11:42
a picture of birds.
245
702400
1305
一张含有鸟的图片。
11:44
So this is a picture of birds generated entirely by a neural network
246
704814
3737
这是一张由一个进行过 鸟类识别训练的
11:48
that was trained to recognize birds,
247
708575
1826
神经网络所生成的鸟的图片,
11:50
just by solving for x rather than solving for y,
248
710425
3538
仅仅是通过解出x,而不是y,
11:53
and doing that iteratively.
249
713987
1288
并且重复不断的运行。
11:55
Here's another fun example.
250
715732
1847
这是另外一个有趣的例子
11:57
This was a work made by Mike Tyka in our group,
251
717603
3437
是我们团队的迈克 · 泰卡制作的 ,
12:01
which he calls "Animal Parade."
252
721064
2308
他称之为“动物大游行”。
12:03
It reminds me a little bit of William Kentridge's artworks,
253
723396
2876
这让我想起了威廉 ·肯特里奇的作品,
12:06
in which he makes sketches, rubs them out,
254
726296
2489
他先画一些素描,然后擦掉,
12:08
makes sketches, rubs them out,
255
728809
1460
再画一些素描,再擦掉,
12:10
and creates a movie this way.
256
730293
1398
用这种方法创作了一部影片。
12:11
In this case,
257
731715
1151
在我们这个案例中,
12:12
what Mike is doing is varying y over the space of different animals,
258
732890
3277
迈克在一个旨在识别和辨认
12:16
in a network designed to recognize and distinguish
259
736191
2382
不同种类动物的神经网络中
12:18
different animals from each other.
260
738597
1810
将y变换成各种不同的动物。
这样你就得到了这个奇特的 动物图像的埃舍尔式变换效果。
12:20
And you get this strange, Escher-like morph from one animal to another.
261
740431
3751
12:26
Here he and Alex together have tried reducing
262
746221
4614
他和亚历克斯还一起尝试了
12:30
the y's to a space of only two dimensions,
263
750859
2759
将这些y降低到一个二维空间内,
12:33
thereby making a map out of the space of all things
264
753642
3438
从而将被该神经网络识别出来的
12:37
recognized by this network.
265
757104
1719
所有对象放到一张图上来。
12:38
Doing this kind of synthesis
266
758847
2023
通过这样的合成
12:40
or generation of imagery over that entire surface,
267
760894
2382
或者在整个表面上生成图像,
在表面上不断的变换y, 你就创造出了一种图像——
12:43
varying y over the surface, you make a kind of map --
268
763300
2846
一个包含该神经网络能够 分辨出来的所有对象的视觉图像。
12:46
a visual map of all the things the network knows how to recognize.
269
766170
3141
12:49
The animals are all here; "armadillo" is right in that spot.
270
769335
2865
所有的动物都在这儿, 犰狳在那个点上。
12:52
You can do this with other kinds of networks as well.
271
772919
2479
你也可以用其它的神经网络 实现类似的目的。
12:55
This is a network designed to recognize faces,
272
775422
2874
这是一个为识别和分辨出不同面孔
12:58
to distinguish one face from another.
273
778320
2000
而设计的神经网络。
13:00
And here, we're putting in a y that says, "me,"
274
780344
3249
这里,我们输入一个y值,代表“我”,
13:03
my own face parameters.
275
783617
1575
我自己的面部参数。
13:05
And when this thing solves for x,
276
785216
1706
当它在解出x的时候,
13:06
it generates this rather crazy,
277
786946
2618
就生成了这张集不同视角 于一体,相当不可思议的,
13:09
kind of cubist, surreal, psychedelic picture of me
278
789588
4428
立体的、超现实的、迷幻版本的
13:14
from multiple points of view at once.
279
794040
1806
我的面部图像。
13:15
The reason it looks like multiple points of view at once
280
795870
2734
它之所以看起来像是集不同视角于一体,
13:18
is because that network is designed to get rid of the ambiguity
281
798628
3687
是因为这个神经网络被设计成将一张脸
13:22
of a face being in one pose or another pose,
282
802339
2476
在不同姿势、不同光线之间产生的
13:24
being looked at with one kind of lighting, another kind of lighting.
283
804839
3376
模棱两可的地方抹掉了。
13:28
So when you do this sort of reconstruction,
284
808239
2085
因此当你开始这项复原工作时,
如果不利用某种影像引导,
13:30
if you don't use some sort of guide image
285
810348
2304
13:32
or guide statistics,
286
812676
1211
或者统计引导,
13:33
then you'll get a sort of confusion of different points of view,
287
813911
3765
那么你就会得到一种 令人困惑的多视角的图像,
13:37
because it's ambiguous.
288
817700
1368
因为它是模棱两可的。
13:39
This is what happens if Alex uses his own face as a guide image
289
819786
4223
这就是亚历克斯在复原 我的面部的优化流程中,
用他自己的脸作为 影像引导时所得到的图像。
13:44
during that optimization process to reconstruct my own face.
290
824033
3321
13:48
So you can see it's not perfect.
291
828284
2328
你可以看到它还不是十分完美。
13:50
There's still quite a lot of work to do
292
830636
1874
我们在完善这个优化流程方面
13:52
on how we optimize that optimization process.
293
832534
2453
还有许多的工作要做。
但是通过将我自己的脸 作为渲染过程中的引导,
13:55
But you start to get something more like a coherent face,
294
835011
2827
13:57
rendered using my own face as a guide.
295
837862
2014
你已经可以得到一个 更清晰的面孔了。
14:00
You don't have to start with a blank canvas
296
840892
2501
你不需要完全从一块空白的画布
14:03
or with white noise.
297
843417
1156
或白噪音开始。
14:04
When you're solving for x,
298
844597
1304
当你在解出x时,
14:05
you can begin with an x, that is itself already some other image.
299
845925
3889
你可以从一个本身已经是 别的图像的x开始。
14:09
That's what this little demonstration is.
300
849838
2556
正如这个小小的展示那样。
14:12
This is a network that is designed to categorize
301
852418
4122
这是一个设计为用来将所有物品——
14:16
all sorts of different objects -- man-made structures, animals ...
302
856564
3119
人造结构、动物等进行分类的神经网络。
14:19
Here we're starting with just a picture of clouds,
303
859707
2593
我们从一张云图开始,
14:22
and as we optimize,
304
862324
1671
在优化过程中,
14:24
basically, this network is figuring out what it sees in the clouds.
305
864019
4486
这个神经网络正在不停地计算 它在云中看到了什么。
14:28
And the more time you spend looking at this,
306
868931
2320
你花越多的时间盯着这张图,
14:31
the more things you also will see in the clouds.
307
871275
2753
你就会在云中看到越多的东西。
14:35
You could also use the face network to hallucinate into this,
308
875004
3375
你也可以使用面部识别 神经网络去产生迷幻效果,
14:38
and you get some pretty crazy stuff.
309
878403
1812
然后就可以得到这种不可思议的东西。
14:40
(Laughter)
310
880239
1150
(观众笑声)
14:42
Or, Mike has done some other experiments
311
882401
2744
或者可以像迈克做的另外一个实验那样,
14:45
in which he takes that cloud image,
312
885169
3905
他还是利用那张云图,
14:49
hallucinates, zooms, hallucinates, zooms hallucinates, zooms.
313
889098
3507
使它幻化、再放大, 幻化再放大,幻化再放大.
14:52
And in this way,
314
892629
1151
这样一来,
14:53
you can get a sort of fugue state of the network, I suppose,
315
893804
3675
我想你就可以得到 这个网络的神游状态,
14:57
or a sort of free association,
316
897503
3680
或者某种自由联想,
15:01
in which the network is eating its own tail.
317
901207
2227
仿佛这个网络正在吞噬自己的尾巴。
15:03
So every image is now the basis for,
318
903458
3421
因此每一张图都是 下一张图的基础,决定了
15:06
"What do I think I see next?
319
906903
1421
“我觉得接下来会看到什么?
15:08
What do I think I see next? What do I think I see next?"
320
908348
2803
接下来又会看到什么? 接下来还会看到什么?”
15:11
I showed this for the first time in public
321
911487
2936
我第一次公开展示这些是在西雅图,
15:14
to a group at a lecture in Seattle called "Higher Education" --
322
914447
5437
为一个团队做的一次名为 “高等教育”的讲座上——
15:19
this was right after marijuana was legalized.
323
919908
2437
刚好就在大麻合法化之后。
15:22
(Laughter)
324
922369
2415
(观众笑声)
15:26
So I'd like to finish up quickly
325
926627
2104
在结束我的演讲前,
15:28
by just noting that this technology is not constrained.
326
928755
4255
我想再提醒各位, 这种技术是不受限的。
15:33
I've shown you purely visual examples because they're really fun to look at.
327
933034
3665
我给你们看了一些纯粹的视觉实例, 因为它们看起来真的很有趣。
15:36
It's not a purely visual technology.
328
936723
2451
它不是一种纯粹的视觉技术。
15:39
Our artist collaborator, Ross Goodwin,
329
939198
1993
我们的合作者,艺术家罗斯 · 古德温
15:41
has done experiments involving a camera that takes a picture,
330
941215
3671
做了一个实验,他用相机拍了一张照片,
15:44
and then a computer in his backpack writes a poem using neural networks,
331
944910
4234
然后他背包里的电脑 基于这张照片的内容,
15:49
based on the contents of the image.
332
949168
1944
用神经网络作了一首诗。
15:51
And that poetry neural network has been trained
333
951136
2947
这个作诗的神经网络已经接受过
15:54
on a large corpus of 20th-century poetry.
334
954107
2234
大量的20世纪诗歌的训练。
15:56
And the poetry is, you know,
335
956365
1499
其实我觉得
15:57
I think, kind of not bad, actually.
336
957888
1914
那首诗还不赖。
15:59
(Laughter)
337
959826
1384
(观众笑声)
16:01
In closing,
338
961234
1159
下面,
16:02
I think that per Michelangelo,
339
962417
2132
再回到米开朗基罗那句名言,
16:04
I think he was right;
340
964573
1234
我想他是对的,
16:05
perception and creativity are very intimately connected.
341
965831
3436
感知和创意是密不可分的。
16:09
What we've just seen are neural networks
342
969611
2634
我们刚刚所看到的是一些
16:12
that are entirely trained to discriminate,
343
972269
2303
完全被训练成去区分,
16:14
or to recognize different things in the world,
344
974596
2242
或辨别世上的不同物品,
16:16
able to be run in reverse, to generate.
345
976862
3161
能够逆向运行、成生图像的神经网络。
16:20
One of the things that suggests to me
346
980047
1783
我从中受到的启发之一就是,
16:21
is not only that Michelangelo really did see
347
981854
2398
不仅米开朗基罗真的看到了
16:24
the sculpture in the blocks of stone,
348
984276
2452
石头中的雕像,
16:26
but that any creature, any being, any alien
349
986752
3638
而且任何的生物、任何人、任何外星人,
16:30
that is able to do perceptual acts of that sort
350
990414
3657
只要能够有这样的感知,
16:34
is also able to create
351
994095
1375
也就能够创造,
16:35
because it's exactly the same machinery that's used in both cases.
352
995494
3224
因为它们都运用了截然相同的机制。
16:38
Also, I think that perception and creativity are by no means
353
998742
4532
另外,我想感知和创意决不是
16:43
uniquely human.
354
1003298
1210
人类所特有的。
16:44
We start to have computer models that can do exactly these sorts of things.
355
1004532
3708
我们开始有了可以 完成这些事的电脑模型。
16:48
And that ought to be unsurprising; the brain is computational.
356
1008264
3328
这应当不足为奇,因为大脑会运算。
16:51
And finally,
357
1011616
1657
最后,
16:53
computing began as an exercise in designing intelligent machinery.
358
1013297
4668
电脑运算最开始是作为 设计智能机器的一种练习。
16:57
It was very much modeled after the idea
359
1017989
2462
它在很大程度上仿照了我们如何
17:00
of how could we make machines intelligent.
360
1020475
3013
让机器变得智能这一理念。
17:03
And we finally are starting to fulfill now
361
1023512
2162
而我们也终于开始能够实现
17:05
some of the promises of those early pioneers,
362
1025698
2406
图灵、冯 · 诺依曼、
17:08
of Turing and von Neumann
363
1028128
1713
麦卡洛克和皮兹
17:09
and McCulloch and Pitts.
364
1029865
2265
这些先驱的一些期望了。
17:12
And I think that computing is not just about accounting
365
1032154
4098
我觉得电脑不仅仅是拿来计算,
17:16
or playing Candy Crush or something.
366
1036276
2147
或者玩游戏的。
17:18
From the beginning, we modeled them after our minds.
367
1038447
2578
从一开始,我们就是 仿照大脑来制造它们的。
而它们也赋予了我们能够 更好的理解我们的大脑,
17:21
And they give us both the ability to understand our own minds better
368
1041049
3269
17:24
and to extend them.
369
1044342
1529
并且拓展其潜力的能力。
17:26
Thank you very much.
370
1046627
1167
非常感谢。
17:27
(Applause)
371
1047818
5939
(观众掌声)
关于本网站

这个网站将向你介绍对学习英语有用的YouTube视频。你将看到来自世界各地的一流教师教授的英语课程。双击每个视频页面上显示的英文字幕,即可从那里播放视频。字幕会随着视频的播放而同步滚动。如果你有任何意见或要求,请使用此联系表与我们联系。

https://forms.gle/WvT1wiN1qDtmnspy7