How close are we to uploading our minds? - Michael S.A. Graziano

539,741 views ・ 2019-10-28

TED-Ed


Please double-click on the English subtitles below to play the video.

00:07
Imagine a future where nobody dies—
0
7063
2880
00:09
instead, our minds are uploaded to a digital world.
1
9943
4000
00:13
They might live on in a realistic, simulated environment with avatar bodies,
2
13943
4530
00:18
and could still call in and contribute to the biological world.
3
18473
4680
00:23
Mind uploading has powerful appeal—
4
23153
3091
00:26
but what would it actually take to scan a person’s brain and upload their mind?
5
26244
5430
00:31
The main challenges are scanning a brain in enough detail to capture the mind
6
31674
4552
00:36
and perfectly recreating that detail artificially.
7
36226
4408
00:40
But first, we have to know what to scan.
8
40634
2680
00:43
The human brain contains about 86 billion neurons,
9
43314
3370
00:46
connected by at least a hundred trillion synapses.
10
46684
3630
00:50
The pattern of connectivity among the brain’s neurons,
11
50314
3070
00:53
that is, all of the neurons and all their connections to each other,
12
53384
4120
00:57
is called the connectome.
13
57504
2199
00:59
We haven’t yet mapped the connectome,
14
59703
2210
01:01
and there’s also a lot more to neural signaling.
15
61913
3020
01:04
There are hundreds, possibly thousands of different kinds of connections,
16
64933
3730
01:08
or synapses.
17
68663
1600
01:10
Each functions in a slightly different way.
18
70263
2640
01:12
Some work faster, some slower.
19
72903
2040
01:14
Some grow or shrink rapidly in the process of learning;
20
74943
3770
01:18
some are more stable over time.
21
78713
2190
01:20
And beyond the trillions of precise, 1-to-1 connections between neurons,
22
80903
4690
01:25
some neurons also spray out neurotransmitters
23
85593
3363
01:28
that affect many other neurons at once.
24
88956
2770
01:31
All of these different kinds of interactions
25
91726
2240
01:33
would need to be mapped in order to copy a person’s mind.
26
93966
3910
01:37
There are also a lot of influences on neural signaling
27
97876
2990
01:40
that are poorly understood or undiscovered.
28
100866
3340
01:44
To name just one example,
29
104206
1570
01:45
patterns of activity between neurons
30
105776
2310
01:48
are likely influenced by a type of cell called glia.
31
108086
4070
01:52
Glia surround neurons and, according to some scientists,
32
112156
3697
01:55
may even outnumber them by as many as ten to one.
33
115853
3650
01:59
Glia were once thought to be purely for structural support,
34
119503
3630
02:03
and their functions are still poorly understood,
35
123133
2850
02:05
but at least some of them can generate their own signals
36
125983
3150
02:09
that influence information processing.
37
129133
2620
02:11
Our understanding of the brain isn’t good enough to determine
38
131753
3140
02:14
what we’d need to scan in order to replicate the mind,
39
134893
3040
02:17
but assuming our knowledge does advance to that point,
40
137933
3010
02:20
how would we scan it?
41
140943
1430
02:22
Currently, we can accurately scan a living human brain
42
142373
3490
02:25
with resolutions of about half a millimeter
43
145863
2560
02:28
using our best non-invasive scanning method, MRI.
44
148423
3820
02:32
To detect a synapse, we’ll need to scan at a resolution of about a micron—
45
152243
5490
02:37
a thousandth of a millimeter.
46
157733
1960
02:39
To distinguish the kind of synapse and precisely how strong each synapse is,
47
159693
5000
02:44
we’ll need even better resolution.
48
164693
2381
02:47
MRI depends on powerful magnetic fields.
49
167074
2970
02:50
Scanning at the resolution required
50
170044
1880
02:51
to determine the details of individual synapses
51
171924
3190
02:55
would requires a field strength high enough to cook a person’s tissues.
52
175114
4620
02:59
So this kind of leap in resolution
53
179734
2032
03:01
would require fundamentally new scanning technology.
54
181766
3290
03:05
It would be more feasible to scan a dead brain using an electron microscope,
55
185056
4580
03:09
but even that technology is nowhere near good enough–
56
189636
3600
03:13
and requires killing the subject first.
57
193236
3290
03:16
Assuming we eventually understand the brain well enough to know what to scan
58
196526
4150
03:20
and develop the technology to safely scan at that resolution,
59
200676
3450
03:24
the next challenge would be to recreate that information digitally.
60
204126
4410
03:28
The main obstacles to doing so are computing power and storage space,
61
208536
4730
03:33
both of which are improving every year.
62
213266
2498
03:35
We’re actually much closer to attaining this technological capacity
63
215764
3760
03:39
than we are to understanding or scanning our own minds.
64
219524
4270
03:43
Artificial neural networks already run our internet search engines,
65
223794
4040
03:47
digital assistants, self-driving cars, Wall Street trading algorithms,
66
227834
4584
03:52
and smart phones.
67
232418
1374
03:53
Nobody has yet built an artificial network with 86 billion neurons,
68
233792
4110
03:57
but as computing technology improves,
69
237902
2430
04:00
it may be possible to keep track of such massive data sets.
70
240332
4380
04:04
At every step in the scanning and uploading process,
71
244712
3458
04:08
we’d have to be certain we were capturing all the necessary information accurately—
72
248170
4670
04:12
or there’s no telling what ruined version of a mind might emerge.
73
252840
5457
04:18
While mind uploading is theoretically possible,
74
258297
2786
04:21
we’re likely hundreds of years away
75
261083
1850
04:22
from the technology and scientific understanding
76
262933
2890
04:25
that would make it a reality.
77
265823
1450
04:27
And that reality would come with ethical and philosophical considerations:
78
267273
4250
04:31
who would have access to mind uploading?
79
271523
2810
04:34
What rights would be accorded to uploaded minds?
80
274333
2880
04:37
How could this technology be abused?
81
277213
2760
04:39
Even if we can eventually upload our minds,
82
279636
2800
04:42
whether we should remains an open question.
83
282436
3110
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7