How sound can hack your memory while you sleep | DIY Neuroscience, a TED series

362,448 views ・ 2018-09-15

TED


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

00:00
Translator: Ivana Korom Reviewer: Joanna Pietrulewicz
0
0
7000
00:12
Greg Gage: Who wouldn't love acing a geography exam,
1
12000
2680
00:14
remembering all the locations of the countries on a map
2
14719
2601
00:17
or avoiding embarrassing situations of suddenly forgetting the person's name
3
17360
3600
00:21
standing right in front of you.
4
21000
1520
00:22
It turns out that memory, like other muscles in the body,
5
22560
2680
00:25
can be strengthened and enhanced.
6
25280
1600
00:26
But instead of practicing with flash cards,
7
26920
2080
00:29
there may be an interesting way
8
29040
1520
00:30
that we can hack our memory while we sleep.
9
30600
2160
00:33
(Music)
10
33000
2960
00:38
Why do we sleep?
11
38200
1200
00:39
This has been a question asked since the early days of civilization.
12
39440
3200
00:42
And while we may not know the exact answer,
13
42680
2240
00:44
there are a number of really good theories about why we need it.
14
44960
3040
00:48
Sleep is when the brain transfers short-term memories
15
48040
2480
00:50
experienced throughout the day
16
50560
1480
00:52
into long-term memories.
17
52080
1240
00:53
This process is called memory consolidation,
18
53360
2180
00:55
and it's the memory consolidation theory that has scientists wondering
19
55560
3300
00:58
if we can enhance certain memories over others.
20
58890
2110
01:01
There was a paper recently in the journal "Science"
21
61040
2400
01:03
by Ken Paller and his colleagues at Northwestern
22
63480
2240
01:05
that seemed to show that this may be true,
23
65760
1960
01:07
and that piqued our curiosity.
24
67760
1440
01:09
Joud has been working on a DIY version of this task
25
69240
2400
01:11
to see if we can improve memories through the use of sound in sleep.
26
71680
3200
01:14
So Joud, how do you test if we can improve our memories with sleep?
27
74920
3360
01:18
Joud Mar’i: We need a human subject.
28
78320
1440
01:20
[Step 1: Play a game]
29
80760
1920
01:22
We have a memory game that we have on an iPad,
30
82720
2600
01:25
and then we make our subject play this game
31
85360
2000
01:27
and remember the images and where they appear on the screen.
32
87400
2840
01:30
GG: So this is like a memory game you used to play as a child,
33
90280
2880
01:33
which picture was where.
34
93200
1240
01:34
And we tie each picture with a sound that represents it.
35
94480
2840
01:37
JM: So, if you can see a picture of a car, for example,
36
97360
2560
01:39
and you would hear the car engine.
37
99960
1640
01:41
(Car engine starting)
38
101640
2160
01:43
GG: Just before you go to sleep we're going to test you.
39
103840
2600
01:46
We're going to see how well you remember where the pictures are.
40
106480
3040
01:49
Every time you see the picture, you're going to hear the sound.
41
109560
2960
01:52
And now comes the experiment.
42
112560
1560
01:54
You're going to go take a nap.
43
114160
1460
01:55
[Step 2: Take a nap]
44
115660
990
01:58
And while you're sleeping, we're going to be recording your EEG.
45
118120
3240
02:01
JM: And then we wait for them to go into what's called the slow-wave sleep,
46
121400
3560
02:05
which is the deepest phase of your sleep where it's really hard for you to wake up.
47
125000
3920
02:08
GG: OK, pause.
48
128960
1200
02:10
So, here's some information on sleep.
49
130200
1800
02:12
There are four stages: we have lighter stages of sleep and REM,
50
132040
2920
02:15
but what we're interested in is called slow-wave sleep.
51
135000
2600
02:17
And it gets its name from the electrical signals
52
137640
2240
02:19
called Delta waves that we record from the brain.
53
139920
2320
02:22
This is the part of sleep where scientists believe
54
142280
2360
02:24
that memory consolidation can happen.
55
144680
1800
02:26
In this deep period of sleep,
56
146520
1400
02:27
we're going to do something that you don't know we're going to do.
57
147960
3120
02:31
JM: Here's where the tricky part comes, and we start playing our cues.
58
151120
3290
02:35
(Car engine starting)
59
155000
1360
02:36
GG: Do you play all the cues?
60
156400
1440
02:37
JM: No. We only want to play half of them to see if there's a difference.
61
157880
3600
02:41
GG: So your hypothesis is
62
161520
1360
02:42
the one that they were listening to while they're sleeping
63
162920
2840
02:45
they're going to do better at.
64
165800
1440
02:47
JM: Yes, exactly.
65
167280
1240
02:49
GG: When you wake back up and play the game again,
66
169920
2360
02:52
do you do better or worse than before a nap?
67
172320
3080
02:55
What we found is that if we played you a cue during your sleep,
68
175440
4280
02:59
for example, a car --
69
179760
1520
03:01
You would remember the position of that car
70
181320
2040
03:03
when you woke back up again.
71
183400
1560
03:05
But if we didn't play you the cue during the sleep,
72
185000
2400
03:07
for example, a guitar,
73
187440
1560
03:09
you'd be less likely to remember that guitar when you woke up.
74
189040
3240
03:12
The memories that were cued they remembered better
75
192320
2800
03:15
than the ones they weren't,
76
195160
1320
03:16
even though they don't remember hearing those sounds?
77
196520
2480
03:19
JM: Yes, we ask them.
78
199040
1240
03:20
GG: We know they're sleeping, they can't hear it, they wake up,
79
200320
2920
03:23
they do better on those than the ones you didn't play.
80
203280
2560
03:25
GG: That's amazing. JM: It's like magic.
81
205880
1800
03:27
GG: Joud ran this experiment on 12 people and the results were significant.
82
207720
3480
03:31
It's not that you remember things better; it's that you forget them less.
83
211240
3440
03:34
I was a huge skeptic when I first heard that you could do better at a memory test
84
214720
3840
03:38
just by playing sounds during sleep.
85
218600
1720
03:40
But we replicated these experiments.
86
220360
1720
03:42
The facts and memories we collect throughout the day are very fragile,
87
222120
3320
03:45
and they are easily lost and forgotten.
88
225480
1880
03:47
But by reactivating them during sleep, even without us being aware,
89
227400
3160
03:50
it seems like we could make them more stable and less prone to forgetting.
90
230600
3480
03:54
That's pretty incredible.
91
234120
1240
03:55
Our brains are still active even when we're not.
92
235400
2240
03:57
So if you're like me and a bit forgetful,
93
237680
1960
03:59
perhaps a solution is a pair of headphones and a soft couch.
94
239680
3720
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