Shadowing Practice: Sleep Is Your Superpower | Matt Walker | TED - Learn English Speaking with YouTube
C1
Reviewer.
⏸ Paused
Speed:
All Sentences260 sentences
If sentences are too short or too long, click Edit to adjust them.
1
Reviewer.
2
Thank you very much.
3
Well, I would like to start with testicles.
4
Men who sleep five hours a night have significantly smaller testicles than those who sleep seven hours or more.
5
In addition, men who routinely sleep just four to five hours a night will have a level of testosterone
6
which is that of someone 10 years their senior.
7
So a lack of sleep will age a man by a decade in terms of that critical aspect of wellness.
8
And we see equivalent impairments in female reproductive health caused by a lack of sleep.
9
This is the best news that I have for you today.
10
From this point, it may only get worse.
11
Not only will I tell you about the wonderfully good things that happen when you get sleep,
12
but the alarmingly bad things that happen when you don't get enough,
13
both for your brain and for your body.
14
Let me start with the brain and the functions of learning and memory,
15
because what we've discovered over the past 10 or so years is
16
that you need sleep after learning to essentially hit the save button on those new memories so that you don't forget.
17
But recently we discovered that you also need sleep before learning,
18
and now to actually prepare your brain,
19
almost like a dry sponge ready to initially soak up new information.
20
And without sleep, the memory circuits of the brain essentially become waterlogged,
21
as it were, and you can't absorb new memories.
22
So let me show you the data.
23
Here in this study, we decided to test the hypothesis that pulling the all-nighter was a good idea.
24
So we took a group of individuals and we assigned them to one of two experimental groups,
25
a sleep group and a sleep deprivation group.
26
Now, the sleep group, they're going to get a full eight hours of slumber.
27
But the deprivation group, we're going to keep them awake in the laboratory, under full supervision.
28
There's no naps or caffeine,
29
by the way, so it's miserable for everyone involved.
30
And then the next day,
31
we're going to place those participants inside an MRI scanner.
32
And we're going to have them try and learn a whole list of new facts as we're taking snapshots of brain activity.
33
and then we're going to test them to see how effective that learning has been.
34
And that's what you're looking at here on the vertical axis.
35
And when you put those two groups head to head,
36
what you find is a quite significant 40 percent deficit in the ability of the brain to make new memories without sleep.
37
I think this should be concerning,
38
considering what we know is happening to sleep in our education populations right now.
39
In fact, to put that in context,
40
it would be the difference in a child acing an exam versus failing it miserably, 40 percent.
41
And we've gone on to discover what goes wrong within your brain to produce these types of learning disabilities.
42
And there's a structure that sits on the left and the right side of your brain called the hippocampus.
43
And you can think of the hippocampus almost like the informational inbox of your brain.
44
It's very good at receiving new memory files and then holding onto them.
45
And when you look at this structure in those people who'd had a full night of sleep,
46
we saw lots of healthy learning-related activity.
47
Yet in those people who were sleep-deprived,
48
we actually couldn't find any significant signal whatsoever.
49
So it's almost as though sleep deprivation had shut down your memory inbox and any new incoming files,
50
they were just being bounced.
51
You couldn't effectively commit new experiences to memory.
52
So that's the bad that can happen if I were to take sleep away from you.
53
But let me just come back to that control group for a second.
54
Do you remember those folks that got a full eight hours of sleep?
55
Well, we can ask a very different question What is it about the physiological quality of your sleep,
56
when you do get it,
57
that restores and enhances your memory and learning ability each and every day?
58
And by placing electrodes all over the head,
59
what we've discovered is that there are big,
60
powerful brainwaves that happen during the very deepest stages of sleep
61
that have riding on top of them these spectacular bursts of electrical activity that we call sleep spindles.
62
And it's the combined quality of these deep sleep brainwaves that acts like a file transfer mechanism at night,
63
shifting memories from a short-term vulnerable reservoir to a more permanent,
64
long-term storage site within the brain,
65
and therefore protecting them, making them safe.
66
And it is important that we understand what,
67
during sleep, actually transacts these memory benefits,
68
because there are real medical and societal implications.
69
And let me just tell you about one area that we've moved this work out into clinically,
70
which is the context of aging and dementia.
71
Because it's, of course, no secret that as we get older,
72
our learning and memory abilities begin to fade and decline.
73
But what we've also discovered is that a physiological signature of aging is that your sleep gets worse,
74
especially that deep quality of sleep that I was just discussing.
75
And only last year, we finally published evidence that these two things,
76
they're not simply co-occurring, they are significantly interrelated.
77
And it suggests that the disruption of deep sleep is an underappreciated factor
78
that is contributing to cognitive decline or memory decline in aging and,
79
most recently we've discovered, in Alzheimer's disease as well.
80
Now, I know this is remarkably depressing news.
81
It's in the mail, it's coming at you.
82
But there's a potential silver lining here.
83
Unlike many of the other factors that we know are associated with aging,
84
for example, changes in the physical structure of the brain,
85
that's fiendishly difficult to treat.
86
But that sleep is a missing piece in the explanatory puzzle of aging and Alzheimer's is exciting,
87
because we may be able to do something about it.
88
And one way that we are approaching this at my sleep center is not by using sleeping pills,
89
by the way.
90
Unfortunately, they are blunt instruments that do not produce naturalistic sleep.
91
Instead, we're actually developing a method based on this.
92
It's called direct current brain stimulation.
93
You insert a small amount of voltage into the brain,
94
so small you typically don't feel it,
95
but it has a measurable impact.
96
Now, if you apply this stimulation during sleep in young,
97
healthy adults, as if you're sort of singing in time with those deep sleep brainwaves,
98
not only can you amplify the size of those deep sleep brainwaves,
99
but in doing so, we can almost double the amount of memory benefit that you get from sleep.
100
The question now is whether we can translate this same affordable,
101
potentially portable piece of technology into older adults and those with dementia.
102
Can we restore back some healthy quality of deep sleep?
103
And in doing so, can we salvage aspects of their learning and memory function?
104
That is my real hope now.
105
That's one of our moonshot goals, as it were.
106
So that's an example of sleep for your brain,
107
but sleep is just as essential for your body.
108
We've already spoken about sleep loss and your reproductive system.
109
Or I could tell you about sleep loss and your cardiovascular system,
110
and that all it takes is one hour,
111
Because there is a global experiment performed on 1.6 billion people across 70 countries twice a year.
112
And it's called daylight savings time.
113
Now, in the spring, when we lose one hour of sleep,
114
we see a subsequent 24 percent increase in heart attacks that following day.
115
In the autumn, When we gain an hour of sleep,
116
we see a 21 percent reduction in heart attacks.
117
Isn't that incredible?
118
And you see exactly the same profile for car crashes,
119
road traffic accidents, even suicide rates.
120
But as a deeper dive,
121
I want to focus on this,
122
sleep loss and your immune system.
123
And here I'll introduce these delightful blue elements in the image.
124
They are called natural killer cells.
125
And you can think of these as a result of these They have natural killer cells,
126
almost like the secret service agents of your immune system.
127
They are very good at identifying dangerous,
128
unwanted elements and eliminating them.
129
In fact, what they're doing here is destroying a cancerous tumor mass.
130
So what you wish for is a virile set of these immune assassins at all times.
131
And tragically, that's what you don't have if you're not sleeping enough.
132
So here in this experiment,
133
you're not going to have your sleep deprived for an entire night.
134
You're simply going to have your sleep restricted to four hours for one single night.
135
And then we're going to look to see what's the percent reduction in immune cell activity that you suffer.
136
And it's not small.
137
It's not 10 percent.
138
It's not 20 percent.
139
there was a 70 percent drop in natural killer cell activity.
140
That's a concerning state of immune deficiency.
141
And you can perhaps understand why we're now finding significant links between short sleep duration
142
and your risk for the development of numerous forms of cancer.
143
Currently, that list includes cancer of the bowel,
144
cancer of the prostate and cancer of the breast.
145
In fact, the link between a lack of sleep
146
and cancer is now so strong
147
that the World Health Organization has classified any form of nighttime shift work as a probable carcinogen,
148
because of a disruption of your sleep-wake rhythms.
149
So you may have heard of that old maxim that you can sleep when you're dead,
150
well, I'm being quite serious now.
151
It is mortally unwise advice.
152
We know this from epidemiological studies across millions of individuals.
153
There's a simple truth.
154
The shorter your sleep, the shorter your life.
155
Short sleep predicts all-cause mortality.
156
And if increasing your risk for the development of cancer or even Alzheimer's disease,
157
were not sufficiently disquieting, we have since discovered
158
that a lack of sleep will even erode the very fabric of biological life itself.
159
Your DNA genetic code.
160
So here in this study,
161
they took a group of healthy adults and they limited them to six hours of sleep a night for one week.
162
And then they measured the change in their gene activity profile relative to
163
when those same individuals were getting a full eight hours of sleep a night.
164
And there were two critical findings.
165
First, a sizable and significant 711 genes were distorted in their activity,
166
caused by a lack of sleep.
167
The second result was that about half of those genes were actually increased in their activity,
168
the other half were decreased.
169
Now, those genes that were switched off by a lack of sleep were genes associated with your immune system.
170
So once again, you can see that immune deficiency.
171
In contrast, those genes that were actually upregulated
172
or increased by way of a lack of sleep were genes associated with the promotion of tumors,
173
genes associated with long-term chronic inflammation within the body,
174
and genes associated with stress and,
175
as a consequence, cardiovascular disease.
176
There is simply no aspect of your wellness that can retreat at the sign of sleep deprivation and get away unscathed.
177
It's rather like a broken water pipe in your home.
178
Sleep loss will leak down into every nook and cranny of your physiology.
179
Even tampering with the very DNA nucleic alphabet that spells out your daily health narrative.
180
And at this point, you may be thinking,
181
oh my goodness, how do I start to get better sleep?
182
What are your tips for good sleep?
183
Well, beyond avoiding the damaging and harmful impact of alcohol and caffeine on sleep,
184
and if you're struggling with sleep at night,
185
avoiding naps during the day,
186
I have two pieces of advice for you.
187
The first is regularity.
188
Go to bed at the same time,
189
wake up at the same time no matter whether it's the weekday or the weekend,
190
regularity is king, and it will anchor your sleep and improve the quantity and the quality of that sleep.
191
The second is keep it cool.
192
Your body needs to drop its core temperature by about two to three degrees Fahrenheit to initiate sleep
193
and then to stay asleep.
194
And it's the reason you will always find it easier to fall asleep in a room that's too cold than too hot.
195
So aim for a bedroom temperature of around 65 degrees or about 18 degrees Celsius.
196
That's going to be optimal for the sleep of most people.
197
And then finally, in taking a step back then,
198
what is the mission-critical statement here?
199
Well, I think it may be this.
200
Sleep, unfortunately, is not an optional lifestyle luxury.
201
Sleep is a non-negotiable biological necessity.
202
It is your life support system,
203
and it is Mother Nature's best effort yet at immortality.
204
And the decimation of sleep throughout industrialized nations is having a catastrophic impact on our health,
205
our wellness, even the safety and the education of our children.
206
It's a silent sleep loss epidemic,
207
and it is fast becoming one of the greatest public health challenges that we face in the 21st century.
208
I believe it is now time for us to reclaim our right to a full night of sleep.
209
and without embarrassment or that unfortunate stigma of laziness.
210
And in doing so, we can be reunited with the most powerful elixir of life,
211
the Swiss Army knife of health, as it were.
212
And with that soapbox rant over,
213
I will simply say goodnight,
214
good luck and, above all,
215
I do hope you sleep well.
216
Thank you very much indeed.
217
Thank you.
218
Thank you so much.
219
No, no, no. Stay there for a second.
220
Good job not running away, though.
221
I appreciate that.
222
So that was terrifying.
223
You're welcome.
224
Yes, thank you.
225
Since we can't catch up on sleep,
226
what are we supposed to do?
227
What do we do when we're tossing and turning in bed late at night or doing shift work or whatever else?
228
So you're right, we can't catch up on sleep.
229
Sleep is not like the bank.
230
You can't accumulate a debt and then hope to pay it off at a later point in time.
231
I should also note the reason that it's so catastrophic,
232
that our health deteriorates so quickly,
233
first is because human beings are the only species that deliberately deprive themselves of sleep,
234
for no apparent reason.
235
Because we're smart.
236
And I make that point because what it means is that Mother Nature,
237
throughout the course of evolution,
238
has never had to face the challenge of this thing called sleep deprivation.
239
So she's never developed a safety net.
240
And that's why when you under-sleep,
241
things just sort of implode so quickly,
242
both within the brain and the body.
243
So you just have to prioritize.
244
Okay.
245
but tossing and turning in bed,
246
what do I do?" So if you are staying in bed awake for too long,
247
you should get out of bed and go to a different room and do something different.
248
The reason is because your brain will very quickly associate your bedroom with the place of wakefulness.
249
And you need to break that association.
250
So only return to bed when you are sleepy,
251
and that way you will relearn the association that you once had,
252
which is your bed is the place of sleep.
253
So the analogy would be,
254
you'd never sit at the dinner table waiting to get hungry,
255
so why would you lie in bed waiting to get sleepy?
256
All right.
257
Well, thank you for that wake-up call.
258
Great job, Matt.
259
Very welcome.
260
Thank you very much.
Download App
AI scoring for every sentence you speak
TRENDING
Popular
4.9/5 on App Store & Google Play
Shadowing English
On Mobile
Learn English anytime, anywhere with the Shadowing English app. Improve your communication skills today!
Track your learning progress
AI grading and error correction
Rich video library
Why practice speaking with this video?
Utilizing the TED talk by Matt Walker about sleep can significantly enhance your English speaking practice. This engaging presentation dives into the science of sleep and its impact on memory, making it an ideal context for practicing spoken English. By listening and shadowing Walker’s insightful delivery, you not only gain valuable information but also develop your speaking skills. Engaging with this content can help you improve your fluency and comprehension while learning to articulate complex ideas.
Moreover, through this shadow speech practice, you can refine your intonation, emphasize key points, and learn how to convey emotion effectively. Regularly using a shadowing app alongside this video can help solidify these new skills by allowing you to record and playback your speaking exercises, ensuring you grasp the nuances of English pronunciation.
Grammar & Expressions in Context
While watching the video, pay attention to the following key structures that Walker employs:
- Conditionals: Phrases like "If you sleep more, you improve your health." These constructions are essential in English to discuss hypothetical scenarios.
- Present perfect: Walker mentions “We have discovered,” which emphasizes recent findings relevant to the topic.
- Comparatives: He frequently uses comparisons, such as “smaller” and “greater,” which are crucial for making distinctions.
- Passive voice: Phrases such as “sleep is needed” showcase how the passive construction can shift focus away from the doer and emphasize the action.
Incorporating these grammatical structures into your own speech will help deepen your understanding of English mechanics and improve your overall communication skills.
Common Pronunciation Traps
As you practice, be mindful of certain pronunciation challenges in Walker's speech. Notably:
- Words like "testosterone" can be tricky due to their length and syllable stress. Break it down into manageable parts to practice clarity.
- “Dementia” has a subtle yet significant stress pattern that can alter the word's reception. Ensure you emphasize the second syllable correctly: de-MEN-tia.
- Compound words: Expressions like “sleep deprivation” often trip learners up due to rapid speech. Focus on practicing these within context.
Utilizing this video for improving English pronunciation will be beneficial. Record yourself using a shadowspeaks technique, mimicking Walker's articulation, and play it back to detect nuances in sound.
What is the Shadowing Technique?
Shadowing is a science-backed language learning technique originally developed for professional interpreter training and popularized by polyglot Dr. Alexander Arguelles. The method is simple but powerful: you listen to native English audio and immediately repeat it out loud — like a shadow following the speaker with just a 1–2 second delay. Unlike passive listening or grammar drills, shadowing forces your brain and mouth muscles to simultaneously process and reproduce real speech patterns. Research shows it significantly improves pronunciation accuracy, intonation, rhythm, connected speech, listening comprehension, and speaking fluency — making it one of the most effective methods for IELTS Speaking preparation and real-world English communication.
☕ Buy us a coffee
ShadowingEnglish remains 100% free thanks to your support. Server and AI costs are high — your coffee keeps us going! 🙏