0:00:00.845,0:00:02.350 Thank you very much. 0:00:02.374,0:00:06.373 Well, I would like[br]to start with testicles. 0:00:06.683,0:00:08.293 (Laughter) 0:00:09.198,0:00:11.952 Men who sleep five hours a night 0:00:11.976,0:00:17.229 have significantly smaller testicles[br]than those who sleep seven hours or more. 0:00:17.253,0:00:20.054 (Laughter) 0:00:20.078,0:00:25.157 In addition, men who routinely sleep[br]just four to five hours a night 0:00:25.181,0:00:27.697 will have a level of testosterone 0:00:27.721,0:00:31.054 which is that of someone[br]10 years their senior. 0:00:33.083,0:00:36.844 So a lack of sleep[br]will age a man by a decade 0:00:36.868,0:00:39.653 in terms of that critical[br]aspect of wellness. 0:00:41.939,0:00:46.363 And we see equivalent impairments[br]in female reproductive health 0:00:46.387,0:00:47.804 caused by a lack of sleep. 0:00:51.086,0:00:53.737 This is the best news[br]that I have for you today. 0:00:53.761,0:00:56.437 (Laughter) 0:00:56.461,0:00:58.838 From this point, it may only get worse. 0:00:58.862,0:01:01.642 Not only will I tell you[br]about the wonderfully good things 0:01:01.666,0:01:03.501 that happen when you get sleep, 0:01:03.525,0:01:08.006 but the alarmingly bad things[br]that happen when you don't get enough, 0:01:08.030,0:01:10.561 both for your brain and for your body. 0:01:11.394,0:01:13.808 Let me start with the brain 0:01:13.832,0:01:16.837 and the functions of learning and memory, 0:01:16.861,0:01:20.130 because what we've discovered[br]over the past 10 or so years 0:01:20.154,0:01:23.051 is that you need sleep after learning 0:01:23.075,0:01:26.362 to essentially hit the save button[br]on those new memories 0:01:26.386,0:01:27.686 so that you don't forget. 0:01:28.948,0:01:34.464 But recently, we discovered[br]that you also need sleep before learning, 0:01:34.488,0:01:37.559 and now to actually prepare your brain, 0:01:37.583,0:01:39.639 almost like a dry sponge 0:01:39.663,0:01:42.106 ready to initially soak up[br]new information. 0:01:43.167,0:01:46.279 And without sleep,[br]the memory circuits of the brain 0:01:46.303,0:01:49.074 essentially become[br]waterlogged, as it were, 0:01:49.098,0:01:51.255 and you can't absorb new memories. 0:01:52.179,0:01:54.068 So let me show you the data. 0:01:54.092,0:01:58.345 Here in this study, we decided[br]to test the hypothesis 0:01:58.369,0:02:00.917 that pulling the all-nighter[br]was a good idea. 0:02:02.244,0:02:04.603 So we took a group of individuals 0:02:04.627,0:02:08.174 and we assigned them[br]to one of two experimental groups: 0:02:08.198,0:02:11.655 a sleep group[br]and a sleep deprivation group. 0:02:11.679,0:02:16.299 Now the sleep group, they're going to get[br]a full eight hours of slumber, 0:02:16.323,0:02:18.991 but the deprivation group,[br]we're going to keep them awake 0:02:19.015,0:02:21.165 in the laboratory, under full supervision. 0:02:21.658,0:02:26.038 There's no naps or caffeine, by the way,[br]so it's miserable for everyone involved. 0:02:26.586,0:02:28.115 And then the next day, 0:02:28.139,0:02:32.439 we're going to place those participants[br]inside an MRI scanner 0:02:32.463,0:02:36.249 and we're going to have them[br]try and learn a whole list of new facts 0:02:36.273,0:02:39.572 as we're taking snapshots[br]of brain activity. 0:02:39.596,0:02:41.575 And then we're going to test them 0:02:41.599,0:02:44.083 to see how effective[br]that learning has been. 0:02:44.948,0:02:47.884 And that's what you're looking at[br]here on the vertical axis. 0:02:48.515,0:02:51.195 And when you put[br]those two groups head to head, 0:02:51.219,0:02:56.258 what you find is a quite significant,[br]40-percent deficit 0:02:56.282,0:02:59.758 in the ability of the brain[br]to make new memories without sleep. 0:03:01.044,0:03:02.894 I think this should be concerning, 0:03:02.918,0:03:05.140 considering what we know[br]is happening to sleep 0:03:05.164,0:03:07.583 in our education populations right now. 0:03:08.538,0:03:10.357 In fact, to put that in context, 0:03:10.381,0:03:13.878 it would be the difference[br]in a child acing an exam 0:03:13.902,0:03:16.802 versus failing it miserably -- 40 percent. 0:03:18.294,0:03:22.490 And we've gone on to discover[br]what goes wrong within your brain 0:03:22.514,0:03:25.635 to produce these types[br]of learning disabilities. 0:03:26.759,0:03:28.333 And there's a structure that sits 0:03:28.357,0:03:32.989 on the left and the right side[br]of your brain, called the hippocampus. 0:03:33.013,0:03:34.798 And you can think of the hippocampus 0:03:34.822,0:03:38.059 almost like the informational[br]inbox of your brain. 0:03:38.634,0:03:41.825 It's very good at receiving[br]new memory files 0:03:41.849,0:03:43.324 and then holding on to them. 0:03:44.931,0:03:46.642 And when you look at this structure 0:03:46.666,0:03:49.728 in those people who'd had[br]a full night of sleep, 0:03:49.752,0:03:53.277 we saw lots of healthy[br]learning-related activity. 0:03:54.644,0:03:57.603 Yet in those people[br]who were sleep-deprived, 0:03:57.627,0:04:01.253 we actually couldn't find[br]any significant signal whatsoever. 0:04:02.732,0:04:07.713 So it's almost as though sleep deprivation[br]had shut down your memory inbox, 0:04:07.737,0:04:10.713 and any new incoming files --[br]they were just being bounced. 0:04:11.898,0:04:15.506 You couldn't effectively[br]commit new experiences to memory. 0:04:18.062,0:04:22.561 So that's the bad that can happen[br]if I were to take sleep away from you, 0:04:22.585,0:04:25.657 but let me just come back[br]to that control group for a second. 0:04:26.444,0:04:29.776 Do you remember those folks[br]that got a full eight hours of sleep? 0:04:30.418,0:04:32.894 Well, we can ask[br]a very different question: 0:04:32.918,0:04:36.522 What is it about the physiological[br]quality of your sleep 0:04:36.546,0:04:38.093 when you do get it 0:04:38.117,0:04:41.929 that restores and enhances[br]your memory and learning ability 0:04:41.953,0:04:43.103 each and every day? 0:04:44.004,0:04:46.986 And by placing electrodes[br]all over the head, 0:04:47.010,0:04:51.057 what we've discovered[br]is that there are big, powerful brainwaves 0:04:51.081,0:04:54.700 that happen during[br]the very deepest stages of sleep 0:04:54.724,0:04:57.009 that have riding on top of them 0:04:57.033,0:05:00.307 these spectacular bursts[br]of electrical activity 0:05:00.331,0:05:02.065 that we call sleep spindles. 0:05:03.066,0:05:07.488 And it's the combined quality[br]of these deep-sleep brainwaves 0:05:07.512,0:05:11.973 that acts like a file-transfer[br]mechanism at night, 0:05:11.997,0:05:16.068 shifting memories from a short-term[br]vulnerable reservoir 0:05:16.092,0:05:20.434 to a more permanent long-term[br]storage site within the brain, 0:05:20.458,0:05:23.848 and therefore protecting them,[br]making them safe. 0:05:25.467,0:05:27.506 And it is important that we understand 0:05:27.530,0:05:32.589 what during sleep actually transacts[br]these memory benefits, 0:05:32.613,0:05:36.747 because there are real medical[br]and societal implications. 0:05:36.771,0:05:38.788 And let me just tell you about one area 0:05:38.812,0:05:42.248 that we've moved this work[br]out into, clinically, 0:05:42.272,0:05:45.485 which is the context of aging[br]and dementia. 0:05:46.870,0:05:50.295 Because it's of course no secret[br]that, as we get older, 0:05:50.319,0:05:53.604 our learning and memory abilities[br]begin to fade and decline. 0:05:55.051,0:05:56.669 But what we've also discovered 0:05:56.693,0:06:03.478 is that a physiological signature of aging[br]is that your sleep gets worse, 0:06:03.502,0:06:07.306 especially that deep quality of sleep[br]that I was just discussing. 0:06:08.620,0:06:11.734 And only last year,[br]we finally published evidence 0:06:11.758,0:06:14.717 that these two things,[br]they're not simply co-occurring, 0:06:14.741,0:06:17.559 they are significantly interrelated. 0:06:18.837,0:06:22.124 And it suggests[br]that the disruption of deep sleep 0:06:22.148,0:06:24.442 is an underappreciated factor 0:06:24.466,0:06:28.379 that is contributing[br]to cognitive decline or memory decline 0:06:28.403,0:06:31.981 in aging, and most recently[br]we've discovered, 0:06:32.005,0:06:34.227 in Alzheimer's disease as well. 0:06:36.329,0:06:40.068 Now, I know this is remarkably[br]depressing news. 0:06:40.092,0:06:42.395 It's in the mail. It's coming at you. 0:06:42.419,0:06:44.704 But there's a potential[br]silver lining here. 0:06:45.760,0:06:50.618 Unlike many of the other factors[br]that we know are associated with aging, 0:06:50.642,0:06:54.301 for example changes[br]in the physical structure of the brain, 0:06:54.325,0:06:57.387 that's fiendishly difficult to treat. 0:06:57.411,0:07:01.967 But that sleep is a missing piece[br]in the explanatory puzzle 0:07:01.991,0:07:04.586 of aging and Alzheimer's is exciting 0:07:04.610,0:07:07.348 because we may be able[br]to do something about it. 0:07:08.530,0:07:12.461 And one way that we are[br]approaching this at my sleep center 0:07:12.485,0:07:15.493 is not by using[br]sleeping pills, by the way. 0:07:15.517,0:07:20.446 Unfortunately, they are blunt instruments[br]that do not produce naturalistic sleep. 0:07:21.532,0:07:24.779 Instead, we're actually developing[br]a method based on this. 0:07:24.803,0:07:28.018 It's called direct current[br]brain stimulation. 0:07:28.042,0:07:31.323 You insert a small amount[br]of voltage into the brain, 0:07:31.347,0:07:33.585 so small you typically don't feel it, 0:07:33.609,0:07:35.501 but it has a measurable impact. 0:07:36.826,0:07:43.167 Now if you apply this stimulation[br]during sleep in young, healthy adults, 0:07:43.191,0:07:47.906 as if you're sort of singing in time[br]with those deep-sleep brainwaves, 0:07:47.930,0:07:52.472 not only can you amplify[br]the size of those deep-sleep brainwaves, 0:07:52.496,0:07:57.040 but in doing so, we can almost[br]double the amount of memory benefit 0:07:57.064,0:07:59.098 that you get from sleep. 0:07:59.122,0:08:01.937 The question now[br]is whether we can translate 0:08:01.961,0:08:06.262 this same affordable,[br]potentially portable piece of technology 0:08:06.286,0:08:09.167 into older adults and those with dementia. 0:08:10.726,0:08:15.312 Can we restore back[br]some healthy quality of deep sleep, 0:08:15.336,0:08:19.955 and in doing so, can we salvage[br]aspects of their learning 0:08:19.979,0:08:21.463 and memory function? 0:08:21.487,0:08:23.653 That is my real hope now. 0:08:24.378,0:08:27.383 That's one of our moon-shot[br]goals, as it were. 0:08:29.335,0:08:32.693 So that's an example[br]of sleep for your brain, 0:08:32.717,0:08:35.930 but sleep is just[br]as essential for your body. 0:08:37.276,0:08:40.951 We've already spoken about sleep loss[br]and your reproductive system. 0:08:41.863,0:08:46.725 Or I could tell you about sleep loss[br]and your cardiovascular system, 0:08:46.749,0:08:49.923 and that all it takes is one hour. 0:08:49.947,0:08:55.455 Because there is a global experiment[br]performed on 1.6 billion people 0:08:55.479,0:08:59.756 across 70 countries twice a year, 0:08:59.780,0:09:01.669 and it's called daylight saving time. 0:09:02.907,0:09:06.365 Now, in the spring,[br]when we lose one hour of sleep, 0:09:06.389,0:09:12.008 we see a subsequent 24-percent increase[br]in heart attacks that following day. 0:09:14.952,0:09:18.127 In the autumn,[br]when we gain an hour of sleep, 0:09:18.151,0:09:22.019 we see a 21-percent[br]reduction in heart attacks. 0:09:23.752,0:09:25.432 Isn't that incredible? 0:09:26.929,0:09:32.605 And you see exactly the same profile[br]for car crashes, road traffic accidents, 0:09:32.629,0:09:34.531 even suicide rates. 0:09:36.928,0:09:39.833 But as a deeper dive,[br]I want to focus on this: 0:09:39.857,0:09:42.348 sleep loss and your immune system. 0:09:43.149,0:09:47.991 And here, I'll introduce these delightful[br]blue elements in the image. 0:09:48.015,0:09:51.193 They are called natural killer cells, 0:09:51.217,0:09:56.067 and you can think of natural killer cells[br]almost like the secret service agents 0:09:56.091,0:09:57.702 of your immune system. 0:09:57.726,0:10:02.709 They are very good at identifying[br]dangerous, unwanted elements 0:10:02.733,0:10:04.130 and eliminating them. 0:10:05.253,0:10:09.197 In fact, what they're doing here[br]is destroying a cancerous tumor mass. 0:10:10.586,0:10:16.522 So what you wish for[br]is a virile set of these immune assassins 0:10:16.546,0:10:18.602 at all times, 0:10:18.626,0:10:22.436 and tragically, that's what you don't have[br]if you're not sleeping enough. 0:10:23.825,0:10:25.469 So here in this experiment, 0:10:25.493,0:10:29.322 you're not going to have your sleep[br]deprived for an entire night, 0:10:29.346,0:10:32.857 you're simply going to have your sleep[br]restricted to four hours 0:10:32.881,0:10:34.659 for one single night, 0:10:34.683,0:10:37.684 and then we're going to look to see[br]what's the percent reduction 0:10:37.708,0:10:39.698 in immune cell activity that you suffer. 0:10:40.774,0:10:43.603 And it's not small -- it's not 10 percent, 0:10:43.627,0:10:45.630 it's not 20 percent. 0:10:45.654,0:10:50.226 There was a 70-percent drop[br]in natural killer cell activity. 0:10:51.786,0:10:55.841 That's a concerning state[br]of immune deficiency, 0:10:57.358,0:11:00.175 and you can perhaps understand[br]why we're now finding 0:11:00.199,0:11:04.055 significant links between[br]short sleep duration 0:11:04.079,0:11:07.992 and your risk for the development[br]of numerous forms of cancer. 0:11:09.892,0:11:12.675 Currently, that list includes[br]cancer of the bowel, 0:11:12.699,0:11:15.961 cancer of the prostate[br]and cancer of the breast. 0:11:17.853,0:11:23.209 In fact, the link between a lack of sleep[br]and cancer is now so strong 0:11:23.233,0:11:25.615 that the World Health Organization 0:11:25.639,0:11:29.829 has classified any form[br]of nighttime shift work 0:11:29.853,0:11:33.035 as a probable carcinogen, 0:11:33.059,0:11:35.726 because of a disruption[br]of your sleep-wake rhythms. 0:11:37.830,0:11:40.560 So you may have heard of that old maxim 0:11:40.584,0:11:42.696 that you can sleep when you're dead. 0:11:42.720,0:11:44.790 Well, I'm being quite serious now -- 0:11:44.814,0:11:47.425 it is mortally unwise advice. 0:11:48.375,0:11:53.412 We know this from epidemiological studies[br]across millions of individuals. 0:11:53.436,0:11:55.417 There's a simple truth: 0:11:55.441,0:11:58.845 the shorter your sleep,[br]the shorter your life. 0:11:58.869,0:12:02.424 Short sleep predicts all-cause mortality. 0:12:04.940,0:12:09.109 And if increasing your risk[br]for the development of cancer 0:12:09.133,0:12:11.377 or even Alzheimer's disease 0:12:11.401,0:12:15.577 were not sufficiently disquieting, 0:12:15.601,0:12:19.299 we have since discovered[br]that a lack of sleep will even erode 0:12:19.323,0:12:23.396 the very fabric of biological life itself, 0:12:24.681,0:12:26.673 your DNA genetic code. 0:12:28.038,0:12:31.974 So here in this study,[br]they took a group of healthy adults 0:12:31.998,0:12:35.737 and they limited them[br]to six hours of sleep a night 0:12:35.761,0:12:37.412 for one week, 0:12:37.436,0:12:41.233 and then they measured the change[br]in their gene activity profile 0:12:41.257,0:12:43.701 relative to when those same individuals 0:12:43.725,0:12:46.272 were getting a full eight hours[br]of sleep a night. 0:12:47.451,0:12:49.267 And there were two critical findings. 0:12:50.204,0:12:55.275 First, a sizable and significant 711 genes 0:12:55.299,0:12:57.627 were distorted in their activity, 0:12:57.651,0:12:59.094 caused by a lack of sleep. 0:12:59.923,0:13:03.050 The second result[br]was that about half of those genes 0:13:03.074,0:13:05.517 were actually increased in their activity. 0:13:05.842,0:13:07.771 The other half were decreased. 0:13:08.448,0:13:11.729 Now those genes that were switched off[br]by a lack of sleep 0:13:11.753,0:13:15.242 were genes associated[br]with your immune system, 0:13:15.266,0:13:18.106 so once again, you can see[br]that immune deficiency. 0:13:19.348,0:13:22.421 In contrast, those genes[br]that were actually upregulated 0:13:22.445,0:13:24.817 or increased by way of a lack of sleep, 0:13:24.841,0:13:28.739 were genes associated[br]with the promotion of tumors, 0:13:28.763,0:13:33.914 genes associated with long-term[br]chronic inflammation within the body, 0:13:33.938,0:13:36.740 and genes associated with stress, 0:13:36.764,0:13:39.793 and, as a consequence,[br]cardiovascular disease. 0:13:41.171,0:13:44.831 There is simply no aspect of your wellness 0:13:44.855,0:13:48.122 that can retreat at the sign[br]of sleep deprivation 0:13:48.146,0:13:49.960 and get away unscathed. 0:13:50.912,0:13:53.920 It's rather like a broken[br]water pipe in your home. 0:13:53.944,0:13:57.587 Sleep loss will leak down[br]into every nook and cranny 0:13:57.611,0:13:59.997 of your physiology, 0:14:00.021,0:14:03.926 even tampering with[br]the very DNA nucleic alphabet 0:14:03.950,0:14:06.790 that spells out[br]your daily health narrative. 0:14:09.866,0:14:12.549 And at this point, you may be thinking, 0:14:12.573,0:14:15.105 "Oh my goodness,[br]how do I start to get better sleep? 0:14:15.129,0:14:17.374 What are you tips for good sleep?" 0:14:18.080,0:14:22.558 Well, beyond avoiding[br]the damaging and harmful impact 0:14:22.582,0:14:25.501 of alcohol and caffeine on sleep, 0:14:25.525,0:14:27.962 and if you're struggling[br]with sleep at night, 0:14:27.986,0:14:30.167 avoiding naps during the day, 0:14:30.191,0:14:32.334 I have two pieces of advice for you. 0:14:33.104,0:14:35.918 The first is regularity. 0:14:35.942,0:14:39.343 Go to bed at the same time,[br]wake up at the same time, 0:14:39.367,0:14:42.428 no matter whether[br]it's the weekday or the weekend. 0:14:42.452,0:14:45.197 Regularity is king, 0:14:45.221,0:14:47.182 and it will anchor your sleep 0:14:47.206,0:14:50.518 and improve the quantity[br]and the quality of that sleep. 0:14:52.372,0:14:55.054 The second is keep it cool. 0:14:56.088,0:14:58.515 Your body needs to drop[br]its core temperature 0:14:58.539,0:15:02.752 by about two to three degrees[br]Fahrenheit to initiate sleep 0:15:02.776,0:15:04.856 and then to stay asleep, 0:15:04.880,0:15:07.372 and it's the reason[br]you will always find it easier 0:15:07.396,0:15:09.777 to fall asleep in a room that's too cold 0:15:09.801,0:15:11.045 than too hot. 0:15:12.013,0:15:15.529 So aim for a bedroom temperature[br]of around 65 degrees, 0:15:15.553,0:15:17.507 or about 18 degrees Celsius. 0:15:17.531,0:15:20.298 That's going to be optimal[br]for the sleep of most people. 0:15:22.446,0:15:25.943 And then finally,[br]in taking a step back, then, 0:15:25.967,0:15:29.160 what is the mission-critical[br]statement here? 0:15:30.771,0:15:32.987 Well, I think it may be this: 0:15:33.011,0:15:38.283 sleep, unfortunately,[br]is not an optional lifestyle luxury. 0:15:39.105,0:15:43.652 Sleep is a nonnegotiable[br]biological necessity. 0:15:44.892,0:15:48.483 It is your life-support system, 0:15:48.507,0:15:53.141 and it is Mother Nature's[br]best effort yet at immortality. 0:15:54.709,0:15:59.225 And the decimation of sleep[br]throughout industrialized nations 0:15:59.249,0:16:04.466 is having a catastrophic impact[br]on our health, our wellness, 0:16:04.490,0:16:07.156 even the safety and the education[br]of our children. 0:16:08.323,0:16:11.339 It's a silent sleep loss epidemic, 0:16:11.363,0:16:14.728 and it's fast becoming one of the greatest[br]public health challenges 0:16:14.752,0:16:17.474 that we face in the 21st century. 0:16:20.294,0:16:25.377 I believe it is now time for us[br]to reclaim our right 0:16:25.401,0:16:26.872 to a full night of sleep, 0:16:28.012,0:16:30.169 and without embarrassment 0:16:30.193,0:16:33.592 or that unfortunate stigma of laziness. 0:16:34.638,0:16:40.622 And in doing so, we can be reunited[br]with the most powerful elixir of life, 0:16:42.038,0:16:44.741 the Swiss Army knife[br]of health, as it were. 0:16:46.667,0:16:49.311 And with that soapbox rant over, 0:16:49.335,0:16:51.430 I will simply say, good night, good luck, 0:16:51.454,0:16:52.604 and above all ... 0:16:54.889,0:16:56.651 I do hope you sleep well. 0:16:56.675,0:16:58.033 Thank you very much indeed. 0:16:58.057,0:17:02.588 (Applause) 0:17:02.612,0:17:03.770 Thank you. 0:17:03.794,0:17:06.636 (Applause) 0:17:06.660,0:17:08.203 Thank you so much. 0:17:08.227,0:17:10.970 David Biello: No, no, no.[br]Stay there for a second. 0:17:10.994,0:17:13.546 Good job not running away, though.[br]I appreciate that. 0:17:13.570,0:17:14.814 So that was terrifying. 0:17:14.838,0:17:17.934 Matt Walker: You're welcome.[br]DB: Yes, thank you, thank you. 0:17:18.314,0:17:23.490 Since we can't catch up on sleep,[br]what are we supposed to do? 0:17:23.514,0:17:27.046 What do we do when we're, like,[br]tossing and turning in bed late at night 0:17:27.070,0:17:30.132 or doing shift work or whatever else? 0:17:30.156,0:17:32.497 MW: So you're right,[br]we can't catch up on sleep. 0:17:32.521,0:17:33.846 Sleep is not like the bank. 0:17:33.870,0:17:35.910 You can't accumulate a debt 0:17:35.934,0:17:38.626 and then hope to pay it off[br]at a later point in time. 0:17:38.650,0:17:41.794 I should also note the reason[br]that it's so catastrophic 0:17:41.818,0:17:44.872 and that our health[br]deteriorates so quickly, 0:17:44.896,0:17:47.633 first, it's because human beings[br]are the only species 0:17:47.657,0:17:50.135 that deliberately deprive[br]themselves of sleep 0:17:50.159,0:17:52.548 for no apparent reason. 0:17:52.572,0:17:53.724 DB: Because we're smart. 0:17:53.748,0:17:58.573 MW: And I make that point[br]because it means that Mother Nature, 0:17:58.597,0:18:00.287 throughout the course of evolution, 0:18:00.311,0:18:04.614 has never had to face the challenge[br]of this thing called sleep deprivation. 0:18:05.295,0:18:08.707 So she's never developed a safety net, 0:18:08.731,0:18:10.859 and that's why when you undersleep, 0:18:10.883,0:18:15.217 things just sort of implode so quickly,[br]both within the brain and the body. 0:18:15.241,0:18:18.014 So you just have to prioritize. 0:18:18.038,0:18:21.340 DB: OK, but tossing and turning in bed, 0:18:21.364,0:18:22.775 what do I do? 0:18:22.799,0:18:27.418 MW: So if you are staying in bed[br]awake for too long, 0:18:27.442,0:18:30.695 you should get out of bed[br]and go to a different room 0:18:30.719,0:18:32.032 and do something different. 0:18:32.056,0:18:36.377 The reason is because your brain[br]will very quickly associate your bedroom 0:18:36.401,0:18:38.720 with the place of wakefulness, 0:18:38.744,0:18:41.433 and you need to break that association. 0:18:41.457,0:18:44.354 So only return to bed when you are sleepy, 0:18:44.378,0:18:47.917 and that way you will relearn[br]the association that you once had, 0:18:47.941,0:18:50.449 which is your bed is the place of sleep. 0:18:50.473,0:18:52.132 So the analogy would be, 0:18:52.156,0:18:55.732 you'd never sit at the dinner table,[br]waiting to get hungry, 0:18:55.756,0:18:58.719 so why would you lie in bed,[br]waiting to get sleepy? 0:18:59.548,0:19:01.548 DB: Well, thank you for that wake-up call. 0:19:01.572,0:19:02.741 Great job, Matt. 0:19:02.765,0:19:04.961 MW: You're very welcome.[br]Thank you very much.