WEBVTT - Ep150 "Can We Engineer Dreams?" with Adam Haar Horowitz 0:00:05.200 --> 0:00:07.000 You're going to go to sleep tonight and you're gonna 0:00:07.000 --> 0:00:10.600 have dreams. But what if you could influence what you 0:00:10.760 --> 0:00:14.280 dream about? And as far as remembering what you dreamt about, 0:00:14.520 --> 0:00:17.639 what if you're spending years of your life in a 0:00:17.800 --> 0:00:22.520 world that you never recall. Can nightmares be manipulated as 0:00:22.560 --> 0:00:26.960 a therapy? And our dreams sometimes predictive of changes in 0:00:27.000 --> 0:00:31.000 your health before you become aware of those changes. Today 0:00:31.040 --> 0:00:34.839 we talk with Adam harr Horowitz, a neuroscientist and dream 0:00:35.040 --> 0:00:38.360 engineer who is spending his working days trying to help 0:00:38.400 --> 0:00:45.640 people during their nighttime. Welcome to Inner Cosmos with me, 0:00:45.760 --> 0:00:48.920 David Eagleman. I'm a neuroscientist and an author at Stanford, 0:00:49.000 --> 0:00:51.880 and in these episodes we sail deeply into our three 0:00:51.960 --> 0:00:56.280 pound universe to understand some of the most surprising aspects 0:00:56.360 --> 0:01:15.360 of our lives. So last night I had another dream, 0:01:15.520 --> 0:01:17.880 not uncommon for me, that I was about to give 0:01:17.959 --> 0:01:22.000 a big talk and none of my slides made any sense. 0:01:22.200 --> 0:01:25.200 There was an audience of about four thousand people, they 0:01:25.240 --> 0:01:29.040 were already seated, but I couldn't actually remember what I 0:01:29.080 --> 0:01:31.959 had agreed to talk about at this conference, and my 0:01:32.040 --> 0:01:35.480 computer was acting very strangely, nothing made sense, and I 0:01:35.480 --> 0:01:37.920 couldn't move stuff around on the slides the way that 0:01:37.959 --> 0:01:40.959 I needed to. So the clock was ticking down to 0:01:41.000 --> 0:01:44.720 my entry on stage, and there was a building tightness 0:01:44.720 --> 0:01:48.280 in my chest. And then bang, I woke up and 0:01:48.520 --> 0:01:51.200 here's my normal life and all my responsibilities. And I 0:01:51.240 --> 0:01:55.440 got up and within minutes all of those details dissolved. 0:01:55.520 --> 0:01:58.800 The conference, the lecture hall, the computer, that pit in 0:01:58.800 --> 0:02:01.480 my stomach, all of it slipped away like I was 0:02:01.600 --> 0:02:05.720 trying to hold on to smoke. Now, this kind of 0:02:05.760 --> 0:02:09.280 thing where we are fully and emotionally immersed in some 0:02:09.680 --> 0:02:13.919 bizarre reality, only to come to realize a moment later 0:02:14.080 --> 0:02:17.080 that this was all false. This happens to us every 0:02:17.160 --> 0:02:19.000 night of our lives. And that's what we're going to 0:02:19.000 --> 0:02:24.079 talk about today. What exactly are dreams about. So let's 0:02:24.120 --> 0:02:27.280 start at the beginning. When you close your eyes at night, 0:02:27.400 --> 0:02:30.280 the world in front of you disappears. As you fall 0:02:30.320 --> 0:02:34.880 into sleep, your incoming senses drift away from you, and 0:02:34.919 --> 0:02:37.519 you might think that your brain goes quiet, but that's 0:02:37.600 --> 0:02:42.200 not what happens. Instead, your brain becomes a generator and 0:02:42.280 --> 0:02:46.320 you find yourself somewhere else. You're running through a building, 0:02:46.480 --> 0:02:49.080 or you're talking to someone you know but they have 0:02:49.120 --> 0:02:52.120 a different body, or you're in a bad situation that 0:02:52.160 --> 0:02:54.640 you need to get out of, or whatever. The key 0:02:54.720 --> 0:02:59.120 is that you are inhabiting a reality that feels completely 0:02:59.440 --> 0:03:03.760 real until you suddenly discover that it isn't. So what 0:03:03.919 --> 0:03:07.560 is going on here? Why does our brain construct dreams? 0:03:08.200 --> 0:03:11.040 There are several ideas in the literature, and like many 0:03:11.080 --> 0:03:14.480 things in neuroscience, the answer depends on the level of 0:03:14.639 --> 0:03:18.200 explanation you are asking about. So some years ago I 0:03:18.320 --> 0:03:22.400 proposed a theory about why we dream, called the defensive 0:03:22.520 --> 0:03:25.959 activation theory, and the idea, in a nutshell, is that 0:03:26.440 --> 0:03:30.720 during sleep, when the planet has rotated into darkness, your 0:03:30.880 --> 0:03:36.920 visual cortex needs to stay active, Otherwise, given the brain's plasticity, 0:03:37.280 --> 0:03:41.360 your other senses will begin to invade that territory. So 0:03:41.640 --> 0:03:46.720 dreaming serves as a kind of internal defense mechanism, keeping 0:03:46.760 --> 0:03:51.440 the visual system active in the absence of external input. 0:03:52.040 --> 0:03:54.800 And in our published research we find this allows us 0:03:54.840 --> 0:03:59.200 to make accurate predictions across different species of animals in 0:03:59.320 --> 0:04:02.680 terms of how much of their time they spend in 0:04:02.840 --> 0:04:05.800 rapid eye movement sleep. If you're interested in this, please 0:04:05.880 --> 0:04:09.720 check out episodes eleven and fifty one. Now, that's a 0:04:09.880 --> 0:04:14.960 mechanistic explanation about why the brain shoots activity into the 0:04:15.120 --> 0:04:18.440 visual cortex. In other words, it's about why the brain 0:04:18.520 --> 0:04:22.120 needs to make sure that the lights stay on at night. 0:04:22.960 --> 0:04:27.000 But I've always emphasized that the brain is a storyteller. 0:04:27.400 --> 0:04:30.720 So when your mid brain blasts random activity into your 0:04:30.800 --> 0:04:35.400 visual cortex, you don't see that as random pixels. Your 0:04:35.480 --> 0:04:39.760 brain weaves all of this into a sensory narrative, and 0:04:39.800 --> 0:04:43.039 the content of that narrative depends on what is in 0:04:43.160 --> 0:04:46.960 your brain, from what happened during the day to what's 0:04:47.000 --> 0:04:50.720 been burned deep down into your wiring based on all 0:04:50.720 --> 0:04:53.960 your experience in the world. And this is why you 0:04:54.080 --> 0:04:58.000 dream about your childhood home, or some conversation you had, 0:04:58.320 --> 0:05:01.800 or some fear that you have. And because the connections 0:05:01.800 --> 0:05:05.920 are much looser during dreaming, these stories can take off 0:05:06.000 --> 0:05:09.040 in bizarre directions. And this is the level that we're 0:05:09.080 --> 0:05:12.120 going to talk about today. And this matters because the 0:05:12.320 --> 0:05:15.800 content of dreams shapes how we feel the next day. 0:05:15.839 --> 0:05:20.480 It reflects what we are processing. Your dream content can 0:05:20.960 --> 0:05:25.480 rehearse threats or revisit memories, and sometimes when things go wrong, 0:05:25.760 --> 0:05:29.800 it can trap you in loops of trauma, which means 0:05:30.360 --> 0:05:33.600 dream content is more than just background noise. We're talking 0:05:33.640 --> 0:05:39.760 about experiences that you are having. You've got emotional landscapes 0:05:39.800 --> 0:05:42.719 that you're walking through, And given that you spend about 0:05:42.720 --> 0:05:47.120 a third of your life in this weird Doppelganger state 0:05:47.240 --> 0:05:50.360 of sleep, it's sort of strange that you're having all 0:05:50.440 --> 0:05:55.120 this experience but you remember almost none of it. So 0:05:55.880 --> 0:05:58.800 what if we could access more of that, and what 0:05:58.880 --> 0:06:01.920 if we could at least part shape it. What if 0:06:01.960 --> 0:06:06.800 we could engineer our dreams. Now, for essentially all of 0:06:06.839 --> 0:06:11.000 human history, dreams have felt like something that happens to us. 0:06:11.040 --> 0:06:15.440 They are mysterious and slippery and uncontrollable. But there's a 0:06:15.520 --> 0:06:19.200 growing field at the intersection of neuroscience and psychology and 0:06:19.240 --> 0:06:24.360 technology that's focused on what is called dream engineering. The 0:06:24.400 --> 0:06:27.479 idea is that we might be able to influence what 0:06:27.600 --> 0:06:31.400 we dream about and how we experience those dreams and 0:06:31.440 --> 0:06:35.440 what we recall. So just imagine being able to nudge 0:06:35.480 --> 0:06:38.839 your dreams towards the things that you want to dream about, 0:06:38.880 --> 0:06:43.479 like problem solving or emotional healing. Imagine being able to 0:06:44.000 --> 0:06:48.480 reduce nightmares by reshaping them. These ideas are being tested 0:06:48.520 --> 0:06:52.400 in laboratories and translated into apps, and today we're going 0:06:52.440 --> 0:06:56.640 to explore that frontier. My guest is Adam harr Horowitz, 0:06:56.720 --> 0:06:59.160 a researcher who has been at the center of this movement. 0:06:59.600 --> 0:07:04.120 His work expands from dream inception, in other words, methods 0:07:04.120 --> 0:07:08.480 for influencing your dream content, to interacting with your dreams 0:07:08.480 --> 0:07:12.160 in real time, to technologies for better recall of your 0:07:12.240 --> 0:07:15.400 dream content. Given that so much of your life is 0:07:15.440 --> 0:07:18.520 spent in this internal world, what would it mean to 0:07:18.560 --> 0:07:27.400 take it seriously? Here's my conversation with Adam horror Horowitz. So, Adam, 0:07:27.440 --> 0:07:31.200 tell us about dreams. What is happening when you fall 0:07:31.240 --> 0:07:34.640 asleep at night and you have these crazy cinematic experiences. 0:07:35.000 --> 0:07:39.320 I think dreams at night are basically thinking while you're asleep, 0:07:39.680 --> 0:07:44.240 And so for folks out there, I think thinking about 0:07:44.280 --> 0:07:46.640 your day dreams can be very, very helpful. What's that 0:07:46.800 --> 0:07:50.400 thing that happens when you stop paying attention in a lecture? 0:07:50.960 --> 0:07:53.680 Why is it you start imagining being on a beach 0:07:54.040 --> 0:07:57.520 in Hawaii? Why is it that you leave the place 0:07:57.640 --> 0:08:00.280 you are and you go to a whole different world. 0:08:00.360 --> 0:08:02.680 What is your brain doing? And so I think day 0:08:02.760 --> 0:08:05.320 dreams are the same thing as night dreams. The reason 0:08:05.360 --> 0:08:08.080 the night dreams are way, way weirder is because you're 0:08:08.120 --> 0:08:11.880 not also processing the world. There isn't all this input 0:08:11.920 --> 0:08:13.680 on top of that imagination. 0:08:13.320 --> 0:08:15.240 Totally unanchored from the external. 0:08:14.880 --> 0:08:17.160 Totally unanchored. So a dream is what happens when you're 0:08:17.200 --> 0:08:18.360 completely untethered. 0:08:18.720 --> 0:08:22.120 Yeah, And what is happening in the brain when you 0:08:22.160 --> 0:08:24.160 make a transition into dreaming. 0:08:24.560 --> 0:08:28.840 Yeah, so there is this wild thing happening when you're 0:08:28.840 --> 0:08:29.920 transitioning into dreaming. 0:08:29.920 --> 0:08:31.960 It is a global process. 0:08:32.040 --> 0:08:35.880 So sleep happens, of course in your brain, but your 0:08:35.920 --> 0:08:39.280 breath is changing, the way your eyes are moving is changing, 0:08:39.480 --> 0:08:43.200 your muscle tone is changing, your whole body is changing. 0:08:43.240 --> 0:08:47.600 Sleep is a global, dynamic, complicated process. People sometimes think 0:08:47.640 --> 0:08:50.440 about falling asleep as your brain turning off. It is 0:08:50.520 --> 0:08:54.200 absolutely not turning off. It is so complex, it is 0:08:54.280 --> 0:08:58.120 metabolically super active. Also, there's a lot happening. There's a 0:08:58.160 --> 0:09:00.839 lot of calories being consumed, and so when you start 0:09:00.880 --> 0:09:03.640 falling asleep and you don't have to process the outside world, 0:09:03.920 --> 0:09:06.880 you can start processing internal information instead. 0:09:07.120 --> 0:09:11.600 Yeah, you know, it's like these giant chip making factories, 0:09:11.600 --> 0:09:16.800 computer chips, They switch over the whole factory to manufacture 0:09:16.800 --> 0:09:19.800 something else. And it's this enormous process where they're switching 0:09:19.880 --> 0:09:23.400 everything over. And I think about the transition into dreams 0:09:23.440 --> 0:09:27.480 and into sleep more generally as being this giant turnover. 0:09:27.679 --> 0:09:27.839 WHOA. 0:09:27.960 --> 0:09:29.760 Let me give you an example, which is so fun. 0:09:30.320 --> 0:09:32.960 When you fall asleep, one of the things your brain 0:09:33.000 --> 0:09:35.320 has to do is clear out waste products from during 0:09:35.320 --> 0:09:35.680 the day. 0:09:35.920 --> 0:09:36.600 Because all this. 0:09:36.679 --> 0:09:41.000 Thinking, using all this atp, all this identity and triphosphate, 0:09:41.040 --> 0:09:43.880 the energy that your cells use, it leaves behind waste 0:09:43.920 --> 0:09:45.439 products and you have to clear them out, just like 0:09:45.480 --> 0:09:47.040 you have to clear out waste products from your gut. 0:09:48.080 --> 0:09:52.120 The distance between your neurons will increase by sixty percent 0:09:52.280 --> 0:09:56.080 every night that you fall asleep, so that you can 0:09:56.480 --> 0:09:59.960 wash away that metabolic waste. So literally falling asleep is 0:10:00.200 --> 0:10:04.480 it's that weird. It's like your brain is expanding to 0:10:04.520 --> 0:10:07.000 have these waves of fluid come through and wash you 0:10:07.080 --> 0:10:08.480 clean from the thinking of the day. 0:10:08.480 --> 0:10:10.200 It is a crazy, beautiful process. 0:10:11.120 --> 0:10:14.719 Excellent. So let's go into dreaming, in particular, the cinematic 0:10:14.840 --> 0:10:18.480 emotional kind of thing. Now, traditionally that's been thought to 0:10:18.520 --> 0:10:22.000 happen during rapid eye movement sleep when you can see 0:10:22.080 --> 0:10:24.040 when you're watching somebody sleep that their eyes are moving 0:10:24.080 --> 0:10:27.319 back and forth beneath their eyelids. But tell us the 0:10:28.000 --> 0:10:31.480 modern view about when we're having those cinematic emotional dreams. 0:10:31.559 --> 0:10:32.040 Yeah, so. 0:10:33.520 --> 0:10:35.600 The consensus in the field now is that we're dreaming 0:10:35.720 --> 0:10:39.160 all night, We're not just dreaming in REM. And it 0:10:39.280 --> 0:10:42.760 is true that if you want those biggest, emotional, most 0:10:42.800 --> 0:10:45.360 cinematic dreams, you're most likely to get them in REM, 0:10:45.760 --> 0:10:47.480 but you're most likely to get them in REM at 0:10:47.480 --> 0:10:50.560 the end of the night. So like the most fun 0:10:50.600 --> 0:10:52.640 thing if I tell folks all you want to have 0:10:52.679 --> 0:10:56.800 big dreams, snooze that alarm, Why because you're most likely 0:10:56.840 --> 0:10:59.320 to have super dense REM right there in the morning. 0:10:59.800 --> 0:11:02.800 But also it looks like in those last two hours 0:11:02.800 --> 0:11:06.200 of sleep, your non REM dreams look very cinematic, look 0:11:06.320 --> 0:11:10.160 very emotional, look very vivid, have first person narratives. They're 0:11:10.160 --> 0:11:12.680 hard to distinguish. So I think the big takeaway is 0:11:12.960 --> 0:11:15.840 you're dreaming all night, and sleep staging needs to get 0:11:15.840 --> 0:11:17.760 a little smarter to tract those dreams. But if you 0:11:17.800 --> 0:11:20.640 want to make a good bet and you're watching a 0:11:20.679 --> 0:11:22.480 partner a kid sleep and you want to get a 0:11:22.480 --> 0:11:24.640 big dream report, and you see those eyes moving, it's 0:11:24.640 --> 0:11:25.719 a good time to wake them up. 0:11:25.880 --> 0:11:28.559 Cool, So why are dreams so bizarre? 0:11:29.720 --> 0:11:30.040 Great? 0:11:30.160 --> 0:11:33.520 So I think you can't answer this question without asking 0:11:33.559 --> 0:11:36.839 about what dreaming is doing in general. And so I 0:11:36.960 --> 0:11:40.560 like a theory called the next up theory, which is 0:11:40.600 --> 0:11:45.920 that network exploration to understand possibilities. And this bobstickled and 0:11:45.960 --> 0:11:49.520 Tony's odra, I'm too wonderful scientists. And the basic idea 0:11:49.679 --> 0:11:54.080 is that, Okay, we go around all day collecting all 0:11:54.120 --> 0:11:57.160 this information into short term memory, but somehow that information 0:11:57.200 --> 0:11:59.160 has to leave short term memory and get integrated into 0:11:59.160 --> 0:12:01.480 the story of our lives. And you can't do that 0:12:01.520 --> 0:12:05.520 integration while you're processing the world around you. So you're 0:12:05.520 --> 0:12:09.040 too busy taking information in into short term memory, things 0:12:09.040 --> 0:12:10.800 that are happening to you right now, prossing the world, 0:12:10.880 --> 0:12:13.880 the physics, the possibilities, the dangers. At night, your eyes 0:12:13.880 --> 0:12:16.319 are closed at night, you're still you don't need to 0:12:16.320 --> 0:12:18.120 be doing any of that work. So what you're doing 0:12:18.160 --> 0:12:21.440 at night is taking that information you learn today and 0:12:21.559 --> 0:12:25.600 fitting them into the memory networks of your whole story 0:12:25.640 --> 0:12:28.520 of your life in particular, so you can predict all 0:12:28.559 --> 0:12:30.800 the possibilities of what's going to happen tomorrow and next 0:12:30.800 --> 0:12:33.720 week and a month later. So we're having this conversation. 0:12:34.160 --> 0:12:37.040 I'll store it in short term memory, but it kind 0:12:37.080 --> 0:12:39.679 of reminds me of that time that I got interviewed 0:12:39.840 --> 0:12:42.160 to get into high school to have this exam, and 0:12:42.200 --> 0:12:43.920 it was kind of intense and emotional. But it's like 0:12:43.960 --> 0:12:45.560 a little bit like this in my stomach. It kind 0:12:45.559 --> 0:12:47.520 of feels stressful, but it's like not that stressful. It's 0:12:47.520 --> 0:12:49.839 like kind of different. I have to understand the similarities 0:12:49.840 --> 0:12:51.760 and the difference is, So maybe tonight I have a dream, 0:12:52.200 --> 0:12:54.360 and that dream is you and me sitting here, but 0:12:54.400 --> 0:12:57.360 you're my high school counselor, and so at night I'm 0:12:57.400 --> 0:13:01.200 associating these things largely based on So dreams are largely 0:13:01.200 --> 0:13:04.840 emotion driven, and I'm trying to fit these memories together 0:13:05.240 --> 0:13:07.760 so I can make sense of the story of my life. 0:13:08.040 --> 0:13:11.160 Because our job isn't and you know this as an neuroscientist, 0:13:11.320 --> 0:13:13.720 our job isn't to store all the information we've ever 0:13:13.760 --> 0:13:16.520 gotten from the world. Our job is to extract patterns. 0:13:16.880 --> 0:13:21.280 Extracting patterns relies on making associations those associations are driven 0:13:21.640 --> 0:13:24.360 by feelings. This is something that Antonio Dimasio writes about 0:13:24.360 --> 0:13:27.199 so beautifully in the feeling of what happens, Dreaming is 0:13:27.240 --> 0:13:30.800 the same thing. Dreaming is a feelings driven association to 0:13:30.880 --> 0:13:33.200 make sense of your day. And you can do it 0:13:33.559 --> 0:13:36.680 because you're not processing all the potholes and hot coffees 0:13:36.720 --> 0:13:38.400 and things that are in front of your face while 0:13:38.400 --> 0:13:38.760 you're awake. 0:13:39.000 --> 0:13:42.000 Great, and so this is what the field calls consolidation, 0:13:42.160 --> 0:13:44.880 where you take all this stuff and you burn it 0:13:44.920 --> 0:13:48.240 into the rest of the system. Okay, so the reason 0:13:48.360 --> 0:13:50.640 that dreams are so bizarre is because of these weird 0:13:50.679 --> 0:13:55.040 associations that are happening while you're stitching this stuff into 0:13:55.200 --> 0:13:56.120 what you already know. 0:13:56.400 --> 0:13:56.679 Yeah. 0:13:56.720 --> 0:14:00.440 So the reason I think dreams are so bizarre you 0:14:00.440 --> 0:14:03.479 can think about as a kind of network or node association, 0:14:03.559 --> 0:14:05.760 a kind of tree of exploration. The first thing you 0:14:05.800 --> 0:14:09.040 want to do with this interaction us sitting here together 0:14:09.120 --> 0:14:13.440 is think of the most similar memories. Oh, okay, sitting 0:14:13.480 --> 0:14:15.680 here is sort of like how I sat in the 0:14:15.720 --> 0:14:18.120 chair this morning, and they feel a little bit similar. Okay, 0:14:18.120 --> 0:14:21.280 I'm gonna associate those two memories. But the longer you 0:14:21.320 --> 0:14:24.520 spend to sleep. The more times you have an altradean cycle, 0:14:24.640 --> 0:14:27.040 the more times you wake up and go back to sleep, 0:14:27.440 --> 0:14:29.880 the more bizarre those things are going to get. So 0:14:29.920 --> 0:14:33.160 that you can understand the most wild and wild and 0:14:33.240 --> 0:14:36.640 wild possibilities of what might happen the next day. And 0:14:36.680 --> 0:14:39.320 the idea here is kind of simple. It's that you 0:14:39.480 --> 0:14:43.320 want to have the widest net of possibilities so that 0:14:43.360 --> 0:14:45.960 you're not surprised when you wake up the next day 0:14:46.000 --> 0:14:48.120 by what happens. You want to be able to predict 0:14:48.520 --> 0:14:52.320 everything that happens tomorrow, and so tonight I rehearse all 0:14:52.360 --> 0:14:54.640 the possible scenarios that are similar to this. And the 0:14:54.720 --> 0:14:59.560 idea is simply that being surprised costs you a lot 0:14:59.560 --> 0:15:03.320 of calories you have to learn. But if you've already 0:15:03.360 --> 0:15:06.680 predicted tomorrow how something's going to feel, what it reminds 0:15:06.680 --> 0:15:08.680 you of, so that you're not surprised the next time 0:15:08.720 --> 0:15:11.200 you sit down in an interview, it basically isn't as 0:15:11.200 --> 0:15:14.200 surprising and doesn't cost you as many calories to understand it. 0:15:14.240 --> 0:15:19.280 So dreaming is a way to explore short term, long term, 0:15:19.480 --> 0:15:22.440 less bizarre and more bizarre associations between a memory and 0:15:22.480 --> 0:15:25.560 experience and all the possible experience that it could be like, 0:15:26.040 --> 0:15:27.480 so that I can predict them happening. 0:15:28.000 --> 0:15:30.880 What about nightmares? What's the story with nightmares? 0:15:31.000 --> 0:15:35.760 Yeah, So the idea is that dreams, when they're working well, 0:15:36.320 --> 0:15:39.040 are a way to integrate today into the story of 0:15:39.040 --> 0:15:42.000 my life and make it make sense. And memory consolidation 0:15:42.240 --> 0:15:46.760 keeping memories, memory evolution, extracting patterns from those memories, and 0:15:46.920 --> 0:15:51.240 just from those memories. Nightmares are when that memory consolidation 0:15:51.320 --> 0:15:55.840 evolution breaks. And so the kind of canonical nightmare that 0:15:56.040 --> 0:15:58.880 folks in my field worry about are these trauma related nightmares, 0:15:58.880 --> 0:16:01.800 and they're often treatment resistant, and so what they look 0:16:01.920 --> 0:16:05.240 like is somebody has an experience and that's a traumatic experience. 0:16:06.240 --> 0:16:09.680 And these dreams are weird because they're not a metaphor, 0:16:10.080 --> 0:16:13.160 they're not a narrative, and they don't change. People have 0:16:13.280 --> 0:16:16.720 the same experience at night that they had during the day, 0:16:17.240 --> 0:16:19.080 and it's like that memory is not evolving. 0:16:19.480 --> 0:16:20.480 It's like you're going back. 0:16:20.640 --> 0:16:23.040 He was chasing me down the hall with the knife, 0:16:23.320 --> 0:16:26.160 just like he did in real life. And every night 0:16:26.480 --> 0:16:28.720 I go to sleep and I know that he's going 0:16:28.800 --> 0:16:30.080 to chase me down the hall with the knife. So 0:16:30.120 --> 0:16:33.280 I actually got into this field because I had a 0:16:33.280 --> 0:16:37.200 traumatic experienced little kid, a violent mugging experience, and I 0:16:37.320 --> 0:16:41.480 had these traumatic nightmares, and a therapist and my mom 0:16:41.680 --> 0:16:44.800 really helped me with it, and helped me by basically 0:16:44.960 --> 0:16:47.600 telling me bedtime stories. We can get into how that 0:16:47.680 --> 0:16:51.240 works in a second, but I had personal experience these nightmares. 0:16:51.440 --> 0:16:52.880 They happen every night, and so. 0:16:52.800 --> 0:16:57.320 That memory can't evolve, that memory can't lose its emotional power, 0:16:57.320 --> 0:17:00.240 that memory can't be integrated into the networks of your 0:17:00.280 --> 0:17:03.160 whole life's story. It just returns every night, and it's 0:17:03.200 --> 0:17:06.920 like an exposure every night. And those nightmares are really stressful. 0:17:07.320 --> 0:17:09.800 You can see that they're stressful all the way from 0:17:10.520 --> 0:17:14.480 cortisol levels to them predicting levels of suicidality and depression 0:17:14.480 --> 0:17:17.600 and dementia and Alzheimer's. Nightmares are really really, really bad 0:17:17.680 --> 0:17:20.720 for you, and so their treatment target. But I think 0:17:20.720 --> 0:17:24.720 of nightmares basically as that memory integration system not quite 0:17:25.119 --> 0:17:27.840 working and instead getting stuck on the memory because it's 0:17:27.880 --> 0:17:28.919 so emotionally charged. 0:17:29.960 --> 0:17:32.159 And let's zoom in on that for a second. About 0:17:32.640 --> 0:17:35.840 predicting dementia, tell us this quite surprising result. 0:17:36.000 --> 0:17:39.760 It's really interesting. So This is a research mostly from 0:17:39.760 --> 0:17:43.520 a person named Obademi O tai Ku. That takeaway is 0:17:43.560 --> 0:17:50.439 that across dementia, across Alzheimer's, across even early death before 0:17:50.560 --> 0:17:54.000 seventy five. If you ask people on a set of 0:17:54.080 --> 0:17:56.480 questionnaires called a PSQI, which you ask everyone about their 0:17:56.480 --> 0:18:00.680 sleep quality, there's this one question, do bad dream make 0:18:00.720 --> 0:18:02.600 your sleep worse at night or keep you up at night? 0:18:03.240 --> 0:18:04.199 If they endorse that. 0:18:04.480 --> 0:18:06.840 If they say yes, bad dreams keep me up at night, 0:18:07.600 --> 0:18:11.200 people seven years later are more likely to have cognitive decline. 0:18:11.800 --> 0:18:15.720 Fifteen years later are more likely to have Parkinsons. They're 0:18:15.720 --> 0:18:20.120 more likely to die early. The reason is kind of obvious, 0:18:20.200 --> 0:18:22.960 which is that during the day, if you spend a 0:18:23.000 --> 0:18:25.280 lot of your time stressed out, we already know it 0:18:25.280 --> 0:18:28.200 has all these consequences in terms of inflammation, in terms 0:18:28.240 --> 0:18:30.040 of physical health during the day. 0:18:30.080 --> 0:18:30.680 It's not weird. 0:18:30.680 --> 0:18:34.040 We think, oh, my psychological health affects my physical health. 0:18:34.240 --> 0:18:36.800 Being stressed out up here changes my whole body. We 0:18:36.880 --> 0:18:40.520 know that it's a treatment target. We haven't really figured 0:18:40.560 --> 0:18:45.000 out the link between stress at night in dreams and 0:18:45.040 --> 0:18:48.040 stress in the body, but it looks like where your 0:18:48.040 --> 0:18:51.719 body should be repairing, whether it's your immune system at 0:18:51.800 --> 0:18:55.399 night or fighting inflammation at night. Instead you're rehearsing the 0:18:55.480 --> 0:18:58.320 worst moments you've ever had and going back to them. 0:18:58.320 --> 0:19:01.359 And so there are these consequences in terms of brain health, 0:19:01.400 --> 0:19:03.120 these consequences in terms of physical health. 0:19:03.520 --> 0:19:05.280 Is there a way for us to know the arrow 0:19:05.400 --> 0:19:06.560 of causality? There? 0:19:06.760 --> 0:19:07.200 Totally? 0:19:07.359 --> 0:19:11.080 So, I mean, the thing you can do is you 0:19:11.119 --> 0:19:14.680 can look at confounding factors. So these things that I mentioned, oh, 0:19:14.920 --> 0:19:18.880 nightmares and stress dreams predict cognitive decline dementia. Those are 0:19:18.960 --> 0:19:24.040 independent of depression, anxiety. Those are independent of sleep quality 0:19:24.040 --> 0:19:26.960 and sleep efficiency and sleep duration. You can be sleeping 0:19:26.960 --> 0:19:29.399 the right amount of hours, but these nightmares are the 0:19:29.480 --> 0:19:32.240 distinguishing factor in terms of whether you are or not 0:19:32.280 --> 0:19:35.000 gonna have cognitive decline later on. So one of the 0:19:35.040 --> 0:19:37.920 ways you look at is confounding factors. The better way 0:19:37.920 --> 0:19:40.720 to determine causality is help with the nightmares, see if 0:19:40.720 --> 0:19:43.359 it changes things. So the kind of amazing punchline is 0:19:43.600 --> 0:19:47.760 there's a behavioral therapy called imagery rehearsal therapy. 0:19:47.920 --> 0:19:49.200 You take the nightmare. 0:19:49.560 --> 0:19:51.920 Oh, he was chasing me down the hall with the 0:19:52.000 --> 0:19:53.879 knife and it was night time and I was running, 0:19:53.880 --> 0:19:56.520 and you stop and say, hey, what if it was daytime? 0:19:57.880 --> 0:19:59.760 You ask the patient this during the day. 0:20:00.080 --> 0:20:03.000 Yeah, you're sitting with them and they tell you about 0:20:03.040 --> 0:20:06.720 their nightmare that they're having every night. Okay, he's chasing 0:20:06.760 --> 0:20:08.600 me down the hall with the knife and it's nighttime 0:20:08.640 --> 0:20:11.200 and I'm running. Okay, what if it was daytime? They said, no, 0:20:11.280 --> 0:20:13.760 it wasn't daytime. No, no, no, okay, but we're we're going 0:20:13.800 --> 0:20:17.359 to try to change it. And you write down, okay, 0:20:17.440 --> 0:20:20.239 chasing me, but it's daytime, and then you rehearse it, 0:20:20.359 --> 0:20:21.680 and then you repeat it, and then you write it 0:20:21.680 --> 0:20:23.320 down again, and you rehearse it, and before bed, they 0:20:23.320 --> 0:20:24.879 rehearse it again, and you do it rehearsing. 0:20:25.200 --> 0:20:26.640 They think through that scenario. 0:20:26.640 --> 0:20:27.280 Okay, that's right. 0:20:27.720 --> 0:20:30.960 They really imagine it, really imagine it chasing, but it's daytime. 0:20:32.000 --> 0:20:34.080 Do it for three or four nights, and eventually the 0:20:34.240 --> 0:20:35.760 nightmare will change. 0:20:36.840 --> 0:20:37.760 They're still getting. 0:20:37.520 --> 0:20:39.880 Chased, but it's the day and they will wake up 0:20:40.200 --> 0:20:43.560 and they will say, oh my god, it's not happening 0:20:43.600 --> 0:20:47.080 to me. I'm making that dream, I'm making that nightmare. 0:20:47.320 --> 0:20:50.560 And so there's this sudden shift in agency what people 0:20:50.600 --> 0:20:54.040 call self efficacy or internal locus of control. I'm in control. 0:20:54.080 --> 0:20:55.680 I'm not a victim of my nightmare every night, and 0:20:55.680 --> 0:20:58.359 anyway it's not happening to me, I'm making it. And 0:20:58.400 --> 0:21:01.280 so then off what will happen is people will stop 0:21:01.280 --> 0:21:04.480 having the nightmares entirely. But also there's a difference between 0:21:04.520 --> 0:21:07.520 having nightmare and being distressed about the nightmare, and saying 0:21:07.560 --> 0:21:11.920 I'm in control changes everything about distress. So in terms 0:21:11.960 --> 0:21:16.879 of causality, it is very clear that, for instance, helping 0:21:16.880 --> 0:21:21.320 people with imagery rehearsal therapy, changing their nightmares, changing the 0:21:21.400 --> 0:21:24.440 level of joy and their dreams will predict, for instance, 0:21:24.480 --> 0:21:28.280 suicidality a day later, a week later, six months later, 0:21:28.920 --> 0:21:30.600 is really important for waking behavior. 0:21:44.040 --> 0:21:45.840 One more question before we move on to the next thing. 0:21:46.000 --> 0:21:48.679 I have nightmares occasionally, not very often, but when I do, 0:21:48.760 --> 0:21:52.239 they're not predicated on real memories. So how does that 0:21:52.280 --> 0:21:55.040 fit with the story that you mentioned about a memory 0:21:55.040 --> 0:21:55.919 that's embedded. 0:21:56.080 --> 0:21:56.600 Yeah, totally. 0:21:56.720 --> 0:21:59.639 So I think it's useful to think of these trauma 0:21:59.680 --> 0:22:04.080 related repetitive nightmares as pretty distinct from the nightmares that 0:22:04.119 --> 0:22:06.640 all of us have sometimes. And then also within that 0:22:07.400 --> 0:22:10.600 dream science says a bad dream happens all the time 0:22:10.640 --> 0:22:12.960 to everyone. The majority of dreams are negative, actually, like 0:22:12.960 --> 0:22:14.439