The Ancient Dream Dictionary Was Basically Google

The Nightly World You Forget

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There's a moment every night when something strange happens. You disappear. Your bedroom is still there. Your body is still under the blankets. The clock keeps moving, but you might be standing in a house you've never seen before, talking to someone who died years ago, or running from something you can't quite see. You might be flying or falling, or living through an entire story that feels completely real. Right up until you open your eyes. And for a few seconds, you just lie there, trying to figure out where you are. Because just a few minutes ago, somewhere else felt real too. That might be the weirdest part. Your brain can create people who don't exist, places you've never visited, conversations no one has actually had. It can make you terrified of something that isn't even there, or make you miss someone who was never in the room. And all while this is happening, you usually have no idea that your brain is the one doing it. So why does it do it? Why every night does the human mind become a storyteller? Are these strange little movies just neurological static? Are they memories being shuffled around? Or are they emotions being processed? Maybe they're practice for dangers that just might never show up. Or are dreams doing something we still don't completely understand? Because humans have been waking up from dreams for thousands of years. And they always ask the same question: what was that? So tonight, being one o'clock in the morning, and I'm recording for some reason, we're gonna follow the rabbit hole into the place that you visit every single night, but you can never quite bring it back with you. We're gonna go down the rabbit hole of dreams.

Why Dreams Felt Like Messages

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I'm Andrew Perry, and this is the show where we follow ordinary questions as far as they'll take us, usually to something extraordinary. But tonight we're gonna talk about dreams. And I'm not talking about dream interpretation, we're gonna go a lot deeper than that. Because dreaming isn't just strange, it's ancient, it's been around forever. Every human being there's ever been, and most animals, have had dreams. Kings, soldiers, scientists, everyone in between. People sleeping in caves a thousand years ago surely woke up confused by the same impossible experiences that we do now. And for most of human history, nobody had any idea where those experiences came from. Some thought they were messages, some thought they were warnings or visits from the dead, glimpses into another world. For a thousand years, those were perfectly reasonable possibilities. And then science showed up, with electrodes and sleep labs, brain scans, and a whole new set of questions. And somehow dreams got even weirder after that. Because now we know a surprising amount about what the brain is doing while we dream. Think about that. Now we know when certain dreams are most likely to happen. We know when parts of the brain become incredibly active. We know other parts can get real quiet. We can even watch pieces of the process unfolding. But there's still one huge question sitting in the middle of all of it. Why? Why does a sleeping brain bother creating a world at all? To answer that, we gotta go backward. Like way back. Way before sleep labs, and before anybody even knew what a neuron was. We gotta go back to a time when waking up from a dream might have felt like receiving a message from somewhere beyond the edge of the known world.

Egypt’s Dream Book And Omens

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And apparently they thought it was important enough to look up. Now that part seems kind of familiar. Now they didn't have a phone or Google or any of that stuff. Like we would search what does it mean when your dream like when you dream your teeth fall out. But they had something else. A dream book. And somehow that feels even weirder than what we would do. So uh it was a papyrus now known as the Chester Beity Dream Book. And it was written around 1220 BC during Egypt's 19th dynasty. It's basically an ancient dream dictionary. Line after line just starts with roughly the same idea. If a man sees himself in a dream, and then comes the dream, and then a verdict after that. Good or bad, and then what it supposedly means. The surviving manuscript contains more than 200 interpretations. And these aren't vague philosophical ideas, they're weirdly specific. Like you see yourself looking out a window? Good. See your bed catching fire? Bad. Definitely bad. Which, to be fair, feels like one ancient interpretation we probably didn't need a papyrus to figure out, but the important thing is not whether any of these predictions were right. It's that somebody wrote them down. And then somebody else kept them. And then somebody else owned the same papyrus after that. This thing appears to have been passed through a whole family for generations. Dreams mattered enough to preserve, so I guess to them it was very important. And Egypt wasn't really alone. Way before anybody understood REM sleep or uh knew the brain was made of billions of cells firing electrical signals. People across the ancient world were trying to answer the same question. We still ask when we wake up from a weird dream, what did that mean? But there was an enormous difference between them and us. So today, when you have a strange dream, you probably assume your brain made it. You might not understand why, but you know where it came from. They didn't. Think about how bizarre dreaming would be without that assumption. You close your eyes and your body stops moving, and then suddenly your dead father is standing in front of you. He speaks, you can hear his voice, maybe he tells you something, and then you wake up. If nobody has ever explained neurons or memory or unconscious brain activity to you, why would your first thought be, my brain generated a convincing internal simulation using stored sensory information? It probably wouldn't. You might think your father actually visited you. And once you allow that possibility, dreaming starts to turn into something a lot bigger than just dreaming. It starts to become communication. Maybe the gods can speak while you sleep. Or maybe the dead can come back. Maybe dreams can warn you about illnesses or sicknesses or whatever's coming your way. They might be able to tell the future. And we can see versions of that idea all over the ancient world. Dreams show up in some of humanity's oldest surviving stories. Like in ancient Mesopotamia, in their traditions, dreams could be treated as omens. They could be studied and interpreted. Uh they were compared against earlier dreams. So people built systems for figuring out what these nighttime experiences might be trying to say. Now that tells us something kind of interesting. Humans didn't just dream, we started collecting them. Like we were categorizing dreams and we were looking for patterns, trying to turn something chaotic into something understandable, which is pretty much what humans do with everything. Like we always want to know why something is happening. Like thunder needs an explanation. And diseases, they really need an explanation. And stars. We've been trying to explain stars forever. And every single night, another unexplained thing was happening inside of our own heads. Except nobody knew that it was happening inside our heads. So naturally, I mean, we started to look outwards. So I guess I get it. They were looking towards the gods, and spirits and prophecies and fate, and eventually, entire cultures developed around the idea that certain dreams might deserve attention.

Greek Healing Dreams And Prophecy

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In the Greek and Roman world, dreams could influence decisions and medicine and religion, sometimes even military strategy. Some people deliberately slept in sacred places, and they would just hope that a god might appear to them in a dream. So uh a lot of followers in in Greece, one of the Greek gods, he was associated with healing. Oh, I forgot what his name was. I think it's like Aslepius or something like that. I don't remember exactly what it was, but he was a Greek god associated with healing, and he practiced forms of ritual sleep in which where dreams could be interpreted as guidance about illness or treatment. And that's how seriously people took this. Like, you don't necessarily go to sleep hoping to get eight uninterrupted hours. You might go to sleep hoping that somebody could tell you how to get better. So, according to the Cambridge University Press, that's what they would do. You could go to sleep and you would just hope that somebody would come to you in a dream to tell you how to get better from whatever was wrong with you, whatever illness that you had. And a lot of the rulers paid attention to that too. Alexander the Great reportedly travel with Aristander of Telemussos, and he was a professional seer known for interpreting dreams and omens. According to later accounts, Alexander had a dream while he was struggling to capture the city of Tyre.

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In the dream, he saw a satyr.

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Aristander supposedly turned the Greek word for satyr into a bit of wordplay that sounded like Tyre is yours. Which is either a really smart interpretation or history's most just consequental dad joke. I mean, I get it. Like Alexander so he eventually captured Tyre in 332 BC. But did the dream predict it? Was the question, and there's no way to know. And the surviving story was written down later, so we should be kind of careful about treating every single detail as eyewitness history. But that isn't really the interesting part. The interesting part is that people believed a dream was important enough to include in the story of a whole military campaign.

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Like dreams belonged in history. And eventually somebody tried to organize all this.

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So in the second in second century AD, a man named Artimodorus traveled from the Greco-Roman world collecting information about dreams. He talked to everybody he could come into contact with. He was studying any earlier writing he could find. He collected all the interpretations, and then he produced five books worth of work. And I don't even know how to say the name of this book because I've tried a few times and I can't find anybody who actually pronounces it. But the interpretation of dreams is what it kind of translated out to. And nearly 2,000 years before like before anybody was on Facebook or doing that any of those explaining videos on YouTube. That's I mean they were saying dreaming about water means change is coming.

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Like there were already professionals that were doing that way back then. But Artemidorus noticed something a little bit off.

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He said, not every dream could mean the same thing for every person. Who you were mattered, your job mattered, your circumstances mattered. A symbol that might be fortunate for one person could mean something completely different for someone else. And that kind of sounds surprisingly modern, I guess. Not because Artimodorus had discovered neuroscience, because he hadn't, but because the dream was slowly becoming connected to the dreamer. And that's a tiny shift with huge consequences. Like, because for thousands of years, the most important question about a dream had been, what is this trying to tell me? But eventually another question started creeping in in the first place. What if the dream isn't a message from somewhere else? But what if it has something to do with you? Like your body and your memories, your fears, your experiences, and your mind. That idea changed everything for them because now they were no longer asking what's waiting for us on the other side of sleep. We're asking what's happening inside the person doing the sleeping. And once humans actually started looking into that and looking in that direction, the mystery behind dreams was about to get a lot more weird.

Aristotle And Descartes On Dream Reality

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But more than 2,000 years ago, one man started wondering whether everyone else was looking in the wrong direction. And we find ourselves again at Aristotle. We've talked about Aristotle on several of these episodes, and Aristotle had a problem with prophetic dreams. And it's not because dreams weren't fascinating, he really did think they were. But he wrote he wrote entire books about sleep and dreaming and whether dreams could predict a future, but he was skeptical that the gods were sending them. His reasoning was, I mean, surprisingly practical. If the gods wanted to communicate with humans, why send important messages through little inconsistent movies that happen to basically everybody? Why would divine revelation be mixed in with dreams about food and arguments and random people? And whatever other junk that the sleeping mind happens to produce. Aristotle started looking for another explanation, and eventually he suggested something kind of radical. Maybe dreams were created by the dreamer. Now he thought sensations experienced while we were awake could just leave behind something like traces, like little echoes of perception that you didn't notice at the time. And when the outside world became quiet enough during sleep, those leftover impressions could continue moving through us. And they they put produce images and experiences and dreams. He wasn't describing neurons because he didn't know anything about them, but some of the biology that Aristotle proposed was completely wrong. But when you dig into it and down in there, buried inside of it, was an idea that feels really, really important now. Like maybe a dream doesn't just show up, maybe you build it, like it's assembled. And that changes the question. Because if dreams come from us, then somewhere inside a dream might be pieces of our waking lives. And humans spent the next couple thousand years trying to figure out exactly what those pieces were. They were trying to figure out if they were memories or physical sensations or emotions, even desires. The answers changed, but the idea never really disappeared. A cold bedroom couldn't influence a dream. The sound outside could become part of the story. You know what I mean? Like if you ever had something happen while you were asleep and you kind of brought it into your dream with you, that's what they're talking about. And they were saying like different things like indigestion might just make some weird imagery in your dreams. Something you saw earlier in the day might show back up hours later while you were asleep. It's very weird to think about, but it makes a weird problem. Because your brain is it's capable of taking something real and changing it and moving it, and then combining it with something else, and then handing the finished product back to you as an experience you completely believe. Which sounds pretty similar to the last episode we did about memory. But then centuries later, another philosopher kind of took that problem in an entirely different direction. So Rene Descartes wondered, how could you be absolutely certain that you were awake at all? I mean, think about it. You've probably had a dream where you were completely convinced that everything was real. Maybe you were sitting in a room or walking down the street, talking to somebody. There's nothing really weird happening to clue you in that it is a dream, and then you woke up. And suddenly you would realize that none of it had happened. So what exactly was missing while you were dreaming? You could see, you could hear and feel and think, and all that stuff. There was a whole world around you, and you You didn't know that it wasn't real. Which is the weird part. Descartes was not really trying to explain why we dreamed. He was using dreams to solve a lot a much bigger philosophical question. How do we know anything is real? Which is an absolutely horrifyingly awful thought to have at 2 o'clock in the morning.

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But it revealed something important. Dreams weren't just stories anymore.

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They were evidence that your brain could convincingly create reality, and yet we still don't know why.

Freud’s Breakthrough Dream And Meaning

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So in the summer of 1895, there was a physician in Vienna. He had a dream that would change the conversation one more time. Most of you will know him because you had to learn about him in high school. His name was Sigmund Freud. And before we go any any further, yeah, I know. That Freud with the cigar and the couch and all that, the guy whose name eventually became shorthand for explaining basically everything in your whole entire childhood. But before b before Freud became Freud, he was just a doctor trying to understand the mind.

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And one night something bothered him.

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Freud had been treating a patient who he called Irma in his later writings, but her treatment hadn't gone the way he wanted it to. Then when Freud's colleagues visited he visited that I can't talk today, guys. Okay, so we'll start that over again. Since apparently I just can't talk tonight. I don't know what's going on. But so Freud was treating that patient, and he called her Irma, and a lot Of the times it was later on they figured out that he called her Irma, but either way, so we got to the part where her treatment wasn't going the way he wanted it to, and then one of Freud's colleagues visited him and mentioned that Irma was doing better. And he wasn't. They mentioned that Irma was doing better, but not completely well. So Freud heard something in that comment, and it was criticism, maybe even blame, I guess, because Freud thought he failed her. So that night, Freud sat down and wrote out her case in entirety, like every bit of history he could think of. Almost like he was preparing for like a defense of himself. And then he went to sleep. Now, during the night of July 23rd into July 24th, 1895, Freud had a dream. He was in a large hall and there were a bunch of guests everywhere, and Irma was also there. Now he confronted her in the dream. She complained about terrible pain, and Freud examined her throat and found just the most ridiculous abnormal stuff. Other doctors showed up in the dream and they examined her too, but it was weird because there was a discussion of an injection that another physician had given her, and something had apparently gone wrong, and the syringe used for it wasn't clean.

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And then Freud woke up. Now none of that made any sense.

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If this has happened 3,000 years earlier, somebody might have looked for, you know, an omen somewhere or whatever. But Freud did something completely different. He started taking the dream apart. He wanted to know why Irma was in it, why in that room, why were those other doctors there? What was the injection? And why, what's the significance of the dirty syringe? He followed every single detail into memories and conversations, every anxiety he could come up with, relationships and events from his waking life. And eventually Freud thought that he saw what the dream was doing. It was defending him. So in the dream, Irma's illness wasn't Freud's fault. There were other explanations, other people, other causes. The dream had built an entire world around the fact that Freud could kind of escape the thing that had bothered him before he went to sleep, which was blame. So for Freud, he called it a breakthrough. Years later, he even joked to one of his friends that perhaps someone would someday put a plaque on that house saying that on July 24th, or 1895, the secret of dreams had been revealed to Dr. Sigmund Freud. And wonderfully enough, I mean, there is now a plaque there, but Freud eventually developed an enormous theory, and it was pretty much based around what he thought he had discovered. Dreams, he argued, were connected to wishes. But those wishes weren't always obvious. The dream you remembered was only the surface. Underneath it was something hidden, as in like hidden thoughts and desires and conflicts. Things the mind transformed before allowing them to come into the dream. Like, you'd be thinking one thing, but your mind would use it and twist it and put it in your dream in a secret way. He called that process the way, well, it was doing the transformation, anyways. He called that process the dream work. Ideas can be compressed together, and one person in a dream might represent several people. Feelings could be shifted from something important onto something seemingly meaningless. Like your brain could turn thoughts into symbols and images that would just be twisted from something else.

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So according to Freud, a dream wasn't really nonsense, it was disguided. Well, misguided. I don't know why I said disguided.

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Why? It's too early in the morning for this. And that idea became enormous, really. Like if you think about it, the interpretation of dreams, it was published at the end of 1899. Although the book itself had the date of 1900 for some reason. Eventually, Freud's ideas about dreams spread way beyond psychology. Like they they crept into literature a lot, movies and art, any popular culture at the time. Even the way ordinary people talk about dreams. Like we still say that we still say things like, you know, what do you think that dream means? And hidden inside that question is a very Freudian assumption that somewhere underneath the surface there's something to find. Now, there's an important distinction here. Modern neuroscience does not treat Freud's dream theory as a scientifically established explanation as to why we dream. His claim that dreams are fundamentally disguised, like wish fulfillment, has not become some kind of law of the brain. And part of the psychoanalytic dream interpretation part, those are kind of difficult to test scientifically at all, anyways. But Freud did help push one idea really deep into modern culture. Dreams could be connected to the life of the dreamer, like your experiences and memories and your fears and relationships. Anything that happened yesterday or years ago, instead of asking, what is the universe telling me, people were starting to ask, what is my mind telling me? And that was progress to a to a point, because there was still a problem. Everyone studying dreams was working with the same frustrating piece of evidence, which was the dreamer's story. You wake up, you describe what happened, somebody writes it down, and then maybe they interpret it, and it they compare it to other dreams, but the dream itself is already over. Nobody can see the dream happening, nobody can measure what's going on. Nobody can watch the moment when a memory becomes a person, or whenever fear turns into a monster. Or like if you're elementary school, if it somehow ends up inside the grocery store, like you, you know, for thousands of years, dreams had one enormous advantage over everyone trying to understand them. They happened behind closed doors and behind closed eyes. So they had to find a way for science to kind of get in. And that finally happened because of something almost ridiculously small.

The REM Discovery That Changed Everything

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It had nothing to do with uh like a dream or a symbol or any hidden childhood memories or any of that. It was an eyeball. Because one night in the early 1950s, there was a researcher who noticed that the eyes of sleeping people were moving. And if you remember from the sleep episode, you know what's happening. And then suddenly, for the first time in human history, we had a way to catch the dreaming brain in the act. Which, I mean, think about it. So in December of nineteen fifty-one, an eight-year-old boy climbed onto an army cot inside a lab at the University of Chicago. And his name was Armand Azarinsky. And if that name sounds familiar to you, it should. His father, Eugene, was a graduate student, and Eugene needed somebody who was willing to sleep conveniently because he had a kid, but you know, the lab itself wasn't a big glamorous place. So Nathaniel Kleitman, Eugene's professor, had established what the University of Chicago describes as the world's first sleep lab back in 1925. But sleep science was still a really, really, really, really small field. Like there was no big monitoring rooms and glowing any nothing. It was just a weird little room. It was creepy, it was dark, it was not the best place anybody would want to go to sleep. But Eugene had been working with an old recording machine called an Offner Dinagraph. And it used pens and like long sheets of paper to physically draw electrical signals as they happened. Now, you've usually seen this. A lot of the times they'll use it as a representation of like a lie detector test on TV, you know, the one with that really long needle that kind of goes back and forth across the page. But this one will, it'll it'll measure brain activity and movement, and eventually they found a way to get it to measure your eyeballs. So Eugene attached electrodes around his son's eyes. Then more electrodes went onto his head, and then Armin laid down. And eventually, after a while, he did fall asleep. Now, Eugene, he watched the machine after that, and for a while everything looked about how he expected. And then something happened. The pens started moving really, really quickly back and forth. Something underneath Armin's eyes, like when his eyelids were closed, he was moving his eyes back and forth with just remarkable speed. His eyes Eugene had seen eye movement in sleeping infants before. And that was actually part of what had led him here, anyways, because he discovered it in the infants and it just snowballed from there. But this was different. These movements were fast and jerky, almost like the eyes of someone who was awake and looking around. Except Armin was obviously asleep. And at first, Eugene wondered whether the machine was malfunctioning or, you know, because technically it was pretty reasonable, they didn't have the best machines back then. When your scientific breakthrough is being delivered by a really, really old piece of lab equipment that you've been tinkering with all by yourself, the machine is broken is probably a safer bit than whatever he'd just come up with. But because he wanted to say that he'd discovered an unknown state of human consciousness. So he had to be thorough. He couldn't just have someone blame it on the machine. So he tried it again. And the movements came back over and over and over again, and they weren't random, they appeared in bursts, like they disappeared, and then later in the night they would come back. So something was going through a cycle at this point. And Eugene Azarinsky had absolutely no idea what he was looking at. Which is my favorite kind of discovery, is when nobody knows what's going on. They just figured something out and it's not normal.

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But it he didn't really. I guess it's hard to explain. He didn't have any idea what he was looking at. He really didn't.

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Azarinsky took the results to Dr. Kleitman, and he was skeptical. He was very skeptical, actually. According to Azarinsky's later account, Kleiteman wanted stronger evidence before accepting that these strange eye movements represented anything real. So Kleitman reportedly volunteered his own daughter as another sleep subject. Which means one of the most important discoveries in the history of human sleep was essentially double-checked using the researcher's children as a whole different era. But anyways, the eye movements appeared again. Now there was a question that they couldn't ignore. What were the sleeping people looking at? And the obvious answer was almost too tempting. They were just trying to, if they would have said dreams, people would have looked at them like they were stupid. Maybe the eyes were moving because the sleeper was watching the dream. But that sounds right, isn't really science. They needed a test. They needed something to be able to prove it. And this is where the experiment kind of got really simple. Wait for the eyes to start moving and then wake the person up and ask him what was happening. And then compare that with the people who woke up while their eyes were not moving. That's it. Forever people had just waited until the morning and then asked, Did you have a dream? Azarensky and Kleitman were about to knock on the door while the dream might still be happening. So they studied 20 adults. Yeah, I know it's a small sample size. But, you know, they had they did what they could back then. During some of the experiments, the researchers watched the recordings until those strange eye movements showed up. And then they'd wake them up. They'd ask what was happening. They did it 27 times. The subjects were woke up in the middle of the night 27 times. Which is, I mean, I'd be Oh, I'd be so mad at that point. But on 20 of those awakenings, they reported really detailed dreams. Like they had vivid imagery and all that kind of stuff. They were able to spit it out. But then researchers tried the same thing when the eyes had been quiet for a substantial amount of time, and so they woke them up 23 times. Nineteen of those people produced no dream at all. Like, it's not perfect. Not every rapid eye movement that woke people up was producing a remembered dream, but later research would show that dreaming isn't confined exclusively to REM sleep either. And that distinction kind of matters, but in 1953, the pattern was unmistakable. Something measurable was strongly associated with dreaming. And that's according to the Semmel Institute. For the first time, scientists didn't have to wait for the dreamer to come to them. They had a physiological signal that would test them and let them know when to go looking. So think about what had just happened. The Egyptians, they had dream books, and then the Greeks had temples, and Artimodorus collected interpretations. Freud would analyze uh symbols, and then every one of them, they'd all been working on the same basic concept, which was a memory of a dream, and something it was already finished. It was already fading away whenever they tried to study it. They'd already been out of the cycle, they'd already woke up, it was done. But now Azarensky and Klyteman had found a crack in the wall. They still couldn't see the dream, though, but suddenly they could see leftover footprints of the dream. And they knew that it would come it would come back.

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So people didn't really go into one long sleep.

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It was in a structure. So the whole time you were asleep, you were going through something. They knew it was structured. And the periods of rapid eye movement appeared and stopped and then appeared again. The original study in 1953 found multiple episodes across the night with the periods of whatever it was, they would recur and sometimes get closer together the closer you got to morning. And that's also from the Semmel Institute. That wasn't a huge deal. Because sleep had often been treated as something passive. You were awake and then you weren't. The brain kind of pulled away from the world and the lights went out, and then morning came. So that was it. That's all they'd really given it at that point. But these recordings, they suggested that something a lot more active was happening. During the rapid eye movement periods, the brain's electrical activity looked surprisingly awake. Like your breathing would become faster, your heart rate would go up and down, uh, the body would show changes itself. The sleeping person wasn't just laying there in silence. Well, neurological silence, I guess. Something was happening. And it was organized and it was repeating, but it was powerful enough to create an entire conscious experience without waking the person up. So Azerinsky and Kleitman published their findings in Science on September 4th, 1953. The title wasn't uh what you would call the best. It's not something that you would see on a movie poster for sure. So it's they titled it Regularly Occurring Periods of Eye Motility and Con concomitant I don't know why I can't say that word.

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Concomitant phenomena during sleep. Yeah, so try saying that twelve times fast. The paper was two pages long.

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That's it, two pages. For however many years that everybody's been studying this, that's what they got, two pages. So according to PubMed, the doorway in the modern science, in the modern dream science, it showed up in a paper you could read while you were waiting for the coffee to cool. I mean, if you think about that, that's pretty I mean it cools down pretty quick. You can finish a whole paper, a whole scientific study in a few minutes. And then the story wasn't finished. Another young researcher in Clytemn's lab became fascinated by what they had found. And his name was William Dement. Dement and Clyteman they started waking sleepers up again and again, over and over and over again. And then they would compare eye movements and brainwaves, and the timing of dreams and the length of dreams, and something else started to show up. Dreams weren't necessarily the instantaneous flashes that people would imagine them to be. They could unfold over like actual stretches of time. In one famous set of experiments they published in 1957, people were awakened right either after five minutes or fifteen minutes of REM sleep. And then they were asked whether they thought they had been dreaming for about five minutes or about fifteen minutes. And they were usually able to choose pretty correctly. So we've reached a point where a dream could have duration. A story could actually be unfolding while the clock beside the bed was still ticking.

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And that sounds obvious now. Of course, dreams take time. But take a second and think about what that means.

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So somewhere in your head, while your eyes are closed, your brain is just constructing a full-on sequence of events. Places and people, movements and conversations, and emotions like fear and surprise. They maybe it's an entire narrative, actually. Like, and that narrative exists along ordinary clock time. You might spend 15 minutes wandering through some impossible city that you've never been to, while fifteen actual minutes go by in your bedroom. And there are two versions of what like there's there's two versions of you experiencing those minutes. You had the body in the bed and the person behind the dream. The discovery became known as REM sleep.

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So rapid eye movement sleep.

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Yeah, really original. If it but it it changed way more than our understanding of dreams. Scientists now knew that sleep wasn't one thing. The sleeping brain moves through different states during the night. And REM was one of them. And as researchers looked Learned to record the brain waves and the eye movements and any muscle activity altogether, there was an entire hidden architecture of sleep that started to show up. You had cycles, stages, and patterns. Like a nighttime, a whole world existed in your dreams. Whether anybody was measuring it or not is kind of the thing. So according to the University of Chicago Chronicle, that is exactly what they said. They said a nighttime world that had always existed, whether anybody was measuring it or not. And so Ram sleep created another problem, though. It's a little bit weirder though. Because researchers weren't finding a brain that was active during dreams.

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They were doing something almost contradictory.

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Parts of it looked really, really, really awake. And your eyes were moving, and the internal world could be vivid, and everything that you could think of. Any emotion could be intense, and a person could run or fight or fall off a building, but your body stayed right there. It almost almost motionless, besides you breathing. So now the question had changed again. The Egyptians wanted to know who was sending the dream. And Freud wanted to know what the dream meant, and then Azarinsky wanted to know what the eyes were doing. But once the scientists could finally watch the sleeping brain, they encountered something a little bit more off. How does your brain your brain how does your brain create a world convincing enough to fool you while simultaneously keeping your body from acting it out? And as we talked about in the sleep episode, we're about to find out. Because while you're dreaming, your brain is doing some really weird things.

Theories On Why We Dream

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We know the brain can build faces and places and conversations and emotions, just impossible worlds while you're lying perfectly still in bed. Which brought us to the question we probably should have asked from the beginning, I guess. Why bother? Sleep itself clearly does important things. It helps the brain organize and strengthen memories, it affects learning and emotions and attention, all that. The body needs it. But dreaming is harder. Because after I mean, even after decades of research, there still isn't one universally accepted answer for why we dream. There's a lot of theories, and a lot of them are kind of interesting. One possibility is that dreams are connected to memory. So while you sleep, your brain doesn't just shut down yesterday and start fresh in the morning. That's where your experiences are being processed, and some memories are strengthened and other ones are weakened, just like we talked in the last episode. But other things seem to be connected with older information. Like pieces of your life are being reorganized while you sleep. So it sounds kind of like a dream, but think about the last weird one you remember. It probably wasn't completely random. I mean, maybe you were at your childhood home with somebody you work with now. Like, doesn't doing something if you were doing something you haven't done in 15 years, so you add those pieces together, all of those pieces are real. But the arrangement makes no sense. It's almost like the brain is just dumping a box of memories onto the floor. And then it started putting them back together without really checking anything. I guess that's kind of where it gets sideways. Maybe dreams are just something we experience while the process is happening. But memory isn't the only possibility, though. There's also emotion. In 2024, researchers reported evidence that connecting dreams, connecting the recall from dreams and the dream content with overnight emotional memory processing. I mean, they tried to say that participants who could recall their dreams, they showed changes in their emotional reactivity pretty much across the whole night. And more positive dream content was associated with greater reductions in emotional response to negative material.

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So they were trying to say that, you know, if you had a real positive dream, just a good, happy dream, and then they introduced something negative, you had a better response.

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Which I guess it makes sense. When you think about it that way, it does. But it doesn't prove that they've discovered the purpose of dreaming. But it adds to the possibility that dreams may be involved somehow in the way we process experiences while we sleep, which would explain something dreams are extremely good at, which are making you feel things. The plot can be completely ridiculous, but the emotion behind it isn't. You can wake up angry at okay, so we all know the thing where the your girlfriend has a dream that you cheated on her, and they wake up angry at you. They didn't do it, they weren't even there, and somehow you're still in trouble. Which is incredible. Your sleeping brain can invent an event and then produce a completely real emotional reaction to the event that it just made up in its head.

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And there's another theory that takes things in a lot more ancient direction. And I don't know about it. It's kind of just you'll see. So Finnish neuroscientist, he was Revanansu.

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I don't know why I said Revanansu. Revonsu. He proposed what's known as the threat simulation theory. And the idea is that threatening dreams could have provided our ancestors with kind of a a virtual training ground, which was run from something and then hide and fight, and it helped him recognize danger. You could practice the problem without really experiencing the actual danger. So basically, the world's oldest simulator. Except instead of landing a plane or, you know, whatever you're doing in the simulator, you're being chased through the woods by something with no face. Now, there is some ex uh some evidence consistent with the theory, but the results across studies have been mixed. So again, interesting idea, not a mystery solver, though. But then there's one more, even simpler possibility. That maybe dreams don't have a purpose of their own at all. Maybe your brain is just doing important work involving memory and emotion and prediction and other processes, and dreaming is just what activity feels like what it feels like on the inside. And that because humans really do like sticking meaning to things, we've been doing this since the beginning of this episode. The Egyptian wakes up from a dream and then asks what it predicts. And then the Greek, they would ask, which God sent it. And Freud would ask, What desire is hidden inside of it? And then you'd wake up in 2026, and we grab our phones and we ask the internet why we dreamed about an ex or why we haven't spoken to this person in 20 years. It's all different technology, but we're still doing the same thing. We want the dream to mean something. And sometimes it just doesn't. But science hasn't given us permission to say that every dream does mean something.

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So it also I mean, it also hasn't told us that it's not. So you never know.

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Dreams contain our memories and people and fears and emotions, anything from yesterday or your childhood. Sometimes things we haven't even consciously thought about in years. So maybe we've gotten pretty close to where the ancient Egyptians started. They believed that dreams carried messages, and they may have been wrong about who was sending them. But if dreams tell us anything, the sender might have just been inside the room the entire time, which is us. And just when you think that might be the strangest thing dreams can do, it's not. Because there are people who realize they're dreaming while the dream is still happening. There are people who have communicated with scientists from inside the dreams. And some people physically do act their dreams out, as we've talked about before. Now, some people will repeatedly visit places that don't exist, and yes, scientists have found ways to ask a sleeping person a question and get an answer back. Which means it's probably time for that's wild.

Myths And Facts About Dreams

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So before we leave it, here are a few things about dreams that are either absolutely true or absolutely not.

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This is that's wild. So the first one is a myth. If you don't remember dreaming, you did not dream.

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It's that's definitely a myth. Dream recall and dreaming are two different things. You can wake up convinced absolutely nothing happened all night, while the dream itself has already vanished before you ever had a chance to see it. Which means your brain may have spent part of the night constructing an entire universe, and by breakfast, you don't remember any of it. Number two, the real world can sneak into your dreams. We talked about this a little bit earlier, but sounds, smells, and touch, like researchers have repeatedly found that sensory information that is given to sleeping people can alter what happens inside their dreams. Sometimes directly, actually. Sometimes the brain gets pretty creative. Like a sound from the real world might turn into something completely different inside the dream. So recent experiments have even used specific sounds during REM to try to push dreams towards memories or certain things that are associated with those sounds. And that was according to PubMed. So the alarm clock becoming a fire alarm is one of them. The inside your dream. The alarm clock is going off, and in your head it's a fire alarm while you're sleeping. Your brain may literally be trying to keep the story going, which is interesting in itself.

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Number three, it's another myth. Dreams can predict the future.

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Now, obviously, it is a myth, but people have believed this for thousands of years, and people still report dreams that seem weirdly predictive. But there's no currently reliable scientific evidence that dreams can actually see the future events. Coincidence and selective memory, and our brains really, really high talent for finding patterns can make a dream feel pretty prophetic after something similar happens later. And that's according to the Sleep Foundation. Which brings us almost exactly back to ancient Egypt.

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Again, 3,000 years later, we're still wondering if last night was trying to warn us about tomorrow. Number four. Now this is a fact.

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Blind people do have dreams, and their dreams can be really, really, really sensory overloaded. People who are blind commonly report sound, touch, smell, and taste in dreams. And it gets kind of interesting because research into people who have been blind since birth have also even found reports of something resembling visual or spatial images. I mean, what those experiences represent is still debated, but the dreaming brain appears capable of building a sense of space without depending entirely on information coming through the eyes.

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Now the brain doesn't just replay a recording, it builds a world, like we talked about before. It doesn't just replay, it builds. Number five. So this is another fact.

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Sleep paralysis, one of the most commonly talked about things when it comes to sleep besides dreams, is basically it's when you're dreaming and you're awake, they're overlapping at the worst possible moment, which is during REM sleep. Your brain normally you know it suppresses those voluntary muscles while you're in REM sleep. Which is pretty useful because it keeps you from physically jumping out of bed and like running across the room every time you're being chased. It's pretty useful.

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There are people who don't have it. But if you listen to the last episode, you know what I'm talking about.

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But sometimes consciousness comes back before the paralysis is gone. So you're awake and you know that you're awake, but you can't move. Now some people also experience incredibly vivid hallucinations, which is including the feeling that somebody or something is standing in the room. And that's I mean, it's very commonly reported. All of you know about the sleep paralysis demon. And it suddenly makes centuries of stories about nighttime demons sitting on people's chests feel a little bit different.

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And finally, number six, is another fact. Sometimes that protective paralysis doesn't work.

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We talked about this before, but we're gonna go into it a little bit differently now. There's a condition called REM sleep behavior disorder. Instead of remaining still during REM sleep, people can physically act out their dreams. Talking, screaming, kicking, punching, even the jumping out of bed. So most people who do the sleep talking and stuff like that, they kinda have this. Eventually, I mean, essentially what happens is the barrier between the dream and the body, like the dream body and the real body, just kind of breaks down. Mayo Clinic said essentially that. For most of us, running from a monster requires absolutely no leg movement in our dreams. Well, physical leg movement. In your dreams, yeah, your legs are moving, you're running. For someone experiencing REM sleep, behavior disorder, the legs may actually run in the bed.

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I've got one more for you here. Number seven. You can realize you're dreaming before you wake up. Everyone knows about lucid dreams.

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So that's kind of the fun part. The dream continues, but all of a sudden you know what it is. You know that it's a dream. Some people can even influence what happens next in the dream. Like they can decide that they're gonna fly or decide to change locations, they can actually interact intentionally with the dream. And the lucid dreaming isn't just part of whatever people claim happened afterwards. Scientists can actually verify in the lab, because lucid dreams they can use predetermined patterns of eye movements to signal from inside REM sleep, which is already wild enough, but scientists went further than that. Actually, oh no, I do have one more written down here that I really wanted to talk about.

Lucid Dreaming And Talking To Dreamers

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So, researchers have had conversations with people who were actively dreaming, and some of you have done this with like your significant other in the bed when they're talking in their dreams. You could kind of talk and they would talk back. It might not make sense though, but they were talking back. Now, this one it does sound made up though. But in a 2021 study and involved independent labs in the US and France and Germany and the Netherlands, researchers communicated with people during lucid REM dreams. They asked questions, including simple math problems, and some participants who were asleep actually answered them correctly from inside the dream. They response they response, they responded using predetermined eye movements or like facial muscle signals. The researchers called it interactive dreaming, and that's from Northwestern now. But just think about where we started. Thousands of years ago, humans went to sleep wondering whether something from the outside could send a message into a dream, and now we're doing it.

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So, who's really the weirdo here? Hmm. But I mean, if you think about it, you're asking people weird math questions all the time.

SPEAKER_01 1:03:34

Somebody standing outside the dream can ask, what is eight minus six? And somewhere inside that whatever sleeping world you've come up with, the dreamer can hear it, understand it, work out the answer, and then send back two. For the first time, we're not just studying dreams after they end, we're essentially just banging in there while somebody's still inside. And sometimes they knock back, which is pretty wild. That we've been asking forever. Where do dreams come from? All that. The Egyptians they looked for messages, and Greeks looked for gods, and Freud was doing Freud stuff. And then scientists were looking for eye movements. But now we can watch the sleeping brain build entire worlds from memory and emotion and sensation and whatever strange ingredient that happens to just be laying around. But after all that, dreams still haven't completely given up their mystery, which is why we keep talking about them.

A Dream That Opens A New Rabbit Hole

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Because even when we know a dream can come from our own brain, sometimes it still feels like it's trying to tell us something. I had one of those recently. I work on an ambulance, as most of you know, I've talked about it a couple of times. I'm an EMT, and emergency medicine has been part of my life for a long time, over a decade at this point. But one night recently, I had a dream that I left the ambulance and became a firefighter. That was it. There was no prophecy or ancient symbol, no mysterious figure standing at the end of a hallway, just me. And I changed uniforms and put on some turnouts to be a firefighter. And when I woke up, I kept thinking about it. Not because I just believed my brain had predicted the future because I'm not not. I don't like fire, I don't like heat. I'm not a big summertime person, and those turnouts are hot. But it's because it reminded me how strange dreams really are. Something that never happened and never will happen created a thought that followed me into the real world. And then that thought did something else. It opened up a rabbit hole. Because an ambulance and a fire engine might sit beside each other at whatever scene we're at, but the stories behind them are completely different. Why do we have ambulances? Who decided sick and injured people should be treated before they reach the hospital? Why do firefighters ride enormous red trucks? Where'd the red come from? Where did emergency numbers come from? And how do we go from buckets and bells and horse-drawn wagons and all that other stuff to an entire system that's built around the idea that when the worst moment of your life happens, that somebody should just show up. So maybe that dream didn't really predict anything. I I guess dreams don't have to, because sometimes a dream only has to leave behind a question.

Final Takeaway And Next Stop

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They can take you almost anywhere. So next time, we're gonna follow the one that I had.

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For the first time ever, we're gonna go from the first people who ran towards fires, or to the first ambulance, to police, to the strange, complicated system we call EMS. Emergency services. And after spending an entire episode inside the sleeping brain, we're gonna wake up. And because mostly the next rabbit hole starts with something really, really real. Somebody needs help. And somebody has to answer.