The Strange Science of Why We Dream

Summary

The video script narrates the fascinating history and theories surrounding dreams, beginning with the famous dream of chemist August Kekulé that led to the discovery of benzene's molecular structure. It explores the evolution of dream interpretation, from ancient Egyptian dream books to Freud's psychoanalytic approach and Jung's collective unconscious. Modern science has shifted focus from decoding dreams to understanding their functions, such as memory consolidation, threat simulation for survival practice, and social situation rehearsal. Dreams are also considered a playground for creative problem-solving, with examples like the Beatles' song 'Yesterday' and Dali's melting clocks. The video ponders the evolutionary purpose of dreaming, suggesting it may serve multiple beneficial roles, including maintaining the visual cortex's functionality during the long periods of darkness. The summary invites viewers to delve into the ongoing scientific quest to unravel the mysteries of our nightly journeys through the realm of dreams.

Takeaways

• 🧪 The structure of benzene, a hydrocarbon, was famously discovered by August Kekulé in a dream, symbolized by the ouroboros where a snake bites its tail.
• 💭 Humans have been pondering the purpose of dreams for millennia, with various theories ranging from spiritual to scientific explanations.
• ⏱️ On average, we spend about two hours dreaming each night, amounting to nearly 60,000 hours, or ten years, over an 80-year lifetime.
• 🧍‍♀️ Women are more likely than men to remember their dreams daily, and almost half of us remember at least one dream per week.
• 🌀 The sleep cycle includes various phases, with dreaming predominantly occurring during the REM (rapid eye movement) stage when the brain is highly active.
• 🐳 Many animals, including whales, wombats, and wildebeest, also sleep and likely dream, possibly about chasing objects like a 'red ball'.
• 📚 Ancient cultures, especially the Egyptians, took dream interpretation very seriously, with entire books dedicated to decoding their meanings.
• 🧐 Sigmund Freud and Carl Jung contributed significantly to the understanding of dreams, with Freud focusing on unconscious desires and Jung on universal symbols.
• 🧠 Modern science has shifted from viewing dreams as mere neurological noise to considering their potential functional benefits for memory, threat simulation, and social interaction.
• 🎮 Studies have shown that dreaming can be related to activities during wakefulness, such as learning new skills, suggesting that dreams may help reinforce and store long-term memories.
• 🤔 The Threat-Simulation Theory and Social Simulation Theory propose that dreams allow us to practice dealing with dangerous situations and social scenarios, respectively.
• 🌟 Dreams have been a source of inspiration for creative works, such as music, art, and literature, and researchers are exploring 'Dream Incubation' to enhance creativity.
• 🌌 The evolution of dreaming is still a mystery, but one theory suggests it may be linked to the visual cortex remaining active during the long nights to prevent rewiring for other tasks.

Q & A

What was the chemical structure problem that the chemistry professor in Belgium was trying to solve in 1862?

The chemistry professor was trying to solve the structure of Benzene, a hydrocarbon molecule with an unusual ratio of hydrogen to carbon atoms, which is 1:1 instead of the typical higher ratio of hydrogen atoms.

How did August Kekulé discover the structure of benzene?

August Kekulé discovered the structure of benzene through a dream, in which he visualized a snake coiling around and biting its tail, symbolizing the ouroboros, which led him to the idea of a ring structure for benzene.

How much time do we spend dreaming over an 80-year lifetime?

Over an 80-year lifetime, we spend almost 60,000 hours, or the equivalent of ten years of waking life, dreaming.

What is the significance of REM (Rapid Eye Movement) sleep in relation to dreaming?

REM sleep is the stage during which dreaming occurs. During this phase, the brain is very active, almost as active as when a person is awake, and it is characterized by faster breathing and rapid eye movements.

What is the Activation-Synthesis Theory of dreaming?

The Activation-Synthesis Theory suggests that dreams are a result of the brain trying to make sense of random neural activity during sleep by weaving it into a narrative or story.

How do dreams potentially contribute to memory consolidation?

Dreams may serve as a form of memory replay, where daily experiences are re-played during sleep to help store them in long-term memory. This is supported by the observation that brain activity patterns just after dreaming resemble those when the brain stores and retrieves episodic memories.

What is the Threat-Simulation Theory and how does it relate to nightmares?

The Threat-Simulation Theory posits that dreams, particularly nightmares, allow us to practice and prepare for dangerous events in a safe environment. This theory suggests that the brain uses dreams to condition us to survive threatening experiences by simulating them.

What is the Social Simulation Theory of dreams and why is it significant?

The Social Simulation Theory suggests that dreams are used to practice social situations, which is significant because social interactions are crucial for human survival and success. The theory notes that dreams often involve social scenarios, providing a platform for the brain to rehearse and improve social skills.

How might dreams contribute to problem-solving and creativity?

Dreams can contribute to problem-solving and creativity because they are not bound by the constraints of logic or physics. This freedom allows the brain to explore unconventional solutions and ideas, which can lead to innovative breakthroughs in various fields.

What is 'Dream Incubation' and how is it being used in scientific research?

Dream Incubation is a technique where individuals are primed before sleep to focus on a specific topic or problem, with the aim of enhancing creativity during dreaming. Scientists are experimenting with this method to study whether it can boost creative problem-solving.

Why do scientists believe that the rotation of our planet might have influenced the evolution of dreaming?

Scientists hypothesize that the long periods of darkness due to the rotation of our planet could have influenced the evolution of dreaming. The visual cortex, being a large part of the brain, might be at risk of being repurposed for other tasks during sleep. Dreams, with their visual nature, may have evolved to keep these areas active and prevent the brain from rewiring itself in potentially detrimental ways.

What is the current understanding of why we dream, and is there a consensus among scientists?

The current understanding of why we dream is still evolving, with several theories suggesting different functions such as memory consolidation, threat simulation, social simulation, and problem-solving. There is no consensus yet, and scientists continue to research and explore the various potential benefits and functions of dreaming.

Outlines

00:00

🔍 The Dream Discovery of Benzene's Structure

The first paragraph introduces the historical account of how August Kekulé, a chemistry professor in Belgium, dreamt of the ouroboros symbol, leading to the discovery of benzene's molecular structure. It emphasizes the peculiarity of benzene's chemical composition and the significance of dreams in scientific breakthroughs. The paragraph also raises the broader question of why humans dream, touching on the long-standing human curiosity about the purpose of dreams and hinting at the potential benefits they might have for our cognitive and emotional well-being.

05:04

🧠 The Evolution and Interpretation of Dreams

The second paragraph delves into the evolution of dream interpretation, from ancient Egyptian dream books to the influential theories of Sigmund Freud and Carl Jung. It discusses Freud's idea that dreams are a window into our unconscious desires and Jung's concept of universal symbols in dreams. The paragraph also explores the modern shift in scientific understanding away from decoding dreams as hidden messages, towards investigating the potential functional benefits of dreaming for the brain, such as memory consolidation and threat simulation.

10:07

🌌 The Functions and Benefits of Dreaming

The third paragraph examines various theories about the functions of dreams, including memory replay, threat simulation, social simulation, and problem-solving. It highlights how dreams may serve as a platform for practicing social interactions and rehearsing responses to potential threats. Additionally, the paragraph touches on the role of dreams in fostering creativity and the potential for 'Dream Incubation' to enhance creative thinking. It concludes with speculation on the evolutionary origins of dreaming, suggesting that dreams may have developed to keep the visual cortex active during the long periods of darkness, thus preventing it from being repurposed for other tasks.

Keywords

💡Benzene

Benzene is a hydrocarbon molecule known for its distinctive smell and flammability, consisting of an equal number of hydrogen and carbon atoms (6 of each). In the video, it is central to the narrative as the chemical structure of benzene is the problem that the protagonist, a chemistry professor, is trying to solve, which leads to the famous dream of August Kekulé and the discovery of the ouroboros-like structure of benzene.

💡Ouroboros

The ouroboros is an ancient symbol depicting a serpent or dragon eating its own tail, which represents the concept of infinity or the cycle of life. In the context of the video, the ouroboros symbolizes the eureka moment in the dream of the chemistry professor, where the structure of benzene is revealed as a ring of carbon atoms with hydrogen atoms attached, similar to the ouroboros shape.

💡Dreaming

Dreaming refers to the experience of having dreams, which are a series of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages of sleep. The video explores the question of why humans dream, suggesting that dreams may have multiple functions and benefits, such as aiding in memory consolidation, threat simulation, social simulation, and problem-solving.

💡REM Sleep

REM, or rapid eye movement, sleep is a stage of sleep characterized by rapid movements of the eyes, faster breathing, and increased brain activity. It is the period when most dreaming occurs. The video mentions REM sleep as a critical phase for dreaming and suggests that many animals also experience REM sleep, implying that they might dream as well.

💡Memory Consolidation

Memory consolidation is the process by which short-term memories are transformed into long-term memories. The video suggests that dreams may serve as a form of memory replay, helping to reinforce and store episodic memories. This is illustrated by the example of participants who played a skiing simulator game and later dreamt about it, indicating that their brains were consolidating the new experiences.

💡Threat-Simulation Theory

The Threat-Simulation Theory posits that dreams allow the brain to practice and prepare for dangerous or threatening situations in a safe environment. The video discusses this theory in the context of nightmares, suggesting that the brain uses dreams to condition individuals to survive threatening experiences by simulating them during sleep.

💡Social Simulation Theory

The Social Simulation Theory proposes that dreams are used to practice and rehearse social situations, which are crucial for human interaction and survival. The video notes that dreams often involve social scenarios, such as conflicts or dates, and that practicing these situations in dreams may offer an evolutionary advantage by helping individuals navigate complex social dynamics.

💡Problem-Solving

Problem-solving in the context of the video refers to the idea that dreams can facilitate the resolution of complex issues or generate creative solutions. The video cites an example where college students were found to dream of solutions to homework problems, suggesting that the unconstrained nature of dreams can be a fertile ground for innovative thinking.

💡Dream Incubation

Dream incubation is a technique where individuals are primed to dream about a specific topic or problem before they go to sleep, with the aim of enhancing creativity or finding solutions. The video mentions that scientists are experimenting with dream incubation, hinting at the potential for dreams to be utilized in a targeted way to boost creative thinking.

💡Visual Cortex

The visual cortex is the part of the brain responsible for processing visual information. The video suggests that the visual cortex, due to its large size and importance, is vulnerable to being rewired for other tasks during sleep if not actively used. Dreams, with their highly visual nature, may have evolved to keep the visual cortex active during the night, preventing such rewiring.

💡Evolution of Dreaming

The evolution of dreaming refers to the development and persistence of dreaming as a biological function over time. The video speculates on why dreaming might have evolved, suggesting it could be related to the visual nature of dreams protecting the visual cortex at night or serving multiple beneficial functions that have been retained over time.

Highlights

August Kekulé discovered the molecular structure of benzene in a dream, revolutionizing organic chemistry.

Humans have been trying to understand why we dream for thousands of years.

We spend about 2 hours dreaming each night, totaling nearly 60,000 hours or 10 years of waking life over an 80-year lifespan.

Almost half of people remember at least one dream per week, with women more likely to recall them daily compared to men.

The brain goes through various phases during sleep, including REM where dreaming occurs and brain activity is almost as high as when awake.

Many animals also sleep and experience REM sleep, suggesting they may dream as well, such as cats and dogs.

Throughout history, dreams have held spiritual significance in cultures worldwide, including ancient Egypt where books of dream interpretations were created.

Sigmund Freud published 'Interpretation of Dreams' in 1900, proposing dreams could reveal unconscious desires.

Carl Jung expanded Freud's theories, suggesting dreams contained universal symbols and served to compensate for repression and provide future hints.

Modern science has shifted from viewing dreams as messages to be decoded, to exploring the potential functions and benefits of dreaming for the brain.

Dreams are not random but often relate to our waking experiences, particularly when learning something new.

Dreaming may serve as a memory replay to help store daily experiences into long-term memory by re-playing them.

In a study, playing Tetris for 7 hours across 3 days led to participants seeing game imagery as they fell asleep, indicating a replay to store skills.

Nightmares may serve a purpose by letting the brain practice and condition responses to threatening situations in a safe environment.

The Social Simulation Theory suggests dreams allow us to practice social situations, providing an evolutionary advantage.

Dreams can facilitate problem-solving and creative thinking, as they are not bound by logic or physics.

Many great works of art, like The Beatles' 'Yesterday' and Dali's melting clocks, were inspired by dreams.

Scientists are exploring 'Dream Incubation' to enhance creativity by priming the brain before sleep.

The origin of dreaming may be tied to the long periods of darkness at night, serving to keep the visual cortex active to prevent rewiring.

While the exact purpose of dreams remains a mystery, they are likely beneficial for multiple reasons and research continues to uncover their secrets.

Transcripts

Imagine this. It’s winter 1862 and you’re a chemistry professor in Belgium 

You’re working on one of the most pressing problems in chemistry: the structure of Benzene.

Benzene is a  smelly and highly flammable hydrocarbon molecule. All hydrocarbons are

made of… you guessed it, hydrogen and carbon. But in benzene the ratio of these elements

is a little weird. Instead of having more hydrogen atoms than

carbon atoms, like most hydrocarbons, benzene has the same number of hydrogen and carbon

atoms: 6 and 6.  What strange molecular structure could let

these atoms fit together? Frustrated, you turn your chair towards the

warm fire and take a nap.  As you sleep, visions of atoms and molecules dance in your

mind’s eye. They turn into a series of snakes. Then, suddenly, one of the snakes coils around

and bites its tail like the ancient symbol of the ouroboros.

You’ve solved the chemical structure of benzene… in a dream! Precisely as German

chemist August Kekulé did in 1862, completely changing the future of organic chemistry in

the process, a contribution to science that earned him a statue that people love to dress

up.  And it all happened while he was asleep.

Thanks to… a dream? It makes you wonder: Why DO we dream? 

Hi Smart People, Joe here. August Kekule’s dream discovery of benzene’s

molecular shape is one of history’s most famous dreams. 

But for most of us, dreaming is about more than making chemistry discoveries. Humans

have been trying to figure out why we dream for thousands of years, probably as far back

as we’ve been asking questions. And since it’s an experience we only have while we’re

asleep, it’s a particularly tough question to answer.

Going back to the Greek philosopher Plato and the Confucian scholar Zhu Xi, great minds

have speculated about the function and meaning of dreams.  But it’s only been in the last

few decades that scientific experiments have started to show us what benefits our nocturnal

narratives could have. That’s right: benefits, with an S. Scientists

think dreams might have many functions that influence our success, our smarts and even

our survival. We each spend about two hours dreaming every

night. Over an 80-year lifetime, that’s almost 60,000 hours, or the same as ten years

of waking life! Dreaming clearly must have some benefit – otherwise

we wouldn’t spend so much darn time doin’ it.

And everyone dreams…. Even if we don’t always remember them. You are more likely

to remember your strangest ones… like I had this one dream where Tom Hiddleston and

I were rowing a boat across the ocean, and then we got hit by a storm, and we were eating

sandwiches. That was weird. (that really happened) Almost half of us remember at least one dream

a week, and women are more likely to remember their dreams daily compared to men. There

are a number of phases the brain goes through during sleep; these phases are repeated in

cycles throughout the night. In the first phase we transition from wakefulness into

sleep, as you begin to relax and your breathing slows. As your body temperature drops and

your breathing slows down even more, you enter light sleep. After that, you enter the deep

sleep phase characterized by a particular pattern in your brain called delta waves.

After that, you start the REM or “rapid eye movement” sleep stage. Your breathing

gets faster, and your eyes move all over. During REM is when dreaming happens. And throughout

this phase, your brain is very active -- almost as active as when you are awake.

Almost all other animals-- whales, wombats, wildebeest…. Sleep. And many also experience

REM sleep. So scientists think that many of these animals also dream -- including your

cat or dog.  Probably about chasing that delicious, juicy,

red ball. The way we think about dreams has changed

a lot throughout history. In most cultures around the world, dreaming has held spiritual

significance. There are even dream interpretations in the Bible.

But there was nowhere where decoding dreams was more popular than in ancient Egypt. The

Egyptians created volumes of books full of common dreams and their supposed meanings.

Professional dream interpreters used these books to help people figure out what their

dreams meant. Dreamer: I had a dream my leg came off!

Interpreter: Oooof, that means dead  people are judging you.

Dreamer: Yikes! — 

Dreamer: I dreamed I died violently! Interpreter: Oh that’s a great!

Dreamer: Really? Interpreter: Really! It means you’ll live

a long life. Dreamer: Okay?

—  Dreamer (beaming): I had a dream I poured

a jug of my pee into the Nile. Interpreter (confused): Really?

Dreamer: Really! Interpreter: Well actually that’s a great

omen too! It means your harvest is going to be bountiful.

Oh right… obviously. The belief that dreams held hidden messages

to be interpreted or decoded remained the dominant way to look at dreams through the

first part of the 20th century. In 1900, Sigmund Freud published the influential

book “Interpretation of Dreams.”  In it, he claimed that dream interpretation could

be used to understand unconscious desires.  It all started when he had a dream, a dream

so famous it has a name… and a Wikipedia page. 

It’s called Irma’s Injection.  “A large hall - numerous guests, whom we

were receiving. - Among them was Irma.” It was about a former patient of Freud’s

that he felt he wasn’t able to completely heal because she refused his treatment. 

“I at once took her to one side, as though to answer her letter and to reproach her for

not having accepted my 'solution' yet.” This dream sparked Freud’s theory that our

wishes that aren’t fulfilled while we’re awake are expressed in our dreams. Because

some of those wishes might be kinda embarrassing, Freud thought our minds deliberately confused

the dreams to hide their true meaning. Carl Jung expanded Freud’s theories. Jung

considered archetypal symbols that often appeared in dreams, like a wise old sage, or a trickster,

to be universal among humans. Jung thought that dreams were interpretable… if we could

crack the code of these universal symbols, the “language” of dreams. According to

Jung, dreams had two functions: they compensated for things that the dreamer ignored or repressed,

and they looked forward to give the dreamer hints about what might happen in the future.

Lots of people still look for meaning in their dreams, especially to do with the future.

In one study, people were more likely to say having a dream about a plane crash the day

before a flight would make them cancel their trip than if they were given a government

warning about a “high risk of a terrorist attack.

But modern science has moved away from Freud and Jung and viewing dreams as buried messages

to decode or interpret. Today researchers are asking what functions and benefits our

brains themselves might get from dreaming. At first, scientists believed that the strange

mish-mash of pictures, stories, and events we experience while dreaming were just side

effects of basic biological processes in our brains, a sort of neurological noise that

we experience as we sleep. Scientists thought that other parts of the

brain tried to make sense of the noise by threading this random slideshow into a story…

often a very weird story. This is called the Activation-Synthesis Theory of dreaming.

But experiments showed that dreams are not actually random. Some things are more likely

to appear in our dreams than others. And scientists began to wonder: Maybe dreams aren’t random

noise… maybe our brains NEED to dream to be healthy. .

What we dream about often has to do with what we do while we’re awake…especially if

we’re learning something new.   In one study, about a third of participants

who played Alpine Racer II, an arcade downhill skiing simulator, had dreams about the game.

Consider this: The things that happen to you every day only happen once. In our short-term

memory, these experiences are fragile, and can easily disappear. Our daily experiences

might only make it into our long-term memory if they’re RE-played several times - you

guessed it - in our dreams. Patterns of brain activity just after dreaming look a lot like

when our brains store and retrieve episodic memories – memories of things that actually

happen to us. So, dreams may be a sort of memory replay of our experiences … with

an extra layer of weird on top just to make it fun I guess.

In one study to test this, scientists asked people to play 7 hours of Tetris across 3

days. Hang on, I have a question… Where do I go to sign up for these studies? Anyone? 

I’m busy right now. I’m doing some science! Woo! Serious brain science here.

Anyway. After some serious Tetris time, participants reported seeing images of tetraminos when

falling asleep. They seemed to be replaying the game to store their new skills in long-term

memory. It’s not all fun and games, though. Dreams

can turn into nightmares. There’s no universally accepted definition of what a “nightmare”

is, but they’re commonly considered a “distressing or terrifying dream,” one that goes so far

as to wake you up.  About one in 40 dreams is a nightmare. So why do our brains replay

our worst fears and memories? The Threat-Simulation Theory suggests that

dreams let us “practice” dangerous events and situations. That’s why some people relive

traumatic experiences in dreams. The brain is trying to condition us to survive threatening

experiences by “practicing” in a safe environment -- inside our sleeping brain.

Back when life-threatening situations were a part of our species’ everyday life, simulating

threats could’ve helped us survive. But in the modern world, reliving awful situations

in chronic nightmares can be debilitating. But we also practice social situations in

dreaming. That’s the Social Simulation Theory of dreams. Scientists noticed our dreams are

heavy on social situations: a fight with a close friend, a date with a crush, a clash

with a coworker, or not wearing pants to school. Since being social is so important to our

species, practicing these situations would have been an evolutionary advantage.

The strange experience of dreaming can be used for problem solving too.  

Novelist John Steinbeck once said: "It is a common experience that a problem difficult

at night is resolved in the morning after the committee of sleep has worked on it.”

When college students were given a homework problem to focus on each night before bed,

a quarter dreamed the answer within a week. Because dreams aren’t limited by...um…

logic… or physics … they’re a great place to problem solve and come up with creative

—and sometimes weird—solutions. Which is especially helpful when solutions to problems

need a very different approach compared to conventional wisdom. And this may be why we

owe many pieces of great art to dreams: The Beatles’ iconic song Yesterday, Salvador

Dali’s melting clocks, Mary Shelley’s novel Frankenstein, and countless others.

So, can you dream your way to a Nobel Prize? Or a Grammy? Well… maybe. Scientists are

experimenting with “Dream Incubation” as a way to prime the brain before sleep to

be more creative. So… because dreaming is so common, and because

we spend so much of our lives doing it, it’s almost certainly useful, for one or many reasons.

But why did dreaming evolve to begin with? Maybe thanks to the… rotation of our planet?

That’s right. Scientists think the origin of dreaming just might have to do with the

sheer amount of time that humans – and all animals – spend in the dark.

Our ability to use our peepers and see the world around us is an extremely important

evolutionary advantage. And because it’s so important, the part of the brain responsible

for sight, called the visual cortex, takes up a big chunk of our brains.

But there’s the thing. Our brains can also be rewired pretty easily. If you were blindfolded,

your brain would begin to change within an hour of not using your sight. The neurons

of the visual cortex start being taken over for other tasks.

The lengthy darkness of nighttime, would have meant that the visual cortex of our human

ancestors was at a high risk of being taken over by other functions while we slept. If

we didn’t use it, we could lose it. Dreams, and their highly visual nature, may have evolved

in mammals to keep these vulnerable brain areas active at night… And keep the brain

from rewiring itself in unfortunate ways. So… which is it? Is it problem-solving,

or practicing, or seeing, or is it problem solving or not about seeing, or a bit about

practicing and a pinch of problems solving? Scientists don’t know if one or many of

these ideas will prove to be correct, and so research continues. Ah, science.  Always

figuring stuff out. But never quite figuring stuff out all the way.

It’s even possible that dreams may have evolved for one function, but stayed around

so long because dreaming ended up helping us in a bunch of other different ways.  Trying

to peer into the workings of the sleeping brain is one of the most challenging problems

in psychology and neuroscience, but we’re building a fuller and fuller picture of the

science of dreaming, one dream …at a time. You wouldn’t believe the dream I just had.