Picture this: It’s the winter of 1862, and you’re a chemistry professor in Belgium, grappling with one of the most perplexing challenges in chemistry—the structure of benzene. Benzene is a peculiar hydrocarbon, composed of an equal number of hydrogen and carbon atoms—six each. This unusual ratio sets it apart from most hydrocarbons, which typically have more hydrogen atoms than carbon atoms.
As you ponder this enigma, you drift into a nap by the fire. In your dream, atoms and molecules morph into snakes, and one snake bites its tail, forming a circle reminiscent of the ancient ouroboros symbol. You’ve just unlocked the structure of benzene, much like the German chemist August Kekulé did in 1862, revolutionizing organic chemistry—all thanks to a dream.
Dreams have intrigued humanity for millennia, prompting questions about their purpose and meaning. From the musings of Greek philosopher Plato to Confucian scholar Zhu Xi, great minds have speculated about dreams. However, it is only in recent decades that scientific research has begun to uncover the potential benefits of our nightly narratives.
On average, we spend about two hours dreaming each night, amounting to nearly 60,000 hours over an 80-year lifetime. This significant investment of time suggests that dreaming serves a purpose. Interestingly, women tend to remember their dreams more frequently than men, with almost half of us recalling at least one dream each week.
Our sleep cycle consists of several phases, culminating in the REM (rapid eye movement) stage, where dreaming occurs. During REM sleep, our brains are highly active, akin to when we’re awake. This stage is not exclusive to humans; many animals, including cats and dogs, experience REM sleep, suggesting they dream as well.
Historically, dreams have held spiritual significance in various cultures, with ancient Egyptians even creating dream interpretation books. Sigmund Freud’s 1900 publication, “Interpretation of Dreams,” posited that dreams reveal unconscious desires. Carl Jung expanded on Freud’s ideas, suggesting that dreams contain universal symbols that can be decoded.
Contemporary science has shifted away from viewing dreams as cryptic messages. Instead, researchers explore the functions and benefits of dreaming. Initially, dreams were thought to be random byproducts of brain activity. However, studies reveal that dreams often relate to our waking experiences, especially when learning new skills.
For instance, participants in a study who played a skiing simulator frequently dreamed about the game, suggesting that dreams help consolidate new skills into long-term memory. Similarly, people who played Tetris reported seeing tetrominoes in their dreams, indicating a replay of the game to reinforce learning.
Dreams can also serve as problem-solving tools. John Steinbeck famously noted that problems often resolve after a night’s sleep. In one study, college students tasked with solving a problem before bed found solutions in their dreams. The creative nature of dreams allows for unique solutions, as evidenced by artistic works like The Beatles’ “Yesterday” and Salvador Dali’s melting clocks.
Nightmares, though distressing, may have evolved as a survival mechanism. The Threat-Simulation Theory suggests that dreams allow us to “practice” dangerous situations, preparing us for real-life threats. Similarly, the Social Simulation Theory posits that dreams help us navigate social interactions, an evolutionary advantage for our species.
Why did dreaming evolve in the first place? Some scientists speculate that dreams may have developed to keep the visual cortex active during the darkness of night, preventing the brain from rewiring itself for other functions. This theory highlights the importance of vision in our evolutionary history.
While the exact purpose of dreams remains elusive, they likely serve multiple functions, from problem-solving to memory consolidation. As research continues, we gain a deeper understanding of the science of dreaming, one dream at a time.
Keep a dream journal for one week, recording your dreams as soon as you wake up. At the end of the week, analyze your entries to identify common themes or symbols. Reflect on how these might relate to your waking life and discuss your findings in a group setting.
Conduct a small experiment by altering your sleep schedule to increase REM sleep. Track your dream recall and quality over a week. Share your experiences and any changes you notice in your cognitive functions or creativity with your classmates.
Engage in a debate on the validity of dream interpretation theories, such as those proposed by Freud and Jung. Research their theories and present arguments for or against the idea that dreams can reveal unconscious desires or universal symbols.
Create an artistic project inspired by a dream you’ve had. This could be a piece of writing, a painting, or a musical composition. Present your work to the class and explain how your dream influenced your creative process.
Before going to sleep, focus on a specific problem you are facing. Record any dreams you have that night and analyze them for potential solutions or insights. Share your experience and any solutions you discovered with your peers.
Sure! Here’s a sanitized version of the transcript:
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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 hydrogen and carbon. However, in benzene, the ratio of these elements is a bit unusual. Instead of having more hydrogen atoms than carbon atoms, like most hydrocarbons, benzene has an equal number: 6 hydrogen and 6 carbon atoms.
What strange molecular structure could allow these atoms to 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, transforming into a series of snakes. Suddenly, one of the snakes coils around and bites its tail, resembling the ancient symbol of the ouroboros. You’ve solved the chemical structure of benzene… in a dream! Just as German chemist August Kekulé did in 1862, completely changing the future of organic chemistry in the process.
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 Kekulé’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. 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! Scientists think dreams might have many functions that influence our success, intelligence, 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 equivalent of ten years of waking life! Dreaming must have some benefit – otherwise, we wouldn’t spend so much time doing it. And everyone dreams, even if we don’t always remember them. You are more likely to remember your strangest dreams.
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 several phases the brain goes through during sleep, which are repeated in cycles throughout the night. In the first phase, we transition from wakefulness into sleep, as we begin to relax and our breathing slows. As our body temperature drops and our breathing slows down even more, we enter light sleep. After that, we enter deep sleep, characterized by a particular pattern in our brain called delta waves.
Then, we start the REM (rapid eye movement) sleep stage. Our breathing gets faster, and our eyes move all over. During REM is when dreaming occurs. Throughout this phase, our brain is very active—almost as active as when we 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.
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. However, nowhere was decoding dreams 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.
The belief that dreams held hidden messages to be interpreted 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 so famous it has a name and a Wikipedia page: Irma’s Injection.
This dream sparked Freud’s theory that our unfulfilled wishes while we’re awake are expressed in our dreams. Because some of those wishes might be embarrassing, Freud thought our minds deliberately confused the dreams to hide their true meaning. Carl Jung expanded Freud’s theories, considering archetypal symbols that often appeared in dreams 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 hints about what might happen in the future. Many people still look for meaning in their dreams, especially regarding 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, viewing dreams as buried messages to decode or interpret. Today, researchers are asking what functions and benefits our brains might gain from dreaming. Initially, scientists believed that the strange mishmash 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 we experience as we sleep.
However, experiments showed that dreams are not actually random. Some things are more likely to appear in our dreams than others. Scientists began to wonder: Maybe dreams aren’t random noise… maybe our brains need to dream to be healthy. What we dream about often relates to what we do while we’re awake, especially if we’re learning something new.
In one study, about a third of participants who played an arcade downhill skiing simulator had dreams about the game. 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 replayed several times—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 creativity on top.
In one study, scientists asked people to play Tetris for several hours over a few days. After this, participants reported seeing images of tetrominos when falling asleep, suggesting they were 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 that can 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 part of our species’ everyday life, simulating threats could have helped us survive. However, in the modern world, reliving awful situations in chronic nightmares can be debilitating.
We also practice social situations in dreaming. The Social Simulation Theory of dreams suggests that our dreams are heavy on social situations: a fight with a close friend, a date with a crush, a clash with a coworker, or an embarrassing moment at 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 also be used for problem-solving. 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 logic or physics, they’re a great place to problem-solve and come up with creative—and sometimes unusual—solutions. 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? Perhaps due to the rotation of our planet? Scientists think the origin of dreaming might relate to the amount of time that humans—and all animals—spend in the dark.
Our ability to see the world around us is an important evolutionary advantage. The part of the brain responsible for sight, called the visual cortex, takes up a significant portion of our brains. However, our brains can also be rewired 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 risk of being taken over by other functions while we slept. If we didn’t use it, we could lose it. Dreams, with their highly visual nature, may have evolved in mammals to keep these vulnerable brain areas active at night and prevent the brain from rewiring itself in unfortunate ways.
So, which is it? Is it problem-solving, practicing, or seeing? Scientists don’t know if one or many of these ideas will prove to be correct, and research continues. It’s even possible that dreams may have evolved for one function but stayed around because dreaming ended up helping us in various 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 picture of the science of dreaming, one dream at a time.
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Dreams – Sequences of images, ideas, emotions, and sensations occurring involuntarily in the mind during certain stages of sleep, often analyzed in psychology to understand the unconscious mind. – In psychology, dreams are considered a window into the unconscious, providing insights into our deepest fears and desires.
Chemistry – The branch of science concerned with the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances. – Understanding the principles of chemistry is essential for developing new pharmaceuticals that can improve mental health.
Benzene – A colorless, volatile liquid hydrocarbon present in coal tar and petroleum, used in chemical synthesis and as a solvent, known for its aromatic properties. – Benzene is a fundamental compound in organic chemistry, serving as a precursor for the synthesis of various polymers and chemicals.
Psychology – The scientific study of the human mind and its functions, especially those affecting behavior in a given context. – Psychology explores various aspects of human behavior, including how we perceive, learn, and remember information.
Unconscious – The part of the mind that is inaccessible to the conscious mind but that affects emotions and behavior, often explored in psychoanalytic theory. – Freud’s theory of the unconscious suggests that repressed memories and desires influence our conscious thoughts and actions.
Memory – The faculty by which the mind stores and remembers information, a crucial area of study in both psychology and neuroscience. – Research in cognitive psychology examines how memory processes can be enhanced through various techniques and interventions.
Problem-solving – The process of finding solutions to difficult or complex issues, a key cognitive function studied in psychology. – Effective problem-solving strategies are essential for success in both academic and real-world settings.
Evolution – The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth, also applied to the development of psychological traits. – The evolution of the human brain has been a central topic in understanding the development of complex cognitive functions.
Sleep – A naturally recurring state of mind and body, characterized by altered consciousness, relatively inhibited sensory activity, and inhibition of nearly all voluntary muscles, essential for physical and mental health. – Sleep is crucial for memory consolidation and emotional regulation, making it a significant focus in both psychology and neuroscience.
Significance – The quality of being worthy of attention; importance, often used in statistical analysis to determine the reliability of results. – In psychological research, statistical significance helps determine whether the observed effects are likely due to chance or represent a true phenomenon.
