Smash Notes
#164 – Andrew Huberman: Sleep, Dreams, Creativity & the Limits of the Human Mind
Andrew Huberman is a neuroscientist at Stanford. Please support this podcast by checking out our sponsors: – MasterClass : https://masterclass.com/lex to get 15% off – Four Sigmatic : https://foursigmatic.com/lex and use code LexPod to get up to 60% off – Magic Spoon : https://magicspoon.com/lex and use code LEX to get $5 off – BetterHelp …
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Notes
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Andrew Huberman says two forces decide sleepiness and wakefulness. The longer someone stays awake, the more adenosine accumulates in the brain. Adenosine binds to adenosine receptors and creates sleepiness, independent of time of day or night. How sleepy a given amount of adenosine feels also depends on a body-temperature cycle. Huberman calls the cycle a well-conserved oscillation that takes 24 hours, plus or minus an hour. He does not think alignment with the 24-hour spin of the Earth is a coincidence. Sunlight covers one portion of the spin and darkness covers the other.
On a schedule of days awake and nights asleep, temperature is lowest around 3 a.m. or 4 a.m. It creeps up through the morning, peaks in the late afternoon, then drops toward evening. Staying up for 24 hours pulls the two forces apart. On the regular schedule Huberman follows, he gets very sleepy around three or four in the morning after staying past midnight, 2 a.m., and 3 a.m. Around five, six, or seven in the morning, his normal wake-up time, he feels more alert even though adenosine has kept accumulating. Adenosine is higher the longer he stays up, yet he feels more alert than a few hours earlier, because the temperature cycle has swung back toward wakefulness.
Adenosine makes you sleepy. The 24-hour temperature oscillation decides how sleepy or how awake you feel.
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On the show, being fasted increases alertness because fasting puts high levels of epinephrine in the system. People always think that going without food will leave them tired. Energy from food is used from glycogen after a long storage and conversion process, and the food itself consumes energy to digest. A lot of people feel better fasted.
The comparison is fasting or being thirsty before exhaustion arrives. The show says people presumably fasted for long periods throughout history and still had to stay up for two or three days. If a family member is sick, staying awake in the hospital can happen without any trouble. The alertness system is all mental.
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Andrew Huberman says depriving people of rapid eye movement sleep makes them selectively bad at uncoupling emotion from things that happened in the previous days. Little things start to seem like big things. People become slightly psychotic in that state. He notices it when he is irritable and when the word the no longer looks spelled right.
Sleep deprivation makes people irritable. Early in the night, more of each 90-minute cycle is slow-wave sleep, sometimes called non-REM sleep. Early bouts help muscular repair and certain forms of learning. Rapid eye movement sleep fills more of each 90-minute cycle later, typically toward morning. Emotional processing happens then, along with the return of feeling refreshed rather than irritated. With more fatigue, sleep drops straight into rapid eye movement and skips stage one, stage two, and stage three, so the system compensates. Huberman says there may be bouts when saying nothing is the better move, to conserve energy. A grind feeling is epinephrine being released, epinephrine that physical effort could use. Humor resets the irritation through dopamine and a fresh perspective. He says the reset is biology, a real chemical event, not a hack, a trick, or a visualization.
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On the show, limiting calories to four, six, eight, or even ten hours of every 24-hour cycle, kept more or less with the light and with when the sun is out, leads to less liver disease, improved metabolic markers, and less body fat. Peer-reviewed papers in journals like Cell report the result.
In the mouse studies, the animals could eat whatever they wanted, and as much as they wanted, inside a limited period of the 24-hour cycle. They did great. They maintained a healthy weight or even lost weight. The same amount of food stretched across the entire 24-hour cycle, with eating every hour or two hours, left the animals fat and sick.
How much of the mouse data translates to humans is not clear. What is really clear with humans is adherence. What people will do in a laboratory is often hard to do in the real world.
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Salt is great unless a person has hypertension, provided they drink enough water. Neurons depend on sodium rushing into the cell, so the brain and nervous system need enough sodium outside the cell. Nerve cells also need magnesium and potassium. People who overdrink water and do not consume enough electrolyte die.
On the show, an article in Science Magazine from about a decade ago is the reference for how salt had been demonized. Hydration is still key, and enough water plus electrolytes keeps the nervous system functioning well. A lot of people get shaky or jittery while fasting and think they need sugar. Put some salt in some water and they feel fine. Potassium and magnesium belong with salt for nerve cells to work.
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On the show, placebo-controlled double-blind studies have shown that getting at least a thousand milligrams of EPA can offset antidepressive symptoms as much as some selective serotonin reuptake inhibitors, including Prozac and Zoloft. The result is called pretty impressive. EPA is high in fish oils and also turns up in some meats and other plants.
On the show, people can get enough amino acids from plant-based sources, and it probably takes a little more work. The benefit of omega-3 and omega-6 ratios, including fish oils, is really clear. The trials were matched, placebo controlled, and double-blind.
In Scandinavia, people know to consume a lot of omega-3s in winter because omega-3s are good for you and good for the brain.
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On the show, rapid eye movement dreams that dominate towards morning divorce emotion from prior experiences and extract general rules and themes. They work as self-induced therapy, like trauma therapy: an intense emotional experience without the fear. Go without rapid eye movement sleep for too long and you become irritable and start linking negative emotions to almost everything.
During the dreams you are paralyzed and cannot move. Epinephrine, the molecule of stress, fear, and excitement, is very low, so you cannot act the dreams out. The dreams are heavily emotionally laden and include theory of mind. A Nobel Prize winner for immunoglobulins, also a neuroscientist, has shown that replay of neurons in the hippocampus and elsewhere is an approximation of the previous episode, and a lot of fear unlearning, uncoupling emotion from hard or traumatic events, occurs in rapid eye movement sleep. People sometimes wake suddenly from one of the dreams and the heart beats really, really fast, a surge of epinephrine on the way out. Atonia, the paralysis, invades the waking state. Pot smokers experience the invasion a lot more than non-pot smokers. Waking paralyzed for a second is terrifying, until a jolt back to alertness.
Rapid eye movement sleep is for forgetting the bad stuff. The dreams are very intense, and they uncouple emotions from bad experiences.
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On the show, a postdoc at Stanford put octopi on MDMA, also called ecstasy. She had a paper in Current Biology showing what the animals did next. The octopi then wanted to spend more time with other octopi. They started cuddling.
Andrew Huberman says she is Turkish, as he believes, and he apologizes because her last name escapes him at the moment. He calls the missing surname a function of his brain. The part he states outright is the experiment. She put octopi on MDMA, on ecstasy, and found the social change. He says the paper is published in Current Biology, and he calls Current Biology a great journal. The published finding is social. After MDMA, the octopi wanted to spend more time with other octopi, and they started cuddling.
He remembers the cuddling even while her last name escapes him. A Stanford postdoc gave octopi ecstasy, Current Biology published the paper, and the animals responded by spending more time together.
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On the show, ecstasy is a very unusual drug in a kit that also includes psilocybin and LSD. Psilocybin and LSD promote heavy serotonin release and ramp up lateralized connections. Ecstasy is different because of the way the drug is designed: dopamine is very high, dopamine release goes through the roof, people feel great, they want to move, and they have a lot of energy, while serotonin levels are also high. The show calls the combination a very unnatural state.
Dopamine is the molecule of pursuit, reward, and more and more. Serotonin is one of bliss and of being content right where a person already is. As far as the show knows, human history had never offered a way to open dopaminergic and serotonergic states at the same time. The show marks the depression claim as uncertain and leaves it as an interesting question: whether ecstasy has particularly high potential for the treatment of certain forms of depression.
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DMT taps a brain state distinctly different from LSD and psilocybin. People experimenting with DMT describe the experience as a freight train through space and time.
The person speaking has never tried DMT and asks what allows hallucinogenic states. DMT is a really interesting molecule, and a lot of people are experimenting with DMT now. They describe it as a freight train through space and time. LSD type experiences and psilocybin are very different. Time and space are very fluid, but the experience tends to be a slower roll. It is clear that DMT is tapping into a brain state distinctly different from the other psychedelics.
The freight train is a separate state from the fluid, slower roll people report with LSD and psilocybin. DMT is not the same passage through space and time.
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On the show, Lex Fridman downloaded every Joe Rogan podcast as video from before Joe Rogan went with Spotify and kept the files as a private collection. Processing extracted all of the faces, then ran blink tracking, pupil tracking, and blink detection.
Computer vision studies the eye by non-contact sensing of humans, including behavior in places such as semi-autonomous vehicles. Lex Fridman says there seemed to be a lot of signal from blinking that is not fully understood yet. In the lab, dilation of the pupil has been used quite a bit to infer workload and cognitive load, but the picture is murky. In the wild, how much signal comes from the eye and the human face is not completely well understood. The careful pass starts around episode 900, when the videos switched to 1080p. Earlier video was much worse. Marijuana consumption and drinking came up as relevant to the people in the data. Only long sequences where the eyes detect exceptionally well were kept.
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On Huberman Lab, the hardest part turned out to be staying on a single topic for three or four more episodes before switching to a new topic. University teaching always brings the temptation to pivot to something else, but drilling into a subject really deeply is where the gems reside.
The challenge is how to make the long stretch interesting, how to keep people on board, how to give people tools along the way, and how to stay close to the scientific data. Listeners bring a tremendous range of backgrounds. Some people have asked for more names, more bits and parts of the nervous system, and cellular molecular mechanisms. Other people have said they do not understand any of it but think they are keeping up. A university course has prerequisites, so everyone comes to the table with more or less the same knowledge. Andrew Huberman has a very limited sense of what the audience knows and does not know. The comment section on YouTube is a source of feedback, and an office hours-like episode every third or fourth episode addresses common questions.
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Andrew Huberman puts at least 10 to 15 hours of passive listening preparation into each podcast. He says the active preparation might be five or six hours. He prepares quite a lot, and coming up at the end with something somewhat crystallized is satisfying. He says it feels like his dopamine circuits just love that payoff.
He looks for the overlap in the different elements. He generally reads 10 or 15 papers, mostly good reviews: annual reviews and the annual review of physiology. He chases a few references and listens to university-level lectures on YouTube. In the morning he works out in the gym in his house and throws random ideas on a whiteboard, including dreams and hallucination. He starts to eliminate, draws lines between the common points of intersection, and distills an outline. On walks with his dog he thinks about what he wants to say, then bothers a couple of people and blabs to them.
The only pain is that a year later, after he has talked about the stuff a bunch of times, the same material is so much more succinct. At some point he pulls the trigger anyway.
Related notes
- What Happens to Your Body During "dream Sleep"
- How Did a Much Later Bedtime Leave Deep Sleep Short?
- Why Does Caffeine Block Sleepiness Instead of Raising It?
- Why Wait Ninety Minutes Before Morning Caffeine?
- What Does Caffeine Do to Your Body
- Why Did Matt Walker Float Three Cannabidiol Sleep Routes?
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