Today’s episode focuses on a second but very different function of dreaming: the ingenious processing and interconnection of memories that inspires creativity and even problem-solving ability. Matt describes how we can think of REM sleep dreaming as a form of informational alchemy, in which we build new connections. As a consequence, we wake the next morning with a mind-wide web of associations capable of divining solutions to previously impenetrable problems. A great illustration of dream-inspi...
May 09, 2022•16 min•Ep. 21
Matt’s back with part three of his series on the science of dreaming! In this episode, he discusses how he and other scientists have discovered that dreams are not simply an unintended by-product of REM sleep. Instead, dreams provide at least two essential benefits for human beings. The first of these functions involves nursing our emotional and mental health and is the focus of this episode. Matt helps us understand that what makes a memory emotional is that, at the time of the experience, we r...
Apr 25, 2022•14 min•Ep. 20
In the second episode of this series about REM sleep dreaming, Matt explores what the science has to say not only about how we dream at the brain level, but what it is that we dream about. T raditionally, civilizations such as those in ancient Egypt, believed that dreams were a form of divine intervention--a message from the heavens. Thereafter, Matt discusses Sigmund Freud, who introduced the notion of dreams originating from within the brain, not the heavens, and thus could be considered a sci...
Apr 11, 2022•17 min•Ep. 19
This week’s episode is the first in a new multi-part series all about dreams! Today, Matt focuses on the question of how your brain generates these things called dreams. Matt starts with an unexpected statement: last night, when you were dreaming, you became psychotic. 5 things happen when you dream that justify his diagnosis: 1) you see things that aren’t there, 2) you believe things that could not be true, 3) you become confused about time, place, and person, 4) you have wildly fluctuating emo...
Mar 28, 2022•16 min•Ep. 18
Matt has a special announcement this week: a new recurring type of episode called, ‘Sleep is Bloody Remarkable’. This series of episodes will share fascinating facts about sleep that will blow your mind! In the premier episode, Matt focuses on something truly (bloody) remarkable: half-brain sleep, or unihemispheric sleep. Unihemispheric sleep is the phenomenon of when one hemisphere of the brain is awake, while the other sleeps. Matt goes on to discuss how the two sides of the brain rotate their...
Mar 14, 2022•14 min•Ep. 17
Matt returns with Part 2 of his series on sleep and weight gain. This time around, he teaches us how a lack of sleep not only makes you eat more food, but changes what types of food you want to eat, and eat to excess. First, Matt describes how underslept individuals that are limited to 4-5 hours of sleep for several nights will experience a 33% increase in the desire to eat obesogenic, sugary treats. In addition, they will suffer a 30% increase in craving for heavy-hitting carbohydrates, like pa...
Feb 28, 2022•11 min•Ep. 16
Matt kicks off a two-part series all about sleep, eating, and weight gain. He starts by introducing two appetite-regulating hormones: leptin and ghrelin. Matt explains how leptin sends a signal of fullness, to your brain. When leptin levels are high, your appetite is reduced, and you feel satisfied by the food you eat. Ghrelin does the exact opposite. It revs up your hunger, so when your ghrelin levels are high, you don’t feel satisfied by the food you ate, so you want to eat more. Matt tells us...
Feb 14, 2022•12 min•Ep. 15
In the previous episode, Matt described the role of temperature in helping us fall asleep. In this episode, Matt teaches us all about the role of temperature in helping us stay asleep across the night, and then more effectively wake up the following morning. First, Matt takes us back to the body temperature suit experiments that were able to warm or cool different parts of the body. Matt explains that, using this same method, when you continue to cool the body throughout the first and middle par...
Jan 31, 2022•10 min•Ep. 14
In today's episode, Matt reveals how 1) your own temperature and, even more precisely, 2) the temperature of different parts of you, as well as 3) the temperature of your bedroom, can change how well or how poorly you sleep at night. Matt describes the basic physiology of how your brain and body needed to drop their core temperature by about 1 degree Celsius, or about 2 to 3 degrees Fahrenheit, for a person to fall and stay asleep across the night. This is the reason why we will always find it e...
Jan 17, 2022•10 min•Ep. 13
In today's episode, Matt takes us on a deep dive into melatonin. He covers four main topics: 1) what is melatonin? 2) how does melatonin work? 3) what does melatonin do, and *not* do, for sleep? 4) how can we think about melatonin supplementation? First, Matt describes that melatonin is a naturally occurring hormone released by the brain. He gleefully notes that melatonin is often called, “the vampire hormone” as it comes out at night. In doing so, it signals that it is nighttime, which in turn ...
Jan 03, 2022•10 min•Ep. 12
In this week’s episode, Matt continues his discussion of sleep and caffeine. Here, we learn about the paradox of coffee, one in which coffee provides health benefits, despite its negative impact on sleep. Before addressing that, however, Matt speaks about one last sleep consequence of caffeine: regardless of your sensitivity to caffeine, it can still disrupt the quantity and electric quality of your deep non-REM sleep. This can lead to a cycle of caffeine dependency 1) you drink more coffee the ...
Dec 20, 2021•10 min•Ep. 11
In today's episode, Matt unpacks the world of coffee, and caffeine in the first of a two-part series on caffeine. Matt describes the numerous health benefits associated with coffee, the fact that Matt has even changed his tune a little and advocates a morning cup for some. Matt may not have anything to do with caffeine itself, with more details on that in part 2. In part 1, Matt then takes a deep dive into the different ways in which caffeine negatively impacts your sleep, some of which you may ...
Dec 06, 2021•11 min•Ep. 10
On last week’s episode, we learned about the three main ways alcohol can harm our sleep: 1) alcohol results in sedation rather than naturalistic sleep, 2) alcohol causes sleep fragmentation, and 3) alcohol impairs REM sleep. Today, Matt dives into each of these negative impacts, explaining exactly how and why alcohol disrupts our sleep in these specific ways. First, alcohol is a class of chemicals called “the sedatives,” and sedation is not natural sleep. Healthy sleep is a very active, highly c...
Nov 22, 2021•8 min•Ep. 9
Although some people may believe that a drink or two in the evening will help them sleep better, today’s episode shows us that alcohol harms our sleep in several different ways. In the first of two episodes on sleep and alcohol, Matt talks about alcohol as a chemical, and the main ways it negatively affects our sleep. Alcohol has a sedative effect that switches off brain cell firing as we sleep. Alcohol also fragments our sleep, making it less restorative, and blocks REM sleep, which is critical...
Nov 08, 2021•11 min
As the great Roman poet, Ovid, once said, “There is more refreshment and stimulation in a nap, even of the briefest, than all the alcohol ever distilled.” But are naps always a good thing? Are we even designed to nap? And if you do nap, when should you do it, and for how long? Today Matt explores the benefits and pitfalls of napping, how napping may fall in line with our pre-programmed sleep patterns as humans (a natural drop in alertness between 1 and 4pm each day), and what it means if you fin...
Oct 25, 2021•11 min
In the final episode of our three-part series about chronotypes, Matt examines the question of whether your chronotype is truly fixed, or if you can change an evening type to a morning type (though you will hear that Matt’s preference is for society to change, not the individual). Matt reviews a fascinating study by an Australian-lead research team that tried to turn night owls into morning larks. Participants had to follow a series of strict rules over the course of a three-week study. This inc...
Oct 11, 2021•7 min
In the second episode of our three-part series on chronotypes, Matt speaks about what happens when you do not sleep in harmony with your natural chronotype. Unlike morning larks, night owls simply cannot fall asleep easily early at night, which leads to the first and most obvious consequence of not sleeping in line with your chronotype—you don’t sleep as much. Matt explains that morning types sleep over 7-hours per night on average, while evening types can only manage 6.6-hours of sleep per nigh...
Sep 27, 2021•10 min
Episode 04: Chronotype: Part 1 Summary Are you a morning type? Or are you an evening type? Perhaps you are neither of the two? Today’s episode is the first in a three-part series all about your chronotype, or your body’s natural biological preference to be awake and be asleep at a certain time. Matt begins by explaining exactly what your chronotype is, then breaks down the three main “flavors” of chronotype (morning lark, night owl, or somewhere in-between). In addition, and listed in the show n...
Sep 13, 2021•12 min
#03 Circadian Rhythms Continuing on from last week’s episode about sleep pressure, today, Matt Walker dives into the second half of the sleep-wake story, circadian rhythm. Matt explains that your circadian rhythm, or your 24-hour internal clock, begins drumming out its loud activating beat just before you wake in the morning and gets louder throughout the day, peaking in the early afternoon and hitting its lowest point in the middle of your sleep phase overnight. Matt describes how circadian rhy...
Aug 26, 2021•11 min
Episode 02: Sleep Pressure Welcome back to the Matt Walker podcast. Today’s episode looks at the story of sleep pressure - how it works, how you can try to block it or fool it, and why you feel so good after a night of full, peaceful sleep. Matt explains that from the moment you wake up, a chemical called adenosine begins to build up in your body. The longer you’re awake, the more adenosine will build up and the sleepier you will feel. This is called sleep pressure. Once adenosine concentrations...
Aug 16, 2021•9 min•Season 1Ep. 2
Episode 01: Highlights Human sleep has been separated into two main types: Non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep NREM sleep is further divided into four stages, with each stage increasing in their depth of sleep REM sleep is named this way because of the bizarre, horizontal, shuttling eye movements that occur underneath your eyelids during this stage of sleep REM sleep is the principal stage in which we dream, although it can occur in the other stages as well NRE...
Aug 02, 2021•13 min•Season 1Ep. 1
The Matt Walker Podcast is all about sleep, the brain, and the body · Matt is Professor of Neuroscience at the University of California, Berkeley · He is the author of the book, Why We Sleep, and has given a few TED talks · Matt is an awkward British nerd who adores science and the communication of science to the public.
Jul 26, 2021•4 min
