The problem with dreams

Summary

Unexplainable Podcast Episode Summary Episode Title: The Problem with Dreams
Release Date: February 19, 2025
Host and Contributors: Noam Hassenfeld, Meredith Hoddenott, and Mark Blumberg
Guest: Dr. Mark Blumberg, Neuroscientist at the University of Iowa

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Introduction: The Mystery of Sleep Twitches

The episode delves into the enigmatic phenomenon of sleep twitches, particularly during REM (Rapid Eye Movement) sleep. Beginning with a charming anecdote about Meredith Hoddenott's three-legged dog, Houdini, the discussion naturally pivots to the broader scientific questions surrounding why animals, including humans, twitch during sleep.

Noam Hassenfeld (00:39):
"So it's like, is he dreaming being a four-legged dog or is he three-legged in his dream?"

---

Traditional Understanding: Dreams and Twitches

Historically, scientists have linked REM sleep twitches to dreaming. The rapid eye movements and limb twitches observed during this sleep phase were thought to be manifestations of dream activity. This belief was supported by experiments where individuals awakened from REM sleep could vividly recall their dreams.

Mark Blumberg (02:11):
"We have been sleeping for thousands of years, yet it was not until 1953 that a graduate student noticed that while you sleep, a dramatic activity takes place."

---

Challenging the Dream Hypothesis

Dr. Mark Blumberg introduces skepticism toward the conventional dream-centric view of sleep twitches. His research indicates that twitches occur not only in young animals, who are rapidly developing, but also persist into adulthood, suggesting that tremors may serve functions beyond dreaming.

Mark Blumberg (04:03):
"And he was like, a newborn animal has had very little waking experiences. What the hell are they dreaming about?"

Mark Blumberg (04:23):
"We move the most when we're young. So what, we're dreaming the most when we're young?"

This led to Blumberg's groundbreaking research, where he surgically disconnected the cortex from the rest of the brain in neonatal rats to eliminate dreaming. Contrary to expectations, twitches continued unabated, indicating that twitches might not be directly caused by dreams.

Mark Blumberg (04:51):
"We literally surgically disconnected the cortex from the other half of the brain."

Mark Blumberg (05:07):
"But we found no effect at all on twitches."

---

Revealing the Sensory-Motor Connection

Blumberg's experiments revealed that twitches generate sensory feedback, activating specific brain regions responsible for sensory input. This finding flips the traditional hypothesis, suggesting that instead of dreams causing twitches, twitches provide essential sensory information that shapes the brain's development.

Mark Blumberg (08:02):
"Every time the animal twitches, you know, 10 milliseconds later, the part of the brain that's responsive to sensory input for that limb shows a huge burst of activity."

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Twitches as Developmental Tools

Blumberg posits that twitches function as a form of "self-pinging," allowing the developing brain to calibrate and fine-tune the sensory-motor system. This process is crucial for young animals as they adapt to their growing bodies and changing environments.

Mark Blumberg (11:20):
"They're bootstrapping their system. They're self-organizing their sensory motor system and it's done from within."

Furthermore, this mechanism may continue into adulthood, serving to maintain and recalibrate the sensory systems as they undergo daily wear and tear.

Mark Blumberg (12:53):
"They shut down the lights, you turn off all that muscular activity, you paralyze the body, and then you just allow these individual twitches to go through."

---

Broader Implications: Beyond Dreams

The revelation that twitches play a fundamental role in sensory-motor development has far-reaching implications. It shifts the focus of sleep research from the nebulous concept of dreams to concrete physiological processes essential for brain development and function.

Mark Blumberg (15:46):
"Because when you label something as a byproduct of dreams, why would anybody spend their time studying it?"

He emphasizes that understanding twitches can unlock deeper insights into how organisms develop and adapt, challenging long-held beliefs about the primary purpose of REM sleep.

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Applications to Robotics and Learning

Blumberg extends his findings to practical applications, suggesting that mimicking twitches in robots could enhance their adaptability and learning capabilities. This interdisciplinary approach bridges neuroscience with artificial intelligence, hinting at innovative advancements in robotic development.

Noam Hassenfeld (25:26):
"Wait, so if we want to make robots that can develop and learn better, we just have to make robots that can sleep?"

Mark Blumberg (25:34):
"Yes. There are people who have used twitching in robots to produce more adaptable robots."

---

Rethinking Sleep: A Multifaceted Phenomenon

The episode concludes with a reflection on the complexity of sleep, advocating for a holistic understanding that encompasses various physiological processes beyond dreaming. Blumberg likens sleep to a Swiss army knife, housing multiple tools necessary for different functions, all contributing to overall survival and adaptation.

Mark Blumberg (19:38):
"Sleep is playing a major role in memory consolidation. And the sleep theory of memory consolidation is so powerful because the idea is that you just can't consolidate memories when you're in the process of learning them."

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Conclusion: A Paradigm Shift in Sleep Science

"The Problem with Dreams" challenges listeners to reconsider the role of twitches during sleep, presenting compelling evidence that these involuntary movements are integral to sensory-motor development rather than mere byproducts of dreaming. Dr. Mark Blumberg's research not only reshapes our understanding of sleep but also opens new avenues for scientific inquiry and technological innovation.

Noam Hassenfeld (25:57):
"This episode came about because Mark listened to the episode we did a while back on the baseball player who had the yips. You know, this kind of performance anxiety that people used to think was only psychological, but is now sometimes being connected to involuntary twitches."

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Notable Quotes

• Mark Blumberg (05:07):
  "We found no effect at all on twitches."

• Mark Blumberg (14:13):
  "They shut down the lights, you turn off all that muscular activity, you paralyze the body, and then you just allow these individual twitches to go through."

• Mark Blumberg (15:46):
  "Because when you label something as a byproduct of dreams, why would anybody spend their time studying it?"

• Mark Blumberg (25:34):
  "Yes. There are people who have used twitching in robots to produce more adaptable robots."

---

Additional Information:
For those intrigued by this episode, further insights and updates can be accessed through Unexplainable’s official channels. Stay tuned for next week's episode, exploring more of the unknown with Vox’s dedicated team.

Transcript

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[Mark Blumberg]

Check, check.

[Noam Hassenfeld]

Hello.

[Meredith Hoddenott]

Hey, Noam.

[Noam Hassenfeld]

Hello, Meredith.

[Meredith Hoddenott]

So, as you know, I have the cutest dog of all time.

[Noam Hassenfeld]

Houdini. Houdini, We've met. He's adorable.

[Meredith Hoddenott]

He is the cutest little boy. And he's a tripod. He's missing his back left leg. He lost his leg, I think, in a car accident. And we call him Houdini. Cause we say that it's. Cause he made his leg disappear.

[Noam Hassenfeld]

He really is like a magic dog.

[Meredith Hoddenott]

Yeah, he just hops around and has this big swinging tail and it just looks like he's always leading a parade. Like, we bring him to airports and just like every child in the terminal is just magnetically attracted to this adorable dog.

[Noam Hassenfeld]

Incredible.

[Meredith Hoddenott]

But there are some times when I wonder, like, you know, does he ever miss having his fourth leg? And I think the place where I see this the most is when he falls asleep and falls into a little puppy dream. He's yipping and all his paws are twitching.

[Noam Hassenfeld]

He's so cute.

[Meredith Hoddenott]

And so I've always thought that in his dreams he must have four legs because his little stump is twitching along with the rest of his leg.

[Noam Hassenfeld]

Oh.

[Meredith Hoddenott]

So it's like, is he dreaming being a four legged dog or is he three legged in his dream?

[Noam Hassenfeld]

The question of exactly what Houdini is dreaming about might be impossible to answer. But Meredith is in very good company in connecting these twitches with dreams.

[Mark Blumberg]

We have been sleeping for thousands of years, yet it was not until 1953 that a graduate student noticed that while you sleep, a dramatic activity takes place.

[Noam Hassenfeld]

During the deepest stage of sleep. When we've got these twitches in our limbs, we've also got twitches in our eyes.

[Mark Blumberg]

Rapid eye movements. REM for short.

[Noam Hassenfeld]

Scientists are pretty sure that REM sleep is when most dreams happen, at least in people, because they've done experiments where they've literally woken people up and asked.

[Mark Blumberg]

Them just sit up and try to remember what was going on. Before I came in, I was dreaming about school and I was flunking the grades, that's all I know.

[Noam Hassenfeld]

But for animals, these twitches are some of the best evidence we've got. There is some scientific theory that when we see our cats and dogs dreaming, or what looks like dreaming, almost barking in their sleep or moving their legs, that they probably are. The idea is that these twitches are bursts of activity that kind of break through the paralysis that happens during REM sleep, which gives us a glimpse of animal dreams. And this has been accepted for a pretty long time. Darwin's protege actually wrote, quote, ferrets dream, as I've frequently seen them, when fast asleep, moving their noses and twitching their claws as if in pursuit of rabbits.

[Mark Blumberg]

The thing about twitches is it looks like obviously it's related to dreams. Right?

[Noam Hassenfeld]

Right. MARK Blumberg Neuroscientist, University of Iowa I.

[Mark Blumberg]

Mean, we know we have dreams, we know that we are moving around. So it just makes sense to think, oh, movements, movements. Why wouldn't they be connected?

[Noam Hassenfeld]

That's what Mark thought at first, but then he started seeing twitches in really young animals, like newborns.

[Mark Blumberg]

And he was like, a newborn animal has had very little waking experiences. What the hell are they dreaming about?

[Noam Hassenfeld]

If twitching was really related to dreaming it, you'd expect that the older you get and the more experiences you have, the more you dream, the more you twitch.

[Mark Blumberg]

But that's not what happens. We move the most when we're young. So what, we're dreaming the most when we're young?

[Noam Hassenfeld]

In case it's not totally obvious by this point, Mark's kind of over dreams.

[Mark Blumberg]

I mean, can we please just not talk about dreams all the time? You know, that's sort of. Sorry, I'm a little bitter. I mean, look, dreams are fascinating, but the focus on dreams is kind of a distraction from what really matters.

[Noam Hassenfeld]

So Mark decided to take dreams fully out of the picture. By experimenting on newborn rats.

[Mark Blumberg]

We literally surgically disconnected the cortex from the other half of the brain.

[Noam Hassenfeld]

He cut off the part of the brain responsible for creating dreams, and the animals twitched completely. Normally, if these twitches were caused by dreams, they should have stopped.

[Mark Blumberg]

But we found no effect at all on twitches. And so I was like, okay, what is this about? You know, this is happening as we counted it up hundreds of thousands of times per day. And pups are in the business of growing, not wasting energy. And, you know, hundreds of thousands of movements, that takes up a lot of energy. Why would you do it unless it had some intrinsic value that had not yet been explored?

[Noam Hassenfeld]

I'm Noam Hassenfeld, and this week on Unexplainable, how this seemingly small question, why do we twitch in our sleep? Has fundamentally shifted how we understand the relationship between the brain and the body. All right, Mark, just to make sure before we dive in here, when I think of sleep twitches, I think of those twitches I get, like, right when I'm falling asleep.

[Mark Blumberg]

Hypnic jerks. Yeah.

[Noam Hassenfeld]

Is that part of this? Is that different?

[Mark Blumberg]

It's a separate phenomenon. It's more akin to what's called a startle than a twitch. You're not in REM sleep when that happens, and there are a lot of theories about it, but the fact is, it's an extremely hard thing to study.

[Noam Hassenfeld]

So we don't really know what's happening there?

[Mark Blumberg]

No.

[Noam Hassenfeld]

Dang. Okay, well, if we're just talking about these REM sleep twitches, then how common are they? Do all kinds of animals and people twitch?

[Mark Blumberg]

Yeah. I mean, I've got a website that collects all these different videos, you know, and what you see across different animals is that the parts of the body that the animals really, really rely on for bringing sensory information into their brain are the parts that twitch the most. So for us, you know, rapid eye movements are twitches of the eyes. We also twitch our fingers a lot when we're adults. With cats, you see their paws moving a lot. Ferrets, you see whisker twitches. Rats, you see lots of whisker twitches. They use their whiskers to learn about the world just as well as we use our eyes.

[Noam Hassenfeld]

And if all of these twitches aren't just, you know, enacting dreams, how do you start figuring out what they actually are?

[Mark Blumberg]

Well, you know, the first thing you have to do is try to figure out what parts of the brain are producing this. I mean, how is this all happening? Okay, and what we started to see when we were recording brain activity is that the brains of neonates, baby rats, were much more active during sleep and much more active when animals were twitching than when they were awake. Okay. It's one thing to think that sleep has brain activity associated with it. That was a huge finding 80 years ago.

[Noam Hassenfeld]

Mm.

[Mark Blumberg]

It's another thing entirely to see that the brain activity is greater, and I mean much greater during REM sleep than during wake.

[Noam Hassenfeld]

And I assume it's reasonable to think all that brain activity is connected with these twitches. Right. Is there a way to actually test it?

[Mark Blumberg]

Yeah, I mean, the biggest problem was methodological. How do you record brain activity in a very, very small baby rat? Which was the best Animal for doing this sort of work, you have to figure out how to get them in a stable situation so you can drop the. These very fine electrodes into the brain. And so it took years to get the methods going. But what we started to see is that every time the animal twitches, you know, 10 milliseconds later, the part of the brain that's responsive to sensory input for that limb shows a huge burst of activity. So twitch activity. Twitch activity, not the other way around. This is a sensory signal. So this timing here matters. If you have a twitch and then you get a burst of activity in the brain after that twitch, then you have a pretty good idea that that's a sensory signal that you're picking up on.

[Noam Hassenfeld]

Yeah. So like a signal the brain is getting from. From a nerve or a muscle or something?

[Mark Blumberg]

Yeah, the sensory input. So every time you move a limb, you have sensors in your muscle, you have sensors in your skin and your joints. And those sensors, when you have movement, they produce neural signals that flow up into the brain. That's how we know when our arms are moving or when you touch something. So we have sensors all throughout our limbs. And so when the limbs were moving, that's when we were seeing the brain activity in parts of the brain that are responsive to those types of sensory signals.

[Noam Hassenfeld]

And just to be totally clear here, the activity that you saw in the brain was happening after the twitches?

[Mark Blumberg]

Yes. I mean, you can't really see it because it's happening so fast. You have to get down to milliseconds. So what my student, his name is Ryan Glanz, what he did was he was recording from the part of the cortex that responds to sensory feedback. And for every neuron that he was recording from, he gave it a different musical note. So that you could easily see that when the limb twitches, there was a burst of activity in this part of the cortex.

[Noam Hassenfeld]

And you have a video of that rat experiment, right?

[Mark Blumberg]

Yeah.

[Noam Hassenfeld]

Can we take a look?

[Mark Blumberg]

Sure.

[Noam Hassenfeld]

Wow. It sounds twitchy. So what I'm looking at here is this kind of little paw, and the twitching in the rat paw is kind of generating these sounds that are mapped onto neurons.

[Mark Blumberg]

Correct. So every time the limb twitches, there's a really, really clear burst of activity. And at these ages, all the neurons are firing together. And that's why it just sounds like a chord and not a lot of, like, little different musical notes happening in sequence. And it's just a lot of activity happening simultaneously.

[Noam Hassenfeld]

Wow. Okay. So you're. You're essentially flipping the traditional Hypothesis on its head. Right? It's not dreams causing twitches. It's twitches causing dreams or twitches. I don't know. It's not necessarily twitches causing dreams, Right? It's twitches causing some impact in the brain.

[Mark Blumberg]

Yeah, I mean, obviously twitches are not going to be the sole source of all things in the dreaming brain, but that it is at least providing sensory input to the brain during sleep that we know for a fact. So it does flip it on its head, and it completely changes the calculus of what's happening in a dreaming brain.

[Noam Hassenfeld]

So then why would the twitching be happening to begin with? Like, what's the. What's the point of all of this twitching?

[Mark Blumberg]

Well, so this is where you have to start to think about, well, what is it that's special about twitches? Right. The first thing that you notice is that the movements are discrete. It turns out that discreteness is incredibly important. So imagine that you're standing at a switchboard with hundreds of different switches. Let's just say they're neurons. And then all the wires from all of those switches lead to a whole bunch of lights. So every switch controls a different light. Okay? And let's say that those lights are muscles. If you're sitting at that switchboard and you want to figure out which switches control which lights, you don't just start throwing all the switches simultaneously, because if you did, you're gaining no information. All you're seeing is a bunch of lights turn on and you've thrown a bunch of switches. The answer is you throw one switch at a time. You see which light comes on, and then you make that connection. And so that's the difference between wake movements and twitches. You know, I'm sitting here talking to you, and I'm gesturing, and I'm moving all my limbs simultaneously. My posture, my neck, everything, my eyes, everything's moving simultaneously. Right? That's waking. That's one of the characteristics of waking movements, is that they're continuous and they're simultaneous, and they're highly complex. But when you're twitching one twitch at a time, you ping your body and the body pings you back. And then you know that the first thing is related to the second thing. And that's the discreteness of twitching. And that explains why these animals are twitching so much. You never grow and develop, develop more than you do when you are young. So.

[Noam Hassenfeld]

So they're literally. Your theory is that the power goes out and they're flipping switches in a fuse box or something to see which switch controls which Light, because there's no other stimuli coming in. Right. They're in a controlled environment. So they're essentially doing sort of an experiment to learn their own body.

[Mark Blumberg]

Yeah, exactly. It's. They're bootstrapping their system. They're self organizing their sensory motor system and it' done from within. It's a big mystery as to how we develop things like our sensory motor system. How do you actually learn about your body? When you're a newborn rat or a human and you're born, you have no idea how your body is formed, you have no idea how it moves. And it's going to be changing every single day as you grow and figure out new things. Right. So how do you figure out how to move that body in real time through the process of development? You can't prescribe this, you can't blueprint this. There's no genetic mechanism that can tell you exactly how you're going to be on day three versus day five. So you need to have a system that's highly adaptable. But you said something that's really important. You said, turn off the lights. And that's actually a metaphor I've used before because that's sort of what sleep paralysis is. Sleep paralysis is like turning off all that background noise, creating a very low noise situation for your body. And now when you ping it with a twitch, you get a really, really clear signal back.

[Noam Hassenfeld]

Yeah.

[Mark Blumberg]

So you shut down the lights, you turn off all that muscular activity, you paralyze the body, and then you just allow these individual twitches to go through. And then you take that information and you put that into the system for the purpose of maintaining your circuits, calibrating your circuits so that you end up with a finely tuned sensory motor system so that we can function in the world.

[Noam Hassenfeld]

And is that, you know, if twitching is about learning, we would assume younger animals would twitch more. Is that the case?

[Mark Blumberg]

Absolutely.

[Noam Hassenfeld]

And then, I mean, older animals also twitch.

[Mark Blumberg]

Yes.

[Noam Hassenfeld]

Why would they be twitching?

[Mark Blumberg]

Good question. First, we don't twitch as much when we're older. But second, some animals do twitch quite a lot. The part of the body that twitches matters. And this is just a theory because nobody has really explored it with the level of sophistication that we need. But we have to calibrate our systems. You know, over the day, we get tired, we lose control. You know, our vision gets worse and worse through the day. And then you wake up the next day and you're rejuvenated. I think it's possible that twitches continue throughout life for some parts of the body for that purpose, to calibrate a weary system. And there's some hints out there in the world that this could be happening, including work that was done in humans. But they're mostly hints and it needs to be done more systematically.

[Noam Hassenfeld]

And why do you think the scientific community missed this for so long? Missed understanding twitches as a developmental process?

[Mark Blumberg]

Because when you label something as a byproduct of dreams, why would anybody spend their time studying it?

[Noam Hassenfeld]

Like it's just closing off further inquiry. It's just being like done.

[Mark Blumberg]

Yeah, I mean, there. Look, I don't want to be too flippant about it. Dreams are fascinating, but they're kind of a red herring when it comes to studying sleep. There is, to my mind, many, many fascinating things about sleep that have nothing to do with dreams. And the focus on dreams is kind of a distraction from what really matter.

[Noam Hassenfeld]

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[Mark Blumberg]

I stream on Twitch. My cooking chef. What the is Twitch?

[Noam Hassenfeld]

So, Mark, if we take a step back from twitches here and just talk about sleep in general for a second, what would you say people get wrong about sleep?

[Mark Blumberg]

I think one thing that people may get wrong about sleep is they think about it as a single thing. They think about it as just a unitary phenomenon. And I think the jury's still out as to what sleep actually is. It's very highly variable across the lifespan, highly variable across different species, and there's no singular definition of sleep that applies. Plus, you know, I Liken it to wake. I mean, there's no singular function for wake. Wake is not a singular phenomenon. And we do all kinds of things in it. We walk, we talk, we eat, we watch tv. We do all kinds of things when we're awake. Why do we think that wake would be any different than sleep? To my mind, sleep is a conglomeration of things, all these separate components. And you got to think about, well, why are all these different parts there? What brings all these things together during sleep? Is it that all these different parts of sleep are like the place settings at a dinner table? So you have your fork, your spoon, and your knife. They all serve one purpose, to eat. But what if they're also more like all the collection of tools in a Swiss army knife? You've got a fish scaler and a magnifying glass and a toothpick and a nail file. What the hell do those things have to do with each other? Nothing, except they're all together in one place. So is sleep more like a dining room setting, or is it more like a Swiss army knife? And the answer is, it's probably a little bit of both. And our task is to figure out how all these different parts of sleep fit together. And that's the big question about sleep. Which parts of sleep do these different animals exhibit? How does it contribute to their survival? How does it contribute to their learning? How does it contribute to their evolution? To me, that's the bigger question about sleep.

[Noam Hassenfeld]

Can you tell me about some of those tools in the toolbox, aside from twitching?

[Mark Blumberg]

Sure. I mean, you know, the more we look, the more we discover new things. You know, we've only scratched the surface of sleep, but there's the glymphatic system, which is basically being called, like a waste clearance system for the brain to remove debris, to remove dead cells. And you have fundamental brain rhythms. For example, you have a rhythm that's involved in movement and learning and things of that nature.

[Noam Hassenfeld]

Okay.

[Mark Blumberg]

And then there's a whole bunch of animal and human work that's been done looking at the role of these very specific brain rhythms for the consolidation of memory. So sleep is playing a major role in memory consolidation. And the sleep theory of memory consolidation is so powerful because the idea is that you. You just can't consolidate memories when you're in the process of learning them. So you have to stop learning new memories in order to consolidate the ones you already have.

[Noam Hassenfeld]

You know, I've been getting back into playing piano again, and I've been going through some Bach inventions, and I Feel like after I sleep sometimes it's like more deeply in me. Does that make sense? Is that something like memory consolidation?

[Mark Blumberg]

It absolutely is. So I have the same thing that happens to me. I'm a drummer. And when I learn a new pattern.

[Noam Hassenfeld]

Oh, I'm also a drummer. I'm more of a drummer. That's my training.

[Mark Blumberg]

So tell me if you can relate to this. So you know, when you've started learning a very complex new pattern, it's all very deliberate, slow and rote. Right. Every limb doing something and you can't do anything else. I mean, all you, you're concentrating on every limb and what they're doing. And then all of a sudden, six days in, I don't know, it's like to do. Right. Everything's happening. And at the same time you can hold a conversation with somebody you know. Right, right.

[Noam Hassenfeld]

It's like gone to a deeper level in your understanding.

[Mark Blumberg]

Yes. It's called automaticity. And you know, it's a pet hypothesis. It has never been confirmed or tested seriously yet. But I just think, wouldn't that be amazing if sleep were involved in that kind of skill transfer? Yeah, you're taking it, that's something very conscious. You're highly attentive to it and turning it into something that you can do on its own. And, you know, maybe that's how we learn how to do things like walk. I mean, they start off as pretty difficult, but eventually we don't think about those anymore either. And we're actually doing an experiment that's in the dancing realm with some colleagues out in California. And we want to know, when people develop these automatic behaviors, does that show up somehow in their sleep patterns? Because the development of automaticity is a very, very natural place to think about how twitching and these sorts of sleep related phenomena might be playing a role in the consolidation of those motor memories that happen, like drumming and playing, you know, Bach and stuff like that.

[Noam Hassenfeld]

Yeah, I think, tell me if this is a wrong way to think about it, but I think about the New York subway system, which is, you know, the biggest 24 hour subway system in the world.

[Mark Blumberg]

And rats are very important for the subway system too. Very important.

[Noam Hassenfeld]

Rats are important. But the 24 hour operation of the subway is kind of one of the reasons why the subway might suck as much as it does. Just because it's harder to fix stuff. Like other cities where even if you could just work from like 2 to 6am you can fix some stuff. But in New York, if they really want to fix stuff, they have to Just do major surgery. They have to, like, shut down a line. And so a lot of the subway just sort of falls into disrepair.

[Mark Blumberg]

That's a wonderful metaphor. You know, there are just some things we do in wake that seems just obviously to be incompatible with the things that need to happen during sleep. And so we take our day and we break it up into two very different states. Here's our moving about the world and being friends and talking and eating and doing things. That's one part of our lives. And the other part of our lives is somehow connected to the first part, but is very different. And they have to be complimentary so that the sleep is supporting what we need to do when we're awake. Consolidating memories, building proteins, repairing systems. All of those things need to go on, but they're just incompatible with wakefulness.

[Noam Hassenfeld]

So then if I were to bring twitches back into the conversation here, are they kind of emblematic of this larger, lights off, recalibrating learning process of sleep? Is that what stands out to you?

[Mark Blumberg]

You know, I'm a behaviorally oriented neuroscientist. I want to understand the role of behavior, how it develops, and how it influences the developmental process. And we have a lot of ideas out there right now in the world, what I would call very simplistic ideas. People think about, well, you know, you have a genetic blueprint, and the animal just develops. And then it's like, blah, blah, blah, okay? And these are just corrosive ideas for thinking about development, because development is a process, right? It's extremely complicated, and it's extremely plastic. You know, brains are not isolated, separate, standalone organs. They're embodied. There's a reason why developing robots is a lot more difficult than it is just to develop, like AI that has no body to control. And it's because controlling a body is hard. And the one thing that robots can't do yet is developing. And I think that there's something fundamentally important about developing in a body that changes and learning how to adapt to those changes. That is partly why we are so facile in terms of how we use our bodies on a regular basis. So for me, it's an extension of everything I've ever believed about the developmental process and what we need to do as developmentalists to understand that process, as opposed to the more sort of static, you know, ways that oftentimes people think about what's happening.

[Noam Hassenfeld]

Wait, so if we want to make robots that can develop and learn better, we just have to make robots that can sleep?

[Mark Blumberg]

Yes. There are people who have used twitching in robots to produce more adaptable robots. Oh, they've mimicked twitches in robots and have produced robots that were better able to adapt to changes in their bodies. Okay, crazy stuff. Now you're gonna ask your robots dream and I'm gonna. My head's gonna explode, you know?

[Noam Hassenfeld]

Yeah. Do. Do androids dream of electric. That was Professor Mark Blumberg and Fun Story. This episode came about because Mark listened to the episode we did a while back on the baseball player who had the yips. You know, this kind of performance anxiety that people used to think was only psychological, but is now sometimes being connected to involuntary twitches. So Mark reached out to me and told me the episode had given him some new research ideas on twitches. We started talking, and then we ended up with a whole episode on Twitch Sleep Twitches. So if you're a scientist out there and you're listening and you're getting an idea for some new research, let us know. We're always on the lookout for more interesting scientific questions, and we'd love to talk to you. This episode was produced by me, Noam Hassenfeld. We had editing from Meredith Hoddenott, who runs the show, mixing and sound design from Christian Ayala, music from me, and fact checking from Katie Penzemoog. Thomas Lu is wondering why things make so much sense. And Bird Pinkerton headed back to the Octopus Hospital, knowing she had her army to fight the birds. But when she got there, she saw the door blown out. Windows were smashed, cables were pulled out, hanging everywhere. She was too late. Thanks, as always, to Brian Resnik for co creating the show. And if you have thoughts about the show, send us an email. We're@ unexplainableox.com and you can also leave us a review or a rating wherever you listen. It really helps us find new listeners. You can also support the show and all of Vox's journalism by joining our membership program today. You can go to vox.commembers to sign up, and if you signed up because of us, send us a note. We'd really love to hear from you. Unexplainable is part of the Vox Media Podcast Network and we'll be back next week.