Science Friday - Vision and the Brain, Jellypalooza. Sept 29, 2023, Part 1

Episode Date: September 29, 2023

After 7 Years, NASA Gets Its Asteroid SampleAbout a week ago, space nerds got the delivery of a lifetime: a sample from Bennu, an asteroid soaring through the galaxy, currently about 200 million miles away. The capsule of rocks and dust came courtesy of NASA’s OSIRIS-REx, the first U.S. mission to collect a sample from an asteroid.Scientists hope it’ll help unveil some of the mysteries of our universe, like how the sun and planets came to exist or how life began. Guest host and musician Dessa talks with Sophie Bushwick, technology editor at Scientific American, about this week in science. They also chat about how antimatter interacts with gravity, the new RSV vaccine for pregnant people, why LED streetlights are turning purple, and how beetles came to dominate all other species, especially ants. How You See With Your BrainEver try to take a picture of a spectacular moon that looks like it fills up half the sky? And then you look at the photo, and the moon looks like a tiny dumb ping-pong ball? And you want to march into the Apple store and demand to know why this pocket-size device fails to capture the wonder of the cosmos properly? The majesty of that supermoon you saw might be in your head as much as it is in the sky—your brain does a lot more than just receive data reports from your eyes. Vision is complicated. Seeing involves a lot of interpretation, of which you’re usually unaware. Guest host and musician Dessa talks with neuroscientist Dr. Cheryl Olman, associate professor in the University of Minnesota’s psychology department, about her work to better understand how the brain processes visual information using sophisticated fMRI techniques, including studying the brains of people with schizophrenia. Are Jellyfish Smarter Than We Think?Jellyfish are known for their graceful, hypnotic movement through the water—and for occasionally stinging swimmers. One thing they’re not known for, however, is intelligence. A study published in the journal Current Biology, however, challenges the idea of the ‘brainless’ jellyfish by showing that at least one species of jelly may be capable of associative learning.The scientists were studying the Caribbean box jellyfish, which normally lives amongst a forest of tangled mangrove tree roots. In the lab, they painted false roots on the walls of the jellyfish’s tank, and watched to see what happened. At first, the jellies judged the low-contrast gray roots to be far away, and tried to swim through them. After a few collisions with the tank, however, the jellies learned that the false roots were closer than they appeared, and learned to keep their distance.Dr. Anders Garm, an associate professor of marine biology at the University of Copenhagen in Denmark, joins guest host Dessa to explain the experiment, and what it tells researchers about the connection between the behavior of small groups of neurons and the process of learning. The Mysteries Of Freshwater JellyfishIn 1933, a high schooler fishing along the Huron River in Ann Arbor, Michigan looked into the water and saw something weird. It turned out to be a freshwater jellyfish – the first ever discovered in the Great Lakes region. Later that year, there was another sighting in Lake Erie.Researchers think the species hitched a ride here on aquatic plants shipped from China, then spread. But there’s no evidence they harm the lake ecosystems they now call home.Since then, the jellyfish have spread across the Upper Midwest, loitering mostly in inland lakes, rivers, and streams. But we still don’t know all that much about them.A biology professor and her field research class at Eastern Michigan University are hoping to change that. Every week, they slap on masks, snorkels, and floaties, and wade out into a southeast Michigan lake on the lookout for jellyfish.Read the rest at sciencefriday.com. To stay updated on all-things-science, sign up for Science Friday's newsletters.Transcripts for each segment will be available the week after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday, and I'm Dessa, writer and musician, filling in for Ira this week. Later in the hour, the neuroscience of sight, and we'll dive into some jellyfish news. But first, about a week ago, space nerds got the care package of a lifetime, a sample from Benu, an asteroid currently around 200 million miles from Earth. This mission, called Osiris Rex, marks the first time the U.S. has collected a sample from an asteroid and then safely brought that precious cargo back down to Earth. Scientists hope that it will unveil some of the mysteries of our universe, like how the sun and planets came to exist, and even how life began.

Here with more science news of the week is Sophie Bushwick, technology editor at Scientific American based in New York. Sophie, welcome back to Science Friday. Thanks for having me. Okay, so Sophie, help me calibrate my enthusiasm. How stoked should I be? Super stoked. This is just like incredibly awesome.

Because Benu is 4.5 billion years old, it dates back to the beginning of the solar system. So by harvesting a sample from it, researchers can learn a ton about the early days of the solar system. And also, because it contains a lot of carbon-based compounds, it can give us clues about the origins of life. So very, very exciting stuff. Okay, can you walk me through some of the logistics? Like, how did they get it? And then the challenge of returning to Earth with it was particularly, onerous, right? How did that all happen? So this is a multi-year mission. It launched in 2016,

and it took two years for Osiris Rex to just get to Benu. Then it spent another two years mapping it and figuring out where it was going to take the sample from. It finally takes the sample, and then it hangs out for a few more months before heading back to Earth, another long trip back here. And then it had to release what's called the sample return capsule. This is a very specialized case for the sample, and it has to be specialized because it has to survive re-entry through Earth's atmosphere. It gets to Earth. It releases a parachute and so it can land safely. And then teams of researchers had to go out and retrieve it. It landed in Utah. And then they partially unpack it, but they mostly get ready for transit to Texas where it's taken to this facility

where it can be unpacked more fully because you don't want to. on Earth's terrestrial atmosphere touching this thing. And just getting this sophisticated case open, it takes hours and hours because they're not just opening it up. They're also like, ooh, did any scraps of Benu dirt get stuck in the head of a screw? We want to harvest that dirt. That's a valuable sample. Osiris Rex ended up grabbing a sample that they think was about 150 to 350 grams. This is maybe a third to three quarters of a pound of material. So that doesn't sound like a lot, but that's more than they initially were hoping to get. The target was just 60 grams, so they've gone over and above that. I had no idea. It was that small. That's like me buying

Brussels sprouts. I don't even like Brussels sprouts. Yeah, but these are like alien Brussels sprouts from outer space. Okay. Other cool space news this week. I know that there was a big story about antimatter and gravity. But first talk, we just set the table. Remind us what is anti-matter? And where where do we go to get some? So anti-matter is essentially, it's sort of like the fundamental particles that make up matter, but with opposite charges. So an antimatter version of an electron is called a positron. An antimatter version of a proton is just called an antiproton.

And if you take an antiproton and a positron and put them together, you end up with an anti-hydrogen atom. So anti-matter, you can't go find it. you would have to either go back to the Big Bang, which is not a trip or equipped to make right now, or you have to go to a particle collider and smash a bunch of things together to make and then harvest your positrons and your antiprotons. And I know that the new finding now really dealt with the way that antimatter responds to gravity. Can you explain that? Right. So scientists know that Einstein's theories are still very good at predicting how gravity works.

But it kind of breaks down when you get into the realm of very, very tiny objects where quantum mechanics holds sway. Then you start having some issues. So in order to understand this better at that tiny realm, researchers want to not just make theoretical calculations, but also to do experiments to see if those calculations hold up. And one of the things that they theorized was that anti-matter atoms would behave the same way that regular atoms do in response to gravity. If you put anti-hydrogens in a gravitational field, they'll fall down. Same thing as if you put regular atoms into a gravity field. But the question is, can we prove that this will actually happen? And so was this study important or was this finding important because it's part of a proof of

concept that it's validating the theorist's ideas about how anti-gravity, about how antimatter would react to gravity? Yes, exactly. First, they had to make some anti-matter atoms, and then they put it in the tube and they measured, are they going to fall at the bottom of the tube or are they going to float out the top of the tube? And the amount that fell at the bottom was roughly what they would have predicted from regular atoms, from normal matter atoms. So that suggests that antimatter and regular matter behaved the same way. But that was under these specific conditions. So now the researchers want to go back to this experimental setup and try changing some aspects of it. What happens if you change the temperature? How does the behavior change

then. So this is just the beginning of a testing process. What does this fundamentally reveal to us about the way that the universe works? Like, how does this fit into our understanding of the cosmos? So one of the big antimatter questions is, why don't we have it? So according to theories, you know, when the Big Bang happens, it really should have made equal amounts of matter and anti-matter. But fast forward to today, and clearly that's not the universe we're living in. So what happened there? Why don't we have this anti-matter version? So when an antimatter particle meets its equivalent matter particle, if the two will annihilate, they destroy each other. You know, you take an electron and a positron and tell them to make friends, and they'll go boom. So if we had equal amounts of

matter and antimatter at the beginning of the universe, maybe some of these particles were annihilating each other, but there was maybe more matter. And that's why we ended up with a matter-based universe today. But researchers are still trying to study this in any way they can. And this experiment is just one part of that. Okay. So zooming the camera in from, you know, the entire expanse of outer space to the tip of a pin. I know that there's been some really exciting news in vaccines this week, particularly for the respiratory syncytial virus, aka RSV. Can you tell us what is RSV and what's new about this vaccine? Yeah. So RSV is a disease. that's not going to be very harmful to you if you are a healthy adult,

but it can be very dangerous for young children and babies and for the elderly. So there was actually a surge of it last year, and in severe cases it can cause pneumonia. It can land kids in the intensive care unit. So it's a really scary illness in that aspect, and so there's been more attention put to it. And so now we finally have a vaccine against it. And this vaccine is specifically, it's not designed for,

children. It's designed for pregnant people. And the idea is that this immunity is passed in utero to the child. Okay, got it. So this is specifically designed for pregnant people to take, then it sounds like some of the antibodies in this vaccine, cross that placental barrier and actually protect the kids after birth. Is that right? That's right. And this is a technique that's been known for a really long time. And there are other vaccines that pregnant people are encouraged to get in order to convey that immunity. But this is the first vaccine that's designed to do that from the beginning. Okay, hard pivot, Sophie. Streetlights. I think this is my favorite story of the week. Apparently, LED streetlights are turning purple around the world. Yes. Tell me why. So this is not a Halloween

prank. This is happening because of the way that we get white LEDs. So if you want to make an LED, you don't make a white LED. You would take, you could take a combination of, of different. colors that would give you white, or you can take a blue LED and coat it with this fluorescent material called phosphor. So when the blue light hits the phosphor, the phosphor releases some red and yellow colors, and the combination of all of these gives you your white light. But the problem is, what happens if that phosphor layer kind of peels off? That could be due to, you know, an issue with the manufacturing of the LED. It might be about exposure to heat, but what actually happens is the layer peels off and that blue light underneath is free to get out and it looks

purple. To my eye, I think the purple looks really pretty, but I know that there's also some concerns about safety. Are there hazards associated with these lights aging into a purple hue? Yes, this is kind of an issue if you want to be driving at night. So if it's dark out, the part of your eyes that's able to process this bluish light, it tends to be your peripheral vision. It could cause issues because your forward vision would be not as good under this purple light as it would be under white light. And so there's the potential safety issue. Like maybe it's harder to see pedestrians and maybe drivers are more likely to make errors. All right. Let's end where all good stories do with Beatles. Sophie, there is a new study out about beetle diversity that is super

counterintuitive. Tell me. So beetles are just this weirdly diverse group. So we know that there's about 1.5 million species known to science. And this is not just animals. This is plants. This is microbes. 1.5 million species. Of that, about a quarter of those species are just beetles. What? It's wild. So the question is, why are beetles so diverse? Why is this particular group doing this and branching out so much? So there's a couple ideas. One is that they've got these external wings that protect their flight wings, that could let them live in a lot more environments. And if you've got them branching off into different environments, they could specialize in those environments and diversify. Another possibility is that a lot of these beetles eat plants. So maybe each one could have evolved

to munch on a specific different species of plant. But the problem with both of these theories is there's this one family of beetles called rove beetles that they're very diverse, but they don't have really highly developed external wings, and they don't even eat plants. So why did the rove beetles get so diverse? That's what this new study wanted to find out. I feel like a special shout out at this point in our show to the one quarter of our listeners who are likely beetles. Okay, so we've talked about the external wings.

We've talked about plant eating. There was also a potential, like a chemical defense against ants. Is that right? That's right. So ants are this big predator in the insect world. They've killed off a lot of species. And in the case of the beetles, these rove beetles developed a chemical defense gland that they could spray at ants. And the idea is maybe they got so diverse because each of them developed different flavor of chemical that was good at targeting a different kind of ant.

It's so rad. It's so cool. Sophie, thank you so much for joining me. Thanks for having me. Sophie Bushwick is technology editor at Scientific American. She's based in New York City. And after the break, our eyes might do the singing, but our brain is what makes an image.

The Science of Sight. This is Science Friday from WNYC Studios. I'm Dessa, and this is Science Friday. Have you ever had that experience of trying to take a picture of a spectacular moon that's like glowing to fill up half of the sky, and then you look at the photo, and the moon looks like a tiny, dumb ping pong ball,

and you want to march into the Apple store and demand to know why this pocket-sized device fails to capture the wonder of the cosmos properly. Well, the majesty of that super moon might be as much in your head as it is in the sky. Your brain does a lot more than just receive data reports from your eyes. Seeing involves a lot of interpretation,

of which you're totally unaware. Vision is, well, complicated. Neuroscientist, Dr. Cheryl Oman, is working to better understand how the brain processes visual information using sophisticated fMRI techniques, including studying the brains of people with schizophrenia. She's a professor in the psychology department at the University of Minnesota, based in Minneapolis, Minnesota. Dr. Olman, welcome to Science Friday. Thank you so much. What a pleasure to be here and what a pleasure to talk to you. Okay, I know that at the core of your work is the idea that you see

with your brain, not your eyes. Can you explain that? I can explain part of it. And And there's about 10,000 of us studying that question. I'll eventually get the full answer to that. So that quote comes from Dr. Baki, Rita. It was one of the early developers of sensory substitution devices for folks who had lost their vision. And I didn't realize for the first 15, 20 years of my career how important that was to me. I thought vision was something that I could describe as a one-directional process. photons hit your eyeballs. Those eyeballs send that information to your brain. Your brain starts by

detecting some edges, then it turns those edges into shapes and into objects and scenes, and it's just this feed-forward one-directional process. And no, it just isn't. Like, that does happen. And there are a few milliseconds during what the input is the best way to describe what's happening in your brain, but almost instantly your brain, it's big and it's been around for a while and it's been living in this world and you have had so much experience with how the visual world works. You're carrying around these amazing internal models of the world and you're relying on them super heavily. So I'm standing there looking at a tree and the tree I'm seeing is mostly the tree that was created by my brain anchored to reality by this input that's coming in through my eyes.

But what I see, that giant moon that you saw is your brain telling you a story. The truest story it can come up with, but it's your brain's work, not your eyes. It feels in some ways like you describe the visual system like a cast iron pan. Like it's seasoned by the world. It's one of one. And it's as much about the treatment it's received and its experience as it is about the object itself. Absolutely. And everybody's brain is doing that interpretation differently, which makes it a challenging sometimes.

do research. And you studied physics before you became a neuroscientist. Did that totally change your approach to understanding vision? Absolutely. I think it's the physicist in me that wanted that one directional process to make sense, just little building box, making something more and more complicated until we got the answer. And I had to kind of do an about face as I started realizing that when I would be studying people's brains and I would in some cases show them nothing. And then I would analyze the responses, and I knew that there was nothing coming in through their eyes, and I would get these responses that looked like vision. And it was because they expected to see something, or they predicted that something was going to be on that part of the image when it wasn't there. And I had to really have a little mid-career crisis there.

You're like, oh, yeah, so I'm going to have to study the feedback processes. Your memory and your thinking brain and your past experiences are feeding back to the earliest stages of visual processing and shaping ways. you see. And I know that some of your research has been about people with schizophrenia and specifically how optical illusions might appear differently to that population. Describe how that has fit into your research. And so the first thing I need to say is I'm not a clinical psychologist. And so as I work to understand how vision is different in folks who are experiencing psychosis, I'm also madly trying to learn for myself what it means to experience psychosis. We've all heard the term schizophrenia. I'm starting to use the term psychosis, and that's because we're trying to move the field, much bigger than me, is trying to move away from specific diagnoses to observable attributes.

Schizophrenia, if we know anything about it, it's that if you've met one person with schizophrenia, you've met one person who's been offered a diagnosis of schizophrenia. It's different for everybody, and it's a collection of things. Some people might experience stronger reality distortions. Other people might experience more negative symptoms, like just a withdrawal from the world. in a difficulty experiencing pleasure, and all of that gets lumped under the category of schizophrenia. So people have been trying for years to come up with more concrete ways of understanding exactly what's going on for individuals. And vision is just a really accessible, relatively understood, concrete feeling kind of system. 40, 50 years ago, people noticed that

individuals with schizophrenia when they looked at some really popular size illusions. Size is notoriously difficult for us to figure out. We know that when some something something's close to my face, it's really big. And when something's far away from me, it's going to look small. But I know it's not actually small. I know it's way over there, and that's why it looks small. So your brain's always doing this calculation, how far away from me is that thing really? And so we can trick your brain. That's what the illusions are doing. They're tricking your brain into changing the context to change how big something looks. And then they showed these illusions to some folks who had been offered a diagnosis of schizophrenia, and they didn't

respond to the illusion the same way. And that kind of started a cottage industry of showing visual allusions to folks early on with the diagnosis of schizophrenia and then more recently with a diagnosis that includes an aspect of psychosis, some kind of a reality distortion. So that also might be folks with bipolar disorder. And looking at these illusions and seeing, does that look as much bigger or as much smaller as I typically get from response from a control population? And does it? Yeah, it does and it doesn't. And so a super hardworking graduate. student in my lab, Victor, he just finished his written preliminary exam doing a meta-analysis of the literature, and he pulled out like 40-something papers that it all kind of asked that question. Are people

with schizophrenia more or less susceptible to these visual illusions? And the answer, frustratingly, is it depends. Part of it depends on maybe your sample size just wasn't big enough and you got this one answer, but it's not going to replicate. And others, it depends on the details of the illusion. And those size illusions turned out not to be particularly robust or reliable, but the family of illusions that we've studied the most for the last 10 years are about contrast. It's like the intensity of an image. When there's lots of whites and blacks, that's a high contrast image and it looks really intense. So your brain does everything it can to just, okay, everything's intense. I'm just going to turn down the knob so my neurons don't have to work

so hard. So there's these gain control mechanisms. And we've spent a lot of of time trying to study those, and those seem to be reliably different in folks who are experiencing schizophrenia, exactly how we're still working on that, the way that the neurons, the brain cells, talk to each other and tell each other, just calm down. There's a lot of this going on. You don't need to do so much. Those mechanisms appear to be different in folks with psychosis and in folks with schizophrenia. And is there any reason to believe that this differential response, potentially, to optical illusions might have anything to do with the kind of hallucinations that people who are experiencing psychosis report?

Maybe, right? A lot of people are asking that question. And there's good reasons to think it could. So if I'm looking at a messy, noisy environment and my brain, instead of like turning down the knob and saying, oh, that's a mess, just calm down for a second, if instead my brain's like, oh, there's a mess, there must be something here where we started talking about the visual system creating so much of your reality for you, it's well equipped to take a mess and make meaning out of it. And so if you have different regulation of the inputs, you could easily see how

a brain with a person who's experiencing schizophrenia could make up some stuff to go with that noisy input, and we could call that a hallucination. That's a theory. We don't know if that's true, but that's a theory a lot of us are chasing. So is it sort of like a post hoc account for why I'm perceiving the things I am? Is that what you're saying? saying might be happening? Yes. Could you please come write my papers for me? Yes. I want to learn more about like how you're actually investigating this stuff. And I know that fMRI technology is involved. So before we delve in to your methods, could you just provide us with a quick and dirty reminder of like what is an fMRI machine? This is my favorite topic.

You know, there's MRI scanners in the hospitals all over the place. The only thing that makes an MRI scanner an F MRI scanner, a functional MRI scanner, is like the way we run it and the fact that we're showing you different stimuli while you're lying in it. So it's just a regular old MRI scanner tricked out with a projector so I can show you pictures

and a button box that has no metal in it that I can hand to you while you're lying in the scanner so you can hit buttons to tell me what you saw. And then you're lying in the scanner and the scanner's going, beep, beep, beep, beep, beep, beep, as I get my images of your brain. And as you're doing my task, your very, very hungry brain, like 20% of the energy that we consume goes to feeding our brains.

They're just wildly demanding. And they have a lot of blood flow and they consume a lot of oxygen. And as you do different tasks, that blood flow and that oxygen gets kind of shifted over to the part of your brain you need the most to do that task. And as you do a harder or an easier task, I'll see bigger or smaller changes in that blood flow. And so that's what I'm measuring with fMRI. It's just taking pictures of your brain, but it subtly changes in intensity as the blood flow changes, and I can see which part of the brain is working harder on which part of my task. Okay. So when one of your research participants goes in the scanner, like what kind of tasks are you asking them to do?

All right. So when I'm putting people in the scanners, I am trying to study how they parse their world. And so the stimuli that I use are incredibly boring. And they're like close-up photographs of a haystack or the side of a basket. And then I'll put these two textures next to each other. And so I want to know how your brain can tell that this image is a transition from one thing to another. And that particular transition invokes all of the mechanisms I want to study that the brain uses to regulate its environment and make meaning out of its environment and find things. And so you lie in the scanner with your little button box, and then I show you different combinations of textures at different intensities for like 20 minutes straight until you just can't take it anymore.

And then I process those data to see if the changes evoked by those boundaries, by those contrast to textures are different in the brains of folks who have schizophrenia or just control participants. And so far, I'm seeing tiny little differences. They're subtle, but I like this task. And I think it's telling us something interesting about how different brains process textures. I will notice that there is an element of masochism in literally displaying haystacks as you look for a needle. Yes, that, yes, it takes a certain kind of person to want to do this for a living, right? And is it difficult, like other limitations to that method itself? How helpful is that fMRI data to you as you're trying to isolate, you know, small differences or zone in like on

particular neuroanatomical regions of the brain? Like, how good is the tool? Oh, it's great and it's horrible. I can see into people's heads with like millimeter precision. And there's just nothing more magical than looking at somebody's brain and actually being able to see it. So I know where I am. I know which part of your visual system I'm studying. I know which part of the visual field, the projector screen you're looking at.

I can tell exactly which part. is evoking the responses I'm measuring. That's great. What's horrible is, even with my millimeter resolution, I'm trying to study neurons. And neurons are like 10 microns. So individual neurons are like a hundredth of a millimeter. And in my resolution element, we call them foxles. They're like volume pixels, because when I'm making images of your brain, it's like I'm slicing it up and looking at one slice at a time. And each slice looks like a picture, so that would be a pixel, but it's in volume, so we call them voxels. And each voxel contains something like 100,000 neurons, and I want to know what each one is doing, but I have one data point. That voxel either got brighter or darker

while I was doing my experiment. And so that summarizes the mass action of like 100,000 neurons, and that's what's horrible about functional MRI, which my colleagues would be very angry if they heard me say that, so I hope they're not listening. It's Science Friday, Cheryl. I think the tea just got spilled. Oops. So frustrating. It's 100,000 things,

and I got to tell them what each one of them's doing from a single number. It's like knowing your neighbor's politics based on who your state representative is. It's so coarse. If you're just joining us, I'm talking about vision and perception with neuroscientist Dr. Cheryl Oman

from the University of Minnesota. This is Science Friday from WNYC Studios. I know that part of your work now is cooperating and collaborating and contributing to the human connectome project, right? Which has a goal of like better understanding in a really high resolution how the human brain works. Can you explain that? Yes. And that's where that's where our hope lies, right? I have a single voxel that represents these 100,000 neurons, one data point to summarize so much. But I'm not the only person getting those data points, right?

We have lots and lots and lots of data. We do lots and lots of scans. And then there's our group. There's 20 other groups. And data sharing is just mandatory now. And so all put together, we're going to be able to figure this out. And what the Connectome Project is, is this massive initiative. You know, they got the name kind of copying it after the genome,

which was this big push to do something nobody thought you could do, 20, 30 years ago, and now they sequence the human genome. And so the connectome's kind of like that. In your brain, there's like 100 billion neurons. And that's not the problem. There's 100 billion of them, and each one of them has 1,000 connections. So the complexity of the system is overwhelming. And so the complexity lies in the connectivity between neurons,

not in the individual neurons himself, because how this one fires depends on how 1,000 other neurons fired at the same time. That connectivity is the target of the connectome. and mapping hundreds, thousands of people's brains using dozens of different perspectives. Is building up a big enough database? We can start answering some of these questions. And they're starting with a more manageable project, right? Are they working on animal brains now before tackling the human brain? Yes. There's like this brain initiative.

And the idea of seeing every single neuron in a brain, it's currently inconceivable for humans. Now I have a small imagination. I bet in 20 years you're going to be interviewing somebody who's like, yes, we just finished mapping every single neuron in the human brain. That's not feasible yet. It's getting feasible for mice. They have much smaller brains, but there's still plenty complex. And then not only figuring out kind of the identity or the class of every neuron on the brain, but then starting to look at who's connected to whom and mapping out that connectivity. That is a conceivable goal maybe in the next decade. And then, you know, science grows faster than we can ever imagine from the memory. from the mouse, they'll move to non-human primates, which have smaller but very complex brains and then on to humans. It's actually really exciting to hear you say that science moves faster than we can imagine because I think so many of us are accustomed to the cautions, right?

We won't know for three more. We can't say anything for certain for five more. And it's exciting to know that in addition to all the double checking, there's some awesome innovations happening as well. Thank you so much for the conversation today, Dr. Olman. This has been the highlight of mine. My pleasure indeed and the highlight of my day again to talk about these favorite things of mine. Dr. Cheryl Ollman, professor in the psychology department

at the University of Minnesota, based in Minneapolis, Minnesota. After the break, another story of vision and perception, but this time in jellyfish. Stay with us. This is Science Friday. I'm Dessa. For the rest of the hour, two stories about the wonderful world of jellyfish. Jellyfish are easy to admire for their translucent

otherworldly beauty, their hypnotic locomotion, but they haven't been celebrated for their intelligence. Scrabble partners, they are not. But researchers have found that even though these fragile organisms don't really have a brain, they're able to learn and change their behaviors in response to past mistakes. Joining me now to talk about this discovery is Dr. Anders Garm. He's an associate professor of marine biology at the University of Copenhagen

and one of the authors of a paper on the findings in the Journal of Current biology. Welcome to Science Friday. Thank you very much. So jellyfish don't have brains. What do they have? Oh, they have lots of things. These jellyfish we're talking about here are pretty special jellyfish. Those are the one we call box jellyfish or Cuba Medusa. They have a sort of a structure hanging beneath the bell. Actually, they have four of them. We call them rapalia. And in there, we have sort of a central nervous system, even though pretty simple. So each of these four structures have about a thousand neurons each. So not much, but still some nervous system. And can you just like provide a little bit of context here? How much is a thousand neurons? Like how many would you find in a in a mouse or something

simple like a fruit fly? Yeah, many more. Like take a fruit fly, which is one of the model systems where we used to study the brain and and they have between 200 and 300,000 neurons. If you take a mouse, it's way many more. It's hundreds of millions. So a thousand's, It's very few. So can you walk me through the experiment as you conducted it and tell me a little bit about your findings? Yes. The ones we did first were a set of behavioral experiments. And what we really wanted to make sure here was that we're testing natural behavior.

So these jellyfish are found in the mangroves in the Caribbean and they are living in between the pop roots of the mangrove trees. So we copied their natural habitat, the mangrove root areas in the lab. in our setup. And in there, we could change the appearance of these root mimics we were using. We could give them a low contrast, which would sort of signal them being far away, even though they were close by. We could give them high contrast, signaling that they were close by as they were. Or we could move contrast completely.

And by combining these three different types of root mimics, we could show that only when they were fooled by a root that was, was nearby but appearing far away and thereby bumping into them and then combining this impression visually of the low contrast but still getting the mechanical stress of bumping into it, they would learn that now actually the low contrast mean close by and then they would learn to avoid it. Got it. So they learned that these gray bars in the tank didn't mean like far away roots.

There were an obstacle that the jellies had to avoid. Exactly. So we were sort of tricking them. into learning by giving them a mimic that appeared further away than it was. And then the two other set up were sort of control experiments. The high-contrast routes where they would never bump into them showed that when taking away the mechanical stimuli, the mechanical stretch of bumping into things,

they didn't learn, they didn't change behavior. And opposite, when we used the no-contrast, the uniform gray wall, and saw that the animals were bumping into the wall constantly, meaning that they got lots of stress signal there, but no visual input, they wouldn't change their behavior either and didn't learn not to avoid the wall. So again, showing that it is the combination of the visual input,

low contrast, and the mechanical stress that enables them to learn. And this is what we call associative learning or operant conditioning. And how long did it take them to learn to avoid these painted stripes? That was where we were surprised. I mean, I have to admit that we were sort of expecting, that they would learn because they would make so much sense for them to be able to learn this in their habitat. But the speed of learning was quite of a surprise because it turns out that only repeating these faulty avoidances getting the mechanical stimuli three, four or five, sometimes they needed six times,

but between three and six times was enough. Then they had learned the distance, contrast relationship, and started avoiding. And this low number of repetitions is basically comparable to a lot of other that are classical in learning experiments like flies, crabs, and mice. Once they had made the association, right, I see these stripes. I've learned to avoid them because otherwise I bash myself into the wall. How long did they retain that information? Yeah, that we are not completely sure. We haven't looked at whether it's only short-term memory or also some kind of long-term memory. But what we can sort of assume is they would not remember it for too long because that wouldn't sort of make sense to them because they need to have it updated

with how the water changes. So we expect that this would maybe last half an hour, an hour, and then they would need to relearn. Wow. And when you say the water changes, like, hey, if the water is really murky, I need to adjust the level of contrast that I would expect from nearby stuff to far away stuff. So you've got to update that constantly. Is that right? If you're a jellyfish. Yeah, exactly. Yes. Okay. Now, can you differentiate this kind of learning from, like a reflexive action. You know, are the jellyfish planning to evade these obstacles? These are different behaviors.

So the thing about learning is that it's one of the major mechanisms behind plasticity and behavior. So it's basically not just a response to a stimulus. It's you can say a clever or intelligent way to response to a stimulus that is sort of dependent on previous experiences. And that's what takes learning apart from other things. It's not a reflex because it will. requires prior experience. We mentioned at the very beginning that there's no centralized system like a brain. There are these approximately 1,000 neurons throughout the jellyfish's body.

Does that mean that without a centralized processing center, certain parts of the jellyfish can learn what other parts of it doesn't know? Yeah, a small correction here. I mean, they have more than 1,000 neurons. But in the center there is learning there is 1,000 neurons, this part of the rapalial nervous system, we call it. And we could show in really nice experiments also because this rapalium can be detached from the animal.

And the interesting part about this is that with simple animal like this, you can take a part of the body out, and that would not really realize it's not part of the body anymore. So it will behave like it's still on the jellyfish. And we have this neuronal fingerprint and nerve activity fingerprint of this avoidance behavior. So we can actually measure directly from what this part of the nervous system is, is trying to tell the animal whether it wants it to do the behavior or not.

And that was how we actually could show that it happens in these 1,000 neurons. But you're completely right. What is an almost philosophical question here is that since they have this repeated four times along the belt, four of these rapalia, if one of the rapalia is learning, is it able to transmit what it has learned to the other four rapalia, which is an extremely interesting question, and we would love to look into this. And these are actually future plans we want to do. Speaking of future plans, what is the next step?

For your own research, does this lead to the next big question about how jellyfish are functioning in the wild? Yeah, I mean, what we would actually like to take is take it out of the jellyfish, because we think that with this jellyfish, we have a really cool model system for understanding some of the fundamental processes, the cellular processes that happens when a cell or a nerve circuit is learning. So with these 1,000 neurons, and this is what we're doing now, we hope to be able to make a complete circuitry, what we call a connectome, of these 1,000 neurons,

map exactly how these neurons look like, where they're arranged in the body, and how they communicate with synapses. And once we have this diagram, We can pinpoint what parts of the circuitry is most likely involved in these learning processes, depending on how they connect. And then we can go in afterwards, both with molecular methods and with physiological methods, and examine these neurons and compare naive neurons to neurons that has been part of this learning process, and then detect what has actually changed, both on the cellular level but also on the circuitry level.

And in this way, we hope to be able to get a much more in-depth understanding, of advanced learning like associative learning and operand conditioning. Okay, speaking of associative learning and revising one's behavior from past mistakes, the Caribbean box jellyfish, that's venomous, right? Have you personally been stung by jellyfish in your trials? I have been stung by a high number of different jellyfish by now. One of the reasons why we have chosen this exact jellyfish, the tripadetist offer as it's called, is it's a copper pot eater.

And there is this very close connection in jellyfish between the size of their prey and the strength of their venom. And since copper parts are really small animals, this one here is as spout as venomous as the common moon jelly. And this actually means you would need to kiss it to actually feel the venom because that's one of the places you have live skin

that is sensitive enough. Oh, I hope you haven't felt as much. Thank you so much for joining me today. That was Dr. Anders Garm, an associate professor of marine biology at the University of Copenhagen in Denmark. Thanks for taking time. Thank you very much. You're listening to Science Friday from WNYC Studios. Nothing complements a jellyfish story like another jellyfish story.

So let's take this show on the road to learn about the jellies of Michigan as we check in on the state of science. This is KERNO, St. Louis Public Radio News. Local science stories of national significance. Now, when I think jellyfish, I think of salty ocean waves, or maybe that sitcom sketch where somebody on the beach desperately seeking relief from a sting, begs a friend for help, and know that home remedy does not work, dear listeners. But it turns out that there are some 20 species of freshwater jellies around the world. And one of them, originally native to the Yanksy River in China,

has been spreading around the U.S. for about 100 years. Ellie Katz is an environment reporter at Interlock and Public Radio. She reported on a student effort in Michigan to learn more about these freshwater jellyfish for the Points North podcast. Ellie, welcome to Science Friday. Thanks, Dessa. Great to be here. Okay, tell me more about these freshwater jellyfish. What are they? What are they doing? Yeah, it's a good question.

They're not doing much, honestly. They're kind of loitering, and they've spread to about every continent on Earth except Antarctica. so they're pretty prolific. And they like calm water, you know, slow-moving rivers, lakes, quarries, ponds, places like that. They're pretty small about an inch across at most, but because they can survive in a lot of different types of waters and have a pretty broad range of water temperature, they've managed to spread. They think that they kind of hitched a ride over on ornamental aquatic plants brought to the U.S. in the early 20th century. And, yeah, like you said, they've been hanging out in the U.S. and over the world for about a century now. Pause, ornamental aquatic plants.

What are you talking about? So things people would use to like decorate their personal ponds or gardens, things like that. The question that probably comes to everybody's mind first and foremost is if we are living amongst them, can they sting? Yes, they can, but just not you and me. Like most jellyfish, they've got stinging cells, but their tentacles are, too small for humans to feel. So like I said, they're about the size of a nickel. They will sting their prey, typically zooplankton or tiny water fleas, just small water animals. But no, you and I wouldn't feel the sting if they did brush against us during a morning swim. And you know, in the story that you covered, as you describe what they actually look like, I mean, they're

large enough to be easily seen with the naked eye, but they're kind of translucent, right? So are they tough to spot in the water? Yeah, you know, they are pretty tough to spot. But it's one of those things where once you see them, you can't unsee them. This woman on the beach who I spoke to describe them as unmistakably jellyfish. And she was so right. They're these beautiful little creatures pulsating in the water, translucent with like a white ring around this beautiful bell shape. And yeah, little tentacles just powering them through the water. I know that a lot of times when we talk about the arrival of a new species, we're worried about an ecological disruption. Is that a concern here with these freshwater jellyfish? It's not as much of a concern

right now. We're no stranger to invasive species in the Great Lakes. And the problem with a lot of those invasive species is that they're eating tons of food that's low on the food chain, things like zooplankton, phytoplankton, the same things that these jellies are eating. But because these jellies pop up so sporadically, like they'll be hundreds of them in one lake in one year, and then the next year they're entirely gone. They're not really causing enough harm. You know, they're not consistently there eating huge bricks of the bottom of the food chain every year. So they're not causing any demonstrable harm or benefit right now. They're just kind of loitering hanging out, but there still needs to be more research to figure out where they are,

when they're popping up, how many there are and what's affecting these different blooms, as they call them, these big groups of them that occasionally pop up. You mentioned that you went out personally with a class that was studying some of these jellyfish. What is the objective of their research? What are they trying to discover? Yeah, I mean, it's nothing groundbreaking, but it is really important because there's so little research on these guys. So I went out with a classroom Eastern Michigan University, some undergrad students, some graduate students, mostly studying biology. they're really just trying to get basic data. Like, they're trying to figure out how best to collect the jellies, whether that's with a jar or a bag.

They're trying to figure out how to measure them. They're recording where they show up in the lake, when, what the temperature is when they pop up. And the idea is that when they're able to get this long-term data about the jellyfish, they can detect changes or patterns over time. And that will be able to tell us, you know, whether they are having a meaningful effect on food availability in this lake. and we could learn why they spread out when they do, what affects whether they'll show up or not in any given year, that kind of stuff. Okay, so if this species is so widespread,

then why don't we know very much about them already? Well, there's a few reasons. One you kind of got at, and it's that they're hard to notice, unless you're going really slowly in a lake or a slow-moving river and looking down and at the right time with the right conditions, they're pretty easy to miss. And then they're also really unpredictable. So some years they'll show up in the hundreds in one,

Lake and then the next year, there's none. But the biology professor who's leading this class at Eastern Michigan University, her name is Kara Shillington. She thinks there's another reason, too. And she thinks it's just that people aren't as interested in invertebrates as they are in studying vertebrates. Invertebrates like jellyfish, you know, aren't as sexy or as lovable as many vertebrate species. There's maybe not a ton of science kids dreaming about studying worms or insects. But invertebrates are pretty foundational to animal life here on Earth. And Kara told me that one hope she has for the class is that these jellies, which are pretty charismatic and interesting invertebrates,

will kind of serve as a gateway to get more students excited about invertebrates. How can you not love them? The diversity is just amazing. The varieties of lifestyles of what they do, of how they look, of their structure is just absolutely phenomenal. How can you ignore 99% of the animal world and focus on just 1%. How can you not want to know more? You're calling them jellies, not jellyfish. Is that just like the cool field slang?

No, that's actually good question. It is the cool field slang, but there is good reason for it, which is that jellyfish is a little bit of a misnomer since they're not actually fish at all. And so scientists who I've spoken to tend to call them jellies instead. I dig it. Kelly Katz is an environment reporter at Interlocking Public Radio. She reported this story for the Points North podcast. Thanks for joining me today, Ellie. Thanks, Dessa. Lots of folks helped make this

show happen this week. Here are a few of them. Annie Nero. Emma Gomez. Charles Bergquist. Daniel Johnson. Thanks, everybody. BJ Leaterman composed our theme music. And if you missed any part of this program or would like to hear it again, subscribe to our podcasts or ask your smart speaker to play Science Friday. You can email us too. The address is SciFri at ScienceFriday.com. I'm Dessa. Thanks for listening. Hi, Ira here. Just a heads up. Starting next week, you'll be hearing a new shape to the podcast, but don't worry, same cool science in slightly different packaging, coming in easy to handle chunks. Think of it as a daily dose of science, delivered straight to your ears. Now, every day really can be Science Friday.

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