Today we discuss how the pandemic has caused physical changes in the brains of teenagers, how geomagnetic disturbances can cause bird migration to go haywire, and why pregnancies in the US are a week and a half shorter on average than they are elsewhere.
Today we discuss how the pandemic has caused physical changes in the brains of teenagers, how geomagnetic disturbances can cause bird migration to go haywire, and why pregnancies in the US are a week and a half shorter on average than they are elsewhere.
Pandemic Brain
Magnetic Migration
Short Pregnancies
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Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/pandemic-brain-magnetic-migration-short-pregnancies
[SFX: INTRO MUSIC/WHOOSH]
NATE: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from Discovery. Time flies when you’re learnin’ super cool stuff. I’m Nate.
CALLI: And I’m Calli. If you’re dropping in for the first time, welcome to Curiosity, where we aim to blow your mind by helping you to grow your mind. If you’re a loyal listener, welcome back!
NATE: Today you’ll learn about how the pandemic has caused physical changes in the brains of teenagers, how geomagnetic disturbances can cause bird migration to go haywire, and why pregnancies in the US are a week and a half shorter on average than they are elsewhere.
CALLI: Without further ado, let’s satisfy some curiosity!
[SFX: WHOOSH]
NATE: There's this famous saying that kids who act older than they actually are are wise beyond their years. But it turns out that most Gen Zers do indeed have more mature brains, and it's because of the COVID 19 pandemic.
CALLI: I mean, that's not entirely surprising. We had a global collective trauma because of the pandemic.
NATE: You're not wrong. And the average kids these days went from a solid social structure in school to a much more isolated online learning environment, all while surrounded by endless news reports of rising death tolls and economic instability. And for teenagers, it had to have been worse because those are some of the most important years in any person's brain development.
CALLI: Okay. That I guess that makes sense, even if it's a little bit grim. But what about the science behind it?
NATE: Okay. So a lot of what we just said is anecdotal, but at this point, a lot of it is also now supported by a new study published in the Biological Psychiatry Journal that looks specifically at how the pandemic impacted brain aging. It was a study that compared brain scans of young people from before and after the pandemic, and their findings are pretty alarming.
CALLI: All right. Nothing sounds good about something called brain aging, but I actually don't know what that is.
NATE: So the concept of brain age is a really popular way to measure overall cognitive well-being. Once a brain is scanned, doctors look at the overall quality of the brain. You know, is it bigger or smaller? Is it covered in wrinkles? Are the ventricles bigger? But the cortex is thinner. So if a brain is smaller, wrinkled with big ventricles and a thin cortex that lines up with somebody having a much older brain.
CALLI: Okay, I think I got it. So, for instance, if somebody is actually 32 years old but has a brain, a one and a half times smaller than an average 32 year old's brain, that means that their brain age is much older than their actual age. Am I getting this right?
NATE: Exactly. Yeah. So this particular study is rooted in research that started back in 2012 where a project was launched in the California Bay Area to look into adolescent depression. The researchers did MRI scans of each participant's brain and continued their research for eight years until lockdown orders were delivered across the globe in 2020. And when they resumed the study in late 2020, the researchers were concerned that pandemic related stress would skew their results. And they were right. Each of the kids reported much higher rates of anxiety and depression than before, and this made them wonder, what did these kids brains look like?
CALLI: I mean, that's usually a question a zombie asks. But I am I am curious.
NATE: Scientists too! Zombie scientists would be very cool.
CALLI: But but but what did they find?
NATE: So the researchers, the researchers conducted a brain scan on 64 different participants in October 2020 and then another in mid 2022. And after comparing the before and after brain scans, the doctors found that virtually every teenager's brain had aged 3 to 4 years over the course of the pandemic.
CALLI: How in the world they measured that time frame?
NATE: So most teenage brains go through a maturing process where the hippocampus and the amygdala get thicker, and the hippocampus is the part of the brain involved with memory and concentration in the amygdala is how we emotionally process things. While this happens, the cortex, which is what regulates emotional functioning, begins thinning. And each of these processes had moved along to the point where each teenager's brain looked more like a 20-somethings brain than the average pre-pandemic teenager.
CALLI: Sure, but how would this affect each teenager in the same way? Was there something specific in the pandemic that triggered this response?
NATE: Nobody knows for sure, But the biggest theory right now is a pretty simple one. It's just stress. Previous studies showed that exposure to violence or even negligence can lead to an acceleration in brain maturation for children. And considering that mental health rates dropped for teens during the pandemic, it makes some sense that brain age and poor mental health could be linked.
CALLI: So what does this all mean in the long term? This doesn't mean that kids are going to start dying at a younger age or anything, does it?
NATE: Well, the good news is we don't know that would happen. The bad news is we don’t know what will happen. The researchers have no idea what the long term effects of brain aging will be on teen health, though they do believe that if your brain is prematurely aging, that's generally not a good thing. The best thing we can do now is to make sure that people have access to affordable or free mental health services because it's crucial for pandemic age teens to survive.
[SFX: WHOOSH]
CALLI: It's kind of common knowledge that weather can lead to birds getting lost. But did you know that it could actually maybe be caused by magnets?
NATE: Magnets? How do they work and what do they have to do with birds? Well.
CALLI: All right. So disturbances to Earth's magnetic field causes vagrancy. Vagrancy is what happens when birds are knocked off their trajectory during migration. It was believed to be something that only happened because of the weather. But over the past few decades, it's been witnessed as happening during perfect weather, especially during fall.
NATE: Cool. What does that have to do with magnets, though?
CALLI: All right. As you know, Earth's magnetic field runs between the north and south poles, and it's generated by a number of factors above and below the surface. We, as humans, can't see or even sense these magnetic fields. But what you might not know is that birds can actually sense those magnetic fields using something called. Wait for it. Dramatic pause. Magneto receptors in their eyes. Mm.
NATE: Magneto receptors. Sounds like an X-Men villain.
CALLI: In reality, a magneto receptor is an additional receptor in a bird's eye that helps it map out routes from one location to the next. Think of it like having a built in translucent compass and your line of sight. They might not always need this compass to find their way, but it's always there.
NATE: Okay, so if the magnets or magnetism is something that is helping the birds, why is it causing problems?
CALLI: Well, that's where the magnetic field disturbance comes in. Sometimes those fields are disturbed by something like weather, solar activity or earthquakes, and it makes the birds geomagnetic navigation go brr.
NATE: Brr.
CALLI: Hey, it's a meme.
NATE: Oh, sure. You you kids and your memes on the meme-too.
NATE: Okay. Bird navigation go brr. So what? What are the birds seeing when these things get all screwy and haywire?
CALLI: We're actually not 100% sure what the bird sees, but it's believed that it scrambles the map the magnetic fields created for them. Think of the compass I told you to imagine earlier. The one that is invisible. But they can see. Now imagine the needles of that compass spinning violently out of control. That's what birds experience when something disturbs the planet's geomagnetism.
NATE: Okay, but if we don't know what the birds can see, how do we know what's happening?
CALLI: By comparing data between 2.2 million birds and historic records of geomagnetic activity. 152 species captured and released between 1960 and 2019 were surveyed. And what the researchers found was that there was a very strong correlation between birds captured far outside their average flight path and the normal geomagnetic disturbances that happened in the fall or spring.
NATE: All right. How do we know that this wasn't just a weather related thing?
CALLI: I mean, it could have been to some extent. Many of the birds were found during neutral weather patterns. So there's not really a basis to explain how they ended up where they did beyond geomagnetism, on the other hand, earlier I mentioned that solar activity can cause disturbance in geomagnetism. Scientists fully expected birds flight paths to change based on the increase of solar activity such as solar flares or sunspots. And the results were kind of split down the middle. Solar activity didn't affect nocturnal birds, but it did affect birds that traveled by day. In both cases, it taught the researchers something interesting. The birds briefly paused their migration around the time of geomagnetic disturbance.
NATE: Kind of like if you're on a good road trip and you see a crazy storm coming up, you think it might be time to pull over, find a motel, let that pass.
CALLI: Exactly. And for the nocturnal birds, they stopped, regrouped and continued on their paths. Daytime birds, on the other hand. Daytime, nighttime! Just full of memes today. Daytime birds, on the other hand. Well, more often than not, they went vagrant. Geomagnetic instability plus less visual cues to get by equaled more confusing travel.
NATE: Oh, those poor lost birds.
CALLI: In short, all of this research is helpful for a number of reasons. First, North America's bird populations are on the decline. If we understand why vagrancy happens, we can understand the threat facing modern birds and how they're learning to adapt to those threats. And second, even if this study only focused on birds, this research could help scientists understand why other migratory species, like whales, also became disoriented, far from their usual territory.
NATE: Whales go brr.
CALLI: We also brr.
[SFX: WHOOSH]
NATE: So pregnancy is a pretty universal phenomenon with most humans. But did you know that how long a woman is pregnant is not universal?
CALLI: I mean, I know it differs from person to person, but isn't it usually like on average between nine and ten months?
NATE: All right. So check this out. Most pregnancies last about 40 weeks across the globe. But in 2020, a whopping 76% of births in the United States happened before the completion of the 39th week. In comparison, almost every other country surveyed averaged a pregnancy that was a week or more longer, which means that for some reason, women in the United States are giving birth sooner. And the rate has been getting worse for decades.
CALLI: That's actually horrible news. That means there's less time for the baby to develop. How was this figured out?
NATE: A study was performed that compared the average pregnancy length in the U.S. to England and the Netherlands. And the researchers looked at gestational age patterns, as well as the timings of at home and hospital births to figure out why there is such a disparity. The records came from 1990, 2014 and 2020 and focused on 3.8 million births in the U.S., 156,000 births in the Netherlands and 56,000 births in England. And what they found was not only that women in the U.S. give birth sooner, but they're giving birth sooner than U.S. women from back in 1990. So the problem is accelerating.
CALLI: That's kind of grim. You say sooner. How much sooner?
NATE: Back in 1990, the average length of pregnancy was 39.1 weeks, and in 2020, that number had dropped to 38.5 weeks. Sheesh. So these numbers are unusual for multiple reasons. First of all, each pregnancy's gestational age, which is the measurement of time used to describe how long it's been since a woman has menstruated was identical in all three countries. But where we start to see any difference is in home births versus hospital births. In England and the Netherlands, there were an equal number of hospital and home births, but they peaked between 2 a.m. and 5 a.m. In the U.S. there were far more hospital births and these occurred between 8 a.m. and 5 p.m..
CALLI: I had no idea that timing would make a difference. Is it making a big enough difference to matter?
NATE: It's making a big enough difference that the study suggests that the U.S. health care system should really start looking into how the European health care system is more successful in making sure pregnancies are carried to term in as healthy of a timeline as possible. Looking at the hours that babies are delivered, it concludes that hospitals in the U.S. are prioritizing organizational needs over birth timing in gestational age.
CALLI: Okay, I hate I hate that. But can you explain a little bit more about what that means?
NATE: Yeah, If if babies are being born between 8 a.m. and 5 p.m., on average, they're being born at a time that's considered more of a professional working hour, meaning there will be a guarantee of more doctors, more nurses and more help. Whether the timing of the pregnancy calls for a baby to be born at that time or not.
CALLI: Holy crap, wheeee the glory of the U.S. health care system.
NATE: Oh, my gosh. It's important to note that in the U.S., pregnancy is overlooked by an obstetrician. But in these European countries, pregnancy care is handled by midwives who are on call 24 hours per day to ensure that pregnant women are getting the care they need. And in those countries, an obstetrician is only called in case of emergency. What this study is proposing is a revamping of the U.S. health care system to, at the bare minimum, make sure that women and fetal health are prioritized over the needs of the hospital.
CALLI: Got it. So the solution is fixing the U.S. health care system.
NATE: That’s all.
CALLI: Duh, we need that. But where do we begin?
NATE: It's definitely hard. I don't know the answer. If you look back at the numbers, I said at the top, 156,000 women surveyed in the Netherlands, 56,000 in England, compared to 3.8 million in the U.S.. It's just so many more people here and therefore more pregnancies. So a change of this nature would need to be something huge.
CALLI: Well, hopefully they can figure it out soon.
[SFX: WHOOSH]
NATE: Let’s recap what we learned today to wrap up. Teens today are “wise beyond their years” - and that’s not a good thing. New research suggests that teenagers coming of age in the pandemic have actually seen their brains age by three to four years due to the general stress of living under lockdown. There is no consensus on how this will affect teens in the long term, but researchers agree that premature brain aging does not bode well for the future.
CALLI: Why do birds suddenly appear every time… geomagnetic disturbance is near? New research suggests that birds have a sort of sixth sense that acts as a magnetic compass allowing them ease of travel along migration paths, but that sense can become disoriented during times of geomagnetic disturbance. Scientists aren’t exactly sure why or how it works, but by understanding the troubles birds across the world have, we can better understand how to save birds within our lifetime.
NATE: A recent study has revealed that pregnancy in the United States is an average of a week and a half shorter than pregnancy elsewhere - and that number is getting smaller as the years go on. The conclusion of the study calls for an overhaul of the US healthcare system to prioritize women’s reproductive health over the bureaucratic needs of the hospital, and if that can be done, maybe this number can start trending the RIGHT way soon!