JUANA SUMMERS, HOST:
Time now for our science news roundup from Short Wave, NPR's science podcast. I am joined by the show's two hosts, Emily Kwong and Regina Barber. Hi, y'all.
EMILY KWONG, BYLINE: Hi, Juana.
REGINA BARBER, BYLINE: Hey.
SUMMERS: OK, so, once again, you've brought us three science stories that have caught your eye. Tell us what they are.
BARBER: Yes. OK, scientists using the video game Minecraft to study how humans learn.
KWONG: Perfecting a classic Roman pasta dish with science.
BARBER: And a possible reason on why more and more young people are getting colorectal cancer.
SUMMERS: OK, we've got a lot of range this week, a lot of options.
BARBER: Yeah, indeed.
SUMMERS: And clearly, you knew you were talking to 'cause we've got a video game story. So I want to start with Minecraft, if we can.
KWONG: (Laughter).
BARBER: Yes.
SUMMERS: It is now a very popular movie based, of course, on a video game that is especially popular among kids.
BARBER: Yeah, it's got very blocky graphics, calming music. And one of the goals of the game is to collect resources around this expansive landscape, mining, building materials, gems and food.
SUMMERS: Right. I'm familiar with this one, but I want to know what can it tell us about the learning process?
BARBER: Yeah.
KWONG: It can tell us a lot about social learning, so learning in groups. A study in the journal Nature Communications tried to bridge this gap between studying how we learn individually and how we learn socially by watching over 100 participants with specific goals in crafted Minecraft environments.
BARBER: Specifically, the lead researcher of the study, Charley Wu, said he was curious about the argument that human success is not only because of individual brains...
CHARLEY WU: But rather, it's the power of our ability to learn socially and culturally from one another.
KWONG: We're stronger together, Juana.
SUMMERS: (Laughter).
BARBER: Yes.
KWONG: And in the past, these two modes of learning - on your own or mimicking another person - were mostly studied in isolation. It was either one or the other.
SUMMERS: But I take it that is not the case in this study?
KWONG: No, no. So in this study, researchers created a few scenarios where it would be more or less advantageous for Minecraft players to mimic other players - to, for example, mine around the spot where they saw other players on their screen gathering gems.
BARBER: In some scenarios, the rewards were clustered, which altered how much players had to interact with each other and learn socially. And what the researchers found is that the most successful players were the most adaptive, like, switching between individual mining and using social learning when the situation called for it.
KWONG: So Charley and his team, they analyzed all of these scenarios, and they created a computer model that was able to take in what each player saw on their screen and predicted, to a pretty good degree of accuracy, how individual learning works in conjunction with social learning.
SUMMERS: OK, but what does he mean by that?
BARBER: It means that individual learning and social learning are informing each other. And, like, that flexibility between switching between both of them is, like, the key to being really successful. And that's actually new. And using Minecraft to find that is also unique.
NATALIA VELEZ: That looks really different from traditional psychology experiments. And it tells us something about the dynamics of social learning that we miss when we put people into really simple environments where they're choosing either to gather information firsthand or to copy someone else.
KWONG: This is Natalia Velez, another cognitive scientist, who didn't work on the study. And she pointed out something else that's cool about it. Video games are incredibly popular among kids. It's where they often meet up and build social connections they may not otherwise have.
BARBER: And it's important that research keeps up with these, like, modern social interactions.
SUMMERS: Very interesting. I'd also point out video games, quite popular with me.
BARBER: Yeah.
SUMMERS: (Laughter).
BARBER: Same. Same.
KWONG: With the three in this room, also popular.
SUMMERS: All right, moving on to the next one - a story I'm very invested in, maybe because I'm hungry. It is about pasta. What are we talking about here?
KWONG: Cacio e pepe.
SUMMERS: Yum.
KWONG: So, that dish, it's so good. It's that symphonic combination of pasta, black pepper and pecorino Romano cheese. And it's a personal favorite of Giacomo Bartolucci and Ivan Di Terlizzi. They're both physicists living abroad that miss the comfort food of Rome, and they were throwing these big dinner parties for other scientists.
BARBER: Go, physics.
IVAN DI TERLIZZI: But the problem with cacio e pepe is actually that it's very, very difficult to cook for a lot of people. This was probably, like, the very beginning of the problem, because it's difficult because you have protein aggregation.
BARBER: Ivan is talking about how, if a home cook is not careful, he can cause proteins in the cheese to clump together, which makes for, like, a stringy sauce that coats the pasta unevenly.
SUMMERS: You're really talking about the stuff of my kitchen nightmares here.
BARBER: (Laughter) Yeah. Yeah, same.
SUMMERS: So how did they go about figuring out the secret to making a perfect cacio e pepe?
KWONG: With starch - for generations, Italian grandmothers have known this. They have added corn starch or potato starch to the water to prevent the cheese from clumping, and it created this creamy, stable sauce that uniformly coated the pasta. Giacomo called it grandma knowledge.
GIACOMO BARTOLUCCI: In Italian kitchens, grandma had somehow, you know, always a scientific attitude, right? So they were doing scientific method.
KWONG: So Giacomo and Ivan, along with a whole team of scientists, decided to investigate the best way to add cheese to hot water, and they published their results in the journal Physics of Fluids.
SUMMERS: Truly news you can use. What did they find?
BARBER: So there is a critical threshold of starch above which the sauce does not separate, and that's 1%. So if you go below 1% starch concentrations relative, like, to the mass of the cheese, you get cheese clumps. And the ideal ratio is 2.5%.
SUMMERS: I am going to need a recipe. Emily, help me. What does that mean?
KWONG: When you're in your home kitchen, Juana, if you're adding, let's say, 160 grams of pecorino cheese, first dissolve four grams of starch into your pasta water and you will have a delicious sauce by the end.
SUMMERS: Guess I'm headed to the grocery store next.
BARBER: Yeah, definitely.
SUMMERS: OK. We've got to make a hard pivot here.
BARBER: Yeah.
SUMMERS: Next up, more young people are developing colorectal cancer, and some new research may help us understand why. Emily, tell us more.
KWONG: Yeah, so colorectal cancer is cancer that originates in the colon or the rectum. Many people think of it as something older adults get, but our colleague Will Stone has reported that in the last two decades, cases have doubled in people under 55, and researchers don't know why. So this recent study from the journal Nature suggests that this rise in young people with colorectal cancer could be related to a harmful bacteria called colibactin. That is produced by some strains of E. coli in people's colons and rectums.
SUMMERS: Wait, so do a lot of people just have E. coli just hanging out in their guts?
KWONG: Some people do, yeah. And not all E. coli produces colibactin, but when it does, that colibactin can damage DNA and cause cancer mutations. So they were curious about what the link was.
BARBER: And in this study, the researchers looked at samples from almost a thousand patients around the world, and the researchers saw that the colibactin left behind DNA mutations that were over three times more common in early-onset cases than when people were diagnosed after age 70. And they looked at the timing of these mutations and think they happen in the first 10 years of a person's life.
SUMMERS: Oh, interesting. So when people are pretty young, which...
KWONG: Yeah.
SUMMERS: ...I guess then would put people on track potentially to develop colon cancer in their 20s or their 30s instead of later in life like we might think.
KWONG: Potentially, yeah. The study doesn't prove that colibactin is the sole cause, but it's a strong association, for sure.
BARBER: And that knowledge is power. With this lead, researchers can ask the big questions like why those changes are happening, what other factors might be important. And if there are aspects of our environment, our lifestyle or diet, they may cause these microbes to behave differently.
SUMMERS: That's Regina Barber and Emily Kwong from NPR's science podcast Short Wave. Follow now for new discoveries, everyday mysteries and the science behind the headlines. Thanks to both of you.
KWONG: Thank you, Juana.
BARBER: Thank you. Thank you.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
