ARI SHAPIRO, HOST:

It's time now for our regular science news roundup with our friends at NPR's Short Wave podcast, Regina Barber and Rachel Carlson. Good to have you both here.

RACHEL CARLSON, BYLINE: Hey, Ari.

REGINA BARBER, BYLINE: Hey.

SHAPIRO: So the way this works is you've brought us three science stories that caught your attention this week. What are they?

CARLSON: Chickadees with incredible memories.

BARBER: A robot that anticipates your smile.

CARLSON: And insects in haiku.

SHAPIRO: OK, my little chickadees...

(LAUGHTER)

SHAPIRO: ...Tell me about these impressive memories.

CARLSON: OK, Ari. So researchers at Columbia University were studying black-capped chickadees, and they really do look like they're wearing a black hat. And these tiny birds are notorious for their big, big memories. In the wild, they stash seeds in hundreds, sometimes thousands of different places. And then they go back to those seeds later. So it's exactly like when I hide stashes of granola all over the office for those classic, treacherous Culver City winters (laughter).

BARBER: And these memories are often a matter of life or death for them in colder months because food sources are lacking.

SHAPIRO: Do scientists know how these very small birds with these very small brains remember where hundreds or thousands of seeds are located?

CARLSON: So researchers recently observed that each time these birds hide a seed in a specific location, a unique brain pattern fires off in the hippocampus, which is a part of the brain that's critical for memory. The scientists liken this pattern to something like a barcode. The work was published last week in the journal Cell.

SHAPIRO: How did scientists figure that out?

BARBER: Yeah, so these teams built these arenas with feeders full of sunflower seeds and small perches around with flaps for birds to hide the seeds.

SHAPIRO: Wow.

CARLSON: The researchers tracked the birds' neural activity with small probes inserted inside of their brains. And each time a bird hid a seed under a flap, they noticed a unique brain pattern associated with each hiding spot.

BARBER: And what's even cooler is that this same barcode-like activity popped up again if the chickadee went back to that specific site and successfully retrieved the seed, but not when the bird just visited the site.

SHAPIRO: Wow. So, like, the barcode is more connected then to the experience than it is to the place?

CARLSON: Yeah. I talked to one of the authors on this study, Selmaan Chettih, and he told me that these barcodes might be a new framework for how the brain binds together a bunch of information - like time, place, context - into a single memory for these birds and possibly for humans.

SHAPIRO: Cool. All right, Gina, from birds to machines, you're going to tell us about a robot that smiles, which sounds like something out of a horror movie like "M3GAN." I watched that on an airplane. Is that what this is?

CARLSON: Yes (laughter).

BARBER: I mean, I love robots. I'm not horrified, but - so let's talk about robotics 'cause it's come a long way in, like, verbal communication using AI. But that's not the only kind of communication.

HOD LIPSON: We humans communicate with each other in much more sophisticated ways through body language and through facial expressions.

BARBER: That's Hod Lipson, and he's a roboticist at Columbia University. And he's part of a team that recently published a study in the journal Science Robotics, and it's describing a robotic face his team created called Emo.

CARLSON: And Emo is a new kind of robot because instead of having pre-programmed facial reactions, it uses AI to learn how to smile by watching hours of YouTube and - exactly like M3GAN - watching itself in the mirror. So now when it's interacting with a human, it can anticipate the person's smile before that happens and then smile at the same time.

SHAPIRO: You can't hear this on the radio, but I'm raising my eyebrows right now.

BARBER: He is.

CARLSON: (Laughter) Yeah.

BARBER: He is.

CARLSON: What you're probably feeling is usually described as the uncanny valley, which is this super eerie space where a robot is almost perfectly human but not quite. So you feel connected to the robot until you realize that its mouth isn't quite syncing up with the words it's saying or something like that, and then that connection becomes something more like disgust.

BARBER: Yeah. So Yuhang Hu, a Ph.D. student and the lead author in the study, says Emo is just, like, the beginning of getting over this uncanny valley and that we shouldn't think of it as human.

YUHANG HU: We're not doing 100% human. We're trying to create a new species.

SHAPIRO: Oh, no. What should we expect from this new species apart from total annihilation of humankind?

CARLSON: (Laughter).

BARBER: I mean, I don't believe that. But both Hod and Yuhang say Emo is still just in the early stages. It's like a baby that knows how to smile, but it doesn't know why you smile. So context is something that Emo can get better at and even learn different reactions in different cultures.

CARLSON: And all of this could help researchers overcome that uncanny valley, which is really important for developing realistic robots that could be useful for things like caretaking. Eve Herold, the author of a book on social robots, told us Emo takes the illusion of aliveness to a whole new level and could make people feel like they're in sync with a living, experiencing intelligence like ourselves.

SHAPIRO: Oof (ph). Well...

(LAUGHTER)

SHAPIRO: ...Let's end this science news roundup with some poetry...

BARBER: Yes.

SHAPIRO: ...Haiku and insects.

BARBER: Yeah. So haiku, for those unfamiliar, are very short poems. They originated in Japan. And the form started with certain rules, but it's been picked up and adapted as it spreads to other languages. It often depicts a single moment and has traditionally referenced nature, including insects.

CARLSON: Like this one that we'd like you, Ari, to read from Japanese poet Kobayashi Issa. It was written in 1821 and then translated into English.

SHAPIRO: OK, I'm looking at this for the first time, but I have to flag for you science experts that the creature in this haiku is not an insect. It reads...

(LAUGHTER)

SHAPIRO: (Reading) Corner spider, rest easy. My soot broom is idle.

BARBER: It's very (inaudible).

SHAPIRO: As we all know...

CARLSON: You've got to love...

SHAPIRO: ...A spider has eight legs, not six.

BARBER: Oh, wow. He's schooling us.

CARLSON: Oh, you're on it.

SHAPIRO: It is an arachnid.

CARLSON: But you do got to love a soot broom.

SHAPIRO: Yeah, I like that.

CARLSON: Yeah. So researchers at the Frost Entomological Museum at Penn State analyzed thousands of haiku written over centuries in English or translated into English that referenced arthropods. So that includes insects and other animals with jointed appendages...

BARBER: See?

CARLSON: ...And exoskeletons.

SHAPIRO: Like crayfish.

CARLSON: And they wanted to see what arthropods get referenced the most and which ones get sadly overlooked.

SHAPIRO: Which arthropod is the winner?

BARBER: So the researchers published the results of their study this week in PLOS One, and they found that - maybe no surprise - the lepidoptera group...

SHAPIRO: Oh, butterflies and moths. Yeah.

BARBER: ...Yeah - get referenced the most. Here's another haiku from Issa.

(Reading) Fresh scooped mud from the little ditch, a little flitting butterfly.

CARLSON: And the paper also tracked which behaviors get referenced, and for butterflies, it was flight or flitting. One of the researchers, Andrew Deans, told us butterflies often engage in a behavior called puddling, where they suck up liquids from, like, mud or riverbanks for the salt and amino acids. So that could be what this haiku Gina just read is capturing.

SHAPIRO: You know, I've seen butterflies do that and never known why. Now I know.

CARLSON: There you go.

SHAPIRO: All right. Which arthropods get sadly overlooked?

BARBER: So aquatic arthropods...

SHAPIRO: Aw, like the crayfish.

BARBER: (Laughter) So, for example, the study cites aquatic insects that live part of their life cycle in water, like caddisflies or stoneflies. And they're very common, and they're important to the ecosystem. But they found few or zero references to them in the haikus they looked at.

CARLSON: But, Ari, you are in luck. The Frost Entomological Museum is holding its annual Hexapod Haiku Challenge right now. It's free and anyone can enter. And a special category this year is aquatic arthropods, so you can really be the one to make sure stoneflies and crayfish, if you want, finally get their due.

SHAPIRO: True story - when I was a kid, I won a poetry contest...

CARLSON: (Laughter) What?

SHAPIRO: ...With the Oregon Zoo where you had to write a poem about one of the animals at the zoo. So I think...

CARLSON: What animal?

SHAPIRO: I wrote about the hippopotamus, which is not easy to rhyme with.

(LAUGHTER)

SHAPIRO: Regina Barber and Rachel Carlson from NPR's science podcast Short Wave, where you can learn about new discoveries, everyday mysteries and the science behind the headlines. Thanks.

BARBER: Thank you, Ari.

CARLSON: Thank you.

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