This week in science: mysterious X-rays, movement and learning, and memory formation : NPR

Emily Kwong and Ari Daniel of NPR’s Short Wave talk about mysterious X-ray objects, the link between movement and learning and how a small part of the brain triggers memory formation.

Transcript

JUANA SUMMERS, HOST:

It’s time now for our science news roundup from Short Wave, NPR’s science podcast. I’m joined now by Emily Kwong and Ari Daniel. Hi to both of you.

EMILY KWONG, BYLINE: Hi, Juana.

ARI DANIEL, BYLINE: Hello there, Juana.

SUMMERS: Hey. So like you always do, you’ve brought us three science stories that caught your attention recently. Tell us what they are.

KWONG: How lightsabers can help with some types of learning.

DANIEL: A surprising area of the brain involved in long-term memory.

KWONG: And some Halloween-y objects in outer space emitting X-rays.

SUMMERS: OK, we have a whole lot to talk about today, clearly. Let’s start with lightsabers. Are scientists just out there battling it out in the lab?

DANIEL: If only. Allow me to illuminate. OK, so the idea for this study, published in the journal Science Advances, came from Luke Rosedahl, now based at Florida Atlantic University. During the COVID lockdown, Luke was playing a lot of virtual reality video games.

SUMMERS: Oh, those are the ones where players put on a headset that totally covers their eyes, and then they’re plunged into this, like, 3-D environment, right?

DANIEL: Bingo. It’s a game that requires your whole body to play. And at the time, Luke was studying the striatum, a region of the brain that controls both motor movement and decision making. And while gaming, he wondered if there was some unexplored link there. Could big movement help people figure out how to sort things? – what’s known as category learning.

SUMMERS: That’s an interesting question. How’d he try to figure it out?

DANIEL: In the lab, Luke got a bunch of participants to put on VR goggles. They were then showed striped objects, and the stripes were a different angle and thickness. And as the game went along, participants learned how to categorize the stripes, how to sort them into one bucket or another.

KWONG: And while some participants pressed buttons to learn, others did much bigger motions, like swinging a lightsaber to hit the stripes or punching a response box in front of them. And the difference in their learning was dramatic.

LUKE ROSEDAHL: With the larger movements like punching, people learned somewhere between four and six times faster, which is just absolutely incredible.

SUMMERS: That is a huge difference, but this was just for sorting stripes in a lab, right? I mean, as we all can attest, the real world is a lot more complicated.

KWONG: So much more. But if VR can be used to teach people how to categorize stripes, maybe it can be used in more complex training scenarios – say, help TSA agents sort bags or radiologists sort mammograms. Though a lot more research would need to be done to make that dream a reality.

SUMMERS: Right. OK, next topic. You mentioned that it’s about the part of the brain that’s involved in long-term memory.

DANIEL: Your recall is impeccable, Juana. So the brain area we want to talk about today is the amygdala. Generally, it’s associated with emotions like fear, but a growing body of research has found the amygdala also plays a big role in forming some long-term memories.

SUMMERS: How’d they figure that out?

KWONG: Yeah, the scientists studied people with epilepsy who recently had electrodes implanted in various parts of their brains. And then the scientists asked these participants to play a memory game and measured how often individual neurons turned on during that task.

UELI RUTISHAUSER: We can listen to a very, very small number of individual brain cells out of billions, and we can gain insights into that person’s mind and thinking.

DANIEL: This is lead researcher Ueli Rutishauser at Cedars-Sinai in Caltech. He told us they could watch amygdala neurons firing in someone’s brain when they were looking at a picture, maybe of a house or a person’s face. And the more those neurons lit up, the more likely people were to remember the image later. Basically, how active a brain cell was predicted whether a person remembered an image later.

DENISE CAI: That’s pretty cool, that you can look at a person’s brain activity and predict what they’re going to remember and what they’re going to forget.

KWONG: Denise Cai, a neuroscientist at Mount Sinai who wasn’t involved with the work, says this is the first time scientists have shown the amygdala in humans could be a kind of control center for visual memory formation, independent of emotions.

SUMMERS: OK, so help me understand. Big picture, how does this type of long-term memory formation fit in with the other ways that the brain makes memories?

DANIEL: It puts the amygdala on the map as a control center of how some memories form in humans. Denise says this idea has been around in rodent models for a while, but knowing it happens in humans could lead to a way more detailed understanding of how memory works.

KWONG: And potential treatments for disorders that affect memory, like Alzheimer’s or epilepsy. Doctors could potentially target this region to try to prevent memory loss, for example. The research was published in the journal Nature Neuroscience.

SUMMERS: OK, let’s round things out with the Halloween-themed portion of this roundup.

KWONG: Greatest time of the year – you got it, Juana. OK, so we are going to turn our attention to objects in the universe that produce X-rays – things that are scorching hot, says University of Alabama astronomer Jimmy Irwin.

JIMMY IRWIN: We’re talking hundreds of thousands to millions of degrees.

DANIEL: Such blazing temperatures can arise due to super high gravity or explosive forces, so studying X-rays offers a window into the dynamics of extreme cosmic phenomena.

KWONG: OK, so NASA’s Chandra telescope has been gathering X-ray data like this from nearby galaxies since 1999. And Jimmy and his PhD student, Mustafa Muhibullah, looked back at the data within a range that’s largely been ignored – the very lowest energy X-rays. And they were stunned when they found 84 new sources of these X-rays spread across half a dozen galaxies.

MUSTAFA MUHIBULLAH: I was initially thinking this could be digital artifacts. They can’t be real.

DANIEL: But they were. The results are published in the journal Nature Astronomy.

SUMMERS: So do they know what was producing all these X-rays?

KWONG: They have ideas. The researchers believe the sources are systems involving something super dense, like a black hole that’s stealing material off a nearby star, like a vampire, Jimmy says.

IRWIN: Instead of stealing blood, they’re stealing material from a companion star. And as that material spirals in towards the compact object, it gets heated up to really high temperatures, giving us this hot X-ray emission that we see.

DANIEL: Another system that could give rise to the low-energy X-rays could be two black holes orbiting one another, pulling matter off a star, a situation where you get a kind of doughnut-shaped void, which was recently named a zombie disk.

SUMMERS: Ooh, so we’re getting vampires and zombies here. You guys are getting real Halloween-y on me today.

KWONG: Yeah, very Halloween-y and it’s very exciting. Kristen Dage at the Curtin Institute of Radio Astronomy in western Australia, who was not involved in this research, is a fan.

KRISTEN DAGE: I never would have guessed that these sources would be there, and so we can come up with these amazing new discoveries that change your understanding of how we do science.

SUMMERS: And these cosmic vampires and zombie disks, do they tell us anything else about the universe?

DANIEL: Unclear, but one possibility is some may detonate violently into a kind of supernova that astronomers can use to measure how quickly the universe is expanding.

SUMMERS: Love it. That is Ari Daniel and Emily Kwong with NPR’s science podcast Short Wave. You can listen to hear about new discoveries and the science behind the headlines. Thanks.

KWONG: Thanks, Juana.

DANIEL: Thank you, Juana.

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