This month we look at a method to raise the bar on the quality and trustworthiness of information shared over social media networks, how fish running a fever heal from infection faster, what miniature bat backpacks can reveal about the eating and hunting habits of our flying mammalian cousins, how kingfishers come by their plumage patterns, and the evolution of spider venom genes. Join Dr Chris Smith for a look inside the science at eLife...
In this episode
00:34 - Making social media sources more trustworthy
Making social media sources more trustworthy
Laura Globig, UCL
According to various sources, about 5 billion of the world's 8-plus billion population regularly use some form of social media. Facebook alone has about 3 billion active accounts. Consequently the societal impact of these media - and specifically the messages and information that people convey through them - is huge. During the Covid-19 pandemic, claims that vaccines contained microchips so that Bill Gates could track us were everywhere. Someone even sent me a circuit diagram for the chips in the vaccine I had! Although when I looked closely, it was actually the circuitry for a guitar effects pedal! But did someone share - and "like" - that information because they too were amused by it, or because they genuinely believed what the post purported to say? That, UCL's Laura Globig argues, is the problem with many social media platforms: engineered to engage and promote information exchange, they don't reward users for the veracity of what they share. So, as she explains to Chris Smith, she's come up with a way to recognise and reward users for the trustworthiness of what they share...
Laura - The spread of misinformation online has skyrocketed and this has had quite drastic consequences such as increasing polarisation and resistance to climate action and vaccines. And so far existing measures to halt the spread of misinformation online, such as, for example, flagging or reporting posts has had only limited impact. So we wanted to know if we could help address this issue of misinformation online.
Chris - Before we come to that with what you just said, that there's been this association between public behaviour and social media. Do we know that's causal? That because of people putting inflammatory things on Twitter and Facebook and all the other places that is translating into people not having vaccines and so on?
Laura - The causal relationship is really difficult to establish. But what we know about the spread of misinformation is that because of the advent of the internet and social media platforms, it's become incredibly easy to reach people and to share information. And that information doesn't have to be reliable. So therefore it can also be true that false information is shared. And in times of crisis, people then turn to the internet as a source of information and then they're more likely to trust it. And that might then lead to vaccine hesitancy, for example.
Chris - And is it true what people hear about these various platforms that they are craftily coded so that they're almost addictive and they appeal to people in a very specific way and encourage them to - a bit like a mainline drug - take more of them?
Laura - It is true that these platforms tend to rely on metrics of engagement - so reward and punishment dynamics - to motivate people to post information online and also to react to posts. And that is very similar to any sort of reward mechanism you would see in the real world. So just like giving you money, your brain behaves the same way. If you receive likes on social media, you process it in a similar manner.
Chris - And are there any particular groups who are more susceptible to this or is, is everyone potentially a sucker for it?
Laura - Everyone is susceptible to a certain extent. It is true that people who tend to not question information as much, so who have less critical thinking ability, tend to fall victim more.
Chris - So what have you done here and would it work for those people?
Laura - People are actually quite good at distinguishing true from false information. So it's not a lack of ability. In fact, existing research shows that lay people are just as good as professional fact checkers at telling apart true from false information. Instead, one reason for the spread of misinformation online is the lack of incentives on social media platforms to share true information and avoid sharing false information. People tend to choose actions that lead to rewards or positive feedback and avoid those that lead to punishment. And on social media platforms, these rewards and punishments come in the form of likes and dislikes. But the issue with these likes and dislikes is that they aren't representative of the accuracy of the information you're sharing. For example, you could like an obviously false post because you think it's amusing. So we now propose that the key to reducing the spread of misinformation online is not to tell people what's true and what's false, but instead to directly incentivise them to share more true relative to false information. And so we need an incentive structure where these social rewards and punishments are directly contingent on the accuracy of the information.
Chris - So what you are saying is instead of there being thumb up, thumb down, like dislike, I could have, "I trust this", "I don't trust this"?
劳拉-没错。So in this study we do this by slightly altering the engagement options offered to users. So we're not taking away the like and the dislike button, but instead we added an option to react to posts using, just as you said, the trust and distrust buttons.
Chris - You can envisage why people would be incentivised to use that because it's an additional badge of honour for them saying, oh, I'm sharing this, but that's a bit iffy. And then if it turns out that it is a bit iffy, they can say, well, I told you so! So it does kind of play into the same reward system, but it's for the benefit of of more clear communication.
劳拉-没错。这里没有歧义use of the trust and distrust. So trust by definition is related to reliability. It's a firm belief in the truth and reliability of something. And so what we found in this study is that people would use these buttons to actually differentiate between true and false posts.
Chris - So what data have you got that suggests this will actually work?
Laura - What we did was we created simulated social media platforms and in these platforms, users saw both true and false information. And then we added an option to react to posts using a trust and a distrust button, in addition to the usual like and dislike buttons. And so then what we found was that people used these buttons to differentiate true from false information more so than they used the like and dislike buttons. And, as a result of that, to receive more trust rewards and fewer distrust punishments, other participants were then also more likely to share true information relative to false information. So what we saw was a large reduction in the amount of misinformation being spread.
Chris - Does the person effectively score points for trusting something that turns out to be true? Is that how it feeds back and endorses that so that person's building reputation? Is that one of the incentives?
Laura - So the incentive is receiving the trust themselves. So we have three experiments and in the first experiment we gave participants the option to react to posts using a trust, distrust, like and dislike button. And the incentive here is just to engage with the post itself. And so what we found was people use the trust and distrust buttons. And then in the second and third experiment we looked at how receiving trust and distrust feedback from other participants would impact sharing. So their people are motivated to share true posts so that they receive a large number of trusts and very few distrusts.
Chris - And of course your timing is perfect because in the UK at least the online safety bill is making its way through the government process. This is the idea of trying to make the internet a safer place where misinformation propagates more slowly. So really the whole world, the business world should be receptive to ways that they can improve, not just the the engagement and uh, but but the quality of the engagement.
劳拉-没错。That's also our hope and what we're doing here is we are not reliant on any fact checkers or anyone definitively determining whether something is true or not, but instead we're putting the onus on the user, which actually increases user autonomy, which also again would be very appealing to the platforms and hopefully to social media users themselves.
09:11 - Fish run fevers to fight infection
Fish run fevers to fight infection
Daniel Barreda, University of Alberta
A common consequence of infection is fever; at least for warm-blooded creatures like us. In response to various inflammatory signals, the brain's hypothalamus turns up the thermostat and our temperature climbs with inevitable consequences. We, in response, reach for the packet of paracetamol and bring it down again. But are we, by doing that, prolonging our illness? The fact that so many animals have this same fever response to infection argues that it must serve a beneficial purpose. But studying it is very difficult, because if we artificially alter a warm-bloodied animal's body temperature, the metabolic stress we inflict clouds our ability to ask questions about the impact on the infection. So the genius solution that the University of Alberta's Daniel Barreda hit upon was to work with a cold-bloodied species, because, yes, fish run a fever when they're infected too, but not by boosting their metabolic rate: by moving to warmer patches of water to force up their temperature. And this means they're perfect for studying the impact of fever on immune function, as he explains to Chris Smith…
丹尼尔-美丽的这条鱼是that it's very comfortable in temperatures between 1.4 degrees and 34 degrees. Goldfish, like other cold blooded vertebrates, do not have the capacity like we do to change body temperature through metabolic means. So instead they actually move to a warmer or colder temperature. So fish will go to a warm side of the pond and be able to induce or stimulate that fever through behaviour rather than through metabolic means.
Chris - You are telling me that goldfish run a temperature when they get sick like we do?
Daniel - They do! So if you look at the pathways that are involved, they are shared. Yes, there are physiological differences and we expect that there's going to be some differences between the febrile responses, but for now they're largely shared and the trigger is just behaviour when you're cold-blooded versus metabolic when you are warm-blooded.
Chris - So what did you do to these fish then to make them do this so you could investigate it?
Daniel - Well, that was the most beautiful thing I think, out of this study. The fact that we were able to stimulate them with a pathogen or with a vaccine, and we simply observed them. So it's not that we really manipulate anything in the animal themselves. What we did have to do was create an environment where they would be able to actually show what that natural behaviour was, and that was the most challenging thing.
Chris - What do you mean a tank that's got hotspots and cold spots?
丹尼尔-没错。这是一个豪华tanks that you'll ever see to hold a fish. Essentially we had a tank that had zero physical barriers, but there were multiple different temperatures within this tank. So everything was controlled through fluid dynamics. We had over five or six engineers working on this for a couple of years and basically got it to the point where we have a very discreet gradient, so different temperatures that were very consistent for over two weeks, and we were able to just simply put the fish there after they were challenged, after they were vaccinated. And look at what happened.
Chris - And what does happen?
Daniel - When the fish encounter a pathogen, they will move to the warm side of the tank. And what was really interesting to us is now that we had that extra resolution to observe this, was that they do so very dynamically and they will go to the warm side of the pond and then they'll stay there for the duration of their fever and they'll come back.
Chris - If you can control the temperature in that way, you can presumably do experiments where you infect or challenge a fish and then you deprive it of access to such a high temperature and it has to, therefore it can still choose to go somewhere warmer, but it might not be as warm. What happens if you do that?
Daniel - Well, in our case, we were able to have what we call a control group that allowed us to see exactly that. And when the fish were challenged, so they they encountered a pathogen but the tank was held at a specific temperature, in this case, the base temperature that they had been acclimated to, they did not get all the benefits that we found with the tank with all the temperatures. So we didn't see their capacity to clear the pathogen being as fast. They weren't as good at controlling inflammation and they weren't as good at repairing the tissue that had been damaged by this infection.
Chris - Some bacteria, though, grow better at higher temperatures. So is it still beneficial to the fish to go to that higher temperature or is there a middle ground and do they know what that middle ground is?
Daniel - That is an excellent question and that was one of the concerns going in. Fever is typically thought about as moving pathogens away from the temperature that they prefer, but yet we understand that many of these pathogens do better at the warmer temperatures. In our case, the aeromonas bacteria that we used grew better at the higher temperatures, yet the fish were much better equipped to combat this pathogen when they got the chance to move to this warmer temperatures,
Chris - Did you look inside the fish to see what effect the higher temperature was having on their immune system and on their physiology to effect this improved recovery at higher temperature?
Daniel - Yeah, absolutely. We looked at the capacity of the white blood cells to come to the site of infection and that was much more efficient. And what was interesting is it wasn't more white blood cells coming to the site, it was just they were coming earlier. And you can imagine if white blood cells come earlier, they find less pathogens at the site because the pathogens have had less chance to grow, so therefore it becomes a much better scenario that is in a favour of the host.
Chris - Do we know how the white blood cells improve their efficiency at these high temperatures? What the mechanism of that is?
Daniel - What we found was that at the site of infection, there was earlier production of various molecules that call on those white blood cells. The other thing that we saw was there was much better engagement of the central nervous system and that is actually able to create what we call a systemic response. So basically a whole body response, to better equip this animal to be able to combat this infection.
Chris - And you think that the same thing is almost certainly going on in us when we run a fever. We've got the same molecules, the same cell behaviour, and therefore the same gains through running a temperature to fight infection just like these fish are?
Daniel - Well, we've been studying comparative systems, so basically different types of animals for many years. And what we find is there's a lot of shared responses, particularly in what we call the innate arm, which are those very well conserved early responses from the immune system. And the second aspect is that there's well-documented survival advantage, not just in fish and other cold blooded vertebrates, but also mammals. Rabbits infected with renderpest, for example, survive much better if you allow them to have that fever response. And there's many other examples in the literature.
Chris - The strange thing though is that because we feel so awful when we run a fever, we end up popping pills like paracetamol to bring our temperature down. Are we therefore making ourselves potentially suffer less but for longer by doing that? Should we just grin and bear it and run a fever then?
Daniel - I think there's a few factors to consider. We do think of fever as a symptom and, and I think that has to change. The second aspect that is also very important is not just taking the antipyretics at the time of, but there's many people in the general public that may take this preemptively, whether it is before a kid goes up for vaccination and you simply do not want him to get cranky after, or if you are a sports person, you may think that, you know, you don't have very good ankles and you, you take one of these drugs right before a game just simply to prevent that inflammation from happening. Yes, you may be alleviating some of the symptoms, but the question is are you losing something? Of course we have to confirm this in mammals, but based on everything that we've been able to observe, it seems that at least a good part of it will be shared.
17:31 - Bat backpacks highlight hunting and diet preferences
Bat backpacks highlight hunting and diet preferences
Laura Stidsholt, Leibnitz Institute for Zoo and Wildlife Research
When I step outside at dusk near my home, I'm often delighted by the sight of local bats wheeling around above my head as they emerge to feed. But what is a bat's ideal meal, and how do they balance different sources of food, particularly as environments come under pressure from climate change or human encroachment? Speaking to Chris Smith, Laura Stidsholt, who's at the Leibnitz Institute for Zoo and Wildlife Research, has been studying one species of European bat by equipping them with backpacks that log where they go and what sounds they produce as they pursue and then tuck into different food choices…
25:06 - How the kingfisher came by his colour patterns
How the kingfisher came by his colour patterns
Chad Eliason, Field Museum of Natural History, Illinois
Fans of Rudyard Kipling's "Just so" stories will recall the yarn about "how did the leopard get his spots"; but now we're going to hear how the kingfisher came by his colour patterns! Speaking with Chris Smith, from the Field Museum of Natural History, Illinois, Chad Eliason…
30:19 - Genes spiders use for venoms
Genes spiders use for venoms
Kartik Sunegar, Indian institute of Science Bangalore
Two of the best-known venomous animal groups on Earth are the snakes and spiders. Both produce venoms that comprise cocktails of different chemicals. Snakes do it by using an assemblage of genes that they've co-opted into venom production over evolutionary time. As a result, these genes produce venom proteins that tend to vary in the way they look and work. Spiders, on the other hand, appear to have done things differently: they've repeatedly used the same genetic template and varied it, as Kartik Sunegar explains to Chris Smith...
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