Smartphones, Black holes, and Pompeii

Introduction

0:00This BBC podcast is supported by ads outside the UK. BBC Sounds. Music, radio, podcasts.

0:10Hello, welcome to 5 Live Science. I'm Chris Smith from The Naked Scientist. Coming up this week, new guidance urges HRT as a first-line treatment for menopause symptoms. Also, the enormous black hole that doesn't appear to obey our existing laws of physics. What DNA analysis is revealing about the people who inhabited Pompeii. And a bit later on... We also found that particularly the amygdala, which is one of those emotional brain regions, was highly correlated with the sensitivity to social feedback on Instagram.

Smartphone Harm

0:47Can smartphones harm our kids' development? The Naked Scientists on 5 Live. First this week, the health assessment body NICE, the National Institute for Clinical Excellence, has said that women with menopause symptoms should be offered hormone replacement therapy as first-line treatment, rather than just therapy. To find out more, we put in a call to Heather Currie. Heather's a gynaecologist. She's the founder of Menopause Matters, and also served as chair of the British Menopause Society.

1:18HRT is hormone replacement therapy, and it is currently the most effective treatment for menopausal symptoms and the consequences of menopause, because menopause is all around becoming low in oestrogen, so it kind of makes sense that the hormones that we're replacing with HRT are aiming to counteract the effects of being low in oestrogen. And what sorts of symptoms does that include? The commonest symptoms are flushes and sweats, and this is related to the lack of oestrogen causing the thermostat in our brain going a bit wonky.

1:50So our body thinks it's overheating when it's not, and switches on these flushes and sweats to try and cool us down when it doesn't need to. But there are also very common mood changes, so low mood, anxiety, depressed mood, difficulty concentrating, often sleep disturbance and joint aches. And these symptoms are probably less well known, although there has been much more awareness

HRT Benefits

2:13of the range of symptoms over the last few years. And what fraction of people might benefit from taking HRT? I don't think we have a definite number. So statistics are produced around the numbers of people that are currently taking it, and that has increased massively over recent years. Following a fall over 20 years ago, with publication of some quite big studies, there was a big loss and confidence, and the numbers of people taking treatment dropped significantly. But after many years of trying to get risks back in perspective, of trying to emphasise

2:46the benefits of HRT, then numbers have gradually increased, and in recent years have gone up massively. So it's up to each woman to work out how are the symptoms affecting her, what is the impact, being aware of what treatments are available, and making an informed choice for herself. And what a nice saying now, then, that's different. They are saying that HRT should be offered first line as treatment for menopausal symptoms. That was also in the 2015 guideline, but there's a bit more focus this time on the role of HRT

3:19for menopausal symptoms. However, you would think we'd know everything there is to know about HRT by now, and we do know a lot, but there are still some aspects that we're not sure about.

HRT Risks

3:29Given we must now have a lot of data over a long period of time on the use of HRT, what sorts of associations are we seeing with different disease outcomes, though? What's it stopping people getting? What is it not affecting, and what might it increase the risk of getting? We know that it is really good for our bone health and reduces the risk of osteoporosis, bone thinning, and osteoporosis-related fracture. The two that are a bit controversial, in particular, cardiovascular disease, so heart disease. Many, many years ago, we strongly believe that HRT, taken within 10 years of the menopause,

4:06did reduce the risk of cardiovascular disease, and that has shifted a bit generally. It isn't so clear that is the case. And what NICE has come out saying is, while there's no increased risk of cardiovascular disease with HRT, there isn't an absolute reduction. Dementia is another reason that women have started to consider the use of HRT to look at, will that reduce the risk of dementia? But the evidence coming out is that it isn't clear that that is the case. What about breast cancer? Because that spooked a lot of people.

4:3720 years ago, there was an association drawn between HRT use and risk of breast cancer. This has put many people off in the meantime. What do the data show around that, and what's our stance now? It has. So, the stats used by NICE, which is shown very clearly on the visual aids, shows that over 20 years, from 50 to 69, if women don't take HRT, 59 out of 1,000 women will develop breast cancer. If women take combined HRT for 5 years, over those 20 years, there would be 20 more women.

5:14And if they took combined HRT for 10 years, over those 20 years, the total would be 33 more women compared to women who do not take HRT. Now, that might sound like a scary number, but it's all about getting risk in perspective. So, in that time, if the women taking HRT had fantastic quality of life and actually were aware of the risk, everyone needs to be aware of the risk, but it is trying to keep it in perspective. And other things are also risk factors for breast cancer.

5:44So, it's not just about taking HRT, it's around other lifestyle factors, such as our weight or taking alcohol, for example. So, it remains a choice as long as it's an informed choice. Thanks very much to Heather Currie there.

Norovirus Vaccine

5:58A vaccine trial called the NOVA301 trial has just launched across the world, actually, to find out if we can protect people against norovirus. This stomach bug is rife at the moment, especially across the Northern Hemisphere. It causes millions of cases of diarrhoea and vomiting every single year, and it spreads like wildfire, partly because each infected person has enough virus leaving their body, both upwards and downwards, to potentially infect the entire world population, and that's not an exaggeration. And it doesn't only hit hospital wards, schools and nurseries.

6:31It can also harm national growth, because the cost to the economy is tremendous. So, how might a vaccine help? Well, it's being made by Moderna, who are one of the companies behind the Covid jabs that were used during the pandemic. And it's based on the same sort of technology. The mRNA message coding for parts of the virus that the immune system can react to is injected, and it hopefully primes a protective response. Dorset GP Dr Patrick Moore is the chief investigator on the study. Norovirus is also known as the winter vomiting bug.

7:04It tends to cause severe nausea and vomiting with diarrhoea. It lasts about one to three days. And how much does this cost the economy, do we think? If you look at the effect on the NHS, so how much does it cost to give patients who have norovirus the treatment, it's about £100 million per year. But when you take into account other financial factors, such as lost earnings, for example, it's probably estimated around £300 million a year. Goodness, it's a lot, isn't it?

7:35There must be millions of cases. To reach that sort of figure, it must be running into the millions of cases per year. Globally, we have about 685 million cases a year. In the UK, it's about 4 million. There's certainly big numbers. And at the moment, there is no way to prevent them, apart from infection control and keeping out of the way of people who've got it, presumably. That's correct. So the only treatment is actually supportive. So it's oral rehydration or intravenous rehydration, which is usually a hospital admission. And how easy is it to catch?

8:05This is one of the most transmissible viruses that we have, actually. It is extremely easy to catch it. So it's either aerosol, someone's vomiting in the same room, or it's what they call faecal oral. What's the strategy that's being taken then to try to prevent people catching it? So we're looking to see if we can vaccinate against this virus. It's quite a difficult virus to vaccinate against, because there are so many different genotypes and genogroups. So norovirus is actually a family of viruses.

8:35And actually, if you look at all of the viruses that are out there, there's 10 genotypes. And in those genotypes, there's 49 genogroups. So presumably, you could catch one and make a response to that. But then if you caught a related one a bit later on, you would have fewer defences against that and you become ill again. So it's pretty tricky to stop it. Yeah, correct. I mean, not all of those viruses circulate within humans, but there are certain viruses that are more popular in humans. And that's what the vaccine is trying to protect against.

9:05So they've taken three of those viruses and they've produced a vaccine to protect against those three common viruses that we have in humans. And what's the nature of the trial you're doing? How does it run? Who's the guinea pig effectively? And what's the nature of the vaccine? So this is what they call a phase three trial. We have been through the earlier phases, the phase one and the phase two trials that has shown good safety profile and also that the bodies produce a good antibody response to the vaccine. We're looking to recruit in the UK about 2,500 participants from about 27 NHS sites.

9:41So it's quite a large trial and it's what they call a double blind randomised control trial, which basically means that nobody knows whether you get the active vaccine or whether you get a sort of a saline vaccine. And what we do then is we then measure the efficacy of how well the vaccine works. Presumably you'll be looking at the people you vaccinate to see what the rates of natural infection are then and seeing if you get fewer of those infections in the people who've got the real deal versus the saline placebo. And if you do, then you can argue, well, it seems to be protecting people.

10:12That's exactly how it works, yeah. And obviously we'll be measuring and monitoring the safety profile of the vaccine as well and whether it's tolerated well and ensure that our participants are safe. How long are you going to follow the participants up for? The trial's running for two years. We vaccinate our participants. We then do a two-year follow-up. So in that time, we'll look to see how well the antibody response is there for, but also we'll then be measuring whether there are any cases of gastroenteritis which are caused by norovirus and that will give us our efficacy endpoint.

10:47And going forward, let's assume that you do get the result we're all hoping you do and this does work. How is it going to be used? That's a decision for the regulatory authorities to decide how it's being used. But certainly from a medical GP perspective, we do have a significant burden in hospitals and care homes, not just with the residents, but also the staff as well. They have a lot of time off work and a lot of pressure on the NHS over the winter months. Ultimately, I see that as the main benefit. That was Patrick Moore.

11:17And if you'd like to find out more information about the trial, you can head over to Nova301trial.com. You're on 5 Live Science with me, Chris Smith.

Black Hole Discovery

11:27And still to come, what DNA is beginning to reveal about the people killed when a volcanic eruption wiped out Pompeii 2,000 years ago, and we'll ask whether we can reduce the harms from smartphone use among young people. But first, astronomers have discovered a supermassive black hole that appears to break the laws of physics. Well, sort of. At the centre of the distant LID 568 galaxy resides an enormous black hole revealed to us recently by the James Webb Space Telescope. It's millions of times more massive than our sun.

12:00But what's weird about it is that it appears to be consuming material and therefore growing at a rate 40 times faster than the theoretical postulated maximum, which is known as the Eddington Limit. Why this matters is it might actually help to resolve a long-standing quandary in physics, which is how galaxies come by these supermassive black holes at their centres in the first place. Maybe, this new study suggests, if some small black holes can binge eat at rates like this one's displaying, perhaps they can grow sufficiently big and sufficiently quickly to account for

12:34what we see out there across the universe. Edward Bloomer is an astronomer at the Royal Observatory Greenwich, and he's been taking a look at the new study for us. This week we are shedding a little bit of light on the development of black holes. How do they start and how do they get to what we observe nowadays? They're quite common in the universe, aren't they, black holes? But they come in a range of different shapes and sizes. So which ones are you referring to? They certainly do come in different sizes. We have everything from stellar mass black holes, that's black holes that are about the

13:07same mass as the sun. But we've also got supermassive black holes, and they can reach millions or even billions of times the mass of the sun. And we're talking about one that's sort of in the middle, it's a couple of million times the mass of the sun. These usually are found at the centres of galaxies, is that right? Well, that's right. So one of the problems is trying to build up information about the population of black holes. They're pretty difficult to detect. But you might have heard that lots of galaxies, maybe even almost all galaxies, have black holes

13:40towards the centre. And I suppose then the big question is, well, we've got a galaxy, it's got this entity at the centre of it, but how did one come by the other? This is where this new discovery is really interesting. So there's two ways to think about it. One might be that in the very early universe, you have truly supermassive stars, they don't live for very long, they explode and they leave behind a black hole that then starts to grow. Or primordial gas and dust clouds collapse down and they produce black holes. And that sounds pretty similar, but one of them starts with a much lighter black hole

14:15and the other one much heavier. So you're sort of starting the race from two different positions. And the question is, how do you grow from that initial position to what we witness when we look at other galaxies and we see these super, super massive black holes? How can that be probed then? How can we get the answer to that? It's a very difficult thing, but this is where this black hole is kind of interesting. It's feeding on a lot, it's incredibly bright, so it's really gobbling stuff up. And the question is, I mean, black holes can feed things, you can throw things into black

14:46holes and they feed and they grow. But the issue is, there's only so much time in the universe. The universe is almost 14 billion years old, so we've only got a certain amount of time to grow. And when we look at young black holes, they've had less time to grow. And so that helps us try to work out the rate that this black hole might be growing. Is there a speed limit at which black holes are thought to be able to grow then? It's not just a question of you just force feed them and rather like foie gras, you get an enormous black hole quickly. That is thought not to be feasible then.

15:17So this is where this is really interesting, this particular black hole, because it's feeding much higher than not a hard limit, but a sort of traditional limit to its luminosity, this so-called Eddington limit. Basically, the more the stuff that falls in, the more radiation pressure gets produced that blows stuff away. Now, you can overcome that, but one of the ideas was that you could only overcome it on short periods of time. This one seems to be feeding, certainly, at a huge rate. And that means that if you could maintain that rate, then it could get to the size that

15:50you want. Or you've essentially bought yourself a little bit of wiggle room. Maybe it doesn't grow so fast at some point, but periodically, or maybe even just once every now and then, it sort of feasts for a little while. It's like a binge eating black hole. Yes. And so the question is, how often does that happen? I guess. Can you maintain it? Is this a characteristic of the black hole in its early development? How does it relate to the galaxy itself? Now, it might be all of these things are sort of linked in a very complex framework. But this one seems a bit of an outlier.

16:25And you hope to use those kind of weird edge cases to sort of illuminate what's going on with everything else. In summary, then, what has been spotted is a supermassive black hole evolving, which is eating material. And normally with a black hole, as it ingests stuff, it produces some radiation as the stuff goes in. And that radiation eventually gets so strong, it stops more stuff going in in the meantime. And that's that theoretical limit you mentioned. But this one seems to buck the trend.

16:56Do we have any theories, though, as to how it could buck that trend, that Eddington limit, so it can binge? You're right in that this is really well beyond that Eddington limit, perhaps by a factor of more than 40. Frankly, I'll be honest, this is something that people are still discussing and still trying to work out what is absolutely possible. What do space scientists think then, off the back of this observation, how does that shift the balance or the viewpoint around which of those models, the ones we outlined at the beginning, for how these galaxies come by their supermassive black holes initially, how

17:30that happens? Well, I think probably what's going to happen is you're going to have a lot of astronomers arguing one way or the other for quite a while. But it does suggest a little bit of support for the idea that you can start off with something much lighter to begin with, that are still able to grow fast enough to achieve what we see. Mind-bending and space-warping stuff. That was Edward Bloomer from the Royal Observatory Greenwich, taking a look at that observation on a binging black hole, which has just come out in Nature Astronomy.

Pompeii DNA

17:57Now, back in 79 AD, nearly 2,000 years ago, a huge eruption of Mount Vesuvius destroyed the ancient Roman city of Pompeii. It covered everything in a layer of ash, and in the process it preserved some of the bodies of the people who lived there. Visitors today can see plaster casts that were actually made in the late 1800s of some of these remains. And incredibly, when those casts were recently taken for restoration, a team of

18:28scientists were able to extract DNA from the remains of the 2,000-year-old victims encased inside, in some of them. But while the bodies are certainly authentic Vesuvius victims, their genetic analysis has also pulled the rug, to some extent, from under some of the more romantic narratives that historians have woven previously about those bodies. Alyssa Mitnick at the Max Planck Institute for Evolutionary Anthropology is one of the team behind the work. Notoriously, DNA preservation is not very good over long term in warm climates such as the

19:04Mediterranean. And then, of course, the extreme heat of the Vesuvius eruption might have also contributed to the destruction of DNA. So first of all, we just wanted to see, would we be able to retrieve authentic ancient DNA? And then we really wanted to test some of these popular narratives that had been projected onto some of the individuals from which casts had been made in the past. I think I've seen those casts because I've been to both Pompeii and Herculaneum. It's a very

19:37striking place, isn't it? But these are the plaster casts of the victims. They were made decades ago, weren't they, some of those plaster casts? Yes. So the method was first developed in the 19th century. And since then, over 100 casts have been made. They would find some kind of cavity in this compacted ash sediment and then pour plaster in and then excavate that and see what it actually was. A human that died there, an animal perhaps.

20:07That's quite interesting to think about what actually happened to the bones inside that cavity. So the soft tissue was decaying and the skeletal elements remained and they kind of followed gravity and fell down in this cavity. And then the actual pouring of the plaster would have moved around the bones some more. So what we were working with was 86 of the plaster casts were undergoing reconstruction at that time, or restoration, because they had been damaged

20:40in the past during the Second World War. So at some of the points in the plaster, we could actually see inside the cast and we could see the bones that were embedded in the plaster. And that's where we could take samples for our DNA study. Do you get good quality DNA out of that, even nearly 2,000 years later? It was difficult. So we sampled a total of 14 individuals. And in the end, we only got usable,

21:11analyzable data for five of them. And then we also have to make sure that this is not any modern contamination that was introduced by any of the researchers, the archaeologists or anthropologists that had been working with these casts in the past. We can check for certain characteristics that are atypical for old DNA. We do have somewhat a picture of what we could expect perhaps for general patterns of ancestry. During the Roman era, there has been a big study done on the city of

21:48Rome during that time period. And what we found was that actually what we see in Pompeii is quite similar. Can this begin to give us some insights into the kinds of people who were in Pompeii? Yes, that was part of the analysis we did. So we looked at different parts of the genome, the nuclear genome that is inherited both from the mother and the father, and then the mitochondrial genome that is inherited only from the mother's side. And we compared that to populations around the world, both modern day populations as well as

22:24contemporaneous populations where there has already been ancient DNA published. And we related the individuals from Pompeii to see who they were most close to. And that gave us some information about who their most recent ancestors could have been from which region of the world they originated. What emerged then? Because Pompeii was an interesting place, wasn't it? Because it was a very rich Roman town. There were a lot of what we were in the modern era would call posh people living there, very well-moneyed, educated. They also had a large number of people working for them who would have

22:58been less so. Does that get reflected potentially in what you see in the DNA? During the Roman imperial era, there is a real explosion of genetic diversity. And there is also a greater influence from the eastern Mediterranean regions like the Aegean, Anatolia, the Levant. And although Pompeii is a much smaller town, we do see the same pattern. So there is a large genetic diversity and we see this more eastern Mediterranean genetic influence.

23:30And of course, this could be because these people were indeed themselves migrants from that region or their parents or grandparents were. The surprising thing was that in some of the cases that we studied, the DNA in fact did not agree with some of these narratives that had been popularly spread. For example, we were looking at this group of four individuals from the House of the Golden Gracelet. These were two adults and two small children. And one of the adults was cradling one

24:05of the children on their lap. And they were traditionally interpreted as being a mother and her child. And the other adult was then the father of this group. And there was a second child. So a nuclear family. What we found is that in fact, all four of these individuals were males. They were also genetically distinct from each other. When we looked at their ancestry, although we maybe can't now create any definitive new story for these people, we don't know exactly who they were and how

24:40they related to each other. But it just shows us that maybe the first idea that comes to mind, the most intuitive or the most dramatic is not the accurate one. And we have to keep open mind. I was quite happy to be able to contribute to these people's story and maybe bring their truth a bit closer to us.

Smartphone Free Childhood

25:02Absolutely remarkable. Alyssa Mitnick from the Max Planck Institute for Evolutionary Anthropology. And she just published those results in the journal Current Biology.

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25:45Now this week, we're broaching a subject that will almost certainly resonate with parents across the country. The smartphone. Is this a force for good, keeping kids in touch with their peers and unlocking educational opportunities that we never had growing up? Or is it a malign distraction that's eroding social development, acting as a distraction in the classroom and causing mental harms to some vulnerable individuals? Or is it both? James Titcoe reports. Initially, the upside to children having access to a supercomputer in their pockets seemed obvious.

26:19Immediate access to the reams of educational information on the internet, seamless communications with their friends, a source of constant entertainment. But has reality lived up to this ideal? As mental ill health amongst our youngsters continues to rise, many are pointing to smartphones, and particularly the social media platforms on them as mainly to blame. And many teachers argued they're often an obstacle to better grades. Some countries have already taken action on smartphones, like in Australia,

26:50where they've been banned in public schools for over a year in some states. Can we harness the amazing potential of this technology in a way that avoids causing harm to developing brains? That's what we're going to be finding out today. A top neuropsychologist will tell us what the screen age is doing to our stone age brains. We'll look at recent studies into how adolescents and adults differ in their social media activity. And we'll examine what the evidence says about an effective ban on smartphones in schools. But first, Joe Ryrie is a parent and co-founder of Smartphone Free Childhood, a collective action

27:26campaign in the UK, which is seeking to delay the age at which parents give their children these devices, staving off peer pressure in the process. Smartphone Free Childhood started accidentally in February. And that was when my wife set up a WhatsApp group. And we realised very, very quickly that parents, the length of Britain, and actually all over the world, were really, really worried about this issue that we were worried about, which is that we didn't want to give our eldest daughter, who was then eight, a smartphone. There were some other children in her class that were starting to get smartphones. And we could see that this issue was

28:00coming around the corner very, very quickly. And it turns out there were tens of thousands of other parents who felt the same way. What are the harms that you're hearing about that you think is the reason this needs to be addressed? The first one is obviously the correlation to the teen mental health crisis. And there was a study in 2023, I think it was nearly 30,000 young adults that showed that the younger they got their first smartphone, the worse their mental health is today. And there's all sorts of other studies that point to a

28:31direct correlation at the very least between the age of first owning a smartphone and the likelihood of facing mental health problems in the future. Harmful content is a huge one, giving children unrestricted access to the internet in their pockets creates a gateway to the kind of content that we'd never dream of exposing children to in real life. Children seeing hardcore pornography or being exposed to extreme political views, sexual content, violent imagery, these kind of things have just become normal. They're kind of part of the fabric of modern childhood. And we're saying that that's not okay. There are all sorts of issues that stand from the back that these platforms are addictive by design.

29:05The fundamental objective of these social media platforms is to maximise engagement, i.e. get people to spend as much time as possible on their platforms. A young person whose brain isn't fully developed, who's can't sort of control their impulses in the way that an adult can. And they're also hardwired the peer approval. And then you put it in their pockets 24-7. I think it was 29 hours a week. There's the average time that the average British 12-year-old now spends on a smartphone. That's a huge amount of time. We start to think about what children aren't doing

29:35in that time. That becomes really, really worrying. Indeed. I guess the central conflict there is your conviction that there's something potentially damaging about giving smartphones to young children against the fact that if many of their peers have them, you really don't want this to damage their social standing in their peer group. Exactly. Yeah. You've hit the nail on the head there. There's become a rite of passage, particularly when children transition to secondary school, so age around 11, that because everyone else in their class has got a smartphone, then you don't really have a choice but to get your child

30:08a smartphone because their social lives start to migrate online. And we think that's an impossible position. You either hand over a device that you know to be harmful or you risk alienating your child just to the point when you want them to spread their wings and become independent. So the main thing that we're trying to do is bring parents together to agree collectively to delay getting their children smart wins because it's very difficult to do on your own. But if 5, 10, 15, 20 parents in the same class all agree not to give their children smart wins for a few more years, then that peer pressure reduces and it becomes a much, much easier conversation.

30:41Do you have an age in mind? I'm thinking about the kind of practicalities of what success will look like for the campaign. This is much debated. Where we've landed is end of year 9, so age 14, which is a bit more of an achievable goal than what a lot of people think is actually a safe age of a smartphone, which is 16. So we're just advocating to delay giving children smartphones for a few more years than what's currently become the norm. I guess then it runs into the problem of the feasibility of pulling something like this off.

31:12As you say, by the end of primary school, a lot of kids have already had smartphones. By 14, I probably contend it's the majority of kids these days have a smartphone. Trying to reverse this almost ubiquitous possession of smartphones among young people when some will say the horse has already bolted. Perhaps we're better off moving with the times and making sure the online worlds that our children inhabit are as safe as they can be. Yeah, look, we absolutely think there's a lot of work that needs to be done to make sure that the

31:44online world is safe and we support anyone who's working in that space. But the situation that we find ourselves in today is one where I think everyone agrees that it's really not safe for young people to have unrestricted access to the internet in their pockets. And so we find ourselves in a position where we either just have to accept the status quo or do something about it. Joe Ryrie from Smartphone Free Childhood will be hearing more about the debate around smartphones in schools a bit later on. But what about one of Joe's central arguments that smartphones and the

32:14platforms on them are addictive? And what other impacts could they be having on young brains as they are still developing? Richard Saitoic is a neuropsychologist and professor of neurology

Screen Age Brain

32:25at George Washington University. His new book is called Your Stone Age Brain in the Screen Age. People are familiar with physical addictions like alcohol and drugs, but there are also then behavioural addictions like gambling and shopping and compulsive sex, for example. And the endless scroll that you do on your phone is an example of behavioural addiction. Because when do you stop? You don't, because there's no end in sight. And so it's like a slot machine that you keep playing and

32:56hoping for a hit, something interesting or funny or important is going to come up and you just keep going at it. And that's called positive intermittent reinforcement, because you get a hit every now and then. And that's enough to keep you hooked. Is it really inducing the brain chemistry changes associated with addiction in the same way a harmful drug does, for example? Yes, there have been some studies both with fMRI and tractography that show that we're getting the same kind of physical changes with these behavioural addictions as we do with

33:29physical addictions. So that's addiction, a serious harm in its own right. You also talk about the risks though of the cognitive load imposed by screen devices and whether this is impacting on our brain functions. Well, it is. The whole reason that I talk about the stone age brain is that we operate under a fixed bandwidth of available energy and no amount of diet, exercise, Sudoku puzzles or supplements is going to be able to change that.

33:59We've now reached the point where we're asking it to do so much that it's like over exercising a muscle. It fatigues and collapses. What are the cognitive costs of that? Well, take a look at school grades for one thing. For attention spans, everybody agrees that our attention spans have all gone to hell. It affects memory, it affects sleep. And of course, the lack of sleep affects your ability to learn or not to learn or retain what you've learned in school if you've been paying attention in the classroom instead of looking at your screens, which is what so many

34:33kids do. They don't pay attention to the teacher. They're looking at TikTok. Quite. Once your attention span deteriorates or your memory gets worse, how easy is it to claw those capabilities back? Are younger people at a bit of an advantage perhaps in this area in that there's time to turn it round up to the development of their brain, as you say? Yeah, well, they still have a lot of plasticity left, but all of us have some degree of plasticity even into our 90s. So the answer is, yes, it's easy. And also, no, it's really difficult. It's easy

35:10because the solution is simple. It's difficult because people don't want to do it. And that is turn the phone off, put it face down, put it in another room, go for a walk, talk to someone on the phone rather than texting them, interact in person. I mean, this is what the pandemic taught us is that kids were doing, you know, Zoom schooling, and they weren't getting the socialization that they need in the first, second, third, fourth, fifth grades. And that really affected their ability to interact

35:42with other people, to make small talk, for example. They're terrified of anything in person. What's the role of face-to-face interaction for the developing brain? Well, we're a social animal. And so socialization is where it's at. The infants and toddlers learn by imitation learning. They mimic their adults. And so that's why playing, you know, So Big and Paddy Cake and imaginative games like restaurant or shoe store, these are imaginative exercises in

36:15socialization. So is being able to talk to other kids or their parents, their relatives and all this. The whole notion of social media, I mean, that is such a misnomer. It's not social at all. It's isolating. And that's why we see so much anxiety in young people, particularly as they head off to college for the first time. They have no idea how to navigate life. It's really sad. This is what I mean by virtual autism is that this heavy screen exposure induces autistic-like symptoms in heavy

36:50users. So poor eye contact, verbalization, and regression of social skills. Now, if you take the phones away, the symptoms go away in a short period of time, something that never happens in real developmental autism. So the solution is easy, but the participants don't want to implement the solution. Is that the only way to row back on the screens? Or is there a way of harnessing the potential for access to so much knowledge, to really positive opportunities to interact with the world

37:25without all the negative aspects as you've outlined them? Of course. I mean, you know, my iPhone is a wonderful device and a tool. I mean, it's far better than anything on Star Trek. But you have to use it wisely, realizing that, yes, it's a great boon, but it's also a narcotizing agent. And so it calls on your emotional intelligence, which is, first of all, self-awareness, the ability to regulate your own behavior, the ability to have

37:56good social skills, adaptability, and most of all, resilience. And people who were addicted to their phones don't show any of this, because they're so sucked into the screen. So this is a big call to action, really. This is something up to this point, we've got badly wrong. The situation has crept up on us, where children have access to these platforms, and we're leaving many vulnerable to harm. Yes, you know, in the beginning, all the tech boosters approached this as if it were an unalloyed

38:29good. And anybody who said, gee, I don't know, maybe there's some downsides here. They were dismissed as a technophobe or a Luddite, they were explained away. And I think now the cows have come home, we're seeing the results of this, the critics would say, well, there's not enough evidence, you know, we should wait until we have evidence. Well, that's misunderstanding the precautionary principle, which is if something might be doing harm, then don't do it, or be careful of what you're how you're using it. Doing research like this is so complicated and multifactorial and messy, that by the time we get

39:08the data that the critics want, the damage will be done. We'll be waiting forever for that evidence to come out. So in the meantime, I say, look, there's a strong likelihood that these devices are doing harm when used in excess. So how about not using them in excess? Neuropsychologist Richard Saitoic there, and his new book, Your Stone Age Brain in the Screen Age, is available to buy now. As Richard was pointing out, establishing a causal link between screen time

39:39and the rise in poor mental health outcomes for adolescents is hard to do, but work in this area is underway. A recent study showed an increased sensitivity in adolescents to a core feature of many social platforms, the like button. Most of us are familiar with it by now. Whenever you post on your favourite feed, other users have the option to engage with you by clicking like. The study, published in Science Advances, links a drop in likes with a comparatively bigger drop in mood in young people. I spoke to one of the authors of the study, Wouter van den Bos, who is an associate

40:15professor of developmental psychology at the University of Amsterdam. There was already a data set, and it was exactly the data that we needed, because it had 8,000 teenagers and 8,000 adults that were on Instagram, and it had all their posts and the likes they got on the posts. And that data could tell us how sensitive they are to the likes that they got on their posts. How are you defining sensitivity in this sense? The effect that likes have on future posting and using the app. So we assume that if you get more

40:51likes, particularly more likes than you expected you would get, you are again more motivated to pick up the phone and start using the app and start posting again. And if you then don't get the likes you expect, you get demotivated and it will take longer before you start using the app again. And the thinking underpinning that assumption is that young people, adolescents, are social creatures more so perhaps than adults. So that sensitivity would be increased.

41:22Yes, we based our hypothesis on the fact that we know that adolescents are really sensitive to their social environment, because also in this developmental period, there's a lot changing. You have this shift, moving away a little bit from your parents, and your peer group becomes more important, and also your position within the group. So those likes might be much more important signals for them. They're much more meaningful. That's what we thought, and in a way what we found in our data. If the adolescents got more or less likes, they were much more responsive to it.

41:54If they got more, they started posting more. If they got less, they started posting less. We also saw that pattern in adults, of course. It's not that they don't care at all, but definitely the adolescents were more sensitive to it. So younger people are more sensitive to the amount of likes on their posts. The next step, I suppose, is to necessarily say that they feel worse as a result. Maybe they just decide it's less worth their time posting. How did you show that lower likes maybe led to lower mood, for example?

42:24Yeah, so for us, that was the next step in the second study, also really looking at their emotional states. And for this, we moved to the lab again, and basically we built a social media simulator, an experiment in which the participants, including teenagers, they could post things from a selection of memes that we gave them. And when they posted them, they got likes based on other people's ratings. So those ratings were real. The only thing is that we manipulated behind the scenes in this app, the memes they could select from. So sometimes we just gave them really poor memes, and basically

42:58that results in not so many likes. For both adults and for the adolescents, if they got more likes for a while, they reported higher moods, as we also asked these questions in between during the experiment, how they were feeling at the moment. And the mood would decline if you gave them all the bad memes and they get less likes. And specifically for the adolescents, these effects were stronger. And again, specifically for the negative mood. So they were definitely more affected by not getting the likes they expected or wanted.

43:29What about a mechanism behind this association between reduced likes and lower mood? Are you able to say what's going on inside the brains of young people to perhaps explain why this enhanced emotional volatility is seen in relation to social media? Well, we think there's two things going on. One is for them, it's much more important, the peer group, the connections they have on social media, it's 90 or more percent, are basically the teens and peers

44:01that they interact with in their daily life. So basically from school and other things. If they're not getting the feedback, this is really a strong signal for not really belonging in the group in a way that they really want. And they don't have many alternatives often. The second thing is that emotion regulation itself is also sort of a skill that's still developing during this period. We know that the prefrontal cortex and the connections with the subcortical brain region, so the smaller emotional brain regions, are still developing during those years. And we also found

44:35some intriguing sort of starting point to further explore this in a neuroimaging analysis that we also did, the third study of the whole paper, where we also found that particularly the amygdala, which is one of those emotional brain regions, was highly correlated with the sensitivity to the social feedback on Instagram. That really stands out as one because it was also correlated with social anxiety and problematic social media use. So I think regulating the activity in that area could be

45:13really helpful to deal with the feedback that they get online. How does this knowledge potentially help us to reduce harms from smartphones? I know Instagram had a push recently to remove the light counter from posts. And they also have more recently been developing accounts specifically for adolescents to mitigate some of the predispositions they have to having a difficult time on social media. Are those steps in the right direction?

45:46Here we've only focused, of course, on one element, the likes. And there's other things that also in very different ways might be very dangerous. But if you talk about the likes, I think that's definitely a good step. Of course, it was only optional and it was still sort of visible, but not entirely. And it's still easy to give the likes. And I think it would be nice if we could focus really on making those interactions online a little bit more meaningful, strip it away even more. Is that something that the social media companies will be happy with?

46:19Wouter van den Bosch, Associate Professor of Developmental Psychology at the University of Amsterdam. Instead of trying to modify online spaces, what about a more prescriptive approach? We mentioned Australia earlier, where smartphones are banned in public schools. And this is something currently being debated in the UK as well. Could this approach have a positive impact on grades and mental health? What about the potential upsides to having access to phones in schools? Sonia Livingstone is a director of the Digital Futures for Children programme at LSE.

46:53She co-authored a recent report titled, Does the evidence support a school ban on smartphones? There's surprisingly little evidence given the amount of publicity that this issue is getting, but what exists is a mixture of some studies showing keeping smartphones out of class improves children's academic outcomes. And some research doesn't really show any effects at all. And we think that's partly because schools aren't really implementing outright bans. They have all kinds of nuances. So there's kind of

47:30weak evidence that restricting smartphones in class is helpful and a little evidence that the benefits are particularly strong for children who are more disadvantaged or struggling in school. And that kind of makes sense. They may need more support to concentrate and learn. In terms of the counterpoints, you know, what are the potential benefits of having smartphones in schools? Well, for a long time, we have thought as a society that children with having smartphones in school

48:03could support their learning, especially if it's embedded within the curriculum and teachers know when to call on children to use their phones because they're powerful computers. They can enable personalised learning. They can enable children to kind of pursue their particular interests. And they're also useful for linking how children learn at home and at school because they can take work there, you know, halfway through, or they can complete work elsewhere, or they can bring something they've done

48:38from home into school and so on. So, you know, as a device that connects spaces of learning and offers children kind of child-led, personally motivated opportunities for learning, the potential is considerable. I think what we're doing at the moment is schools find it too hard to control how children use their smartphone in class. So schools would prefer, if they have the funding, to provide children with school-owned tablets or laptops.

49:11Broadening our conversation out now, we've been hearing throughout the programme that social media is addictive by design, takes children away from the activities that are crucial to their healthy development, playing face-to-face, sleep, of course. Do we see these harms borne out in any of the studies when comparing children who have less smartphone use? I think we can certainly see evidence that children who use their phones a lot are more likely to report some adverse outcomes like losing sleep or missing out on social interaction or indeed

49:49seeing their grades, their school grades drop. The children who don't use the phone very much at all, some research says they miss out on the kind of social interaction and the peer culture that is part of school life and part of growing up. And the ones in the middle, the ones who use it are kind of what's become a normal amount, if you like, we see all kinds of outcomes. For some children, it gets in the way, it becomes a problem, they don't feel quite in control of it. For other children,

50:20it's a welcome relief or a source of relaxation or fun. So, you know, the outcomes of using the phone are about as variable as our children's lives. And that's why it's so hard to summarise. It's not that there are no effects, but there are lots of different effects, depending on children's backgrounds and starting points and what it is they want to do with the phone. I do think on your point about addiction, we have seen a shift in what the phone represents in

50:52the last few years from a fantastic device that children can do many things with to a device that increasingly has apps on it that are designed to grab and hold children's attention. And, you know, so if we can separate the phone from some of the apps and platforms on it, we might want to talk about restricting use of some of those apps or thinking again how to support children to use them in a way that is healthy for them and not excessive. That was Sonia Livingstone from the LSE.

51:29Thanks very much to James Titko for that analysis of smartphones and their impact on young people. Next time, we're also talking impact. We're talking about the impact of weight loss jabs, which are all the rage, but how do they actually work? And how can they help to solve the obesity pandemic? If you'd like to join in that conversation, why don't you drop us a line? It's fivelivescience at bbc.co.uk. In the meantime, from me, Chris Smith, thank you for listening, and do join us next time. Goodbye. bbc radio five live weekdays from nine nicky campbell takes your calls on the day's biggest news you're

52:06very welcome to the nation's opponent the health suffers the family life suffers the only solution really the tech companies know what these algorithms do they have an ability to stop them today such passionate opinions on both sides of this argument there's just a huge worry for me i don't think people understand how serious this is nicky campbell weekdays from nine bbc radio five live listen on bbc sounds