This week, The Naked Scientists go global as we explore language - can speaking more than one exercise our brain? And is our ability to save money purely down to the way we talk? Plus, the rodents that provide new information for stroke therapy and how very hungry caterpillars could solve our plastic problem...
In this episode
00:50 - Naked mole rats could help stroke victims
Naked mole rats could help stroke victims
with Dr Ewan St John Smith, University of Cambridge
Stroke occurs every 2 seconds worldwide and is the second largest cause of death. When a stroke happens, the most important tissues of our body, the brain and heart, are starved of oxygen causing cell damage. To improve therapies for stroke patients we need to understand how the human body copes without oxygen and one researcher at the University of Cambridge thinks he may have found the answer in the form of a small rodent called a naked mole rat. Dr Ewan St John Smith and his colleagues were able to identify a new mechanism used by the naked mole rats to maintain an energy supply to the cells in their body without using oxygen. He told Tom Crawford more about these fascinating creatures…
Ewan - Politely, one can describe them as a cocktail sausage with legs and teeth, but they are very unusual rodents. They are about the same size as a mouse and they are very unusual for a number of aspects. They are the only cold blooded mammal we are aware of, they live for over 30 years even though based on their maths you’d predict them to live somewhere between 3 and 5. They also have a very unusual social structure which is what we call eusocial, so that’s when you have a colony of animals up to 300, but usually near a hundred for the mole rats, and it’s led by a queen who’s the only breeding female. There’s a couple of males who are the breeding males and all the other animals are workers so it’s a very highly social mammal.
Tom - You’ve discovered how they are able to survive without oxygen and still produce energy but why is this important?
Ewan - The mole rats live in these large colonies underground, so they are permanently subterranean rodents and, obviously, if you’ve got a lot of animal underground they’re breathing. If you’re breathing they’re using up the oxygen and you’re generating a lot of carbon dioxide, but there’s not the same supply of fresh air there is for us when we’re just walking around above ground. So these animals have adapted throughout evolution to an environment that’s low in oxygen so it’s important for them to be able to function normally that they can deal with much lower levels of oxygen than we can.
Tom - What did you do specifically in these experiments?
Ewan - In these experiments we first wanted to identify how resistant is the naked mole rat to this lack of oxygen, a condition we call hypoxia. If we compare this first of all to the human condition; when a human has a stroke there's a blood clot usually in the brain which prevents oxygen getting to the brain and the nerve cells - where there is no oxygen - die. What we want to do in stroke is try to protect the nerve cells from dying so that fewer cells die, so it’s all about getting oxygen to the right place.
What we were trying to see in the mole rat was how, considering they evolved in this low oxygen environment, how resistent were they to a lack of oxygen. So when you expose a mouse -a model of our human - to a lower level of oxygen they, like humans, experience brain death quite quickly. Whereas the mole rat is able to go for almost 20 minutes with experiencing no brain death and the animals are perfectly happy and are able to survive this period of complete absence of oxygen.
Tom - Having identified this behaviour i n the mole rate, the question facing Ewan and his colleagues was how are they doing this on a cellular level? In particular, what’s going on with the key organs that are needed to sustain life - the heart and the brain?
Ewan - When the naked mole rat is exposed to this long level of lack of oxygen, the heart rate drops dramatically to about 20/25% of its normal rate, but it keeps going. So somehow, it must be getting energy from somewhere in the absence of oxygen. It can’t generate energy by the normal processes that we, as mammals, do, so the heart keeps on going. Similarly, if we look at the brain, the brain activity is able to keep on going in the absence of oxygen. Obviously not forever, but for a much longer period of time compared to the mouse.
So the question is then: how is the mole rat able to do this; how is that the cells and the heart and the brain can keep on going? And again, coming back to stroke, this is really exciting. If we can understand how the mole rat cells keep going, maybe this is way for which we can generate new therapies to prevent nerve cells in a human patient dying when they have a stroke.
Tom - As humans, there are different ways that we can generate energy in cells. Some of them require oxygen, which we call aerobic respiration, and some of them don’t and this is anaerobic respiration. An important part of the anaerobic respiration process is called glycolysis and this requires glucose, so sugary syrup. But the mole rats are actually doing glycolysis using something else…
Ewan - What we were able to identify is that the mole rat is able to use fructose to generate energy in the absence of oxygen. Now we can also use fructose, but the difference is in the mole rate in the heart and in the brain, it’s got much higher levels of a protein that enables cells to transport fructose from the blood into the cells. So in this period where there’s a lack of oxygen and it uses up all the normal glucose supplies within cells, the mole rat can utilise fructose in the blood to keep on generating energy. And again, this can’t go on forever, but it’s able to for a much longer period of time, sustain a basal level of activity in the cells so they don’t die.
Tom - So now that we understand how the mole rats do this, is the idea to try and make human brain cells and heart cells do this glycolysis using fructose?
Ewan - I think part of the problem is, obviously, if you have stroke patient we know that we can’t just inject them with a large bolus of fructose because they don’t have the transport proteins to get them into the brain cells, for example. So we’ve got this new way of understanding how the mole rat cells keep going. And I think what it’s really done is open our eyes up understanding more about what is enough, what is sufficient for nerve cells to keep going so they don’t need to be performing aerobic respiration as we usually think. It’s a huge way forward in understanding how the nerve cells, or how the nerve cells can survive without oxygen, and the more we understand about that, the greater chance we have of generating a novel neuroprotective strategy for preventing nerve cell death in humans who’ve had a stroke.
06:36 - Using heartbeats to read minds
Using heartbeats to read minds
with Punit Shah, Anglia Ruskin University and King's College London
Can you read minds? Well, maybe not to Derren Brown’s standards, but actually - most of us do this every day. We can usually gauge how other people are feeling - whether they’re sad or happy - this is known as empathy. Some people are better at doing this than others, and research out this week suggests that it may be linked to how well you can monitor your own heartbeat. Punit Shah, lecturer and researcher at Anglia Ruskin University and King’s College London, got people to estimate their own heart rate - a measure of something called intraception, and to perform a task involving working out the emotions of other people - a measure of empathy. Georgia Mills went to see Punit to find out what he and his team discovered...
Punit - We found, after performing both sets of tasks, that there was quite a close link between people’s performance on the heart rate task and the task involving watching social situations.
Georgia - Why on earth would this be the case?
Punit - It was almost guaranteed to be the case when you think about the way in which we deal with emotion. When we see someone that we dislike, we might feel our heart rate elevate slightly. When we see a dangerous situation, we might feel our heart rate increase. And it’s in those situations where we need to be able to perceive our heart rate and respond appropriately and this seems very closely linked to emotion. It’s something that’s been known for almost a hundred years but the evidence for this link has actually been remarkably sparse.
Georgia - Thinking of an example, a time I would feel an emotion of someone else - you’re watching someone do a live talk and they forget their lines and you go ‘owh.’ Would this be a case of your own heartbeat increasing as a result of their sort of struggle and you hear, or feel, this and as a result feel like you’re feeling the emotion too?
Punit - Yeah, that’s a very good example where what you described really is empathy happening, where you sort of feel their pain almost. This process whereby you're feeling your internal sensations, feeling your stomach sort of clench up, where your heart rate increases - feeling all of those things helps you to understand that situation.
Now although the way you’ve described it seems incredibly intuitive and many people think everyone is able to do this, but what we’re finding is there are quite striking individual differences. Some people are really able to do this well. Equally however, there are others who really struggle at perceiving their own heartbeat and, therefore, struggle to understand others.
Georgia - OK. I’m quite keen to see where I’d fit on this. Is it alright if I try the dialled down version of the experiment?
Punit - Yeah, I think we can give that a try - yeah, absolutely.
Georgia - So what should we do?
Punit - First of all I’d like you to just sit on your chair upright and just try to relax, even though you’re holding a mic. But just try to have your arms as relaxed as possible on the armrest. Now what I’m going to do is try and find your pulse. I’m going to say ready, steady go. And as soon as I say go, I’d like you to close your eyes and try and count your heartbeats…
Georgia - OK then.
Punit - Close your eyes… go. Stop. OK, what did you think?
Georgia - 15?
Punit - 15? It was actually 28.
Georgia - Oh, no. What does that mean?
Punit - It doesn’t mean anything specifically. It doesn’t mean that your abnormal in any way - there’s a natural variation in it. I can’t do the full calculation now but it suggests that you aren’t perhaps as good at intraception as some other individuals.
Georgia - So, if I was on your chart, you’d expect me to have low empathy?
Punit - It’s possible that you may have slightly lower levels of empathy or theory of mind but, it’s like most people, that you sit somewhere in the middle. You sit somewhere around average where you make a reasonable number of mistakes and it’s likely you have quite an average score on the theory of mind or the social situations task.
Georgia - With your link here, how certain are you that once causes the other? Could it not be that there’s a third factor - say intelligence? Are intelligent people just good at measuring their own heartbeat and good at telling what other people think?
Punit - Within my research, I use what we call a “time estimation control task.” So, when I said “ready, steady go” there, you counted your heartbeat. In the control task people actually count the number of seconds. By doing so we expect that to also be related to IQ or intelligence, if there is any relationship. We don’t necessarily find this, nor do we find this relationship we found between internal sensations and emotion to actually break down after factoring in people’s performance on the time estimation task.
Georgia - Apart from telling people like me I need to go and be more empathetic, what implications does this have in the real world?
Punit - I think clinical implications, if there are any, may be some of the most important that we have seen. We know, for example, that people with autism spectrum disorder struggle with understanding social situations and may also have difficulty with processing their internal signals. So it may help us better understand, and even manage, their condition. The same applies to a whole host of other clinical and psychiatric conditions so by understanding this whole process, it may help us to understand and manage those conditions.
12:24 - Mythconception: Newton's Apple
Mythconception: Newton's Apple
Each week, The Naked Scientists get to the bottom of some suspicious science. Kat Arney has been getting her teeth into a fruity legend with this mythconception...
Kat - The history of science is peppered with fascinating and funny anecdotes explaining how great minds hit upon their brightest ideas. One of them is the image of Sir Isaac Newton sitting quietly under an apple tree, only to be bonked on the head by a falling fruit and inspired to come up with the theory of gravity. It’s a wonderful and well-loved image that tells a simple story, but sadly it’s simply not true.
The legend starts in the late 1660s, when Newton had been sent back to his childhood home at Woolsthorpe Manor near Grantham in Lincolnshire due to an outbreak of bubonic plague at Cambridge University where he was studying.
According to William Stukeley, who wrote a biography of Newton in 1752, Newton himself recounted that “After dinner, the weather being warm, we went into the garden, & drank tea under the shade of some apple trees… he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind…. occasion’d by the fall of an apple, as he sat in a contemplative mood.
“'Why should that apple always descend perpendicularly to the ground,' thought he to himself. 'Why should it not go sideways, or upwards? But constantly to the earth's centre? Assuredly, the reason is, that the earth draws it. There must be a drawing power in nature.'"
Nice as it is, something doesn’t quite add up here. Newton only told Stukeley the story in 1726, a year before his death in 1727 and a full 60 years after the alleged ‘apple incident’. The French writer Voltaire also mentioned the story in an essay penned in 1727, saying "Sir Isaac Newton walking in his gardens, had the first thought of his system of gravitation, upon seeing an apple falling from a tree."
It seems strange that Newton wouldn’t have mentioned such a key moment sooner - although maybe he was embarrassed about something so humble leading to such a great idea. As a clincher, Newton’s own notes show that he was grappling with ideas about gravity before he went back to Woolsthorpe.
Like all good legends, the story of Newton’s apple tree probably has a root in the truth - watching the apples falling from the trees might have helped to focus his mind on the nature of gravity and shape his theory, we can certainly say that it probably wasn’t an instant inspiration - and definitely not a bonk on the head.
But even if it’s a bit of scientific fabrication, the story of Newton’s Apple is still a great piece of scientific communication - it’s certainly a handy and easily-understandable example of gravity that most people would have witnessed, which doubtless Newton used when explaining his theory.
15:31 - Can a pill make you fitter?
Can a pill make you fitter?
These days it seems that we are always hearing about the latest ‘wonder pill’ that will help you to get fit - often with very little science to back it up. Well, this time things are a little different. Scientists at the Salk Institute in California have discovered a new pathway used by the body during exercise and are able to recreate its effects in mice by simply giving them a pill. The mice were able to run for a much longer period of time and gained less weight! Tom Crawford spoke to senior researcher Weiwei Fan to find out how it all works.
Weiwei - This involves a protein called PPL-delta. So it is a lipid sensor and exercise activates this protein and this turns up genes that burn lipids, and turn down genes that burn sugar for energy that your muscle needs.
Tom - So basically, when we exercise this protein is activated and it causes the muscles to burn fat instead of sugar?
Weiwei - Exactly. So that’s why we think this is really interesting because previously people thought that turning up the genes in lipid burning is more important, but now we’re showing the glucose is the limiting factor in endurance determination.
Tom - I guess the next question then is if you’ve identified this protein which switches from burning sugar or using glucose to instead burning fat, then can we make this more active and would that give a boost to endurance?
Weiwei - Exactly. Yeah, that’s what we showed in the study. When we gave mice this drug called GW1516, this is a chemical that activates PPL-delta. So the mice that had this drug for 8 weeks, when we test their endurance capacity, they can run for about 270 minutes. The control mice, the mice that were not on this drug, they could only run about 160 minutes. And the increase was about 70%, and that’s huge.
Tom - With the idea here being to increase fat burning in the muscle instead of glucose, then surely this should also, for example, result in weight loss?
Weiwei - Yes. I think this drug will give enormous health benefits and something we can think about is obesity, type 2 diabetes, and fatty liver disease.
Tom - Did you actually see any changes in the weight of the mice?
Weiwei - Actually yes. These mice: we call them normal diet, so this is just where the diet was normal amount of lipid and sugar. When we give the mice a normal diet they slightly lost some weight and the weight loss was mostly on fat. But when we gave these mice a high-fat diet the change is enormous. When we compare the mice on high fat and with the drug to mice on high fat without the drug, we saw a 50% reduction on weight gain, so that’s huge. And the good thing is it mostly happened on fat mass so the muscle mass doesn’t change, but the mice they just had less fat.
Tom - Are you planning to hopefully try this out in humans? If you could say to somebody I can give you a pill and you will reduce your weight or something by 50% - that’s incredible.
Weiwei - Yeah. So I think that’s our ultimate goal is to apply our finding in humans. Right now this drug is not allowed to be used in humans because it has some really bad side effects. But our lab is developing what we call the next generation PPL-delta activator. Now we have some prototype that can give the same benefits - increasing endurance and fat loss. We are pretty sure that this new drug has very limited side effects are we are hoping that this PPL-delta activator can be tested in humans soon.
20:03 - Will hungry caterpillars reduce our plastic problem?
Will hungry caterpillars reduce our plastic problem?
with Chris Howe, University of Cambridge
Worldwide, we still use over a trillion plastic bags every year. And one of their constituent materials, polyethylene, can be very difficult for nature to degrade. Katie Haylor investigated a new, unlikely ally in the fight to reduce our waste.
Katie - The plastic carrier you took home from your last shopping trip could be sitting on a landfill site for years and some don’t even get there. A plastic bag can end up in the natural environment threatening wildlife and damaging ecosystems. So how can polyethylene bags be quickly broken down? Surprising research from scientists at Cambridge University and the Universidad de Cantabria suggests that a humble worm could be the answer. I spoke to Cambridge biochemist Chris Howe…
Chris - The wax moth is a moth that is a serious pest inside beehives. Specifically we’ve been looking at the caterpillar - sometimes known as the wax worm - the caterpillar of the wax moth. They are a serious pest inside beehives - they will break down beeswax. But, on the other hand, one of the more interesting, more exciting things that we found that they can do is that they can actually also break down plastics, so we found they can break down the plastic polyethylene.
Katie - This is plastic bags, right?
Chris - This is plastic bags. A lot of the experiments that we did, we did with plastic bags that we got from a supermarket in the marketplace.
Katie - This is not just any old plastic bag?
Chris - It’s just any old plastic bags, yeah.
Katie - No points for guessing which supermarket! How did this come about - was this in the lab?
Chris - Well, this was a discovery by Fredericka Bertacchini, who is the lead author on the project. She’s also a keen beekeeper as well as being a developmental biologist. She was cleaning out her beehives for the winter and they had some of these wax worms in them and she picked the out and put them in a plastic bag. And then came back a few days later and discovered that actually they’d made holes in the plastic bag and they’d escaped. As a good scientists she thought that’s interesting, I want to know how they managed to do that and if we can exploit it.
One of the experiments we did involved putting about a hundred wax worms on a plastic bag and leaving it for about 12 hours, they managed to break down about a hundred milligrams of plastic. This particular plastic is actually very difficult to break down so to get any breakdown at all is really quite significant.
Chemically it’s made of a whole string of carbon atoms end to end with hydrogen atoms atoms attached to them. But that carbon-carbon, carbon-carbon backbone is really quite stable and quite difficult to breakdown.
Katie - And it’s that you think these moths are targeting?
Chris - Absolutely. That’s what we think they’re breaking down. One of the things that’s important is that the worms are actually chemically breaking down the plastic and not just chewing it up. So we made a homogenate of the caterpillars…
Katie - By homogenate you mean you squish them together?
Chris - We squish, yes. Technical term - we squish them to make a kind of caterpillar - I can’t say that no caterpillars were harmed during the course of these experiments. We squished them in a pestle and mortar, spread some of the caterpillar puree on top of the plastic and then left it for a while, and then measured the amount of plastic that had been broken down. That showed us that it must be some kind of chemical process rather than live caterpillars physically chomping away at the plastic.
Then another approach was to use a microscopy technique called atomic force microscopy to look at the surface of the plastic. You can see that the plastic has become much more corroded, if you like, as a result of the treatment with the caterpillar puree.
Katie - So these carbon-carbon bonds are being broken - what is being produced?
Chris - One of them, we think, may be a compound called ethylene glycol, which is a chemical that contains two carbon atoms in it and it also the chemical that is better known as antifreeze, but there are certainly other things being produced as well.
Katie - You can’t see them so how do you know that they are being produced?
Chris - For that we used a chemical technique that’s a kind of spectroscopy to look at the ability of particular compounds to absorb light of particular wavelengths. It gives you a kind of signature of particular compounds.
Katie - Why do you think these caterpillars are breaking these bonds? What’s in it for them?
Chris - The plastic is actually chemically quite similar to the beeswax. They’ve evolved to be able to break down the beeswax. We don’t actually know if it’s the caterpillars themselves or if it’s the bacterial living in the guts of the caterpillar and that’s one of the things that we need to find out. But, because they are able to break down beeswax, that means that they’ve also become able to break down this plastic.
Katie - What does this all mean for recycling? Are we going to be seeing caterpillar farms next to every recycling centre?
Chris - One thing that it definitely doesn’t mean is that we should be able to carry on using plastic in a reckless way. It’s going to be a long time before this approach, if indeed it ever does, become applicable for breaking down plastic.
One of the things that we need to do is to find out more about how the caterpillars are chemically breaking down the plastic. We think it must be an enzyme that’s involved and if we can isolate the enzyme then we can understand more about its mechanism. We can also, we hope, get hold of the gene, or genes, if it’s more than one enzyme that contain the information for making it. Then what we might do is put that gene into bacteria that we can grow up very easily at large scale and that would give you a large vat, if you like, of bacteria that are then able to break down the plastic.
Katie - So there’s not going to be beehives and caterpillar farms all over the cities?
Chris - I don’t think so. But I’m happy to be proved wrong if that’s how it turns out.
26:47 - How do we understand language?
How do we understand language?
with Usha Goswami, University of Cambridge
How does your brain turn speech, which after all is just a series of vibrations at different pitches and volumes, into meanings? It’s the primary method of communication in every culture in the world – but we don’t totally understand how it works. Georgia Mills went to see one group who are investigating how patterns of syllable use come into it, by putting hats on babies and playing them nursery rhymes…
Usha - I’m Usha Goswami and I’m Director of the Centre for Neuroscience in Education at the University of Cambridge.
We know that there are energy patterns in the speech signal which, of course, we’re not consciously aware of hearing but which provide acoustic landmarks for the brain so that the sets of neurons in the brain, which are basically firing electrical signals at different rhythmic rates, can synchronise themselves with those rhythmic rates in the speech signal.
Georgia - Does that mean that say when I’m talking neuron cells in your brain are lighting up in the same pattern of speech that I’m actually using?
Usha - Exactly so. In a very complicated pattern, because there are lots of different speeds of rhythm in what you’re saying and the brain is tracking all of those speeds at the same time, in a kind of hierarchy of rhythms, which then get bound together and you just perceive speech. You are not aware of all that hard work your brain’s doing in the background.
Georgia - How did we find out about this pattern of firing in the brain and why do we think it’s important in understanding speech?
Usha - This is actually very recent work, mainly with adults. I think we’re the first project in the world to look at the same mechanisms in the infant brain for babies. But it became clear without these acoustic landmarks, which are these energy changes, the brain didn’t know how to synchronise with the signal. So it didn’t know where the syllables were for example. If you take these acoustic landmarks out, then you can’t understand speech at all. If you put back just little click noises at the right point in the signal, then speech becomes intelligible again. So all of us will stress some syllables more than others; so words like mother, father, they have a strong first syllable and even if you’re whispering them there will be a stress signature or energy difference. It’s those energy patterns that the brain’s interested in.
Georgia - If you say mothER - that already sounds really weird.
Usha - And that’s something a child with dyslexia finds it hard to hear. They don't really hear those mispronunciations of stress. But we’re interested in the very beginning, the very get-go of how infant brains process those patterns of stress and unstressed syllables.
Georgia - Are these stress syllables common across all languages?
Usha - Well, one finding motivating our project is that on average all human languages produce two stressed syllables a second. So that’s a kind of acoustic skeleton that the brain can use, whichever language you’re born into, to begin requiring the hierarchical rhythms that we were talking about that were in the signal when we speak. The reason it’s the same across languages is because we all make speech the same way. We all have similar throats and larynxes, and so it’s the way our mouths operate that determine this twice a second beat.
Georgia - So how are you looking into this exactly?
Usah - We’re hoping that mothers will bring their babies in from the age of two months so that we can listen to their brain, listen to these electrical signals taking place in response to being sung nursery rhymes...
Eating her curds and whey
Along came a spider and sat down beside her
And frightened Miss Muffet away.
To hearing somebody saying a syllable at this twice a second rate… dat, dat, dat, dat. And we’ve also got a drum beat at that rate as a very sort of pure stimulus of this acoustic landmark theory.
Kirsten - My names Kirsten.
Georgia - And who’s this?
Kirsten - This is Lexi.
Georgia - How old is Lexi?
Kirsten - She is nine and a half weeks.
Usha - We collect the data by putting a sort of swimming cap of sensors onto the infant’s head and these are very like little sponges - very sensitive to any electrical activity that’s happening underneath the scalp. The computer just measures that and measures whether that synchronises itself with the different nursery rhymes, or the different drum beats, or whatever we’re playing.
Georgia - So you can look at the electrical patterns from the brain and see if they’re synchronised on the screen with what you’ve been playing out to the babies?
Usha - You can see whether they’re synchronised with millisecond accuracy. It’s a really, really temporally accurate measurement.
Georgia - Over the next few years, Usha and the team will be following up with children like Lexi to track how their language skills develop and to reveal if there is a link between how well their brain synchronised with rhythms and their growing language ability…
Usha - I think individual differences in this ability to align your brain rhythms with speech rhythms could be really important for how quickly and efficiently you acquire language.
Georgia - It seems incredible this sort of fundamental pattern in the brain that’s across everyone. Can we use this somehow to learn language faster, or help our memory, or may learn different languages?
Usha - We can definitely use it to help children who have language difficulties because different projects in my group are looking at helping children with dyslexia through learning drumming, for example, and drumming in time with speech. And also children who have speech and language difficulties can be helped by having a background pattern of beats that helps them with the phrasing of speech.
Georgia - So could the importance of synchronising to a rhythm explain why we all love telling babies nursery rhymes?
Usha - I think there’s something fundamental about metrical patterns, so poetry exploits the same thing, or Shakespeare. This patterning is very perfectly aligned when we’re stressing our syllables at regular intervals and that’s what we do in nursery rhymes with symmetrical poems…
Ride a cock horse to Banberry Cross
To see a fine lady ride upon a white horse
With rings on her fingers and bells on her toes
She shall have music wherever she goes.
33:06 - Is it better to be bilingual?
Is it better to be bilingual?
with Roberto Filipi, University College London
There are 7,099 known living languages across the world. Whilst we won't be attempting to learn all of them, we started to wonder about bilingualism. Does speaking multiple languages exercise the brain? Roberto Filipi from University College London talked to Tim Revell about the benefits of being bilingual...
Tim - We heard there that every language has the same pattern of stressed syllables, but apart from that there is incredible diversity. And many people are able to speak multiple languages. But what affect does this have on your brain?
Here with us now is researcher and bilingual, Roberto Filipi from University College London.
Tim - What advantages can you get from being bilingual?
Roberto - There is recent research that shows that speaking two or more languages may enhance your attention.
Tim - Why should that be the case?
Roberto - If you think how a bilingual mind may work. If you speak two languages you need to suppress one and activate the other one and you do this every time, even at night when you dream because you dream in two languages and you switch between languages. So this constant switching may, in turn, give you the advantage of being more focussed on what you need to do, even if it’s nonverbal material and, therefore, your attention is more enhanced.
Tim - Are there any other benefits other than increasing attention?
Roberto - Being bilingual, I would say, gives you lots of benefits. First of all you can communicate with lots of people and when you travel you don’t feel awkward because you can’t talk to people. I would say that being more immersed in a language is good to understand the culture of a different country or different people. So bilingual is always a good thing.
But, again, it wasn’t like this all the time. If you take old research that was carried out at the beginning of the twentieth century, bilingual speakers were considered delayed in many aspects of cognitive development. This is because, compared to monolingual speakers, they failed IQ tests. Therefore there was a belief that speaking two or more languages was detrimental to cognitive development. More recent evidence, of course, disproved this and now we can say that there are advantages and, for sure, there are not disadvantages of learning two or more languages for children especially at school. So I would start really, really early to learn two languages.
Tim - That’s really interesting and good to hear. Recently I’ve started learning Danish because my girlfriend is Danish. So I was wondering whether, you mentioned that learning when you were younger can be a bit easier, but do you get any of these benefits from learning a second language later in life, perhaps when you’re not longer a child?
Roberto - Yes, definitely. Of course you need good motivation and you have one which is really good. But, if you see also my case, I learnt English when I was already quite old in life, and when I moved to this country I was already 38. Still, you can reach a good level of proficiency of course. You don’t sound maybe as a native speaker of english like my children. They leant English and Italian since birth so they really sound Italian when they’re speaking Italian - they sound English when they’re speaking English. This is not my case.
But in terms of proficiency and the way you communicate with people I would say there are not particular differences.
Tim - What about children who are raised bilingually versus learning it at school - do we see any differences in the way they pick up language or the way it affects their brain?
Roberto - Children are really like sponges. They absorb every kind of signal that they can get. Clearly, speaking two languages within a family is an advantage because they are exposed to two languages since birth. Learning at school early in life is equally good anyway because the practice of learning two languages is always good for cognitive development.
Tim - Is there any evidence that being bilingual can have impacts later in life - for example, prolonging things like Alzheimer's or dementia?
Roberto - Yes. There is research showing that lifelong bilingualism may protect the brain from neurodegeneration. In particular, in one study they compared monolingual speakers and bilingual speakers who had diagnosed Alzheimer’s late in life, and the bilingual speakers had reported the onset of dementia and Alzheimer’s five years later. Clearly, this is quite a significant result but, clearly, we also need more evidence about this before claiming that bilingualism may protect the brain for developing Alzheimer’s.
38:08 - How language shapes your life
How language shapes your life
with Keith Chen, UCLA Anderson
Can language impact how much money you save, or even whether you smoke? Keith Chen from UCLA Anderson found that languages that have a future tense make the speaker think of the present and the future as two separate events in life. He spoke to Georgia Mills about how a future tense influences your behaviour...
Keith - This is very widespread. So, for example, what’s interesting is that even though English is a germanic language, it’s actually an outlier amongst germanic languages on this dimension of needing to grammatically indicate that you’re speaking about a future tense or about a future event. For example it’s very, very natural to say - “morgen regnet es”- it “rain tomorrow” or “tomorrow it rain”. Whereas if in English you have to say “it will rain tomorrow” or “it’s going to rain tomorrow”. You basically have to indicate that this is going to happen in the future.
Georgia - Does this difference in the way the languages are built affect how we think?
Keith - Yeah. So there’s a lot of evidence in both cognitive linguistics and in psychology that when you languages force you to pay attention to the fact that a future is different than the present, that that subtly makes the future feel a little bit further away than if your language didn’t - like German. Where I’m most interested in this effect is the fact that languages that grammatically differentiate between the future and the present make the future and the present feel ever so slightly more psychologically distant from each other. Or, another way of putting that is that it makes your future self feel slightly further away than your current concerns. What I was interested in was whether or not that makes it harder for you to engage in either savings behaviour, or healthy exercise and savings behaviours, like exercising now so that you’ll be healthier in the future. Or not smoking now so that you’ll be healthier in the future. Or not engaging in unsafe sex so that you’ll be healthier in the future.
Georgia - So if we have a future tense your, say, future me “I will be going to the gym”. The fact that I’m changing the way I talk is making me separate the future from the present to a greater degree than if I didn’t have this future tense - is that right?
Keith - Exactly, exactly.
Georgia - How did you test this then?
Keith - What I do is I gather these very, very large datasets that are collected from all around the world where some families speak a language that equate the future and the present, while other families speak languages that make no grammatical distinction between the present and the future. Then what I’m interested in is whether those families, after controlling for a whole bunch of features of the family, whether those families appear to save more, whether those families appear to smoke less. Whether they exercise more and in the long run whether they’re in better health.
What’s amazing is because of these large datasets we’re actually able to control for a tremendous amount. So we’re able to say “let’s find two families both of which live in Brussels, on the same block, and attend the same church. Both of whom have exactly the same level of education and the exact same level of income, but one family speaks Flemish while the other speaks French”. What we find is that between those two families, the family whose language does not break apart the future and the present, saves 30% more each year and, as a result, retires with 25% more in total retirement savings.
In addition to that in any given year they're 20-24% less likely to report smoking - the adults in the family. They’re 13-17% less likely to be medically obese at the time of retirement. And, amazingly in surveys, when asked the last time you had sex with someone who was not your partner, did you use a condom? They’re 21% more likely to say yes.
Georgia - So this is quite some numbers here!
Keith - Yeah. These are amazingly large effects.
Georgia - In your study you’ve controlled for lots of things like wealth and location. But language, I suppose, comes with a lot of cultural baggage. Someone who speaks French is likely to come from a different culture than somebody who speaks Flemish, so have you been able to control for that?
Keith - Absolutely. That’s the number one confound here is that you worry, as you say, that language carries with it, or is highly correlated, with a lot of different cultural values. One thing that makes us confident that while cultural effects are there, they are not what are causing these results, is that that there are nine countries around the world where native speakers speak both future and futureless languages and in every single one of those countries, the speakers whose language break the future and the present from each other save less, smoke more, are more obese, and tend to retire with less in savings. So if it’s a cultural feature, for some reason all around the world it seems to tie extremely tightly to this grammatical dimension.
Georgia - Does this mean that we see in countries like Germany that, as a whole, the country’s just doing a little bit better because everyone’s being a bit wiser?
Keith - This actually has national effects. When you look at the OECD, which is association of already developed, rich, democratic countries, there’s a good amount of variation. You’ll be upset to know that both the United States and the United Kingdom, because they speak English, and we’re the second and the third worst countries in the OECD in terms of how much we save every year. We’re on an average like 10-15% lower in our national savings rates than Germany, Finland, the Netherlands, Norway, Luxembourg, Sweden, Estonia. We save less than all of these countries. There’s only one country that’s worse than the United States or the United Kingdom and its language also breaks the present from the future, and that’s Greece.
Georgia - Ooops! So the next question is: is there anyway as English speakers we can adopt this way of thinking and get the benefits of a future tenseless language?
Keith - A common feature of self-help advice in English is to make lists, and goals, and plans that you want to achieve, and to write those things in the present tense without grammatically separating them from your current self.
Georgia - From a personal point of view - say I want to go to the gym more, I should write a list saying “Georgia go to gym,” instead of “Georgia will go to the gym.”
Keith - Absolutely! I think your listeners should definitely try this, and in many studies it’s been shown to help. For example, one simple thing would be instead of saying something like “I will go to the gym.” You can just say “this week I go to the gym,” or “tomorrow I go to the gym.” You could try and make it seem much more of a concrete plan and literally express it in the present tense. Maybe even more powerfully you could try and frame it as an identity. You can say “this week I’m an exercise maniac” or “this week I’m a gym rat.”
45:37 - Are emojis a language?
Are emojis a language?
with Linda Kaye, Edge Hill University
Language isn't just limited to the spoken word. Non-verbal communication starts with sign language and runs all the way down to those little colourful smiley or winkey faces. You guessed it, Emojis! In 2015, the “tears of joy” emoji made it into the Oxford Dictionary as the Word of the Year. But should we take them seriously? Tim Revell speaks to Cyberpsychologist, Linda Kaye, about those popular yellow icons.
Linda - Well, certainly what we found in our lab is that people report that they’re a really good way to enhance an emotional tone within a text message or on Facebook and things like that. Certainly it’s a way of adding an extra element of emotion that is more difficult to portray in written language. So, if you think about a face to face interaction, obviously we have things like facial expressions, posture, tone of voice. In a written communication obviously that’s a lot more difficult to portray so people report that they use emojis, a lot of the time, to add an extra layer of emotional tone to a message.
As well as that, is the role of how emojis can help reduce ambiguity in messages as well, particularly if you're trying to be sarcastic, for example, in a message. So as not to offend the recipient of it you might use a wink emoji for example just to ensure that the intended meaning behind the message is not ambiguous.
Tim - Yes, that sounds like a really important addition to language. On their own or in combination, do they really form a part of the language? How do we distinguish between what’s language and what’s just a smilie?
Linda - Absolutely. That’s the key is looking at them in conjunction with language. If you think about the context of a text message conversation, you might see the odd emoji cropping up as response in itself without any written language there. So like a ‘crying with laughter’ emoji response to what somebody might have said. But in terms of them as a language in themselves, that’s quite difficult to identify because I don’t think you could have an entire conversation just in emojis. You could try - challenge accepted. But in most cases it wouldn’t necessarily make a lot of sense. Looking at them in conjunction with language is important but we tend to assume that they have more of a non-verbal function.
Tim - Can we say anything about the way our brain interprets emojis, or the way we interpret it when we see an emoji? Do we know anything about that area of the science?
Linda - We know a little bit. There has been some research that’s been done. It was looking at emoticons rather than emojis, so the actual textual punctuation that forms the facial features rather than the yellow icon things. And this research actually used fMRI to look at brain activation for the participants who were looking at sentences that included emoticons and those that didn’t include emoticons.
What you find is that there’s different activation in the brain that goes on. So when people are looking at sentences that include emoticons, some areas of the brain light up that tend to be more associated with non-verbal function, which don’t seem to light up when just reading sentences without them. From that kind of neurological perspective, there's certainly something to say about how the kind of processing of them does have some kind of non-verbal function. But, at the same time, the verbal functions light up so they’re kind of in-between, probably serving a dual purpose - verbal and non-verbal communication, which is kind of interesting to pin down really.
Tim - Yeah. I really like the idea that emojis are the hand gestures of the written world. Does the use of emojis affect how we perceive someone? Often we think of it as a simple way or, perhaps, we think of them in a derogatory manner. How do we perceive people when they use emojis?
Linda - That’s a good question. That’s something we’ve been looking at quite a lot in our lab. When we look at whether people using emojis on Facebook, for example, particularly what we found is when people use smiley emojis, other people who have never met these people before, they’ll just be maki
ng a first impression by looking at their Facebook page. What we see is that using those smiley emojis is related to how other people judge them to be agreeable, they judge them to be open to experience, so kind of open minded, and also conscientious as well.
So it’s kind of interesting that something as simple as just using a smiley emoji seems to have some relation to what other perceive other people to be at a first impression basis. Those perceptions might be very different if those emojis were being used on an email, for example. We know there’s an awful lot to be said about when and why you might be using them, who you’re using them with. Facebook’s a kind of informal, social environment, so using emojis on there isn’t necessarily deemed such a bad thing. It’s a kind of socially acceptable thing to do. So it’s interesting that we see those findings.
Time - Perhaps as our final question - do you have a favourite emoji?
Linda - My favourite emoji is probably the crying with laughter one. That’s probably the one I use most. Maybe I just have very funny conversations with people. I don’t know what it reveals about me.
Why does a piano's A# sound different to a trumpet's?
Katie Haylor asked Mike Newton from the University of Edinburgh to sound out this question from John...
Mike - The sound produced by a musical instrument isn't, in fact, just a simple vibration but is made up from many different vibrations happening at the same time. For example, when you pluck a guitar string the sound you hear is remarkably complex. Such a sound is made up of many simple vibrations, each with it’s own frequency and all of which sound together.
For the guitar string the frequencies of these sound components, as we call them, are related to each other in very simple ways. The lowest frequency component in the sound is called the fundamental frequency. [music] The next lowest is called the second harmonic and it has a frequency that’s almost exactly twice that of the fundamental frequency [music]. The next highest again is called the third harmonic and it’s frequency is three times that of the fundamental [music] And so it goes.
A typical piano note might include several dozen frequency components [music].
Katie - So the sound produced by any musical instrument is made up of different amounts of these tones. The particular combination of these tones is what makes instruments sound unique. But why do these combinations differ?
Mike - The two most important factors here are the size and shape of the main resonating components of the instrument, such as the guitar string and body, and the way the vibrating part of the instrument, such as the strings, are driven into motion. This is why a guitar can sound both dull if gently plucked with the pad of your finger, or bright if aggressively struck with a plectrum.
Katie - Right then Mike - get some instruments out of their cases and play us an example!
[music - 2 notes, one played on a trumpet and one on a guitar]
Mike - Two musical sounds with different amounts of exactly the same simple building block tones. One is clearly a trumpet and the other unquestionably a guitar. The basic sound components are the same in these examples and so the perceived pitch we here as listeners is the same, but the sonic texture of each of the sounds is clearly different. This sonic texture is a property of sound somewhat loosely referred to as ‘timbre.’
As human listeners we have a pretty incredible hearing system that analyses the multiple simultaneous sonic building blocks in any sound and weighs them all together so that we only hear something that seems relatively simple.
Katie - So there you go John. The frequency or pitch of a piano A sharp, for example, is the same as a trumpet’s A sharp. But the different combinations of sound components contributing to the overall signal of a note explains why the timbre or sound quality sounds different and that’s how we pick out one instrument from another.
Next time we’ll be thinking over Kevin’s tiring topic:
When we exercise our bodies we get tired and have to stop after a bit but, eventually, we get fitter and more endurant at those tasks. I know we can suffer fatigue in certain mental faculties too - decision fatigue springs to mind. If we perform difficult mental tasks, does our endurance at those tasks improve over time too or are we doomed to make poor decisions in the afternoon forever?