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Mind shift: How always-on digital technologies are changing our brains

By Shane Huntington

Neuroscientist Prof Baroness Susan Greenfield examines the scientific bases of how constantly-on digital environments may bring about changes in our brains.

SHANE HUNTINGTON
I'm Shane Huntington. Thanks for joining us. The days when we thought of the human brain as a static part of the human body are long gone. There have been many examples, particularly in patients recovering from stroke, where the brain demonstrates exceptional capability to essentially rewire itself. The brain's ability to dynamically adapt and change as we grow and age enables us to learn new skills and adjust to the environment that we live in. Essentially, it is the cornerstone to our intelligence. Given this plasticity of our brains in responding to our environment, what is the impact of our growing exposure to online and screen based devices? Are our brains changing as a result of our expanding interactions with networked digital media and their capacity to keep us endlessly in touch with others? To discuss the impact on the human brain of our new always on world we're joined today on Up Close by Professor Baroness Susan Greenfield whose 2014 book on the topic is Mind Change: How Digital Technologies Are Leaving Their Mark on Our Brains. Susan Greenfield is a Senior Research Fellow at Oxford University. She's visiting the University of Melbourne as an Honorary Professorial Fellow and is a guest of the Melbourne Medical School. We previously interviewed Susan on Consciousness in episode 225 of this program. Welcome back to Up Close, Susan.

SUSAN GREENFIELD
It's great to be here.

SHANE HUNTINGTON
When we are first born we start take in our environment. What happens to the brain at this particular time?

SUSAN GREENFIELD
Well this is the most exciting thing about being a human being as opposed to - I've often targeted the goldfish perhaps unfairly for comparison but the wonderful thing about being born a human being is that when you have individual experiences that's what makes you an individual. What is brilliant is that - all the other animals do this to greater or lesser extent, the goldfish to a lesser extent - we occupy more ecological niches than any other species on the planet because of our ability to adapt. We don't run fast and we don't see well, we're not strong compared to other animals but because we have this superlative ability to adapt to our environment this means that we can learn and benefit from experience. This is something called plasticity. It doesn't mean to say the human brain is plastic but it comes from the original meaning of the word, from the Greek "plastikos", to be moulded. What happens was even if you're a clone, that's to say an identical twin, when you're born you're born with your full complement of brain cells but it is the growth of the connections between them that accounts for the growth of the brain after birth and indeed makes your brain unique. For the hundred thousand years we've been around you will have a unique pattern of brain cell connections because these are constantly upgraded, updated, forged, strengthened, weakened as you are in dialogue with the outside world.

SHANE HUNTINGTON
You mentioned after birth. Is there also an element of environmental conditions changing our brain before we're born?

SUSAN GREENFIELD
Some people think that there are because there's been studies done on non-identical and identical twins and they found that you actually have to factor in now the uterine environment. And that actually harkens back to something we may have talked about two years ago which is the foetus conscious, is it aware? And my own view is that a foetus certainly is rehearsing certain skills that they will be required, like sucking their thumb for example will mean that they are exercising their thumb and their mouth and it is in later time that the digits and the mouth have a high representation in the brain because of course they're going to be required to make finer movements than say the muscles in your torso.

SHANE HUNTINGTON
As we grow through early childhood and into adolescence, what sort of changes are actually occurring in terms of the brain as a result of this environmental exposure?

SUSAN GREENFIELD
Well there's lots of changes occur. First of all, up until about the age of six you have this exuberant connectivity in the brain. But then after that, up until say about the age of 10 things start to focus and you start to get modules if you like because - you'll be familiar with perhaps people born to bilingual parents. Those children will have a completely authentic accent if they've learnt the language before 10 but after that I'm afraid the doors closed however. In the early stages of life it's a bit as if you're standing at a crossroads and all paths are open to you and all paths are there but as soon as you start to go down one path, as soon as you have a certain lifestyle so other options close because you become specialised at doing certain things. So what happens is you have what's called pruning of your connections just like you prune a plant. So the connections that are not being used start to wither and this gives you a very distinct picture or configuration or landscape of your connections. Then the other big milestone is when we get into adolescence. There's an area of the brain that still is underactive called the prefrontal cortex, a very important area of the brain which is about 33 per cent of the human brain but only 17 per cent in chimps. That comes on-stream to be fully operational only late in life, in late teenage years, early 20's. And it's while you're a teenager that you have this big surge of a very important transmitter called dopamine which underlies reward and excitement and so on. This can account for some of the seemingly baffling behaviour of adolescents who take risks and are very excitable and emotional and don't think things through. So there's a lot of stages we go through but really all the time we are alive irrespective of our age our brain is constantly evolving and changing as we interact with the environment. And we can look at some examples of that. It's not just head injuries. It's also everyday life where you can look at either individuals that do something unusual or sustained or that have different types of size brain regions. For example, very famously in London taxi drivers who remember, golfers is another one, basketball players is another one. There's many mental and physical activities that have been shown to be related to different brain structures. Or you can take ordinary human beings and train them to do something like juggling and again you can see changes in the brain within a few weeks. So we know that everyone is adapting all the time to the environment.

SHANE HUNTINGTON
Let's talk a little bit about the way the brain does grow because I suspect the common view of this may not be correct. Is it sort of layer upon layer like you're building up a cake or is it sort of putting down some connections and then essentially erasing them and regrowing new connections? What is the function?

SUSAN GREENFIELD
Okay, let's start with the cake model. This was actually popularised in the mid 20th Century by someone called Paul McLean. Now he had a very interesting idea that he called the triune brain and the reason he was interested in this was at the time, like many people, he couldn't explain why people at the Nuremberg rallies in the 1930s were capable of what they were capable of. How could people, a civilised nation become so mindless? He couldn't understand how they could be so swayed and act in such a what he called reptilian way. To try and explain the behaviour of the people at the Nuremberg rallies in Hitler's time he suggested, he looked at the anatomy of the brain and he suggested what you've called a cake model. I don't think he used that term but he said look, the brain's in three parts, hence the term triune and the first bit is the most basic and primitive part and this is an elaboration of the spinal cord. He called this the reptilian brain and the reptilian brain just mediated atavistic urges of destruction and creation and that was it. Layered onto that, the next layer like the layer of an onion was what we now call the limbic system and he called it the mammalian brain and he suggested that those basic urges in more sophisticated creatures were channelled through context dependent situations like running in a maze, a trivial example. Layered onto that, the final crown of creation was the neomammalian brain which was characteristic of primates for example which was a very sophisticated part of the brain that then layered on further constraints on behaviour such as morality, knowing actions have consequences and so on. And his argument was that the people in the Nuremberg rallies behaved as they did because those outer two layers had become disabled. That is to say that the reptilian brain was surging and you had these very basic desires. Now I think that is wrong for two reasons. Firstly, the people at the Nuremberg rallies weren't behaving in a mindless way. It's not as if it was like road rage or a "crime passionnel". It wasn't like that. They had a narrative. They knew exactly who they were angry at. They knew who they despised. They had a story they were telling so I don't think they were behaving in this non-specific destructive way so I challenge that idea anyway. And secondly, we know the brain doesn't live in three separate layers or compartments so the cake model doesn't really work because we know everything is connected to everything else. So it's more like ingredients in a dish of food or instruments in an orchestra that leads to this wonderful holistic and yet complex situation. What was the other model you suggested? The...

SHANE HUNTINGTON
The idea of the brain essentially...

SUSAN GREENFIELD
The erasing...

SHANE HUNTINGTON
Yes, rebuilding itself as you get into new experiences.

SUSAN GREENFIELD
Yeah, I think it doesn't just wipe everything out and then rebuild again. It builds on what there is. A better image that I like is the kaleidoscope model and you remember those old fashioned kaleidoscopes? For the younger listener these were magical seeming cardboard tubes that you rotated while looking through a little hole and the most beautiful patterns due to gelatine shapes were conjured up that through the mirrors reflected - you had sort of six images repeating around and every time you rotated it yet a different pattern would come and you rotate it and a different pattern would come. It's more like that. In the brain as soon as one changes other things will all change as well and you'll never have the same scenario twice. If you think about it, that would make sense because otherwise you'd have the same consciousness twice and you never do.

SHANE HUNTINGTON
You mentioned before certain experiences like playing certain sports and so forth have effects on the brain and change the brain. Are we able to actually measure those changes today?

SUSAN GREENFIELD
Up to a point, yes. With brain imaging which I'm sure everyone's heard of such as fMRI, you can see gross changes. For example, with these London taxi drivers and this is a lovely example, London taxi drivers unlike my experience here in Australia of Melbourne taxi drivers, London taxi drivers have to pass a two year exam called "The Knowledge" where they remember all the streets of London and all the one-way systems so without recourse to a manual they can say to the examiner how they would drive from A to B. There's a huge burden on what's called their working memory. And there's an area of the brain called the hippocampus which is one of lots of brain areas that's involved in memory but in this particular case the hippocampus is larger in London taxi drivers than other people. This fact has not been lost on the London taxi driver. Most of them have heard of the hippocampus. But even over much shorter times you can measure changes. For example, there's a wonderful study involving piano playing where even over five days, the poor old controls just stared at a piano for five days and nothing much happened whereas those who learnt five finger piano exercises, even over five days in the area relating to the digits there was a greater area of activation that you could measure. But most exciting was there was a third group who were merely asked to imagine they were playing the piano and their brains changed in comparable ways to those that were physically exercising. Yes, you can do it with brain imaging but I think I need to put down a word of caution about brain imaging. It doesn't mean to say that the areas that are changed are the centre for this or that and also the changes have to be quite long term because the time resolution of brain imaging - it's a bit like those old Victorian photographs where you could see buildings and you could see static objects but you couldn't see anything moving. You couldn't see people or animals because the exposure time was too slow. It's a little bit like that, it has a resolution of several seconds, brain imaging, whereas we know the brain operates most of its processes on a thousandth of a second. You're not going to see moments of consciousness captured on brain imaging, not using that technique but you are going to see long term changes and that's what one's interested in if one's looking at the effects of certain types of behaviour.

SHANE HUNTINGTON
When we speak about plasticity and it's great you give the example of piano playing because I find it curious that some people are able to pick up a skill like music very quickly whereas others are not and often the term plasticity comes into play. Why is there that difference between individuals? Is it an intelligence type relation or is it the ability of different brains to rewire themselves more quickly?

SUSAN GREENFIELD
I think it's more. Let's turn that question around and say if we accept that we're all individuals and no two people, even identical twins don't have the same brain then clearly people are going to have different talents and different skills mixed up with their predispositions and their knowledge and their motivation, their arousal levels. There are so many factors that will determine how readily or quickly you learn something. One particularly, I think, exciting example for any educationalist listening, this was by someone called Dweck this study, Dweck and Blackwell. They took some kids, some teenagers in the States who were performing very poorly at maths because the children thought they were born thick, born stupid. They took half the class and gave them insights into the plasticity of the brain. They explained how the brain was changing all the time and according to the environment that will leave its mark on the brain and that people weren't necessarily born thick but you could shape your own environment and therefore change your performance. And what was interesting, children equipped with this insight in the class, those that had been informed about plasticity of the brain and were liberated from thinking they were just born stupid, they started to perform better than the other half of the group. We know if we're talking about abilities that factors such as that will make a difference. The more information you have that you're not convinced you're stupid through to yes there must be certain genetic dispositions. For example, however much I try I'm never going to be able to sing in tune, never, ever, ever. Nor am I ever going to be able to cook. There's various things that I think one shouldn't go there but one should never constrain oneself. There are so many different factors that will determine how readily the brain adapts or doesn't but I say we should be not surprised at that. It's not that we will start off from the same. We are individuals and that's what makes life so exciting.

SHANE HUNTINGTON
I'm Shane Huntington and you're listening to Up Close. We're discussing brain plasticity with neuroscientist Baroness Susan Greenfield. Now Susan, today the environment we're living in, the one our brains are continually exposed to is perhaps, one might say, more based on silicon than anything else. What do we know about this new environment of technology we're in and how it is affecting our brains?

SUSAN GREENFIELD
Well we're really only now starting to realise what a huge impact this new world is having and although it seems second nature to us bear in mind that Facebook for example only started in what, 2006, 2007 and yet we now take this new life for granted. Now you could wake up, you could work, you could go shopping, you could play games, you could go dating all without actually having any face to face contact with another human being. And so for the first time ever I think that we're living in an alternative possible world, a sort of parallel universe if you like. For that reason I call it mind change because I've drawn parallels in a book I've just written as you've said with climate change and I think it's similar in four ways. One is undoubtedly it's global. Second, it's unprecedented. Third, it's controversial and the most important and what we can unpack and what I try and unpack in my book is that it's multifaceted. It's not as if one can simplistically say are computers good or bad or is the screen good or bad because there's so many different types of aspects to this new lifestyle. You can talk about video games and attention spans and addiction and aggression or you can talk about social networking and identity and interpersonal relationships and empathy or you can talk about search engines and how you differentiate information from knowledge, how you use the facts, how that's use pedagogically. There's so many different questions that you need to unpack. It is multifaceted and I think that is because it's such a big new impact rather like climate change is where you talk about carbon sequestration and water shortages and alternative energy. There's lots of different implications emanating from an advance that we've had but I think the big difference between climate change and mind change is whilst in both cases it's in our hands to do something, with climate change as far as I understand it it's damage limitation. We're just trying to put the hand brake on. Whereas with mind change it doesn't have to be like that. It could be very positive so long as we decide what we want. I think what we need to do is to say look instead of being an end in and of itself, couldn't we have it as a means to an end? If it's a means to an end as I argue it should be, that does beg the question of what is the end? I don't know, Shane, if you have kids but...

SHANE HUNTINGTON
I do.

SUSAN GREENFIELD
Yeah? Well don't answer. This is a rhetorical question. What kind of people do you want them to be? What kind of skills do you want them to have? If I was waving a wand for their education what kind of priorities would you want in the education system? These are not easy questions and different people have different views but it is something we collectively need to debate because until we reach a consensus for your children on what kind of life you want them to have, what kind of education you want them to have, until we agree on that we're not going to be able to deliver it and I think we're not doing them a service or ourselves a service if we just sleepwalk into this silicon world saying that nothing can be done. Of course things can be done and of course we are in control of it. That's the whole point but we need to decide what we want and I think that's why it's challenging and exciting. It's not a reason to be depressed as some people think and I'm certainly not saying it's all bad as some people think. I'm saying it's a fantastic opportunity but please let's get on and talk about it rather than pretending it's not there.

SHANE HUNTINGTON
When we hear about these threats I have to say I think back and there was many technological threats as we've heard over the centuries, even over a thousand years going back to the printing press, the telephone. All of these things seem to disengage us from other human beings in various ways and the printing press is a great example of that, keepers of stories, no longer needed. What is different about this one? When you compare it to something like climate change we're talking about a potentially catastrophic species ending type scenario so this is not my mother saying you're playing too many computer games. This is something else, completely different. How is it different?

SUSAN GREENFIELD
Well I think it's changing reality in a very deep way for certain people. Let's take the so-called digital natives or the millennials, not people like you and I who have already had a traditional education, a three dimensional childhood. You and I have climbed trees, played cowboys and Indians, made up stories. And we've done that and we can now, I hope, embrace this new technology as a complement, as an adjunct to our real lives, our real world but say you've never had those things. Imagine growing up in a world where you've never said to friends let's make up a game, you be a cowboy and you be an Indian. We grew up in a world where a tree didn't ask you to climb it and drawing pads didn't ask you to draw on them and your soldiers and my dolls didn't ask to be played with and traditionally and most famous, the cardboard box that the toys came in would become the car or the castle. You and I grew up at a time when, as all previous generations have, where imagination dominated and above all and I will get to the point now, an inner narrative. That is to say you were driving something from inside you and you were using these rather low grade things in the outside world. They weren't driving you. You were using them. You were in control, right? It was your narrative. I would argue therefore your identity and this gave you a robust notion of who you were. It was all driven internally. Now one example of why I think there's a very profound difference for a lot of these younger people is driven externally so identity is constructed externally. It's very much at the mercy of the so-called friends who aren't really friends because you never met them. They're an audience and like all audiences they demand entertainment, you want to impress them so what do you do? You exaggerate what you tell them. You don't necessarily confide in them. You don't tell them the truth and so the real you becomes even lonelier while you're fabricating this ideal wonderful life where you have lots of boyfriends or girlfriends and you're out every night and so on. No one has a life like that and yet you feel the pressure on you and there's the pressure on you to constantly relate what you're doing and this is another thing I find strange, why people will want to take photos of their food. Why? Why is that interesting? Who's going to look at it? But it does betoken to me people who are in some kind of existential crisis. That rather like a small child you need constant feedback in a rather needy way and constant reassurance and your confidence is much less robust. Now this ties in I think having recently arrived in Australia and I know this is going out internationally and I'm sure it's the same but I just happen to know this Australian study from a psychology organisation here where they said the most stressed people and the people showing the most depression and anxiety were the 18 to 25s. Now obviously one can say that for young people around the world there's global warming, there's job insecurity, there's terrorism, there's a whole range of things that could make you feel depressed and insecure but it was ever thus. Human beings have always been depressed and insecure. My mum had to live in the Blitz for example and didn't know if she was going to be bombed night after night. So the difference is how you cope. You can't wave a wand and make the problems go away as much as we'd like to. You can't make life easy for any generation. What I'm wondering is whether this generation is more needy and insecure with a much more fragile sense of their own identity because they haven't learnt that inner narrative, that strong confidence that you've learnt, most of you, when you were kids. I think one can tie in a lot with this as well. For example, communication. When you first meet someone words are only 10 per cent of impact and what's really important is eye contact, body language, voice tone, physical contact possibly. Now if you haven't rehearsed those skills you're not going to be any good at them which means that when you do meet someone you're going to be very uncomfortable so you'll prefer to use your thumbs rather than your voice and this has now been shown in the UK. There was a recent study this year by Ofcom showing that young people, they sort of lost their voice. They don't talk anymore because they want the security and the distancing of a screen. Now I think this is profound. This is not just like driving around in a car when previously you had a horse and cart. This is not just like watching the occasional TV program of an evening that was all incorporated into your three dimensional real life. This is an alternative life where the previous experiences and activities and skills you learnt are no longer being rehearsed. And I think whilst there's so many good things about the screen technologies we should be seriously looking at the most basic things like identity and interpersonal communication because even beyond education even and what you're learning, this affects every human being, how you're going to live in society and how you're going to communicate with others. I think we should be thinking very carefully about what the implications could be.

SHANE HUNTINGTON
When we talk about this, I mean the one thing I have to come back to is this issue of plasticity in the brain and presumably in this sense it's our Achilles' heel. Our brains are changing as a result of this but you would also have to assume that it's the cure in a sense in that we can get out of it.

SUSAN GREENFIELD
There's a wonderful study and this has only just come out so it won't be found in Mind Change, in my book but it's by (Yalda T.) Uhls. It's such an unusual name I think anyone Googling on that would find it easily. It's a really nice study. What they did is they took some pre-teens in the States and for five days confiscated all their digital devices and sent them off to summer camp and compared to the control group and compared to how they performed before that excursion afterwards their interpersonal skills had rocketed. Now this shows us lots of things. Obviously you can't say is it the absence of the digital devices or is it the fact that they were engaging and having a stimulating experience in summer camp? You don't which it is but you'll never know because if you're not engaged with digital devices you'll always be doing something else anyway. You're not going to just go and sit in a cupboard. To me it doesn't matter. What they did and why I find it encouraging is a five day different lifestyle, one combined with the absence of digital devices and an engaging outdoor activity, that combined lifestyle led to serious changes. That shows the plasticity of the brain. But that does beg the question then and again I'll ask you a rhetorical question, Shane. What kind of environment would you like for your kids? There's a lovely story from actually someone in Melbourne as it happened, I had an email and it's a lovely story. He said he wrenched his kids away with great protest from their screens one weekend and took them on a bike ride and they were riding up and down the Yarra River and there was some steep dog's leg bend and he said they were cycling up and down this steepish bend and they started giggling. You know you giggle sometimes? He said that is music to the ears of a parent; I never hear that when they're sitting in front of a screen. And I think we should pause and think of that. Some parents are very impressed that their kids appear to multitask or that a baby will look at an iPad and to my horror you can now buy potty training with the potty having an iPad attachment on it. I mean please. So parents sometimes think this shows the kid's clever because they're engaged with a screen but I would have thought just pause and think how many times you hear spontaneous giggling. Again there's a study done with adults that if you're outside that enhances creativity for example. I think we need a portfolio of activities and one that's restricted to just two dimensions, hearing and vision. You're short changing people by wishing that on them as a life.

SHANE HUNTINGTON
When we make this case to this new generation, as you said the 18 to 23 or 24 year olds and so forth, the one thing they can always come back on of course is that we're not exactly leaving them with a world in a good state so one argument is without all that stuff how well have we done and they're going to be left to fix it. How do we - we can't really come back against that argument, can we, in one sense?

SUSAN GREENFIELD
Well we can. There's a 19 year old I've been speaking with who's into video games and he actually wrote me an email saying that he loves video games so much because it's a haven from the real world, it's a haven from all the challenges and the difficulties presumably of his personal life as well as the world that we've given them but as I say, it was ever thus. Human beings have always inherited a world that wasn't perfect, a world where we've tried our best to make life better for people and on the whole if you look at the march of civilisation over the last hundred or 200 years people are living longer, they're healthier. Whether they're happier of course is another question because expectations have changed but I would say to a young person what you should be doing is getting out there and equipping yourself to change the world. As someone once said, we shouldn't ask what's going to happen in the future, we should ask how can we shape the future? Because it is for us to do that and unlike a lot of people, for example in West Africa at the moment or in the Middle East and many parts of the world, they do not have this option of deciding who they are as people, how to stretch themselves whereas in our developed world, a kid has a one in three chance now of living to be 100 so what are they going to do for the second 50 years of their life? After they've got perhaps financially secure and the kids have left home, what are they going to do? Just play Grand Theft Auto for 50 years? What are you going to do? I think this is a wonderful time to explore what we mean by an individual, how we bring out the best in a person, what that best is, how can we give people a fulfilling life. If we just say there's not a problem, there's not an issue I think we're doing a disservice to everyone.

SHANE HUNTINGTON
How do we actually make this case in terms of evidence? What sort of evidence do we need at this point to be able to people in this situation that this is detrimental to presumably their health and the health of the community?

SUSAN GREENFIELD
Well in science as you'll be aware, Shane, as a scientist yourself there's never the smoking gun paper. It's not as if one paper is published and everyone says you know what, you're right, we're all converted, this is absolutely consensus. As you know with science you ask a specific hypothesis, not a general one with limited equipment and techniques and you have a rather limited goal and then that paper is challenged and some people will interpret the data in a different way and you do more data and use the exact forward. That's the way science is done and it's not as if there's a single experiment that could be done. I've been criticised rather I think stupidly for not having done the single experiment. Well there's no such thing. It's like saying with climate change what single experiment could one have done? Evidence is accumulating, it's not definitive, it's not exhaustive and there's some evidence of good things and evidence of bad things which is why both on my website and in my book there's about 500 peer reviewed papers there. I've said to people you're welcome to your own views but you're not welcome to your own facts and what you need to do is look at the facts and then form a view. That's where we are. There's evidence accumulating, much of it concerning for most people and to say it doesn't exist or it's not good enough is not good enough because we are where we are and we can't wait for evidence to accumulate over the next 10 or 20 years because by that time people are going to be grown up and will have formed characters and personalities and so on. We need to make do with what we have and to look at what we have, imperfect though it is, ill-defined and non-definitive though it is and decide where we want to go. What I've tried to do is stimulate debate which is why it's great for doing this podcast because I think the more we talk and think about it as an issue the more we'll reach a collective informed decision. But we need to do that; we can't just say there's not enough evidence so let's all go back to sleep or let's just sit around and wait for a whole generation to grow up and then cry foul because they haven't turned out as we want them to.

SHANE HUNTINGTON
You're listening to Up Close. I'm Shane Huntington and my guest is neuroscientist Baroness Susan Greenfield. We're talking about brain plasticity. Let's shift gear a bit now, if you don't mind, Susan, and talk about plasticity that occurs later in life. It's certainly - to me anyway it feels as though it gets harder to learn things when you're older. Does the brain's actual level of plasticity change as we age?

SUSAN GREENFIELD
Up to a point. Psychologists have long drawn a distinction between two types of intelligence that actually corresponds to what we know how the brain works of fluid intelligence versus crystalline intelligence. Now fluid intelligence is characterised in children and young adults where, as we're aware for example driving, a young person will learn much more quickly and have a much more agile brain. We all know the younger generation have taken to the screen in a way that the older people don't do so well because they learn very quickly but there's a difference between learning something and understanding it. Fluid intelligence is where you can absorb a fact and regurgitate the right answer. Crystalline intelligence is where you relate that fact to other facts so that you understand it. For me understanding is seeing one thing in terms of something else. An example I give all the time, rather unfairly perhaps, my little brother who's often cited, is when he was three and I was 16, just for fun as part of the torture because I hated him so much, one of the many forms of torture was to force him to learn Shakespeare. He was only three years old but he could recite off the lines from Macbeth "To-morrow, and to-morrow, and to-morrow; Creeps in this petty pace". Now that goes on "Out, out, brief candle!; Life is but [a walking shadow,] a poor player". He learnt that very quickly, probably much more quickly than an adult would learn a slab of Shakespeare. But had you said to him, Graham, what does that mean, "Out, out, brief candle!" he would have said something like well I have a candle on my birthday cake and I blow it out. He wouldn't have seen it as a metaphor for death because he was unable to make the connection between the extinction of the candle and the extinction of life. And it's only when you can do that that you truly understand something. Now that's crystalline intelligence. It's called crystalline because things are related to each other just like components of a crystal. I like that a lot because it does square up with the growth of neuronal networks and the fact that as you grow these isolated experiences that you evaluate just by purely sensory interpretation, how sweet, how fast, how cold, gradually they start to make sense because you are making a pattern, a crystal. You're seeing one thing in terms of something else. An example I often give is a wedding ring which initially you'll have a sensory take on it, it's a gold shiny thing, you might want to put it in your mouth, it won't mean anything but as you interact in a culture that has these things you'll learn that it goes on fingers and if it looks like that it only goes on one finger and only under certain circumstances so it stands for something. You'll understand or it will have a meaning in a way that for a small child it won't. So I think that as we go through life yes we are less agile and fast at processing information, but information isn't knowledge and we are much better at understanding things. I was slightly irritated. Our previous education minister in England, someone called Michael Gove, a little while ago said every child should learn a poem and I said no, that's wrong, every child should understand a poem. A parrot can learn a poem as my brother proved. I think we need to really explore what we mean by intelligence, what we mean by understanding rather than assuming that just because you're young and you can give the right answer, basically a computer can give the right answer. It doesn't mean to say the computer understands it.

SHANE HUNTINGTON
It's interesting because once we start talking about this from an evolutionary advantage point of view we have to consider the fact that most of our evolution happened when humans weren't living to the ripe old age we are now so ideas of plasticity beyond the age of about 30 really made no difference to our species. So as you say, we're finding this balance now between intelligence, plasticity and so forth. Do we have some idea of how we can perhaps maintain that level of plasticity into our older age?

SUSAN GREENFIELD
Yes, well this is for me particularly interesting because my actual research area is dementia and I should say for anyone listening, although it's a characteristic of older people it's not an actual consequence of ageing. It's a disease of older people and it's becoming more to the fore now because people are not dying as they used to, as you've said. Even more recently than living to be 30, even the generation ago people are no longer dying of TB or heart disease or cancer as much as - they're still very serious conditions of course but they're now much more treatable and the survival rate is much higher which means that diseases are coming to the fore now of older age. My own view is that for dementia, if it's a disease there must be an underlying mechanism or cause which means if only we knew what that was we could intercept it. Now that means that if you are not going to be a victim of that disease then your brain can carry on evolving and become more and more individual and even though most people perhaps didn't live very long in the past, old age was always considered a sign of wisdom. The white beard was considered a sign of the wise old man. You'd never talk about a child being wise. I think that really we're just seeing more of the same. That is to say that the longer we live the more individual we become, which is lovely and the more experience we have to harness so the deeper the meaning of things and the greater the understanding of things in a way that an agile newly minted little brain will never be capable of.

SHANE HUNTINGTON
Coming back to your concerns with the digital age of course there's an entire industry out there to try and stop our brains from decaying and we can get - keep us active. What are your thoughts on that?

SUSAN GREENFIELD
My thoughts on that are well obviously it's a simple idea that if you exercise the brain like you exercise muscle then it will stay agile and fit but it does beg the question of what we mean by intelligence and quality of life. My own view is that normal human interaction, going and having an argument with someone say, a nice argument, let's call it a debate is more challenging and fun than doing solitary sudoku say or brain exercises. No one likes the term exercise. It already sounds worthy. If it works for people that's fine and if they have no other possibilities that's fine but I think there's so many other things that you could be doing. As well as having arguments you could be learning a new language for example. You could be reading lots of books and discussing it with people. There's so much in the world that can be explored and thought about and experienced that would also benefit your state of mind plus also make you happy. You'd have a nice fulfilling life. My own view and I'd probably get sued by all the game industry brain improvement companies is that although that's just one possibility, don't think that if you do that as opposed to live a real life you're going to have a superior brain. In any event, what do we mean by a superior brain? What did Einstein and Mozart have in common with Shakespeare? They didn't just have good memories. That's not what it's about. It's about being creative and that means you join up the dots in a new way. It means being an individual and for me you're not going to become an individual by doing sudoku or computer games. You are going to become an individual by having individual experiences and having the time to put the book down, stare at the wall and say if that then that but if that then that but that means that and then you say eureka. You know, you join up the dots in a new way and that's what I think we should be aiming for, is shaping the environment where people can join up the dots in a new way not just where they've got fit brains like they've got fit muscles, although that's of course a good thing. Incidentally, it's also been shown that the most beneficial way of staying healthy mentally is physical exercise but proper physical exercise.

SHANE HUNTINGTON
Yeah, not picking up the sudoku book.

SUSAN GREENFIELD
Not just strolling around. Not just strolling around the block but making yourself sweat and your heart rate going up.

SHANE HUNTINGTON
In the cases of degenerative diseases of the brain we're not just talking about plasticity here are we? There are other features of the brain that are presumably changing quite significantly.

SUSAN GREENFIELD
Yeah, well it's very sad that there hasn't been a new drug for the last 10 or 15 years for Alzheimer's disease so whatever the current dogma is clearly it's not completely accurate because given the muscle of the pharmaceutical industry you'd think by now if everyone was on the right track we'd have something to give to people and we don't. Because of that I'm very left of field. I have a very different view to others but that's because I think one should always challenge dogma especially when that dogma's not delivering, which it's not. So my own view is some of the features that people point to such as the deposition of certain markers in the brain - you've probably heard of plaques and tangles. They play their part but they're not the primary target, these almost like footprints, the effects of what has gone on. And what we need to do is explore the full picture and try and explain it. For example, why do we often have Alzheimer's and Parkinson's disease co-occurring? Why is it that only certain regions of the brain and not others are affected in these diseases? If it was a generic property of neurons if damaged to embark on neuro degeneration then you wouldn't have the recovery that you have famously after strokes. I think that we need to develop an idea or a model that encompasses all the known facts. And my own view, talking of plasticity, is that neuro degeneration is a misplaced form of development and I would stress to anyone listening, this is my view, it's not the universally accepted dictum so please do not - but nonetheless I've published on this and justified why I think this because I suggest that there's a special hub of cells in the brain that come from a different part of the embryo that have different mechanisms to the other cells and it's those mechanisms where they try and grow again that goes wrong in neuro degeneration. So that's what we're working on but I want to stress again this is not universally accepted; it's just an idea. But frankly we need as many ideas as we can get because the current ideas haven't got us very far.

SHANE HUNTINGTON
Presumably if you're correct though that would mean that a better understanding of plasticity itself would potentially be [attributed].

SUSAN GREENFIELD
Totally. Totally it would. Totally it would, which is to say that what's called the signalling molecules, that's to say the chemicals that mediate these effects, what limit it, what happens inside the cells, the more we understand these things and we're understanding a bit, then we can see how if it's inappropriately activated how it could be a Jekyll turned Hyde, Dr Jekyll turned into a Mr Hyde in neuronal terms.

SHANE HUNTINGTON
Susan, thank you very much for being our guest again on Up Close.

SUSAN GREENFIELD
My pleasure, Shane.

SHANE HUNTINGTON
Professor Baroness Susan Greenfield is a Senior Research Fellow at Oxford University.