Mind Shift: how did our brain come to be?
Katie Haylor reflects on the elusive and mysterious subject of the “mind” with pharmacologist John Parrington from Oxford University, who has recently written a book all about the topic, called Mind Shift. First up, Katie asked, what actually is the "mind"?
John - We know on the one hand, there's the brain. And then on the other hand there's the individual mind, individual consciousness. And it's been trying to pull these two things together that has plagued people over the centuries, really. And I'm trying to bring these two things together. So on the one hand, yeah, the brain is this physical entity, 1.5 kilograms. It's got the consistency of porridge apparently. On the [other] hand, we've got this amazing kind of individual consciousness and also a social kind of consciousness between human beings, that seems to transcend really the idea of it being just this physical object. So it's trying to pull these two things together.
Now to some extent over the last few centuries, there's been an undermining of this idea that humans are special. So for instance, Copernicus showed that the earth is just another planet. It goes around the sun. Darwin showed that we are connected to all of the life forms on the planet by evolution. But I think it's also important - while acknowledging that we do have this massive amount in common with other species - to recognise what makes us very different. I mean, the fact we're talking through a computer, we are talking over the internet. This is just one of many technologies that distinguish human beings from other animals. And I wanted to explain what is the consciousness that has created these amazing technologies. What makes us different in that sense.
Katie - So what do you reckon does make us unique then? What sets humans apart in terms of the mind?
John - Well, I think it all goes back to how we evolved from apes. And I draw inspiration from things that Darwin said. But surprisingly, a thinker who is not often associated with science, Friedrich Engels - who was Karl Marx's colleague and political activist, friend. He was the first person to recognise that human beings started to diverge from apes when we started walking on two legs. Then this freed the hands to allow us to use tools. Tool use, social cooperation, using tools to transform the world, became a key part of what it means to be human. And this then led to the need to communicate. So that then led to language. And both of these two things - transforming the world around us with tools, but also language - then led to the development of the brain.
Katie - But the thing is, other animals have been documented using tools to a certain extent and communicating between, you know, individuals. So what really sets humans apart?
John - That's a very good point. I mean, it's absolutely true that there are other animals that use tools, not just other primates. Crows are quite sophisticated in this sense. I think what's very different about human beings is the way that we use tools as such a systematic part of our lives and also how we keep on creating new technologies with each new generation. So we can see how in 40,000 years, we've gone from scratching a living from the earth to sending rockets to Mars. And I think that's the big difference between us and other species.
Katie - So how does this uniqueness relate to the mind? You mentioned consciousness earlier. Is this a big part of the argument?
John - Well, what I did in the book was to very much take inspiration from a psychologist Lev Vygotsky who worked in Russia in the years after the Russian revolution, in the twenties and early thirties. He basically took Engels' argument that tools allowed us to transform the world around us, but had also led to the development of the human brain. And said, well imagine that words are also a kind of a tool, but in this case a tool that re-fashions the human brain from the inside. And taking that basic idea, he then developed some very sophisticated ideas about the human mind and what makes it different from other species. So what I've tried to do in Mind Shift is to take Vygotsky's basic idea, inspiration about how words transform the human brain, both evolutionarily and also, you know, as we grow up as children and then into adults. And then say, well how can we use this idea, but then connect it to the findings of modern neuroscience and modern psychology?
Katie - Would you be able to lay out your argument for what the mind shift was?
John - Yes. I mean on the one hand, the human brain has definitely grown in size relative to that of other primate species. So there's been a fantastical growth just in the very size of the brain. And that's reflected also in structural changes. But I argue in the book that it's about far more than size, and it's also about a complete restructuring of the brain. And also the interactions between different parts of the brain. So I show, for instance, in thinking about imagination and creativity, there seems to be a new role for a part of the brain called the cerebellum, which was unsuspected only a few years ago, but it seems to be showing how the human brain has really been radically transformed, both structurally and functionally.
Katie - In reading some of your book, I think what you're saying in your argument is that you've got tools and language or words as being a tool, facilitates the idea of conscious awareness in that if you can articulate either internally or externally your thoughts, then you can make a world, even if that's an imaginary one. And then that facilitates a whole bunch of rich aspects of culture.
John - Very much so in the sense that thought is based on language. So we have this thing called inner speech and actually there's different levels of inner speech. So when I try and articulate my thoughts, to some extent I'm drawing on this kind of inner speech. But I think there's a much more fluid speech going on there when we think that's actually quite hard to explain exactly how that would sound. So that's on the one hand, language is a kind of key part of all this. But I also believe there are fundamental biological differences that also have changed within the human brain. So that explains why there's not really been any real success in teaching chimpanzees to talk in the kind of way we mean talking - in terms of language, using concepts. None of that's really been shown to be possible with any of the species besides us. So although we use language and we can teach words to chimps for instance, the actual human consciousness based on human language is also based on biological differences in the brain, I believe.
Katie - What evidence do you have to put forward that other animals don't have this sort of inner voice or conscious awareness?
John - Well, that's a really good point, obviously. And the big difficulty is that we can't ask, you know, our cat or dog other the species, what they're actually thinking. They can't express themselves through language. I think we really have to see it in terms of the way that we affect the world around us. So I said before about chimps, there's nothing to suggest that the way they interact with the environment has really changed over millions of years. Apart from in a very gradual way, as happens with all biological evolutionary processes. Whereas with human beings, we've seen this dramatic transformation in the way we interact the world, you know, the fact we have electricity now and modern medicine and we're sending rockets to Mars and even beyond.
Of course, there's a negative side to this, and I talk about this in the book as well, which is that we are also destroying the environment. So this isn't all good. It can be very destructive. But it's definitely a major difference between us and other species, our ability to transform the world around us through technology.
Katie - Can we come back to some of the nitty-gritty brain stuff you mentioned before? Could you give us some examples of how you think that being social, developing language, using tools, change the brain on a cellular and structural level?
John - Yes I think that's a really important point actually. And of course one of the problems we face here is that there are - I believe there are important differences and we can see signs of these. For instance, if we look at the expression of certain genes linked to cell signaling in the brain, there are some quite fundamental differences there. There are apparently important differences between the connections between different parts of the brain. And I think this is just this kind of information is just starting to really take shape.
That was one of the reasons that inspired me to write the book was I could see a sign that the incredible technology we have now, whether it's imaging technologies or molecular and cellular analysis, are allowing us to identify major differences between the human brain and that of other species.
Katie - Could you give us a little bit more about which ones you draw attention to?
John - One thing that struck me was dopamine. It's one of the neurotransmitters in the brain. It's the classical neurotransmitter involved in reward, for instance. And I found it interesting that one of the genes that is involved in the production of dopamine was found to be expressed in some areas of the brain that are linked to more, what we call higher functions - imagination, creativity. And there didn't seem to be the same expression in, say, a Chimp. So that was an indication that there are, even at the most basic level of neurotransmitter action, there are potentially some quite important differences. The cerebellum is another important part of the brain I looked at. Up till now, until recently, the cerebellum was thought to be really just involved in repetitive movements. If you learn to play the piano or to ride a bike, or to throw a ball into a hoop, that that's all been known for some time to be related to the work of the cerebellum, which is this little part of the brain that sits in the back of the brain.
But what we're starting to realise is that things like imagination, creativity that were thought to always be part of more a function of the kind of frontal structures in the brain, also seem to involve the cerebellum in some quite important ways. And there's also evidence that the interaction between the front parts of the brain and the cerebellum are quite different in humans compared to other species. So there's been a transformation there in that sense.
Katie - Can you give me a few more sort of concrete examples?
John - Yeah. I think that's the bit where it comes difficult to connect all of this together in the sense that ... well, first of all language itself, it's not just communication. It's about a radical new way of looking at the world. It allows us to conceptualise about the world. It allows us to see past, present and future. Somehow or other that must have transformed our basic, you know, mental process. And I go through different ways in the book of how that state transformed imagination, creativity, even our emotions, practically any human emotion is affected by this role that language plays in the brain.
Now connecting that to actual brain structure, individual neurons, is the more complicated bit. I do go through some very interesting studies that have looked at how individual neurons seem to register memories. How they seem to be involved in connecting different things in the world together. So there are some glimmers of understanding there. But it's very much the kind of the first step really of trying to understand how language itself transforms the brain in the ways I'm talking about.
Katie - Okay. So you gave us an example of dopamine. And I think what you're saying is that genetic expression, when it comes to neurotransmission, there's evidence that that varies between different species, but also these structural differences that you mentioned.
John - I think there's another aspect as well that I didn't mention, which is that I've been very inspired by some of the work of Earl Miller who works at MIT in Boston, USA. And he's come up with some very interesting ideas recently about the way that brain waves of different frequencies can regulate interactions between different parts of the brain. So based on this, and then thinking about my thesis that human brain is quite different in its structure and function from other species, I postulate that this coordination between different parts of the brain that I see as being quite different in human beings, is potentially being regulated by these frequencies, different frequency brainwaves.
Now that's not to say that brain waves of different frequencies don't regulate what happens in an animal brain. I can imagine that if you have a pet cat who suddenly sees you or spots a mouse or whatever, there may be this dynamic change going on between parts of the brain. What I'm speculating about in the book is that language may completely transform the way these brainwaves regulate brain function. I mean, of course it's difficult in some ways to prove all of this. This is very much a hypothesis. And in fact in the book I, towards the end of the book, I go through a number of ways we might start to test this as an idea.
Katie - I see. So it's a work in progress, this idea.
John - It is definitely a work in progress because I think it would be amazing if a single book could explain consciousness. And that certainly wasn't what I was expecting to achieve! What I hope I do in the book is to raise this is a very provocative idea that there is this radical difference between human brains and those of other species. And I think this has research implications because although as a research scientist myself, I'm completely of the idea that we can learn fast amounts from studying other species - mice, but also controversially, primates - I do think there are, if there are these fundamental differences between human brains and those of the species, it does say there's a limitation to what we can learn from those studies alone. And maybe we have to be more creative about the ways we use opportunities to learn more about how the human brain works. You know, there are some non-invasive ways - imaging, different kinds of imaging techniques, are allowing us to probe the human brain in all sorts of ways. There are opportunities to even make recordings of a human brain while people are undergoing surgery, say for epilepsy treatment. So there are possibilities, but none of this is necessarily that easy. I guess one thing I'm saying in my book is that we need to take more seriously the idea that human studies need to compliment animal studies, if we are truly to understand what makes human consciousness unique.
Katie - The thing is the brain is just so incredibly complex. And there's so much that we don't understand about what's contained within our skulls. Do you think there's a possibility that actually other species are equally complex, equally fascinating in the way that their brains work. It's just, it could be quite different to humans?
John - Absolutely in the sense that I don't think we can ever underestimate just how complex the brain is say of a primate, for instance, or even a mouse for that matter, or even a fruit fly. I mean, one of the reasons I'm skeptical about the potential for so-called artificial intelligence to overtake human intelligence - this idea that computers might soon be able to think like a human being or maybe even surpass our kind of thinking - is that I think we often do estimate the complexity at the molecular and cellular level that we have within our brains. But also those of other species. So that's one thing to say.
But I do think that the way that language has transformed the brain, both in the way our brains have then evolved through that interaction via language with other human beings, but also the way that we grow up within a human society and that radically transforms our brains. Because learning has this incredibly important role to play in human culture, I think. Far more in a sense than it does in those of other species. All this I believe has led the human brain to be a different level of complexity compared to brains of other species.