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Consciousness for Beginners: the best book, articles and one movie

recommended by David Carmel

What is consciousness? Can we measure it? Cognitive neuroscientist David Carmel introduces some of the philosophical and scientific complexities of identifying what was formerly known as the 'soul.'

Interview by Sophie Roell, Editor

We’re talking about the concept of ‘consciousness.’ Shall we start with the introductory book you’ve recommending? It’s called Introducing Consciousness and it’s by the British philosopher David Papineau and Howard Selina. It’s presumably trying to make a very complex topic accessible by presenting it using graphic art?

Yes, it’s part of the Introducing… series that presents various topics in graphic form, a bit like a comic book. What I liked about this one is that it takes a very complex issue and shows that you do not need to be a great philosopher, or have a very deep understanding of the science, to understand why it’s a complex issue and what the fundamental questions we’re dealing with are.

And the truth is that with consciousness we’re still at the point of raising the interesting questions, as philosophers have done for the last 2,000 years, rather than at the interesting, complex, answers stage. Despite being highly approachable, this book is a serious piece of work that gives a great overview of past and current thinking about consciousness, especially from the philosophical perspective. Most books or articles will look at the issue of consciousness from a different angle, and I’ve tried to balance that out in my choices. This particular book was written by a professor of philosophy, David Papineau, in conjunction with an illustrator. So it’s mostly about the philosophy of mind, with particular reference to consciousness, and while it mentions science here and there, that’s really not the main focus: where it mentions the science, this is done to describe potential methodologies with which to address the philosophical questions that have been raised.

Whereas you would say there is actually more to the science than that?

Not necessarily. I’m a scientist, and my own approach to these questions is scientific. But I got interested in consciousness because of the philosophical issues. What is consciousness? How can we possibly understand it? One of the frustrating things for scientists who deal with consciousness is that nowadays we have lots of great methodologies to look at the brain and at complex forms of behaviour. But we still lack a conceptual framework with which we could recognise an answer if it came along. The answer might be all around us: we may just not see it yet.

But wouldn’t pinpointing consciousness be the same as pinpointing the soul?

That’s one of the main issues: is there a soul that is separate from the brain or from brain activity? Most scientists nowadays, including me, don’t believe there is. The biggest question in consciousness, what David Chalmers has called the ‘hard problem,’ is how can brain activity, the activity of something physical like neurons, give rise to something that to us is mental, that feels like something? It isn’t just about information processing: ‘Oh here’s the visual input, this is what it means, therefore it should induce this kind of action.’ Computers can do that, but we really don’t ascribe a soul to them. So what is it about brain activity that makes red look specifically like red? Or pain actually hurt – rather than just serving as a signal to say “avoid doing this in the future”? How does brain activity lead to things feeling like something? How does brain activity make us creatures with consciousness, with self-awareness, with a mental life? That’s still a philosophical question, and here’s why: we know a lot more about brain activity than we did several years ago. But say, for example, that I can now associate visual experience with a particular area of the brain, meaning I now know that whatever it is that gives rise to my visual experience happens in a particular location of the brain. How does that help me understand how that that activity leads to red looking like red? It really doesn’t. It just takes the question one step further back. Now I know that activity here leads to that. That still doesn’t tell me why that particular brain activity leads to things feeling or looking a certain away…

Do you think you’ll find the answer in your lifetime?

Well I, personally, won’t! Others might…When I got into this originally, when I started graduate school, I thought: ‘Yes! Here’s an interesting question, give me a few years and I’ll solve it.’ I no longer think that. Science works incrementally; we will know a lot more than we know now by the end of my lifetime – we already know a lot more than we knew when I started graduate school in 2002. But all we know are details, we’re still looking for that conceptual framework – and that would require a revolution in thinking, and there’s no way of knowing when those might occur.

So the first article you’ve chosen is ‘Detecting Awareness in the Vegetative State’ by Adrian Owen et al, published in Science in 2006, and two critiques of it, (available here and here along with the author’s response) which is right at the forefront of research, but only one page long and fairly accessible to the lay person. Why is it on your list?

One of the big questions in consciousness research is how do we tell when someone – or something – is conscious? There are a range of opinions, from ‘anything alive is conscious including bacteria’ through to people who think only “high” animals are conscious: so dogs and cats may be conscious, but spiders aren’t. And there are people who say that only people are conscious – or go even further and say, ‘Hang on, the only person each of us has access to the consciousness of, is ourselves. We actually don’t know if anyone but ourselves is conscious.’ We may act and behave as if all other people are conscious – and we’re hardwired to naturally believe so – but we don’t actually have direct access to that.

So how do you know whether someone is conscious or not? And specifically, what if you look at someone who is non-responsive, and is diagnosed as being in a vegetative state? Can you be certain that they are indeed unconscious, that they don’t have an inner mental life, that they don’t understand what’s going on around them? Or even if for some reason their sensory input is cut off, and they don’t know what’s going on around them, maybe they’re still in there screaming ‘I’m alive!’ So this is one thing newer techniques might be able to answer. These researchers took a woman who had been in a vegetative state since being in a car accident and put her in an MRI scanner. They gave her two different kinds of instructions that involved mental imagery – which they say is something that only conscious people can do: they asked her to imagine either playing tennis or walking through her home. And they got her to respond: her brain responded in the same way that normal healthy people’s brains responded, showing a different pattern of activation to each type of imagery. So their conclusion was that she was conscious.

And what were the criticisms of the paper?

No one disputes that the paper itself is fascinating. The question is, does this brain activity really indicate that she’s conscious? When we first read it in our journal club after it appeared, everyone said, couldn’t this just be evidence of how much the brain can do without consciousness? No one can say this isn’t actually unconscious brain activity. One of the limitations of functional MRI is that it’s correlational. You can’t infer from the brain activity itself that that activity is causing a behaviour  – it’s just happening at the same time. Which means, in this case, that it could be happening without actually indicating any consciousness. So two commentaries were published, from the many criticisms that were made of the researchers’ claim. One was based on the fact that we already know a lot of semantic brain activity can be evoked by stimuli that we’re not aware of. For example, if you expose people to written words, subliminally, too fast to notice what was written, there will still be brain activity related to the meaning of those words. This is a different situation, of course, but it could very well be that brain activity is evoked by certain words and doesn’t necessarily indicate consciousness. So that’s what one commentary said: that maybe these are just areas of the brain that respond to the word tennis, or home or room. The other criticism was based on logic. The fact that we know that certain mental thoughts lead to certain brain activity does not imply the opposite, that certain brain activity means that you’re having certain thoughts. The researchers took conscious people and when they told them to think about tennis or walk through the rooms of their house, these were the areas that lit up. They concluded that if these areas light up, this means that someone is thinking about playing tennis or walking through the rooms of their house. That’s a logical fallacy, it’s like saying if all cucumbers are green, then everything green is a cucumber.

So what was the upshot?

That particular group of researchers, their work is fantastic: they do really interesting research. And just because you can’t get to a conclusive answer, doesn’t mean it wasn’t worthwhile. One of their responses was to say, OK, in order to infer from certain brain activity that it’s conscious, you have to be able to associate with some kind of decision-making. So the answer is we give the person several choices: if they’re conscious they can choose one thing and not the other. So they found more vegetative patients whose brains responded in this way, and they taught them to associate thinking about tennis or walking through the rooms of their house, with the answers ‘yes’ and ‘no’ to specific questions, questions that had nothing to do with tennis or walking through the rooms in their house – like, ‘Is your name so-and-so?’ That’s a newer paper that appeared only this year.

And that worked?

With some patients. Again, one of the things you learn about science when you’re actually doing it is that it’s messy. You never get a really clear-cut, definite answer. What you get are data-points that are more consistent with one answer than with another. So not every vegetative state patient responds to these kinds of instructions, those who do may do so to different levels of success… But I chose this paper because it has now been the topic of a lot of discussion, and it really gets to the conceptual issue of how do we know if someone is conscious, or whether we can ever really know? The back and forth is fascinating.

Your next choice, this video clip and the research based on it is just absolutely brilliant. [Spoiler alert: follow the instructions in this 82-second clip before you continue reading!]

This phenomenon is known as inattentional blindness: Among people counting passes in the white t-shirt team, about 90 per cent – including me, when I first saw this – completely miss the gorilla. The phenomenon is a whole field of research in psychology nowadays. Why do people miss very obvious, highly-salient events? Under what conditions does this happen more than in other conditions? For example, if people are counting the black shirt passers, the chances of spotting the gorilla are increased, because there is more similarity between the gorilla and the people in the black shirts. Inattentional blindness was known before this research. There had been several demonstrations of it going back for quite a few years. But many of them did it with very quick flashes of pictures that you had to do some task with, and in one of them there would be an extra element and you were asked if you saw it. And that works, but it’s a lot less interesting than a big gorilla walking across the screen for nine seconds, stopping in the middle to beat his chest, and people actually having to walk around it to pass the ball to each other. What was so interesting to me was how a really, really simple instruction can block out half of your visual world.

How does it relate to consciousness?

Well, my first choice – the book Introducing Consciousness – dealt with the philosophical issue of how activity in a physical system can lead to something feeling like something. My second choice, the discussion of awareness in the vegetative state, looks at the issue of what it is about brain activity that defines our state of consciousness – whether we are conscious, not conscious, or something in between. This third choice, a demonstration of inattentional blindness, is about the content of our consciousness. We know that the brain can process a lot of things that it’s unaware of, for example words presented subliminally, too quickly to consciously see – we know there is something in our brain’s semantic system that can still process their meaning. There’s experimental evidence of that. The question is, in that case, what makes the distinction between the things that we see and become aware of, and the things that our eyes are exposed to but we remain unaware of? We walk around thinking our eyes are a bit like cameras, picking up the world around us and relaying whatever they see to the brain, and that what is relayed is what we’re aware of. But that’s simply not true. We remain unaware of a lot of what we see. And this is a pretty surprising or striking demonstration that gets that point across.

So now on to ‘Failure to Detect Mismatches between Intention and Outcome’. Why have you chosen this article?

When we talk about consciousness, there is also the consciousness of self. And this is what this particular article sheds an interesting light on. We each walk around the world, constantly telling ourselves a story. The narrative of our lives is the narrative we use to construct our sense of self, who we are, why we do what we do, why we choose what we choose – everything we do we justify to ourselves. And we have this illusion of stability. We think we know why we did what we did, why we chose what we chose. And what this article does really well is to show that, actually, that sense of self, that narrative, is a lot more fragile than we might normally think. We’re probably updating it on-line all the time. We probably know why we did something because we see what we did – rather than the other way around.

Tell me how the experiment works.

OK. So, imagine a researcher is holding up two pictures of women, and you are asked to choose which one is more attractive. You pick one, and the researcher puts the pictures face down. Then he picks up the one you chose, shows it to you again, and asks you to explain why you chose it. Easy enough. But as it happens, the researcher is a magician and, using sleight of hand, he’s switched the pictures and is actually showing you the one you liked less. Surely, you’d say, ‘No, I picked the other one’, right? Well, turns out about one-third of people don’t – they happily go on to explain why they chose the picture they are being shown.

So isn’t this experiment also saying that the narrative is more important than the outcome?

In this particular case, the narrative is shaped by the outcome. Now if you look at the paper, you’ll see that not everyone fell for this. But still a huge number of people, if you think about the scenario for this, which is really, really simple. So I would say that at least of those people that fell for it – instead of saying, ‘I have a narrative, I remember I chose that picture, not this one, what’s going on here?’, they’re thinking, ‘Oh, here’s a picture, I’m being told I chose it, I must remember wrong…’ or ‘Something’s wrong here, but I just saw that he picked up the picture that I remember pointing at, it might be different to the one I remember, but it must be one I chose…’ Something like that. I don’t know what’s going on these people’s minds. But what this suggests is that the outcome is a very strong retrospective force in shaping the narrative. So if inattentional blindness had to do with relationship between awareness and perception, this one has to do with the relationship between awareness and memory.

Not so much work has been done on choice blindness as inattentional blindness. There’s a lot of scope for finding out what influences it, what makes more or less of it happen. It’s a fairly untapped phenomenon.

Also, one last thing I’d like to add: it’s a great example of how stage magic can help us shed light on human psychology. In this case, the key to the experiment working was the experimenter acting as a magician – he had the ability or skill to use sleight of hand where he put the picture face down and he picked up a different one. The whole experiment hinged on that. They didn’t check it, but I think if they’d done the same thing simply using a computer screen showing two pictures, asked which one was chosen, and then just showed the other one on the computer screen, a lot of people would have been more likely to say, ‘No, there’s a glitch in the program, I chose the other one. But in this case they actually saw the person put down the picture and pick it up again and show it to them again, so they remained unaware of the fact it was a different one.

That gorilla one also reminds me of stage magic – isn’t that how they do it? They get you to look at something to the left, while they do something to the right…

Yes, misdirection. Do you know Richard Wiseman? He’s at the University of Hertfordshire, and is a Professor of the Public Understanding of Psychology – which means that he tours the world giving lectures on funny stuff. And he’s a great speaker – he has a YouTube video. He has a great demonstration he does on there – it’s magic essentially, and he has a gorilla suit in the background to show people where he’s coming from…

On to your last choice, the 2008 movie, Synecdoche, directed by Charlie Kaufman.

This movie is a flawed masterpiece – it’s way too long, it’s a lot more depressing than the subject matter necessarily requires, but it’s fascinating. It’s the story of a theatre playwright/director’s mind and his attempt to portray the mind in a play. So there’s a lot of introspective, self-aware art-making going on. He is trying to make a play that is true: that is truly true, meaning he is trying to portray his life in a play, he is trying to portray the entire outside world as it’s perceived in his mind, he’s trying to portray every event in his life. But then, of course, in the end you get the problem that he tries to portray himself making the play about his life, and there’s a kind of infinite regress loop going on there. And it makes for a lot of interesting thinking about theatre and art and representation. But when I was watching it, I kept thinking, ‘This is exactly the sort of thing that we in the lab do every day! We try to build models of the human mind, we try to understand how it is that our brain can represent the outside world, and if there’s something in the brain that represents the outside world, what represents that bit of the brain to itself? It reminded me of this naïve image I had as a child of what goes on in the brain, I also saw it in the Woody Allen movie, Everything You Wanted to Know about Sex, but Were Afraid to Ask. There’s a brilliant scene in there that takes place in someone’s brain, while he’s on a date. I always imagined the brain as being something like that, populated by little people, who walked around carrying out various roles. You can imagine someone sitting behind each eye, looking out and relaying the information on. But then, of course, the problem becomes, who is in their heads? And who is in the heads of those people who are in their heads? And that leads to what philosophers have given the grand term, infinite regress. But I used to wonder about these things aged four or five. It’s not hard to grasp this problem on a philosophical level, and understand why it’s a problem – and I think this particular movie does a really good job of portraying it in a work of art.

Interview by Sophie Roell, Editor

April 8, 2010

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David Carmel

David Carmel

David Carmel is a lecturer in the Psychology Department at Edinburgh University. He runs the Brain Stimulation lab in the Cognitive Neuroscience Suite, and uses brain stimulation and psychophysics techniques to investigate human consciousness.

David Carmel

David Carmel

David Carmel is a lecturer in the Psychology Department at Edinburgh University. He runs the Brain Stimulation lab in the Cognitive Neuroscience Suite, and uses brain stimulation and psychophysics techniques to investigate human consciousness.