The Nature of Consciousness


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James Ayers:

Welcome to LaTrobe University Podcasts. I'll be your host, James Ayers, and today we have Professor Jason Mattingley, a neuroscientist and neuropsychologist from the Queensland Brain Institute and the School of Psychology at the University of Queensland. Jason, thanks for joining us.

Jason Mattingley:

My pleasure.

James Ayers:

You're coming here today to speak about consciousness and the conscious. Can you explain exactly what that is?

Jason Mattingley:

Well, that's the great mystery, actually. It's trying to be able to define what consciousness is. We all have an intuition about what it might be. But really, scientists have not been able to agree on what it might constitute. And so, what we've tended to do is to break it into manageable subcomponents.

So, consciousness might be, for example, the difference between being asleep and being awake. That's how many of us think about being conscious. It might be the quality of experience we have when we smell coffee in the morning or when we see the red color of the rose. That's the thing philosophers are interested in. That's something they call qualia, the subjective aspect of consciousness.

From a psychologist's perspective, consciousness is really about the mind. It's about the mental processes that underpin thinking and learning and perceiving and using language and so on. And from a neuroscientist's point of view, it's really about what goes on in the brain. What are the neural processes that allow us to maintain that conscious state of our environment and of ourselves? And of course, from the medical point of view, what goes wrong when someone is rendered unconscious? When somebody has a head injury that damages the brain, then typically those people will lose consciousness for a short period of time, sometimes for a long period of time. And one of the enduring questions is why do we lose consciousness after brain injury. How do we help people regain consciousness after such injuries?

James Ayers:

I wanted to also ask, as a scientist and with the advent of medical technology, has that definition changed from the time of psychoanalysis and back when psychology was first beginning?

Jason Mattingley:

It has. So, of course, Freud and many others talked about the conscious or the unconscious. In particular, Freud was very interested in repression of unconscious desires, for example. If you go back even further, philosophers were interested in things like moral consciousness. But really, today we do think about consciousness as this concept that's very fractionated. And it really depends on what you're trying to understand. That's how you'll define the concept.

In medical science now, consciousness is very much about maintaining an alert state, a state in which you can respond flexibly and adaptively to things happening in your environment, a state in which you're aware of yourself and your thought processes and so on. Of course, those things can go wrong for lots of different reasons. I mentioned one before which is damage to the brain after traumatic brain injury, for example. But in many different psychiatric diseases, we see alterations in conscious state as well. Individuals who experience hallucinations have an altered state of consciousness. People who have schizophrenia and suffer hallucinations, for example, arguably have a different states of consciousness.

So, I think what we have now really is a more nuanced view of what consciousness is. It's not just one thing; it's many different things. And that probably reflects the workings of many different parts of the brain.

James Ayers:

And is there an exception among the community that consciousness is not simply a human thing, that it is part of nature and possibly in the future part of the machines as well, that machines might develop?

Jason Mattingley:

Excellent question. It's really one of the hot topics in neuroscience, in philosophy and psychology at the moment. Are we humans the only species to be conscious? Of course, philosophers like Descartes, for example, believed that humans were somehow unique in having a spirit and a mind as opposed to just the physical body?

But really again, increasingly we see that other animals have what we would consider to be something analogous to state of consciousness as well. Certainly, self-consciousness if you look at other non-human primate species, if you look at the great apes, they all exhibit behaviours that we as scientists would consider to be reflective of consciousness, of self-awareness and of constant state of awareness of what's going on in the world around them.

We would increasingly attribute consciousness to other species, non-primate species as well. So for example, dolphins, even elephants have been suggested to have conscious abilities. Maybe we could extend that into sedentary life. Plant life, for example, is arguable. I'm not sure whether anyone really looks at consciousness of plants. But I'm sure there are people who look after their plants who would consider that they have a consciousness, too. I think the point is it's up for grabs. We now have more and more tools to be able to bring to bail on this question of what consciousness is. So, who knows what the next 10 or 20 years will bring?

James Ayers:

What are the ways that we track consciousness with the brain? Is it through technology?

Jason Mattingley:

Yeah. Technology is a big part of it, but it's not the only answer. People have really grappled with this issue of how one would assess consciousness. There's a famous mathematician in Cambridge 50 or 60 years ago, Alan Turing, who developed what's called the Turing Test of Consciousness.

And his idea was that if you imagined sitting in a room with a keyboard and looking at a computer screen with responses coming in from another human in a unseen place and something else like the computer in a unseen place, you had to work out just on the basis of your typed interaction with these two sources which was the human and which was the computer. The idea was if you as a human operator were unable to distinguish between the computer and the human sending you information, then that computer would be considered to have consciousness of some sort. So, that's the so-called Turing's Test of Consciousness.

There are lots and lots of other ways in which we might assess that. The way that regular people assess consciousness is just by talking or by having people interact with them in ways that seem logical and sensible and predictable. To a neuroscientist, we might use other tools to, for example, assess whether somebody who looks to be unconscious or somebody who perhaps is not communicating anymore, somebody perhaps with a brain injury, whether there's any evidence of consciousness lying just underneath the surface.

And there's quite a bit of very exciting research just coming out now looking at some brain imaging techniques in individuals who have lost the ability to communicate, people in what we call a persistent vegetative state, people who have had brain trauma, who are apparently unresponsive. And these new brain imaging techniques have allowed us for the first time to look at physiological markers of what we would consider to be conscious mental processes, having people for example imagine themselves in certain situations and looking at tracking patterns of brain activity and seeing how those patterns match up with what we know occur in normal, healthy and conscious people.

So, I think your question about technology, it's an enabling thing but it's not the only thing that we need to be able to assess and to establish consciousness in a human.

James Ayers:

Is there hope that if you can look at and identify parts of the brain that eventually you'll be able to stimulate these parts and hopefully stimulate these people back into some type of non-vegetative state?

Jason Mattingley:

That's exactly what's happening at the moment. So, there are a couple of recent cases in the United States of people who had been in a prolonged vegetative state. And in a last-ditch effort to try and rehabilitate these individuals, electrodes were surgically implanted into the brain and brought into contact with what we think is a crucial structure for maintaining consciousness, a structure called the thalamus, and stimulating that structure over a period of time and then looking at the effects on these individuals' behaviour, and really with quite remarkable consequences.

So, this person who had been completely unresponsive previously for many years, previously had been unable to feed himself, unable to communicate, with the brain stimulators in place suddenly was able to feed himself again, was able to make goal-directed limb movements, even was able to communicate using single words or sometimes clusters of words in a sentence-like way.

So, for the first time we have some suggestion that by appropriately stimulating core areas of the brain that we think are involved in maintaining the conscious state, we might be able to bring some of these people in this minimally conscious or vegetative states back toward a more normal state. But it's very early days yet.

James Ayers:

Could you explain to us your research and what your hope to become of your research later on?

Jason Mattingley:

Yes. So, one of the things that I've been very interested in for several years now is a syndrome called unilateral spatial neglect. And this is a syndrome that occurs typically in adults, older adults, who have had a stroke. And that stroke will cause an area of damage to the brain, typically parts of the so-called cortex in the cases that I see. And these individuals, once they recovered from the acute phases of their illness will act as if half of their world has just ceased to exist altogether.

So, it's like the unconscious of all of the sensory events to occur to one side of their body. Most of the patients we've seen have damage to their right side of the brain, which we think is a core structure for maintaining attentional abilities. And these individuals will neglect the left side of their sensory world. Even though they have normal vision, normal hearing, normal tactile sensation, they'll act in their world as if none of that information is present.

And so, we see these people if they're able to walk, they'll walk in the doorframes on the left side. When they're given a meal, they'll eat food from the right side of the plate and leave everything on the left. So, nursing staff are taught to come in and turn the plate around by 180 degrees so the half they neglected is now on their good side again and they happily eat the rest of their meal. They'll read words from only the right hand side of the page, so they suddenly read they're not very interested in reading anymore because they don't understand what they're reading. This is an incredibly debilitating condition. It can be quite long-lasting and it occurs in up to about 50% of all the right hemisphere stroke patients.

So, there's an enormous number of these people out there. So, my research has really been involved in trying to understand why this syndrome occurs in the face of relatively intact sensory processing in the brain and also directed toward trying to find better ways of rehabilitating or treating these people.

And we now know through research in my lab, so there are research done in my other labs, that it's a chronic form of inattention. And it's something we don't think much about. But if you don't direct your attention to what's happening in the world around you, you can be remarkably insensitive to what's going on. It seems intuitive. But what seems to have happened in these patients is they have lost the attention centers of the brain. And so, they have lost the ability to selectively pick up sensory information that's coming in through the sense organs and to then use that to guide their behavior.

So, we know that this syndrome of spatial neglect is due to a chronic inattention, and we know that the way to treat this syndrome is to try and boost or improve attentional functioning in these individuals. And then, there are a couple of treatments, pharmacological treatments but also behavioural treatments, that are being trialled at the moment to try and improve those abilities in the stroke patients and with some degree of success, too.

James Ayers:

You call yourself a neuroscientist and a neuropsychologist. Do those professions tend to shy away from the social side or the structure side of things and focus on things like neurons and brain patterns and the way the brain files without looking at other certain social aspects of problems in this sense?

Jason Mattingley:

It is increasingly but you're right. You've identified another important issue, which is that science by its nature tends to be reductionist. So, we try and go down to the smallest fundamental elements of the system and try and understand those. And then, we hope that by understanding the small parts, we add them altogether again, we can come up with some understanding of the whole.

Now, with something like consciousness or many cognitive processes, it's not so easy to do that. You could understand everything there is about how a neuron works or even how a small network of neurons communicates with one another. But to then take that into the realm of cognition and behaviour, it becomes very difficult.

And it's really just in the last 10 years or so that the social element of cognition and of consciousness has become prominent. I think part of that is because people have become interested in consciousness in other animals, social animals in particular for example are the non-human primates. And I think it's also partly because people have become increasingly aware of how debilitating social, psychological conditions can be.

For example, people who have autism spectrum disorder, Asperger syndrome, people who seem to have lost some of the abilities to interact in a normal social way, for example, losing the ability, having an impaired ability to pick up on facial expression information or to try and guess at the intentions of others. That's something that we all use our consciousness for. But people who have autism spectrum disorder really struggle with those things. And you see the consequences of that for their daily lives. In some respects, they're very isolated.

And so, increasingly neuroscientists, particularly cognitive neuroscientists and neuropsychologists have really tried to build the social aspect of cognition back into that typical reductionist approach. What is it about the social environment that we're adapted to, that we presumably evolved within? What has that added to the brain and what has that added to consciousness and the way in which it works?

So, I'm pleased to say that we're not moving away from the reductionist approach but we're in parallel with the very productive reductionist approach. We're looking at these other elements as well, social elements, individual differences, even genetic factors that make each of us different and maybe give each of us a unique and very different kind of consciousness or way of experiencing the world.

James Ayers:

Is there a way that we are going to be able to measure that cultural influence or that social influence? Is there hope in the future that they will be able to measure cultural differences?

Jason Mattingley:

People are doing it already. So, one of the techniques that we use very often in our research is a functional magnetic resonance imaging. So, people have heard of MRI. Most people have heard of MRI, maybe had an MRI scan if they've been in a hospital. And this technique of FMRI or functional magnetic resonance imaging allows us to measure physiological changes in the brain as they occur in parallel with cognitive functions or with changes in states of consciousness.

And so, we're increasingly using that technique to look at things like social effects on brain functioning and some quite a big social psychology literature on this concept of in-group and out-group relations. It's an intuitive idea that we tend to feel a closer affiliation with our in-group. It might be a peer group. It might be a football team, a soccer team, a cricket team. It might be a political party. That's part of that in-group. And the other political party or the other team or people outside their peer group, they would be considered an out-group.

And neural responses to just photographs of images of people in our in-group and our out-group, even though superficially those photographs might look very similar, the brain's response to those things are actually very different. And it can be developed in a very arbitrary way. There's quite a lot of research now showing that if you just sought people who come into our room at random into a red team and blue team and you tell them you're part of the red team or you're part of the blue team, you have them perform some activities with their team, they'll quickly develop those in-group and out-group differences not only in their behaviour but also in the way that neurally their brain responds to information pertaining to those in- and out-groups.

James Ayers:

Something like 2001 movie Space Odyssey, HAL, the machine with a personality, a machine with a conscience, are we getting closer to something like that?

Jason Mattingley:

Well, again I would come back to the Turing's test. It's very hard to know whether what would be the test of consciousness.

James Ayers:

The problem might be the definition almost.

Jason Mattingley:

Exactly. So, who am I to say that when I turn my laptop off at night, it doesn't feel pain for example or it doesn't have a sense of loss or grief. I assume it doesn't, but it's very difficult to know whether it does or not. We think that probably consciousness arises from complexity and it arises from the massive amounts of information that a human brain at least processes and has to integrate over time.

The question of whether computers will in the near future get to a point where they also have to integrate as much information at any one time and have massive interconnectivity that we see in a normal human brain, that's really going to be the stepping-off point for when we might start to see evidence of consciousness in a machine. But I would reiterate that the real point is how would we measure it, what would be the test of consciousness in a sedentary or an inanimate object like a computer.

James Ayers:

Well, Professor Mattingley, thanks very much for joining us.

Jason Mattingley:

A pleasure.

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