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The decision by the National Institute of Mental Health to part
company with the APA’s forthcoming DSM-5 should not be taken as evidence
that biological psychiatry is entering a terminal decline. Far from it,
as the Director of NIMH Thomas Insel’s blog of 29th April 2013 (http://www.nimh.nih.gov/about/director/2013/transforming-diagnosis.shtml)
makes clear, the reason NIMH has opted for its own Research Diagnostic
Criteria (RDoC) is because they believe psychiatric patients deserve
something better.
Psychiatric diagnoses, he correctly points out,
are symptom-based. Scientific advances in molecular genetics and other
basic sciences (including neuroscience) over the last fifty years has
enabled the rest of medicine to abandon syndromal systems of
classification in favour of systems based in a deeper understanding of
molecular pathology. The RDoC
(what an evocative acronym, redolent of crushed velvet loons, Jason
King, platform heels, Zapata moustaches, and Robert Spitzer) is a new
project drawing together genetics, imaging and cognitive science to lay
the foundation for a new system of classification based in a set of
assumptions that include the beliefs that ‘…mental disorders are
biological disorders involving brain circuits that implicate specific
domains of cognition, emotion, or behavior. Each level of analysis needs
to be understood across a dimension of function, and [m]apping the
cognitive, circuit, and genetic aspects of mental disorders will yield
new and better targets for treatment’ (Insel, 29th April, 2013).
Dr. Insel stresses the point that the RDoC is a research not a clinical tool. Doubtless he will have his eye on some of the $100 million pledged by President Obama for the BRAIN initiative on 2nd April this year ( http://www.whitehouse.gov/infographics/brain-initiative) in his quest for the neuro-validity of psychiatric disorders. Indeed, in a blog published on 10th April 2013 (http://www.nimh.nih.gov/about/director/2013/new-views-into-the-brain.shtml) Dr. Insel indicates that this is the case. And of course, the neuroscience brigade over here will be hot on their coat tails, following the announcement in January by the European Commission of the Human Brain Project (http://www.humanbrainproject.eu), as a ‘European Flagship’ (Maybe they meant a European Flagship of Fools). Enough jocularity! This is meant to be a serious post, and it is, but the world seems to be going neuro-mad, or suffering from neuromania as the writer and polymath Raymond Tallis has put it. In this blog I want to raise some serious questions about the nature of the understanding of ourselves as human beings that neuroscience provides. Indeed, there are strong arguments from within philosophy that neuroscience has nothing to say about what it means to be a human being, to be conscious of the world and others, to have feelings, emotions, beliefs, to love, to hate, to be in despair, to hear voices, and to be mad. There have been a number of recent critiques of neuroscience, and all are to be commended. Alva Noë is a neuroscientist and philosopher. In Out of Our Heads (Noë, 2009) he argues that consciousness is not ‘in our head‘ but originates in our engagement with the world we find ourselves in. Nikolas Rose and Joelle Abi-Rached’s Neuro, is a comprehensive social critique of the origins and role of neuroscience in contemporary culture (Rose and Abi-Rached, 2013). Both these books are illuminating and thoroughly worth reading. However, the most erudite and detailed critique of neuroscience is to be found in Raymond Tallis’s (2011) recent book, Aping Mankind. Tallis, whose until recently was a clinician and Professor of Geriatric Medicine in the University of Manchester, is deeply sceptical that neuroscience has anything to tell us about what it means to be a human being. Much of his ire is directed at neuroscientific research that claims to have identified the neural basis of romantic love (Bartels & Zeki, 2000), or our responses when we listen to a piece of music we haven’t previously heard (Salimpor et al, 2013), but his criticisms are applicable to recent neuroscience research into the neural basis of madness. A good example are functional Magnetic Resonance Imaging (fMRI) studies that claim to show that the experience of verbal auditory hallucinations is caused by activity occurring in specific areas of the brain (see, for example van Lutterveld et al’s 2013 meta-analysis). Tallis’s arguments about studies of functional Magnetic Resonance Imaging (fMRI) in perception are directly pertinent to their use in people diagnosed with schizophrenia or other psychiatric disorders, especially the assumption that brain activity causes experiences like hearing voices. At first glance the latest generation of functional brain imaging technology, offers an attractive view of consciousness. This view is a literal one; fMRI scans enable us to see activity in different areas of the brain when subjects are involved in different tasks, or in people who have psychiatric diagnoses like schizophrenia. Neuroscientific explanations of consciousness appeal to simplicity because they are fundamentally flawed. This is because it fails to engage with one of (Western) philosophy’s most difficult and enduring problems: the relationship between body and mind, or brain and consciousness. The problem can be posed as a question: what is the nature of the relationship between the physical events that occur in our brains and the contents of our consciousness, our thoughts, emotions, beliefs, perceptions, memories and so on. Tallis argues that although neuroscience appears to address the problem of the body/mind relationship it only does so because it confuses three different types of relationships, correlation, causation and identity. This has three main consequences, which in turn have profound implications, not only for how we think about consciousness, but also about what it means to be a human being. It follows that this is true also for the way we understand of madness and distress, unless you argue that there is something intrinsically different about the brain/consciousness relationship in mad people. That way leads to the extermination camp. The first consequence concerns the role of the observer (or subject) in consciousness; the second concerns the role of the world (or contexts) in consciousness; the third concerns the problem of intentionality. Neuroscience, Tallis argues, tries to account for consciousness in ways that avoids or evades all three.
Seeing correlations between event A (neural activity) and event B (say, reported experience) is not the same as seeing event B when you are seeing event A. Neuromaniacs, however, argue, or rather assume, that the close relationship between events A and B means that they are essentially the same thing. (Tallis, 2011: 85) For example it follows from the identity argument that if I look at a yellow flower the experience I have of yellow should be the same as the activity in my brain. This is clearly not so. As Tallis points out, there is nothing ‘yellow’ about the nerve impulses and brain activity in the relevant parts of my visual cortex. Or, to take another example, if someone has an fMRI scan when they hear the voice of God saying that the moon will crash into the Pacific Ocean tomorrow morning, then if the brain activity is the same as the experience, then this activity should have a divine quality about it. More than that, it should also have lunar and oceanic qualities, as well as an emotional quality of catastrophe and impending disaster. This is clearly nonsense. All the qualities associated with the experience of hearing the voice of God saying that these things will happen, and the neural activity in the relevant parts of the cortex, are completely different. Neuroscience tries to get round this difficulty by the ‘double aspect’ theory. This states that although there is only one set of (physical) events in the brain, these events have two aspects, a neural side and experiential side. A good example of this is to be found in the work of the philosopher John Searle (1983), who used the theory to explain how it is possible for water, which in our experience is wet, shiny and slippery, to be constituted by molecules of H20 which have none of these qualities. We can understand the relationship between brain activity and the contents of consciousness in the same way. Consciousness is made up of experiences (like the colour yellow, or hearing the voice of god) and although these are nothing like the nerve impulses that occur in association with the experience, they are nevertheless different aspects of the same thing. Tallis unpicks this by asking what is meant here by ‘aspect’ For example, does it bear comparison with an object like a house that has different aspects, front, side and rear. If so, it is impossible to think of any sort of thing that has a mental or experiential front aspect, and a neural or material rear aspect. The double aspect theory breaks down because the different aspects of a house are nothing like the difference between a physical event such as the pattern of cortical activation in the brain of someone hearing a voice, and the qualities of that experience for the person who has it. Indeed, it is only meaningful to talk of the two aspects of a house from the point of view of an observer who is free to vary her or his position in relation to the house by walking around it, and seeing it from different angles: To invoke doubled aspects is to cheat: it smuggles consciousness in to explain how it is that neural activity, which does not look like experience, that actually is such experience. (Ibid: 86, emphasis in the original) The critical point that Tallis draws our attention to is that like the different aspects of a house, both aspects of water, the experience of its wetness and so forth, and H20 molecules, require an observer who can see that these are both aspect of the same thing. In order to be aware of the difference, however, the observer requires different ways of seeing, one through the senses directly (in the case of water), the other through an electron microscope or similar technology that makes it possible to be aware of the existence of molecules of H20. Furthermore, Searle argues that the experiential qualities of water experienced by an observer or subject, are caused by the physical properties of the molecules of H20. In other words in the double aspect theory of consciousness maintains that brain events stand in a causal relationship to the experiences of consciousness. But it doesn’t make sense to say that brain activity is the same as consciousness, and that it causes consciousness. Cause and effect stand in a different relationship to identity and sameness. It is nonsense to say that the front aspect of a house causes the rear aspect. The relationship between the two requires something else, an observer who is free to explore the house by walking around it. The key issue here is that neuroscientific accounts of consciousness overlook the need for a conscious observer, a subject, a seer, feeler, an experiencer. Water looks and feels the way it does because someone is conscious of it. The same holds for the experience of hearing voices; we may observe the experience in different ways. In one, the subject of the experience introspects, or is simply aware of the experience, and hears the voice of God. In the other the fMRI scan reveals activity in the brain, but here the comparison breaks down, because an fMRI of the brain activity of someone hearing the voice of God is not something that can be experienced in the sense that the voice of God is experienced by the person hearing it. Likewise, the voice of God has the qualities it possesses because an observer, a conscious subject, is aware of it. 2. The role of the world If consciousness is nothing more than brain activity, then we are entitled to ask what role does the world play in it? After all, two sets of observations suggest that the external world may not be that important for consciousness. The Canadian neurosurgeon Wilder Penfield became famous for his work in the surgical treatment of intractable epilepsy. He surgically removed the area of the cortex responsible for the focus of seizures, but to do so safely he had to make sure that he removed only the area of responsible for the fits, and not areas that were important for speech, movement or sensation. Apart from a local anaesthetic to the scalp and bone of the skull, his patients were fully conscious (brain tissue itself is insensitive to pain) so he was able to get them to report what happened when he electrically stimulated the exposed cortex. When he did this to the temporal lobes, patients reported vivid and complex experiences often relating to past experiences. It was as though they were watching a familiar scene from outside. These experiences, remember, were generated internally, through brain activity, without reference to what was happening in the world at the time. The second strand of evidence is the complex experiences such as perceptual changes and hallucinations that people have when they are under the influence of psychoactive drugs. This gave rise to a famous thought experiment in philosophy, Hilary Putnam’s ‘Brain in a Vat’. (The influence of Putnam’s though experiment can be seen in the film The Matrix) The experiment proposes that if neural activity alone is sufficient for experience, and the origins of this activity are irrelevant (as is the case in Penfield’s experiment, or someone on LSD) is it possible that we are deceived as to our true nature? For example, how do I know that I am nothing more than a brain suspended in a vat of nutrient fluid and kept at the correct temperature? Neuroscience holds that in theory my brain could be connected to a powerful computer which stimulated it in such a way that gave rise to all the experiences that I have at the moment, sitting in my study, an ache in my right shoulder, listening to Steve Reich’s Music for Eighteen Musicians, aware of an itch I want to scratch on my left ankle, and rushing through writing this article because there’s a football match on television I want to watch in half an hour. In principle all these contents of my consciousness could be generated by a computer stimulating my brain. It would be impossible for me to know whether or not the world existed, or at least if it did, that it simply wasn’t relevant to the contents of my consciousness. If such a situation were possible, it would justify a wide range of sceptical positions about the world we experience. The obvious flaw in the experiment, as Putnam (1982) points out, is that it would be impossible to conceive of the thought ‘I am a brain in a vat’ without a world that contained brains, vats, computers laboratories, and scientists necessary to run the experiment and so on. Tallis points out that the experiment is valuable because it reveals the absurdity of claiming on the one hand that neural activity is correlated with conscious experience, and then claiming that brain activity causes conscious experience and indeed is the same thing as it; ‘This way lies the madness of concluding that a stand-alone brain could sustain a sense of a world’ (ibid: 92) The problem with cognitive neuroscience is that it accounts for consciousness without reference to the world outside. It makes no difference if those representations originated in external stimuli in the here and now, or whether they are representations of memories, images and words from or past. All that matters are the mechanisms, processes and calculations carried out by the brain in processing the information that constitutes these experiences. It is important to remember, though that in Penfield’s experiments stimulation of the cortex evoked real memories his patients had had in a real world. These experiences had a vividness and an ‘aboutness’ for his subjects that indicates that these were real experiences that had happened to real people. “…it is necessary to appreciate that our ordinary memories, and our ordinary current experiences, make sense because they are part of a world. Yes, we are located in this world in virtue of being embodied and we access it through our brains; but it makes sense to us, as a world, not solely on account of its physical properties but as a network of significances upheld by the community of minds of which we individually are only a part.” (ibid: 93, emphasis in the original) This sense of ‘aboutness’ leads to the third problem, that of intentionality. Intentionality This really highlights the difference between the view of consciousness provided by neuroscience, and consciousness as we experience it as human beings. The two are incommensurable, and we run into serious difficulties if we accept that the neuroscience view is the ‘correct’ one. We can see why this is through the difficulty that neuroscience has in dealing with intentionality. This concept rose to prominence through the work of the German philosopher Franz Brentano, in the second half of the nineteenth century. He used the word to refer to the experience we have that the contents of consciousness have the quality of ‘aboutness’. Our perceptions are about things, but this applies to other contents of consciousness, such as our beliefs, fears, hopes and memories. Tallis uses perception because it is relatively straightforward, and he takes as an example a red hat on the desk in front of him. Neuroscience has no problem generating a causal chain of events that starts with the incident light on the hat, interacting with the atoms in such a way that light of a particular wavelength is reflected on into the eye. There the light produces physical changes in the retina that triggers nerve impulses that pass to the visual cortex located in the occipital lobes at the back of the brain. However, Tallis points out that our conscious awareness of the object involves much, much more than that. I am aware of presence of an object in space a couple of feet in front of me (Let’s assume for the moment it is Tallis’s red hat). It has its own properties, and a reality of its own. This means that my awareness of the object is as Tallis puts it, located causally upstream from the physical processes and events in my brain that are associated with my awareness of the object. The causal links from object to visual cortex pass in one direction, out -> in, but my experience of the paperweight passes in the opposite direction, from my brain to the paperweight, in -> out: The key point, however, is that intentionality – my awareness of the hat – points in the opposite direction to the arrow of causation. It points from effects (nerve impulses in the higher levels of the visual pathways) backwards to their causes (the interference between the object and the light). And then it points further backwards to the partners producing the effects: the red hat and the light it is bathed in. (ibid: 105, emphasis in the original) This curious but fundamental feature of consciousness has been the subject of years of study, research and scholarly work in philosophy, psychology and the physiology of perception, and is a deeply complex issue. The irony is that it takes banal neuroscientific accounts to remind us through intentionality of the wonder and complexity of consciousness. Neuroscience is incapable of explaining how physically-based activity in nerve cells can reach causally upstream back to the interaction between object and light to present in my conscious awareness an object that is clearly out there. More than that, it is not simply an object out there, but an awareness of something out there: It is a revelation: of an object to a subject in which object and subject are kept separate and distinct, with the subject (me) being here and the object (the hat that I am looking at) being over there. (ibid: 106) Neuroscience finds this aspect of consciousness so difficult to account for that it tries to conceal intentionality by incorporating it into causal theories of perception. The problem here is that we end up with a theory of consciousness that is possessed by the brain, not a person. My experience of the world is that of a person looking out at it, and as I do so, objects in the world stand out as meaningful for me. Particular objects have meaning for me because they are tied in some way to what has happened to me in my past. Perception reveals the paradox of being human, our separation from a world of physical objects, and at the same time our immersion in a world of meanings and significance in that world. The most important feature of this in relation to madness is our struggle to find meaning in it, or impose meaning on it. There is no place in a causal neuroscience for these aspects of being because it is incapable of explaining them. Indeed neuroscience and neurophilosophy reject any discussion of ‘persons’ or relegate it disparagingly to what it calls ‘folk psychology’. Intentionality, as Tallis points out, is fundamental to what it means to be a human being. It lies at the heart of our self-awareness, our sense of others as beings like ourselves, and our ability to form intentions and thus become agents in the world. Consciousness is fundamentally relational. My awareness of the world stands in relation to that world and the way in which is stands out as meaningful for me. Implications – a thought experiment you can try for yourself Tallis’ critique has much in common with other critiques of scientific accounts of human experience, especially those of continental philosophers like Merleau-Ponty (1962). Both draw attention to the importance of understanding human experience as an embodied and encultured experience. This gives rise to a different way of thinking about consciousness and I want to illustrate this with a thought experiment. I would like you to look at an image that means a great deal to you. It might be a photograph of someone special, a painting, or some other image that moves you. First, I want you to ask yourself a question: how is it possible for this image to be present in front of me? In front of me is an image captured by Don McCullin, the photographer, called Shell-shocked marine, Hue, 1968 (McCullin, 2003). As I try to answer this question I think of the light falling on the marine all those years ago. I think of the camera, the lens and its optical elements, the diaphragm that set the aperture to regulate the depth of field, the shutter screen and the intricate mechanisms for controlling its speed, and thus the amount of light that reaches the film. That light impinged on the invisible silver salts in the emulsion, where photons caused physico-chemical changes that resulted in the release of visible silver particles. Then I move to the darkroom where more light and lenses, this time in an enlarger, were followed by more chemical processes as the first image developed. More recently someone has scanned the image and converted the light reflected off its surface into binary information to store and manipulate it in a computer so it can be printed out in the book that sits on my desk. Finally in this chain of causality are the events that I have just described, the light entering my eye, falling on my retina which is converted to nerve impulses that are transmitted back to the visual cortex of my brain, which lights up as I look at the image. Now I want you to look at the image again, and consider the question why is it important to you? Why does it matter? I remember vividly the first time I saw the Shell-shocked marine. I was waiting for a tram in Piccadilly Station, Manchester two a few years ago. The image was on the other side of the platform, advertising an exhibition of McCullin’s work at the Imperial War Museum North. The following weekend I had to see it. I stood in front of it and was drawn to the soldier’s eyes. Even today they strike me as intense and glazed at the same time. How can that possibly be the case? It doesn’t make sense to have eyes that are glazed and intense, but that’s how they seem to me. He stares through me, but I don’t know what he is staring at. Then it struck me; that’s not true. The truth is I’d rather not think about what he’s staring at. I dread to think about the horrors this man has witnessed, flickering in the space a thousand yards behind my head. At the same time the fixity and terror of his gaze is at odds with his appearance. He seems to have no neck. As he cowers in fear his head seems to be set directly on his shoulders, and is also somehow too big for his body. This gives him a faintly mechanical appearance, like a child’s puppet frozen in time. Perhaps that is how he sees himself, were it possible for him to have seen himself in the state he was in. Then I wonder if this is how he felt, a petrified toy soldier, an automaton without any will, under someone else’s control. His fingers curl around the barrel of his rifle as though they were carved from the same piece of wood. He is inseparable from his gun; they are one and the same. All these reflections, conflicting, paradoxical, puzzled, flashed through me the first time I saw the image. Finally I think about the man who took the photograph, of Don McCullin and the courage it took to do his work. I also think about the camera he used to capture the image. It was a Nikon F, which was tied to his life in a terrifying way. In Vietnam a sniper’s bullet hit his camera, saving his life. When I try to answer the question, how did this image come before me, I find myself making a deliberate effort to break it down into discrete stages or processes involving optics, chemistry, quantum physics and the manipulation of digital data. Each has its own set of rules and laws, ending up with the physical processes in my brain. As I try to answer the question, something changes in my relationship with the image. It is not possible for me to answer the question how did this image come before me, and be engaged with it in the way I am when I try to answer the second question, why. I have to disengage from the image so that it is no longer present to me in the way that it was when I first encountered it in Piccadilly Station, a powerful icon of war and suffering. On that first occasion the image had a powerful emotional impact on me. It stood out before me as something that I could not avoid grappling with, the soldier, the suffering he was involved with, his suffering, and the courage of the man who took the photograph. In this mode of being I am drawn into the image. It preoccupies me and fills my awareness to the exclusion of everything else, evoking a range of responses, some contradictory, but never ending. Each time I engage with it in this way I become aware of new responses, and in that sense the image is endless and never fixed, impossible to be determined. Indeed, we may see the question ‘how’ and the scientific explanations that arise from this, as simply one aspect of my continuing responses to the presence of the image before me. The neuroscience account of consciousness denies the possibility of free will. Everything that makes us human is determined by physical processes in the brain that obey natural laws. The thought experiment also questions this view of ourselves. We can choose to look at another human being as an object determined by physical laws, or as a person like but apart from ourselves, with fears, terror, hope, and in need of human comfort and care. Setting philosophical arguments aside, the clearest evidence that a neuroscientific psychiatry is seriously off track has been the rise of the survivor, service user, c/s/x, or ervaringsdeskundigen. The work of organisations like the Hearing Voices Network and the Icarus Project is proof of the sterility and lack of humanity of science-dominated psychiatry. We have a great deal to learn from this, most of all about the importance of supportive and caring human relationships in helping people who experience madness and distress.
References
Bartels, A. & Zeki, S. (2000) The Neural Basis of Romantic Love. NeuroReport, 11, 3829 – 3834.McCullin, D. (2003) Don McCullin, London, Jonathan Cape. Noë, A. (2009) Out of our Heads: Why you are not your brain, and other lesons from the biology of consciousness. New York, Hill and Wang. Merleau-Ponty, M. (1962) Phenomenology of Perception. (Trans. C. Smith), Routledge & Kegan Paul, London. Putnam, H. (1982) Reason, Truth and History. Cambridge, Cambridge University Press. Rose, N. & Abi-Rached, J. (2013) Neuro: The New Brain Sciences and the Management of the Mind. Princeton, Princeton University Press. Salimpoor, V., van den Bosch, I., Kovacevic, N., McIntosh, A., Dagher, A., and Zatorre, R. (2013) Interactions Between the Nucleus Accumbens and Auditory Cortices Predict Music Reward Value. Science Vol. 340 6129 pp. 216-219 DOI:10.1126/science.1231059 Searle, J. (1983) Intentionality: An essay in the philosophy of mind. Cambridge, Cambridge University Press. Tallis, R. (2011) Aping Mankind: Neuromania, Darwinitis and the Misrepresentation of Humanity. Durham, Acumen. (Chapter Three, pp 73 – 146) van Lutterveld, R., Diederen, K, Koops, S. et al (2013) The influence of stimulus detection on activation patterns during auditory hallucinations. Schizophrenia Research. 145, 27-32. doi: 10.1016/j.schres.2013.01.004 |
Saturday, August 3, 2013
Why Neuroscience Cannot Explain Madness
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