Wednesday, November 24, 2010

Out of Our Heads

So first of all, I realize that I haven't posted in forever. I am very sorry about that. My only excuse is the ungodly amount of classwork I have. But I promise, as soon as it is all done for the semester (which will only be a couple more weeks) I will be back, posting like a fiend. In the meantime, I thought some of you might find a paper I just wrote for class rather interesting. It is a review of a book by a philosopher/neuroscientist titled Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness. Obviously, it is about philosophy of consciousness/perception. I highly recommend it. If you're interested, read on; if not, no hard feelings. If you have any questions about anything in the paper, feel free to comment like usual. I'll be back with my regular posts (and the completion of the series I started long ago) soon. Stay tuned.

            Philosopher, cognitive scientist, and neuroscientist Alva Noë’s recent book Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness purports itself to be something of a game-changer in the world of neuroscience and the philosophy of perception. Says Noë in the preface: “I am writing the book to change the world. Or at least to shake up the cognitive science establishment. I am aware that that’s a tall order and that in some ways it may seem presumptuous even to try” (Noë xiv). Presumptuous indeed. I will suspend judgment on whether or not he succeeded for now. But there is no doubt that what he proposes here would certainly require a rethinking of what philosophers and scientists in the related fields have taken for granted for some time: namely that consciousness, whatever else it may be, resides in our heads. This Noë denies repeatedly and with conviction, arguing instead for what he calls variously an “ecological,” “embodied,” “enactive” approach. Here I will examine the main ideas and arguments of the book and provide some brief critical comments. As it turns out, Noë is an entertaining writer and illustrates his points well, and so I will be quoting from him extensively.
            In chapter one, “An Astonishing Hypothesis,” Noë sets forth the establishment view as epitomized by Nobel laureate Francis Crick:
you, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules…This hypothesis is so alien to the ideas of most people alive today that it can truly be called astonishing (5).
Noë disagrees. Not only is this view not “astonishing,” it is what has been assumed unquestioningly since Descartes himself, if not longer. “It isn’t surprising to be told that there is a thing inside each of us that thinks and feels and wants and decides,” says Noë (5). The only difference between this view and Descartes’ is that the “thinking thing” is now supposed to be physical rather than immaterial. But far from solving the problem of consciousness, Noë says, this distinction merely restates it in new terms. Instead, he proposes what he thinks is “a really astonishing hypothesis”:
…to understand consciousness—the fact that we think and feel and that a world shows up for us—we need to look at a larger system of which the brain is only one element. Consciousness is not something the brain achieves on its own. Consciousness requires the joint operation of brain, body, and world. Indeed, consciousness is an achievement of the whole animal in its environmental context. I deny, in short, that you are your brain…To have a mind…requires more than a brain. Brains don’t have minds; people (and other animals) do.
In essence, consciousness is not something we have somewhere inside us; it is something we do (24).
            To illustrate his point, he critiques the classic “brain in a vat” line of thought experiment, pointing out that such a thing could never amount to what we would call real consciousness without many adjustments. For one, brains don’t have faces, or any of the other markers by which humans are used to identifying consciousness. Also, in order to achieve an even remotely analogous situation to real-life brain processing, what might the vat have to look like? Says Noë, “If you actually try to think through the details of this thought experiment…it’s clear that the vat would have to be, in effect, something like a living body” (13).
            Just in case we might think the current discussion one for the academy, Noë brings it a little closer to home by highlighting direct clinical application in cases of patients diagnosed with persistent vegetative state (PVS) and locked-in syndrome. In the former, the patient is thought to be “brain-dead,” often permanently, even though the body will still often respond to external stimuli. In the latter, the patient is by all appearances vegetative, but she remains fully conscious, though unable to communicate. Patients with locked-in syndrome can sometimes learn to communicate by elaborate systems of blinking, and some have even written memoirs describing the experience. Noë asks us to imagine having a family member with such a diagnosis. Would we be content with the brain scan which tells us that our loved one has PVS rather than locked-in syndrome? Is neuronal activity as measured by positron emission tomography (PET) or functional magnetic resonance imaging (fMRI) a reliable indicator of consciousness? Reliable enough to make a life-ending decision? Of course Noë is not denying the usefulness of such imaging technology, but he is careful to remind us that it does not actually provide us with a direct picture of consciousness in action, as is so easily assumed:
Brain scans thus represent the mind at three steps of removal: they represent physical magnitudes correlated to blood flow; the blood flow in turn is correlated to neural activity; the neural activity in turn is supposed to correlate to mental activity (24).
In chapter two, “Conscious Life,” Noë offers something of a solution to the age-old philosophical problem of how we arrive at and justify the widespread belief that there are minds other than our own. Rather than attempting to solve it logically as so many before him, Noë denies the need to raise it to begin with. This is because “our commitment to other minds is…not really a theoretical commitment at all,” but rather “a presupposition of the kind of life we lead together” (32-3). The knowledge that there are minded beings other than ourselves just comes with living in the world we find ourselves in. It is not an abstract knowledge to be arrived at by inference, but rather a necessary feature of our experience, a natural element of our relationships with other persons. As Noë puts it, “I cannot both trust and love you and also wonder whether, in fact, you are alive with thought and feeling, just as I cannot dance well if I am counting steps and trying to remember what comes next” (33). Noë sees the consciousness-contained-in-the-skull establishment view as promoting a “detached, mechanistic attitude to human beings,” which essentially denies the relational nature of consciousness and encourages an unnecessary problem. Instead, he suggests that the proper perspective from which to study consciousness is the biological one, viewing the organism as a unit that is bound up with its environment. For Noë, “the problem of consciousness…is…the problem of life” (41). He apparently means this quite literally; to live is to be conscious, and vice versa. And of course to be conscious is to be intentionally and actively engaged in one’s environment. Noë grants that there are of course internal neural correlates of consciousness, but points out that “there are external correlates of consciousness too,” namely the activities in which we find ourselves engaged on a daily basis (42). This is further supported by the observation that sudden, significant changes in one’s environment, such as a move or the death of a loved one, are often devastating. This is not surprising when one considers the intimate relationship between consciousness and one’s daily routine. Such a change is quite literally to lose a part of oneself, a theme to which Noë returns frequently later in the book.
Chapter three, “The Dynamics of Consciousness,” provides additional argument for Noë’s novel approach in the form of some very interesting experiments involving ferrets, phantom limbs, and video cameras, respectively. MIT researcher Mriganka Sur “re-wired,” as it were, newborn ferrets, routing the connections between their eyes and brain so that the cells in the eye that normally made neural connections with the “visual” centers of the brain now made those connections in areas of the brain normally thought of as auditory. The result was both surprising and instructive: rather than hearing with their eyes, the ferrets developed vision, even though an entirely different area of the brain was involved. Clearly, the touted neural correlates of consciousness do not tell the whole story. What this experiment shows is that far from being sufficient for conscious experience as the establishment view would have it, “there is no necessary connection between the character of experience and the behavior of certain cells” (54).
Similarly, the phenomenon of so-called “phantom limbs” further illustrates the point. Sometimes after the amputation of a limb, the patient will report the persistence of sensations in that limb. It is not that the patient is having convincing hallucinations of feeling in the missing limb; when touched on the face, the patient actually feels a touch on the hand that is no longer there. This is presumably because the “face region” of the cortex somehow becomes entangled with the “hand region” (apparently they are next to one another), so that a touch on the face activates the hand region of the cortex (albeit by way of the face) and so produces the sensation of being touched on the missing limb. When contrasted with the ferret case, this shows that changes in the stimulation of brain areas do not always result in changes in the character of the resulting experiences.
In case we are still not convinced, Paul Bach-y-Rita’s tactile-visual sensory substitution system (TVSS) ought to do the trick. The late Bach-y-Rita was actually able to devise a system which allowed blind patients to attain some level of what can only be called vision. Basically, TVSS involves mounting a video camera on the patient’s body and wiring to it a system of vibrators that are in turn attached to the subject’s thigh or abdomen. The vibrations correspond with the visual information presented to the camera, and, remarkably, when given a little while to adjust to the system (a matter of hours or even minutes), patients are able to correctly judge the size, shape, and number of objects across the room from them, pick up objects, and even successfully swat a ball with a paddle. It is important to note that the subject is not experiencing the feeling of being touched on the abdomen and then somehow correlating this with the location of spatial objects; she reports an actual visual experience, and apparently an accurate one. As in the ferret case, the areas of the brain usually devoted to touch are changing their function in order to allow for vision. But with TVSS, the brain is not exhibiting the same sort of plasticity we see in the ferret case; it is using fully matured neuronal connections in novel ways to achieve new ends. But how can vibrations on the abdomen allow one to see? Noë is very glad you asked:
We see with Bach-y-Rita’s system because the relationship that system sets up and maintains between the perceiver and the object is, in ways that can be made precise, the sort of relation that we bear to things when we see them. What causes the effects for consciousness of neural activity in the touch-dedicated parts of the brain to change? Answer: the world and our relation to it (59).
“But,” one may object, “can we really call what TVSS accomplishes vision? After all, doesn’t seeing require the use of eyes?” In response to this, Noë points out that normal vision and what TVSS does “share a style.” That is to say, sensory stimulation in each depends on movement in much the same way: things get bigger when they move closer; they disappear when you turn away from them, etc. More to the point still, this movement is what fixes the visual character of TVSS, not the neural activity in the somatosensory cortex. In short, conscious experience is not confined to the limits of the nervous system; it is actively engaged with the world around us. Noë likens the relation between brain and consciousness to the relation between a musician and her instrument, concluding that “the idea that consciousness is a phenomenon of the brain…is as fantastic as the idea of a self-playing orchestra” (64).
            In the chapter entitled “Wide Minds,” Noë elaborates on the influence of the external world on our conscious experience. We are, he says, “tangled up…with the places we find ourselves. We are of them” (69). He illustrates this with the “rubber hand phenomenon,” in which a rubber, lifelike hand is placed on a table in front of a subject who is seated at the table, her own hands out of view under it. A second person taps the rubber hand repeatedly, while one of the subject’s hands is simultaneously tapped in synchrony, under the table. Oddly enough, the subject experiences the feeling of being tapped on the rubber hand on the table. Alternately, we may consider how our visual experience affects our auditory perception. For example, we experience dialogue in a movie as coming from the actors’ mouths, even though it is actually coming from speakers elsewhere. Similarly, the ventriloquist utilizes this phenomenon to make it seem as though her own voice is coming from the puppet. Clearly, the environment impinges heavily on conscious experience. In fact, the rubber hand case seems to suggest that “attachment or connectedness is not necessary for something to be a part of me,” or at least to be experienced as a part of me (75). But just how far Noë intends for us to take this connectedness is not entirely clear. He says later, “there is no principled reason not to think of the wristwatch, the landmarks, the pen and paper, the linguistic community, as belonging to my mind” (82). Of course he is not advocating some weak solipsism here; he is merely stressing our involvement in the world and its involvement in our conscious experience. Nonetheless, it raises the question of exactly how far our selves extend. More on this later.
            Chapter five, “Habits” expands on this theme with a thorough discussion of the role of habit—and how that habit is shaped by our environment—in our conscious experience. Noë utilizes the distinction between expert and novice, pointing out the interesting fact that for the novice, there is a positive correlation between the amount of deliberate focus on a skill and the success with which it is performed, but for the expert, the opposite is true: the correlation is negative. If an expert attempts to focus on the mechanics of a mastered skill, the performance suffers. If, however, the expert concentrates on something else, say the next pitch from the mound or the next movement in the piece of music being played, the performance improves. Noë draws the analogy between this and our being expert perceivers. Just as the expert musician is automatic and flexible in her performance, so we are with our perception. We are creatures of habit. And those habits are formed by our landscape.
            Why then do researchers persist in the establishment view that our brains are somehow sufficient for our conscious experience? In the next three chapters, “The Grand Illusion,” “Voyages of Discovery,” and “A Nothing Reserved for Everything,” Noë deals with this question. “The Grand Illusion” attacks those scientists who want to say that our perception of the external world is merely illusory, i.e. that our brain essentially creates for us a representation (and a crude one at that) of whatever may actually be out there. Noë calls this both “bad philosophy” and “bad science,” pointing out that science in principle couldn’t tell us such a thing if it wanted to, since our interaction with the world around us is presupposed by the scientific enterprise itself (146).
“Voyages of Discovery” treats the work of David Hubel and Torsten Wiesel, who in 1981 won the Nobel Prize for their research on the neurophysiology of vision. Suffice it to say that Noë is far less impressed with their work than the Nobel committee must have been, since its usefulness and relevance to visual perception essentially depends on their assumption that the mind is a product of events in the brain. Part of this assumption is the still-popular “information-processing” view of the brain, advanced by Marr and others, in which the brain and nervous system are likened to a computer. Detailed analogies are drawn between how a computer processes information and how the brain might do it. Noë does not deny that there are interesting parallels here; he merely highlights what ought to be obvious: that none of this locates seeing in the brain. In fact, it doesn’t even make sense to say that the brain is entirely responsible for seeing. “Computers can’t think on their own any more than hammers can pound in nails on their own…In any case, brains don’t think: they don’t have minds; animals do” (169).
“A Nothing Reserved for Everything” examines the final holdout of the establishment scientist: what Noë calls the “Foundation Argument.” The Foundation Argument is roughly that since we can generate experience by direct stimulation of the brain, the brain itself—and the brain alone—must be the basic ground of experience (173). For Noë, this amounts to one big non sequitur. First, being able to produce some perceptual experience in no way amounts to being able to produce anything like our full, regular experience. Second, even if we could do this, it still wouldn’t follow that the brain alone is sufficient for all of our consciousness, or even for those hallucinations (a manipulating scientist at least is required). And third, producing these experiences by direct stimulation actually involves altering already existing conscious states, not creating them out of nothing (174). Noë concludes, persuasively,
There is no empirical or philosophical justification for the idea that the brain alone is enough for consciousness…there is something perverse about the very idea that we are our brains, that the world we experience is within us. We don’t need to have the world within us: we have access to the world around us; we are open to it (181).
            In the end, Noë makes a very compelling case for an enactive approach to neuroscience and biology of consciousness. While some knowledge of the orthodox view he criticizes is assumed and helpful, his representations of it are fair and balanced. And his criticisms of it are, in my view, devastating. There just is no convincing reason that I can see to continue with the assumption (or to posit it to begin with) that the whole of our conscious experience lies within the confines of our skull. However, with the admittedly liberating insight that we are actively involved and co-determinate with our environment, the concern arises that it will now be a bit more difficult to define what exactly the limits of consciousness are, and what are the boundaries of “self.” Of course, this is no reason to abandon the paradigm shift Noë is proposing; we should not run from difficulty, after all. But if the obvious boundary of my skin is not in fact the edge of “me,” then where to draw the line after that point is not at all clear and may in fact be arbitrary. Unfortunately, Noë does not address this criticism in the book. But this is not an argument against anything he says; it is merely a concern regarding the application of his model—a model we can hope is developed and employed more widely very soon.

Noë, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness. New York: Hill and Wang, 2009.