Gerald M.Edelmann A UNIVERSE OF CONSCIOUSNESS Basic 2000

The Special Problem of Consciousness . pg. 10  Science has always tried to eliminate the subjective from its description of the world. But what if subjectivity itself is its subject? In this chapter, we first explore the special status of consciousness and the assamptions necessary to study it from a scientific point of view.  We then examine a fundamental problem posed by the existence of consciousness?one that needs to be explained by any scientific account. Consider this simple example: Why is it that when each of us performs certain discriminations, such as between light and dark, each of us is conscious, but a similar discrimination performed by a simple physical device is apparently not associated with conscious experience?  This paradox suggests that attempts to understand consciousness that rely on the intrinsic properties of certain neurons or certain areas of the brain are doomed to failure.  Next, we discuss the kinds of new approaches required if the bases of consciousness are to be understood. Finally, we delineate our strategy ? to identify and characterize not just the neurons but the neural processes that can account for key properties of conscious experience. ______________________________________________________ We have looked at some of the obvious difficulties and uncertainties faced by both philosophers and scientists when dealing with consciousness. It is important to recognize the origin of these difficulties.  Consciousness poses a special problem that is not encountered in other domains of science. In physics and chemistry, we are used to explaining certain entities in terms of other entities and laws. We can describe water with ordinary language, but we can also describe water, at least in principle, in terms of atoms and the laws of quantum mechanics. What we are really doing is connecting two levels of description of the same external entity - a commonplace one and a scientific one that is enormously powerful and predictive.  Both levels of description?liquid water, or a particolar arrangement of atoms behaving according to the laws of quantum mechanics?refer to an entity that is out there and that is assumed to exist independently of a conscious observer. When we come to consciousness, however, we encounter an asymmetry. What we are trying to do is not just to understand how the behavior or cognitive operations of another human being can be explained in terms of the working of his or her brain, however daunting that task may be. We are not just trying to connect a description of something out there with a more sophisticated scientific description.  Instead, we are trying to connect a description of something out there?the brain?with something in here?an experience, our own individual experience, that is occurring to us as conscious observers.  We are trying to get inside?to know, as the philosopher Thomas Nagel felicitously phrased it?what it is like to be a bat.' We know what it is like to be us, bot we would like to explain why we are conscious at all, why there is "something" it is like to be us? to explain how subjective, experiential qualities are generated. In short,  we wish to explain the "I think therefore I am" that Descartes posited as the first, indisputable evidence upon which any philosophy should be built. No amount of description will ever be able to account fully for a subjective experience, no matter how accurate that description may be.  Many philosophers have used the example of color to make their point. No scientific description of the neural mechanisms of color discrimination, even if it is perfectly satisfactorv, will make you understand what it feels like to perceive a particular color. No amount of description or theorizing, scientific or otherwise, will allow a color-blind person to experience color. In a famous philosophical thought experiment, Mary, a color-blind neuroscientist of the foture, knows everything about the visual svstem and the brain, including the physiology of color discrimination. Yet, when she finally regains color vision, all her knowledge in no way substitutes for her genuine experience of color, for the way it feels like to see a color. John Locke clearly anticipated this problem long ago: A studious blind man, who had mightily beat his head about visible objects, and made use of the explication of his books and friends, to understand those names of light and colours which often came in his way, bragged one day, that he now understood what scarlet signified. upon w hich his friend demanding, what scarlet was? the blind man answered, It was like the sound of a trumpet. Locke also anticipated the so-called inverted spectrum argument, the idea that behavior may be identical, but subjective experience may be different, by wondering whether "the same object should produce in several men's minds different ideas at the same time; for example, the idea, that a violet produces in one man's mind by his eyes, were the same that a marigold produced in another man's, and vice versa." Philosophers have also imagined another conundrum, namely, the possilility of "zombies," creatures who look act, and speak exactly like us, except for the fact that they are not conscious?that is, there is nothing it is like to be them. In fact, if one is a philosopher, one can easily imagine that everybody is a zombie (there would really be no way to find out) and that everybody's behavior could be described in terms of neurophysiology. But what about ourselves? We emphatically are conscious; we are not zombies. Yet no amount of description can account for the occurrence of first-person, phenomenal experience.   THE CONSCIOUS OBSERVER AND SOME METHODOLOGICAl ASSUMPTIONS Is a satisfactory scientific account of consciousness thus forever out of reach? Is there no way to untie the world knot? Or is there a way to break through both theoretically and experimentally to resolve the paradoxes of conscious awareness?  The answer, we believe, lies in recognizing what scientific explanations in general can and cannot do. Scientific explanations can provide the conditions that are necessary and sufficient for a phenomenon to take place, can explain the phenomenon's properties, and can even explain why the phenomenon takes place only under those conditions.  But no scientific description or explanation can substitute for the real thing.  We all accept this fact when we consider, say, the scientific description of a hurricane: what kind of physical process it is, why it has the properties it has, and under what conditions it may form. But nobody expects that a scientific description of a hurricane will be or cause a hurricane. Why, then, should w e not apply exactly the same standards to consciousness?  We should provide an adequate description of what kind of physical process it is, why it has the properties it has, and under what conditions it may occur.  As we shall see, there is nothing about consciousness that precludes an adequate scientific description of the particular kind of neural process it corresponds to. What, then, is special about consciousness?  What is special about consciousness is its relationship to the scientific observer. ^ Unlike any other object of scientific description, the neural process we are attempting to characterize when we study the neural basis of consciousness actually refers to ourselves?it is ourselves?conscious observers. We cannot therefore tacitly remove ourselves as conscious observers as we do when we investigate other scientific domains. Unlike any other entity, which we can describe in two different ways, commonsensically or scientifically as an outside object, with consciousness we are what we describe scientifically. This statement recognizes the special epistemic status of consciousness.  If we accept it and devise new methods of description, we can avoid many paradoxes and, unencumbered by philosophical roadblocks, can still attempt to provide a satisfactory scientific account of consciousness as we do for any other scientific object: what kind of physical process it is, why it has the properties it has, and under what conditions it may occur. As we shall see, to do so, we have to develop a new view of how the observer may usefully investigate consciousness. Before addressing this task, we adopt three related working assumptions as a methodological platform for the rest of this book:  the physics assumption,  the evolutionary assumption, and  the qualia assumption. THE PHYSICS ASSUMPTION The physics assumption states that only conventional physical processes are required for a satisfactory explanation of consciousness?no dualism is allowed. In particular, we assume that  consciousness is a special kind of physical process that arises in the structure and dynamics of certain brains.  The question is, of course, just what kind of physical process? In chapter 3 we note that conscious experience as a physical process can be characterized by certain general or fundamental properties. Two such properties are that  conscious experience is integrated (conscious states cannot be subdivided into independent components) and, at the same time, is highly differentiated (one can experience billions of different conscious states).  The scientific task, then, is to describe what particular kind of physical process can simultaneously account for these properties. THE EVOLUTIONARY ASSUMPTION The evolutionary assumption states that  consciousness evolved during natural selection in the animal kingdom.  This assumption implies that consciousness is associated with biological structures, that it depends on dynamic processes generated by a certain morphology. Insofar as that morphology is the product of evolutionary selection, consciousness is not only such a product but it influences behaviors that are subject both to natural selection and to selective events within an individual animal's lifetime. Consciousness is efficacious. The evolutionary assumption also implies that because  consciousness is a relatively recent development, not all animal species share it.  This assumption about the evolutionary origin of consciousness helps us avoid fruitless efforts, such as attempting to characterize consciousness as a by-product of computation or applying exotic scientific notions like quantum gravity while ignoring neurology. THE QUALIA ASSUMPTION Finally, in accord with our wiew of the conscious observer, the qualia assumption states that  the subjective, qualitative aspects of consciousness, being private, cannot be communicated directly through a scientific theory that, by its nature, is public and intersubjective.  Accepting this assumption does not mean that the necessary and sufficient conditions for consciousness cannot be described, only that describing them is not the same as generating and experiencing them. As we shall see, qualia can be considered forms of multidimensional discrimination that are carried out by a complex brain.  We can analyze them and give a prescription for how they emerge, but obviously we cannot give rise to them without first giving rise to appropriate brain structures and their dynamics within the body of an individual organism.  This assumption helps us avoid the notion that a successful scientific theory of consciousness can act as a surrogate for conscious experience itself or allow one to grasp the expenence of any quale simply on the basis of scientific descriptions and hypotheses, however pertinent they may be. Exploring the philosophical implications of these assumptions in any depth would lead us into territories of ontology and epistemology that would distract us from our main task?a scientific explanation of consciousness and its properties. We therefore forgo the discussion of several interesting corollaries, which we consider only at the end of the book. Here, we simply mention useful points that will help us keep in mind the proper order of things. These points follow from our three methodological assumptions and, as we shall see, are important in understanding the special problems that must be addressed by a scientific analysis of consciousness. To avoid becoming mired too deeply in philosophical arguments, we should ponder the following: Being and Describing. Being comes first, describing second. If consciousness is a physical process, albeit a special one, only embodied beings can experience consciousness as individuals, and formal descriptions cannot supplant or provide such experience. No description can take the place of the individual subjective experience of conscious qualia.  The physicist Schrödinger once put it this way: No scientific theory itself contains sensations and perceptions. As the evolutionary assumption reminds us, not only is it impossible to generate being by mere describing, but, in the proper order of things, being precedes describing both ontologically and chronologically.   Doing and Understanding. A biological observation that is also connected to the evolutionary assumption is that during learning and in many matters of human comprehension, doing generally precedes understanding.  This is one of the great insights derived from studies of animal learning (animals can solve problems that they certainly do not understand logically); from psychophysiological studies of normal human subjects and those with certain kinds of frontal lesions (we choose the right strategy before we understand why); from studies of artificial grammar (we use a rule before we understand what it is); and, finally, in innumerable studies of cognitive development (we learn how to speak before we know anything about syntax). Although this order can occasionally be inverted in linguistic animals such as ourselves, doing almost always comes first. This insight is important for the case we are making, since it helps avoid the difficulties encountered by formulations based on physics and artificial intelligence that do not take embodiment and action into account but instead assume that our perception and behavior are the result of a coded program.   Selectionism and Logic. The physics and evolutionary assumptions make explicit claims about what comes first and what follows. In other words, they force us to consider what is historically, pragmatically, and ontologically prior and what is derivative.  Logic is, for example, a human activity of great power and subtelty. If the evolutionary assumption is correct, however, we can conclude that the workings of logic are not necessary for consciousness.  Logic is not necessary for the emergence of animal bodies and brains, as it obviously is to the construction and operation of a computer. The emergence of higher brain functions depended instead on natural selection and other evolutionary mechanisms. Moreover, as we shall see, selectional principles akin to those of evolution apply to the actual workings of individual human brains well before they operate according to logic. This view has been called selectionism. To encapsulate our position: Selectionism precedes logic. Later, we suggest that selectionist principles and logical principles each underlie powerful modes of thought. Now, however, it is essential to grasp that selectionist principles apply to brains and that logical ones are learned later by individuals with brains.  Only with such notions in mind can one avoid the paradoxes that result from attempts to explain consciousness solely in terms of computation.

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