Reality and Representation Qualia, Computers, and the “Explanatory Gap” Michael Pauen Hanse Institute for Advanced Study, University of Bremen Lehmkuhlenbusch 4, D-27753 Delmenhorst, Germany Email: [email protected] Abstract · Three problems concerning the mutual called “qualia” are often regarded as something relation of reality and representation are discussed. over and above the functional properties of mental Although there is no direct access to reality, a struc- states. This makes it difficult to understand why tural similarity between reality and representation these states came into being at all; moreover it can be assumed. A holistic account of qualia can would be doubtful whether a scientific account of help to explain how this structural similarity emerg- these experiences is possible. es. On this account, qualia have a relational, not an More recent findings in AI and neurophysiology intrinsic status. A proposal is made how the “ex- planatory gap” between the first person perspective support an alternative view. This theory dispenses and neurobiological theories of brain processes with the analogy between the brain and a traditional could be closed. While corresponding with the computer. Instead, it refers to the activity states of PDP-approach in AI, the results contradict the tra- neural networks, it does not require innate programs ditional brain/computer analogy. All in all, these and symbols. This gives room for a different view considerations may help to dissolve some of the on the mutual relation between representation and philosophical puzzles around the mind/brain rela- reality which has two important aspects: on the one tionship and demonstrate that the relevant questions hand, we can ask how representation produces or can be solved by empirical research. constructs reality, conversely, it might be asked how reality produces representation. I will address the Introduction former question in section one and two of the fol- lowing paper while the latter will be discussed in Until recently, mental representations were usually the third and final part. Hence, in section one, I will regarded as discrete entities whose computation depict some basic principles of mental representa- accounts for mental processes. This view is popular tion. These principles give reason to believe that our especially among the adherents of functionalism. mental representations can be regarded as “reliable” Probably the most famous example is Jerry Fodor’s if we suppose that there is a structural analogy “language of thought” theory (see Fodor 1975; between representation and reality. In the second Fodor 1994). Following this hypothesis, the human part, I will try to demonstrate that a holistic account brain is comparable to a computer with a Turing/ of phenomenal states, the notorious qualia, can von Neuman architecture: the symbols of the “lan- make a significant contribution to an explanation of guage of thought” correspond to the symbols of a this structural analogy. Finally, I will discuss the programming language, the syntax corresponds to consequences of the present account for the debate the program-rules, and the brain corresponds to the on the so called “explanatory gap argument.” Fol- hardware (see Fodor 1994, p. 9; Fodor 1990). This lowing this argument, it is impossible to explain theory faces several problems. Apart from obvious how neurons produce consciousness. In the third differences in the architecture, it is hard to explain part, I will try to outline how the present proposal where the symbols and the program come from. can help to disentangle some of the puzzles that Fodor assumes that both are innate, but this would have stirred up this debate. seriously impair the flexibility of our mental activ- One remark concerning my use of the term “men- ities. Another problem concerns the qualitative tal representation” seems to be in place. I will use character of our conscious experiences: these so this term in a very broad sense, as a placeholder Understanding Representation in the Cognitive Sciences Edited by A. Riegler, M. Peschl, and A.von Stein. Kluwer Academic/Plenum Publishers, New York, 1999 257 258 Michael Pauen which refers to all kinds of mental states that have a take no notice of them: after all, the brain is not sen- content. Among these states are perceptions, memo- sitive to lightwaves. If it were, we could do without ries, feelings, and emotions. Moreover, it does not our eyes, but then we would have to explain how the imply any a priori constraints concerning the neural brain is able to transform lightwaves, and chances substructure or the reference to the outside world. In are that it would need, among other things, a pair of particular, the use of this term does not indicate an “mental eyes” to do so. affinity to the language of thought approach which This point does not depend on our ontological treats mental representations like the discrete sym- preferences. Even if an external stimulus pattern bols in a traditional computer architecture. It’s an would be represented by “purely mental” activities empirical question how these representations work, of a Cartesian “spirit,” the mental activities must the use of the term doesn’t imply any commitment to result from a transformation of the external pattern. a particular answer. On the other hand, if there would be a theater inside As far as the relation between mental representa- the brain where the spirit would enjoy all the tion and reality is involved, I will refer primarily to colours, odors, and sounds in small-scale format, perceptual representations. It has been argued that then all the neural activities that bring about these the term is misleading since, due to the constructive marvels were superfluous: The spirit could leave the character of mental representation, nothing is really theater and perceive the outside world directly. re-presented (This point has been argued in detail by The upshot of these considerations is that there can Thompson 1995). I agree with this, nevertheless I’ll be neither direct similarity and nor a direct compari- prefer to stick to the standard terminology. son between representation and reality. This means also that mental representation is neither principally I. Transformation and Transfer “right” nor “wrong”—these concepts just do not apply. Representation may be rich in one case, say in I will start with some fundamental considerations on humans and primates, and poor in the other, say in the mental aspects of the problem of representation, ticks or bacteria. Moreover, we might say that certain leaving questions of neural representation aside for forms of representation are more or less adequate now, if not otherwise indicated. given what we know about the needs of an organism On the face of it, our representation of reality in a certain environment: ticks are much better than might seem arbitrary since it has no direct access to humans in detecting their prospective victims the outside world but, in fact, is the product of a con- although they have a very simple sensory system. structive process (see Roth 1994, chapters 6 and 14; Any judgement on the principal “truth” or “falsity” Glasersfeld 1995). Thus, it might seem that this pro- of mental representation, however, would require an cess is not governed by the structures of reality but independent standard as to what is reality. But, unfor- only by the constraints of our neural architecture. tunately, any conceivable access to reality, and thus This might lead to the conclusion that any talk about any standard, must itself be based on mental repre- “reality” is fallacious: What is commonly regarded sentation; therefore it can’t be independent. as an independent environment is—for the most This does not mean that we have to dispense with part, at least—just a product of the human brain. our conviction that mental representation gives us On further reflection, things look a bit different, access to reality. The first reason is that any skeptical though. It is true that there is no way to “compare” objection must refer to an idea of “genuine reality” reality and representation from an independent point in order to discredit our reality as an illusion. But of view, thus it is misleading to suppose a direct what could count as a possible referent for the con- “similarity” between reality and representation if we cept of “reality” if not reality itself? The same seems mean by “similarity” something like the relation to be true for “illusion.” What would count as an between a naturalistic painting of a landscape and its “illusion” if not some view that differs from “real- real counterpart. This lack of direct similarity is ity?” It might be questionable in any particular case unavoidable because representation, no matter how whether what we see is reality or just an illusion. the physiological process is conceived of, must Nevertheless, it doesn’t make sense to say that real- imply a transformation—otherwise it would be use- ity as a whole is an illusion because this move less. Patterns of external stimuli have to be trans- destroys the distinction between illusion and reality formed into neural activities, otherwise we could on which both concepts depend. Reality and Representation Qualia, Computers, and the “Explanatory Gap” 259 Apart form these theoretical considerations, an such an approach is that it makes it difficult, if not argument can be made that pertains to some facts we impossible, to understand the acquisition of new know, or can infer, about representation. It seems symbols. Thus, it comes as no surprise that Jerry that there must be a stable connection between real- Fodor’s “language of thought” theory which ity and representation if the latter is supposed to be assumes that mental representation works with lan- successful in its function to acquire information on guage-like symbols supposes the innateness of those relevant environmental properties.