Psychophysical Reduction

The Mind-Brain Identity Theory lived a short life as a respectable philosophical position in the late 1950s, until Hilary Putnam developed his famous argument on the multiple realizability of mental states. The argument was, and still is, taken as the definitive demonstration of the falsity of Identity Theory and the foundation on which contemporary functionalist computational cognitive science was to be grounded. In this paper, in the wake of some contemporary philosophers, we reopen the case for Identity Theory and offer (...) a solution to the problem of multiple realizabilty. The solution is based on the necessity, at the time of establishing identity relations, of appealing to the notions of “homology” and “analogy” developed in the nineteenth century by Richard Owen. We also suggest that these notions are useful in order to correct certain shortcomings of some recent attempts at rebutting the Multiple Realizability argument. (shrink)

From its genesis in the 1960s, the focus of inquiry in neuroscience has been on the cellular and molecular processes underlying neural activity. In this pursuit neuroscience has been enormously successful. Like any successful scientific inquiry, initial successes have raised new questions that inspire ongoing research. While there is still much that is not known about the molecular processes in brains, a great deal of very important knowledge has been secured, especially in the last 50 years. It has also attracted (...) the attention of a number of philosophers, some of whom have viewed it as evidence for a ruthlessly reductionistic program that will eventually explain how mental processes are performed in the brain in purely molecular terms. As neuroscience developed, however, there emerged a smaller group of researchers who focused on systems, behavioral, and cognitive neuroscience. These investigators have also made impressive advances in the last 50 years and they have been the focus of an even larger group of philosophers, who have appealed to systems level understanding of the brain as providing the appropriate point of connection to the information processing accounts advanced in psychology. (shrink)

Neural organization attempts to thwart, at least in part, modern neuroscientists' tendency to focus reductionistically on ever smaller microsystems. But although emphasizing higher levels of systems organization, the authors end up enforcing reductionisms of their own, principally the reduction of their domain to the study of invariable normal functioning, without explicit modeling of the deviations that constitute disease states or aging. This reductionism seriously weakens the authors' claims about the truth of their quantitative models.

Bipedalism in the earliest hominid specimens is always accompanied by the reduction of projecting canine teeth. Body size is smaller than chimpanzees or humans, but molar teeth are markedly larger. Use of a pointed stick for defensive purposes on the one hand, and digging for USOs on the other, may be why bipedalism was selected for. Passing such learned behavior to the next generation may have played a role in selecting for language.

In the light of what appear to be clear counterexamples, I argue that Jaegwon Kim’s comparative evaluation of functional reduction and reduction via necessary identities is problematic. I trace the problem to two sources: a misplaced metaphysical assumption about the explanatory role of identities and an excessively strong and narrow criterion for successful reductive explanation. Appreciating where Kim’s critique runs astray enhances our understanding of the role of necessary identities in reductive explanation.

We reconsider the Nagelian theory of reduction and argue that, contrary to a widely held view, it is the right analysis of intertheoretic reduction. The alleged difficulties of the theory either vanish upon closer inspection or turn out to be substantive philosophical questions rather than knock-down arguments.

What would be sufficient to show of some apparently higher-level property that it is 'nothing over and above' some complex configuration of more basic properties? This paper defends a new method for justifying reductions by demonstrating its comparative advantages over two methods recently defended in the literature. Unlike its rivals, what I'll call "the semantic method" makes a reduction's truth epistemically transparent without relying on conceptual analyses.

Evolutionary psychology presupposes relations between theories of different domains that the two traditional models, reduction and autonomy, cannot properly account for. We aim to construct a model of relations between theories that succeeds where traditional models fail. We show that the multiple realizability argument, on which the autonomist model is thought to rest, is compatible with reductionism and, following Kim, that an autonomist reading of the argument deprives psychology of its scientific status. We therefore opt for a reductionist model compatible (...) with functionalism and multiple realizability, but show that, within evolutionary psychology at least, the very application of the conditions of reduction requires strong interactions between psychology and various other adjacent disciplines. We also show that reduction must be preceded in evolutionary psychology by an of the reduction base, which brings still other disciplines into play. Finally, we present a model of the interaction between disciplines we believe accounts best for these relations and discuss the problems facing this kind of enterprise. (shrink)

The main message of the paper is that there is a disconnect between what many philosophers of mind think of as the scientific practice of reductive or reductionist explanation, and what the most relevant scientific work is actually like. I will sketch what I see as a better view, drawing on various ideas in recent philosophy of science. I then import these ideas into the philosophy of mind, to see what difference they make.1 At the end of the paper I (...) address a possible objection: the familiar package of ideas I reject in the philosophy of science should not be lightly discarded, because other popular views on fundamental issues depend on positions that I want to reject. I reply that those apparently attractive further ideas are not worth holding onto. (shrink)

Towards the end of Beyond Reduction Horst hypothesizes that ‘it is a general design principle of the cognitive architecture of humans that the mind possesses multiple models for understanding and interacting practically with different aspects of the world’ . The suggestion is made following a discussion of recent research in cognitive science. According to Horst, the hypothesis is also consistent with what recent non-reductionist tendencies in the philosophy of science teach us. Taken together, Horst claims these two sets of evidence (...) motivate a new post-reductionist approach to the philosophy of mind. After outlining the route Horst takes to reach this claim, I shall raise a worry I have about the claim and the route taken to it.Beyond Reduction is in three parts. Part one frames the debate. In Chapter 1 Horst notes how naturalism is a view to which nearly all philosophers of mind, some of whom hold quite disparate views, would subscribe. He formulates a schema for naturalism that he thinks most would accept: ‘naturalism about domain D is the view that all features of D are to be accommodated within the framework of nature as it is understood by the natural sciences’ . Horst acknowledges that the schema under-describes matters. The notion of ‘accommodation’ may be understood as involving either explanation or metaphysical determination; it is also unclear how we are to understand ‘the …. (shrink)

Open peer commentary on the article “A Computational Constructivist Model as an Anticipatory Learning Mechanism for Coupled Agent–Environment Systems” by Filipo Studzinski Perotto. Upshot: Constructivist theory gives a nice high-level account of how knowledge can be autonomously developed by an agent interacting with an environment, but it fails to detail the mechanisms needed to bridge the gap between low levels of sensorimotor data and higher levels of cognition. AI workers are trying to bridge this gap, using task-specific engineering approaches, without (...) any principled theory to guide them; they could use help from psychologists. (shrink)

All thinking is done by our brains. They are also responsible for our feelings of love and hate, and for our ability to make and appreciate art. But there is a popular reluctance to credit the brain with some of these so-called higher functions. We have difficulty associating our appreciation of beauty with electrical impulses propagating down nerve fibres. We don't see love as residing in the organ that is hidden away inside the skull, where it sits, shaped like a (...) boxing glove, grey, motionless, and seemingly inert. Instead, the icon of love is that fist-sized muscle in your chest. (shrink)

This chapter examines the relations between psychology and neuroscience. There is a strong philosophical intuition that direct study of the brain can and will constrain the development of psychological theory. When this intuition is tested against case studies from the psychology of perception and memory, it turns out that psychology has led the way toward knowledge of neurophysiology. The chapter presents an abstract argument to show that psychology can and must lead the way in neuroscientific study of mental function. The (...) opposing intuition is based on mainly weak arguments about the fundamentality or objectivity of physics or physiology in relation to psychology. The chapter argues that psychological phenomena are methodologically prior to neurophysiological concepts and descriptions, that psychology provides the functional descriptions that guide the behavioral brain sciences, that psychological concepts are not reducible, but that neurophysiological data and concepts are nonetheless evidentially and explanatorily relevant for psychology. (shrink)

This volume collects contributions that comprise each view point, and incorporates articles by William Bechtel, Jerry Fodor, Jaegwon Kim, Joėlle Proust, and ...

Contemporary philosophers of mind tend to assume that the world of nature can be reduced to basic physics. Yet there are features of the mind consciousness, intentionality, normativity that do not seem to be reducible to physics or neuroscience. This explanatory gap between mind and brain has thus been a major cause of concern in recent philosophy of mind. Reductionists hold that, despite all appearances, the mind can be reduced to the brain. Eliminativists hold that it cannot, and that this (...) implies that there is something illegitimate about the mentalistic vocabulary. Dualists hold that the mental is irreducible, and that this implies either a substance or a property dualism. Mysterian non-reductive physicalists hold that the mind is uniquely irreducible, perhaps due to some limitation of our self-understanding. In this book, Steven Horst argues that this whole conversation is based on assumptions left over from an outdated philosophy of science. While reductionism was part of the philosophical orthodoxy fifty years ago, it has been decisively rejected by philosophers of science over the past thirty years, and for good reason. True reductions are in fact exceedingly rare in the sciences, and the conviction that they were there to be found was an artifact of armchair assumptions of 17th century Rationalists and 20th century Logical Empiricists. The explanatory gaps between mind and brain are far from unique. In fact, in the sciences it is gaps all the way down.And if reductions are rare in even the physical sciences, there is little reason to expect them in the case of psychology. Horst argues that this calls for a complete re-thinking of the contemporary problematic in philosophy of mind. Reductionism, dualism, eliminativism and non-reductive materialism are each severely compromised by post-reductionist philosophy of science, and philosophy of mind is in need of a new paradigm. Horst suggests that such a paradigm might be found in Cognitive Pluralism: the view that human cognitive architecture constrains us to understand the world through a plurality of partial, idealized, and pragmatically-constrained models, each employing a particular representational system optimized for its own problem domain. Such an architecture can explain the disunities of knowledge, and is plausible on evolutionary grounds. (shrink)

In their recent book Philosophical Foundations of Neuroscience, Max Bennett and Peter Hacker attack neural materialism (NM), the view, roughly, that mental states (events, processes, etc.) are identical with neural states or material properties of neural states (events, processes, etc.). Specifically, in the penultimate chapter entitled “Reductionism,” they argue that NM is unintelligible, that “there is no sense to literally identifying neural states and configurations with psychological attributes.” This is a provocative claim indeed. If Bennett and Hacker are right, then (...) a sizeable number of philosophers, cognitive scientists, neuroscientists, etc., subscribe to a view that is not merely false, but strictly meaningless. In this article I show that Bennett and Hacker's arguments against NM, whether construed as arguments for the meaninglessness of or the falsity of the thesis, cannot withstand scrutiny: when laid bare they are found to rest upon highly dubious assumptions that either seriously mischaracterize or underestimate the resources of the thesis. (shrink)

In this dissertation I seek to overthrow the most sacred dogma in the philosophy of mind: the doctrine that the mind is multiply realizable. Ever since Hilary Putnam introduced Turing machine functionalism, the idea that the mind is multiply realizable has gone unquestioned, and a form of the multiple realizability thesis now permeates the thinking of most functionalists. Nevertheless, I argue, this thesis is mistaken. And precisely because multiple realizability is the main obstacle of a psychophysical reduction of the mind, (...) by undermining the multiple realizability thesis I open the way for such a reduction to take place. I argue further, however, that analog computationalism is the only form of computationalism that is compatible with psychoneural reduction. I then describe the salient properties of analog computers and explore the implications of these properties for psychoneural reduction. (shrink)

This volume is a collection of essays presented at the 31st International Wittgenstein Symposium, Kirchberg, in August 2008. It has the character of a high-quality journal issue. There is no introduction, and the papers do not all directly bear on the topic of the original conference, which was "Reduction and Elimination in Philosophy and the Sciences". In what follows, I offer a short description of each paper, and add critical remarks in some cases.

Because biologization of psychiatric constructs does not involve derivation of laws, or reduce the number of entities involved, the traditional term of ‘reduction’ should be replaced. This paper describes biologization in terms of redefinition, which involves changing the definition of terms sharing the same extension. Redefinition obtains through triangulation and calibration, that is, respectively, detection of an object from two different spots, and tweaking parameters of detection in order to optimize the picture. The unity of the different views of the (...) same object does not occur through derivation from one of them, as reduction suggests, nor does it obtain through mechanistic unity or the goal of explaining one mechanism, as the phrase ‘mosaic unity’ suggests. Instead, it depends on finding a specific angle of observation, from which linguistic consistency matches sound localization in the brain, so that all observations make sense together, just as an anamorphic picture makes clear sense only when observed from the right spot. (shrink)

This paper offers a novel view of unity in neuroscience. I set out by discussing problems with the classical account of unity-by-reduction, due to Oppenheim and Putnam. That view relies on a strong notion of levels, which has substantial problems. A more recent alternative, the mechanistic “mosaic” view due to Craver, does not have such problems. But I argue that the mosaic ideal of unity is too minimal, and we should, if possible, aspire for more. Relying on a number of (...) recent works in theoretical neuroscience—network motifs, canonical neural computations and design-principles—I then present my alternative: a “flat” view of unity, i.e. one that is not based on levels. Instead, it treats unity as attained via the identification of recurrent explanatory patterns, under which a range of neuroscientific phenomena are subsumed. I develop this view by recourse to a causal conception of explanation, and distinguish it from Kitcher’s view of explanatory unification and related ideas. Such a view of unity is suitably ambitious, I suggest, and has empirical plausibility. It is fit to serve as an appropriate working hypothesis for 21st century neuroscience. (shrink)