Rick Grush

Consciousness and experience, William G. Lycan. Cambridge, MA: MIT Press, 1996. ISBN 0–262–12197–2 (hc)Mind as motion: explorations in the dynamics of cognition, Robert Port & Timothy Van Gelder (Eds). Cambridge, MA: MIT/Bradford, 1995. ISBN 0–262–16150–8Perception, Kathleen Akins (Ed.). New York: Oxford University Press, 1996. ISBN 0–19–508461 (hbk); 0–19–508462–4 (pbk)Context and consciousness, B. Nardi (Ed.). Cambridge, MA: MIT Press, 1996. ISBN: 0–262–14058–6Catching ourselves in the act, Horst Hendriks‐Jansen. Cambridge, MA: MIT Press, 1996. ISBN 0–262–08246–2The search for mind. A new foundation for cognitive science, Sean O'Nuallain. Norwood, NJ: Ablex, 1995Mindblindness: an essay on autism and theory of mind, Simon Baron‐Cohen. Cambridge, MA: MIT Press, 1995. ISBN 0–262–02384–9.

Sensory Individuals: Unimodal and Multimodal Perspectives provides an interdisciplinary, well-balanced, and comprehensive look at different aspects of unisensory and multisensory objects, using both nuanced philosophical analysis and informed empirical work. The research presented in this book represents the field's progression from treating neural sensory processes as primarily modality-specific towards its current state of the art, according to which perception, and its supporting neural processes, are multi-modal, modality-independent, meta-modal, and task-dependent. Even within such approaches sensory stimuli, properties, brain activations, and corresponding perceptual phenomenology can still be characterized in a modality-specific way. The book examines the basic building blocks of human perception, and whether they are best understood as sense modality dependent units of different forms or multimodal perceptual objects. The book combines a variety of innovative and integrative angles to explore the topic and acts as a catalyst for an increasingly diverse field of research, which is in an exciting phase of growth and advancement. New questions are arising as quickly as they are being answered, and the collection Sensory Individuals provides an original and up-to-date addition to the field.

This collection of new essays on sensory individuals in unimodal and multimodal perception features contributions by outstanding researchers in the fields of philosophy of perception, experimental psychology, and cognitive neuroscience. The topics investigated include conceptual, developmental, and methodological aspects of object perception, and especially how various sense modalities construct their objects from sensory features and feature bearers. The interdisciplinary approach offered has enabled new directions in research on this subject. As ordered in this volume, the topics of the contributions progress from treating neural sensory processes as primarily unisensory towards approaches that take perceptual processing to be modality-independent, meta-modal, and multimodal. Even within these latter approaches, sensory stimuli, sensory properties, brain activations, and corresponding perceptual phenomenology have often been characterized in a modality-specific way. Thus, it is timely to explore the relation between those processes that are unisensory and those that are multisensory. One of the primary themes of this collection is examining whether the basic building blocks of human perception are best understood as modality-dependent units of different forms or in terms of multimodal perceptual objects. Another theme is the relation between low-level object processing (segmentation and perceptual grouping processes) and high-level object knowledge embracing object concept and object-related expectations. A final theme is the role that perceptual objects play as loci of unification in unimodal and multimodal perception, namely that they enable binding and integration of sensory properties to individual entities or events.

b>: The problem of how physical systems, such as brains, come to represent themselves as subjects in an objective world is addressed. I develop an account of the requirements for this ability that draws on and refines work in a philosophical tradition that runs from Kant through Peter Strawson to Gareth Evans. The basic idea is that the ability to represent oneself as a subject in a world whose existence is independent of oneself involves the ability to represent space, and in particular, to represent oneself as one object among others in an objective spatial realm. In parallel, I provide an account of how this ability, and the mechanisms that support it, are realized neurobiologically. This aspect of the article draws on, and refines, work done in the neurobiology and psychology of egocentric and allocentric spatial representation

The emulation theory of representation is developed and explored as a framework that can revealingly synthesize a wide variety of representational functions of the brain. The framework is based on constructs from control theory (forward models) and signal processing (Kalman filters). The idea is that in addition to simply engaging with the body and environment, the brain constructs neural circuits that act as models of the body and environment. During overt sensorimotor engagement, these models are driven by efference copies in parallel with the body and environment, in order to provide expectations of the sensory feedback, and to enhance and process sensory information. These models can also be run off-line in order to produce imagery, estimate outcomes of different actions, and evaluate and develop motor plans. The framework is initially developed within the context of motor control, where it has been shown that inner models running in parallel with the body can reduce the effects of feedback delay problems. The same mechanisms can account for motor imagery as the off-line driving of the emulator via efference copies. The framework is extended to account for visual imagery as the off-line driving of an emulator of the motor-visual loop. I also show how such systems can provide for amodal spatial imagery. Perception, including visual perception, results from such models being used to form expectations of, and to interpret, sensory input. I close by briefly outlining other cognitive functions that might also be synthesized within this framework, including reasoning, theory of mind phenomena, and language. Key Words: efference copies; emulation theory of representation; forward models; Kalman filters; motor control; motor imagery; perception; visual imagery

[1] It is well-known that Evans laid the groundwork for a truly radical and fruitful theory of _content_ -- a theory according to which content is a genus with at least conceptual and nonconceptual varieties as species, and in which nonconceptual content plays a very significant role. It is less well-recognized that Evans was also in the process of working out the details of a truly radical and groundbreaking theory of _representation_, a task he was unfortunately unable to bring to any satisfactory stage of fruition. I am here drawing the distinction between a theory of

  I argue against a growing radical trend in current theoretical cognitive science that moves from the premises of embedded cognition, embodied cognition, dynamical systems theory and/or situated robotics to conclusions either to the effect that the mind is not in the brain or that cognition does not require representation, or both. I unearth the considerations at the foundation of this view: Haugeland's bandwidth-component argument to the effect that the brain is not a component in cognitive activity, and arguments inspired by dynamical systems theory and situated robotics to the effect that cognitive activity does not involve representations. Both of these strands depend not only on a shift of emphasis from higher cognitive functions to things like sensorimotor processes, but also depend on a certain understanding of how sensorimotor processes are implemented - as closed-loop control systems. I describe a much more sophisticated model of sensorimotor processing that is not only more powerful and robust than simple closed-loop control, but for which there is great evidence that it is implemented in the nervous system. The is the emulation theory of representation, according to which the brain constructs inner dynamical models, or emulators, of the body and environment which are used in parallel with the body and environment to enhance motor control and perception and to provide faster feedback during motor processes, and can be run off-line to produce imagery and evaluate sensorimotor counterfactuals. I then show that the emulation framework is immune to the radical arguments, and makes apparent why the brain is a component in the cognitive activity, and exactly what the representations are in sensorimotor control

Nothing is more obvious than the fact that we are able to experience events in the world such a ball deflecting from the cross-bar of a goal. But what is the temporal relation between these two things, the event, and our experience of the event? One possibility is that the world progresses temporally through a sequence of instantaneous states – the striker’s foot in contact with the ball, then the ball between the striker and the goal, then the ball in contact with the cross-bar, and so forth –, while the perceiver’s experience is likewise a sequence of experience states, each one of which corresponds to, or is experience of, a corresponding state of the world – for example, a perception of the foot in contact with the ball, followed by a perception of the ball in the air, following by a perception of the ball in contact with the cross-bar. This way of understanding the relationship between experience and the world is very natural, and nearly universal. However, it rests on two assumptions that can be brought into question.

I have argued elsewhere that imagery and represention are best explained as the result of operations of neurally implemented emulators of an agent's body and environment. In this article I extend the theory of emulation to address perceptual processing as well. The key notion will be that of an emulator of an agent's egocentric behavioral space. This emulator, when run off-line, produces mental imagery, including transformations such as visual image rotations. However, while on-line, it is used to process information from sensory systems, resulting in perception (in this regard, the theory is similar to that proposed by Kosslyn (1994)). This emulator is what provides the theory in theory-laden perception. I close by arguing briefly that the spatial character of perception is to be explained as the contribution of the egocentric behavioral space emulator

This paper is largely exegetical/interpretive. My goal is to demonstrate that some criticisms that have been leveled against the program Gareth Evans constructs in The Varieties of Reference (Evans 1980, henceforth VR) misfire because they are based on misunderstandings of Evans’ position. First I will be discussing three criticisms raised by Tyler Burge (Burge, 2010). The first has to do with Evans’ arguments to the effect that a causal connection between a belief and an object is insufficient for that belief to be about that object. A key part of Evans’ argument is to carefully distinguish considerations relevant to the semantics of language from considerations relevant to the semantics (so to speak) of thought or belief (to make the subsequent discussion easier, I will henceforth use ‘thought’ as a blanket term for the relevant mental states, including belief). I will argue that Burge’s criticisms depend on largely not taking account of Evans’ distinctions. Second, Burge criticizes Evans’ account of ‘informational content’ taking it to be inconsistent. I will show that the inconsistency Burge finds depends entirely on a misreading of the doctrine. Finally, Burge takes Evans to task for a perceived over-intellectualization in a key aspect of his doctrine. Burge incorrectly reads Evans as requiring that the subject holding a belief be engaged in certain overly intellectual endeavors, when in fact Evans is only attributing these endeavors to theorists of such a subject. Next, I turn to two criticisms leveled by John Campbell (Campbell, 1999). I will argue that Campbell’s criticisms are based on misunderstandings – though they do hit at deeper elements of Evans’ doctrine. First, Campbell reads Evans’ account of demonstrative thought as requiring that the subject’s information link to an object allows her to directly locate that object in space. Campbell constructs a case in which one tomato (a) is, because of an angled mirror, incorrectly seen as being at a location that happens to be occupied by an identical tomato (b). Campbell claims that Evans’ doctrines require us to conclude that the subject cannot have a demonstrative thought about the seen tomato (a), though it seems intuitively that such a subject would be able to have a demonstrative thought about that tomato, despite its location is inaccurately seen. I show that Evans’ position in fact allows that the subject can have a demonstrative thought about the causal-source tomato in this case because his account does not require that the location of demonstratively identified objects be immediately accurately assessed. What is crucial is that the subject have the ability to accurately discover the location. Second, Campbell criticizes Evans’ notion of a fundamental level of thought. I show that this criticism hinges on view of the nature and role of the fundamental level of thought that mischaracterizes Evans’ treatment of the notion.

Philosophy interfaces with cognitive science in three distinct but related areas. First, there is the usual set of issues that fall under the heading of philosophy of science (explanation, reduction, etc.), applied to the special case of cognitive science. Second, there is the endeavor of taking results from cognitive science as bearing upon traditional philosophical questions about the mind, such as the nature of mental representation, consciousness, free will, perception, emotions, memory, etc. Third

The question of whether time is its own best representation is explored. Though there is theoretical debate between proponents of internal models and embedded cognition proponents (e.g. Brooks R 1991 Artificial Intelligence 47 139–59) concerning whether the world is its own best model, proponents of internal models are often content to let time be its own best representation. This happens via the time update of the model that simply allows the model’s state to evolve along with the state of the modeled domain. I argue that this is neither necessary nor advisable. I show that this is not necessary by describing how internal modeling approaches can be generalized to schemes that explicitly represent time by maintaining trajectory estimates rather than state estimates. Though there are a variety of ways this could be done, I illustrate the proposal with a scheme that combines filtering, smoothing and prediction to maintain an estimate of the modeled domain’s trajectory over time. I show that letting time be its own representation is not advisable by showing how trajectory estimation schemes can provide accounts of temporal illusions, such as apparent motion, that pose serious difficulties for any scheme that lets time be its own representation.

It is an under-appreciated fact that we have no significant understanding of the neurobiological mechanisms supporting any aspect of cognition, broadly construed. The limited understanding we do have is a combination of a multitude of enticing empirical fragments, scattered sparsely on a background of noise, and a number of vastly underdetermined theoretical frameworks. But however incomplete the answers, the questions posed by cognitive neuroscience are compelling. Indeed, it is nothing less than ourselves -- our decision making abilities, our command of language, our own consciousness -- that we are seeking to understand.

I examine one of the conceptual cornerstones of the field known as computational neuroscience, especially as articulated in Churchland et al. (1990), an article that is arguably the locus classicus of this term and its meaning. The authors of that article try, but I claim ultimately fail, to mark off the enterprise of computational neuroscience as an interdisciplinary approach to understanding the cognitive, information-processing functions of the brain. The failure is a result of the fact that the authors provide no principled means to distinguish the study of neural systems as genuinely computational/information-processing from the study of any complex causal process. I then argue for two things. First, that in order to appropriately mark off computational neuroscience, one must be able to assign a semantics to the states over which an attempt to provide a computational explanation is made. Second, I show that neither of the two most popular ways of trying to effect such content assignation -- informational semantics and 'biosemantics' -- can make the required distinction, at least not in a way that a computational neuroscientist should be happy about. The moral of the story as I take it is not a negative one to the effect that computational neuroscience is in principle incapable of doing what it wants to do. Rather, it is to point out some work that remains to be done

An attempt is made to defend a general approach to the spatial content of perception, an approach according to which perception is imbued with spatial content in virtue of certain kinds of connections between perceiving organism's sensory input and its behavioral output. The most important aspect of the defense involves clearly distinguishing two kinds of perceptuo-behavioral skills—the formation of dispositions, and a capacity for emulation. The former, the formation of dispositions, is argued to by the central pivot of spatial content. I provide a neural information processing interpretation of what these dispositions amount to, and describe how dispositions, so understood, are an obvious implementation of Gareth Evans' proposal on the topic. Furthermore, I describe what sorts of contribution are made by emulation mechanisms, and I also describe exactly how the emulation framework differs from similar but distinct notions with which it is often unhelpfully confused, such as sensorimotor contingencies and forward models

b>: In this article I outline, apply, and defend a theory of natural representation. The main consequences of this theory are: i) representational status is a matter of how physical entities are used, and specifically is not a matter of causation, nomic relations with the intentional object, or information; ii) there are genuine (brain-)internal representations; iii) such representations are really representations, and not just farcical pseudo-representations, such as attractors, principal components, state-space partitions, or what-have-you;and iv) the theory allows us to sharply distinguish those complex behaviors which are genuinely cognitive from those which are merely complex and adaptive

Sensory Individuals: Unimodal and Multimodal Perspectives provides an interdisciplinary, well-balanced, and comprehensive look at different aspects of unisensory and multisensory objects, using both nuanced philosophical analysis and informed empirical work. The research presented in this book represents the field's progression from treating neural sensory processes as primarily modality-specific towards its current state of the art, according to which perception, and its supporting neural processes, are multi-modal, modality-independent, meta-modal, and task-dependent. Even within such approaches sensory stimuli, properties, brain activations, and corresponding perceptual phenomenology can still be characterized in a modality-specific way. The book examines the basic building blocks of human perception, and whether they are best understood as sense modality dependent units of different forms or multimodal perceptual objects. The book combines a variety of innovative and integrative angles to explore the topic and acts as a catalyst for an increasingly diverse field of research, which is in an exciting phase of growth and advancement. New questions are arising as quickly as they are being answered, and the collection Sensory Individuals provides an original and up-to-date addition to the field.

It is the aim of work in theoretical cognitive science to produce good theories of what exactly cognition amounts to, preferably theories which not only provide a framework for fruitful empirical investigation, but which also shed light on cognitive activity itself, which help us to understand our place, as cognitive agents, in a complex causally determined physical universe. The most recent such framework to gain significant fame is the so-called dynamical approach to cognition. Explaining and exploring DST is the purpose of the collection Mind as Motion: Explorations in the Dynamics of Cognition, edited by Robert Port and Timothy van Gelder.