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. (shrink)

It is common to distinguish two great families of representation. Symbolic representations include logical and mathematical symbols, words, and complex linguistic expressions. Iconic representations include dials, diagrams, maps, pictures, 3-dimensional models, and depictive gestures. This essay describes and motivates a new way of distinguishing iconic from symbolic representation. It locates the difference not in the signs themselves, nor in the contents they express, but in the semantic rules by which signs are associated with contents. The two kinds of rule have (...) divergent forms, occupying opposite poles on a spectrum of naturalness. Symbolic rules are composed entirely of primitive juxtapositions of sign types with contents, while iconic rules determine contents entirely by uniform natural relations with sign types. This distinction is marked explicitly in the formal semantics of familiar sign systems, both for atomic first-order representations, like words, pixel colors, and dials, and for complex second-order representations, like sentences, diagrams, and pictures. (shrink)

The literature on time perception is discussed. This is done with reference both to the ''cognitive-timer'' model for time estimation and to the subjective experience of apparent duration. Three assumptions underlying the model are scrutinized. I stress the strong interplay among attention, arousal, and time perception, which is at the base of the cognitive-timer model. It is suggested that a multiplicative function of two key components (the number of subjective time units and their size) should predict apparent duration. Implications for (...) other cognitive domains are drawn, and in particular an analogy is suggested between apparent duration and apparent movement. (shrink)

It is commonly supposed that perceptual representations in some way embed concepts and that this embedding accounts for the phenomenon of seeing-as. But there are good reasons, which will be reviewed here, to doubt that perceptions embed concepts. The alternative is to suppose that perceptions are marks in a perceptual similarity space that map into locations in an objective quality space. From this point of view, there are at least three sorts of seeing-as. First, in cases of ambiguity resolution, the (...) schematicity of the figure leaves us with a choice as to where in perceptual similarity space to place a mark. Second, in cases where expertise affects perception, the accumulation of perceptual landmarks permits a more precise placement of a mark in perceptual similarity space. Third, extensive experience with an object allows similarity to that object to serve as an acquired dimension in perceptual similarity space, which in turn affects the relative similarities of other objects. This is an open access publication. (shrink)

When we imaginatively picture what might happen, we may take what we imagine to be either realistic or fantastic. A wine glass falling to the floor and shattering is realistic. A wine glass falling and morphing into a bird and flying away is fantastic. What does the distinction consist in? Two important necessary conditions are here defined. The first is a condition on the realistic representation of spatial configuration, grounded in an account of the imagistic representation of spatial configuration. The (...) second is a condition on the manner in which realistic courses of mental imagery may be grounded in remembered perceptions. This is defined in terms of an account of the representation of comparative similarity. This is an open access publication. (shrink)

Naturalist theories of representation have been attacked on the grounds of being too liberal on the minimal conditions for intentionality: they treat several states that are not representational as genuine representations. Behind this attack lies the problem of demarcation: what are the minimal conditions for intentionality that a state should satisfy to be genuinely representational? What are the limits of intentionality? This paper develops a dual proposal to solve this problem. First, I defend the explanatory role criterion in order to (...) assess proposals of minimal conditions for intentionality. I start by proposing the success pattern condition: a state represents a given external feature provided that there is a success pattern present in the behavioural output, and the system uses this state as a proxy for the presence of this external feature. However, this condition is not sufficient for minimal intentionality – there are both intentional and non-intentional success patterns. Another minimal condition is, hence, required to draw this distinction. I propose the constancy mechanism condition: a state is representational provided that the system employs a constancy mechanism in its production. The success pattern and constancy mechanism conditions jointly constitute the dual proposal for minimal intentionality. I argue that this proposal is explanatorily justified and, so, properly demarcates the limits of intentionality. (shrink)

Cohen Kadosh & Walsh (CK&W) present convincing evidence indicating the existence of notation-specific numerical representations in parietal cortex. We suggest that the same conclusions can be drawn for a particular type of numerical representation: the representation of time. Notation-dependent representations need not be limited to number but may also be extended to other magnitude-related contents processed in parietal cortex (Walsh 2003).

Realistic uses of Virtual Reality technology closely integrate user training on virtual objects with VR-assisted user interactions with real objects. This paper shows how the Interactive Theory of Perception may be extended to cover such cases. Virtual objects are explained as concrete models that have an inner generation mechanism, and the ITP is used to explain how VR users can both perceive such local CMs, and perceptually represent remote real objects. Also, concepts of modeling and representation are distinguished. The paper (...) concludes with suggestions as to how the ITP methodology developed here could be extended to iconic external representations and models generally. (shrink)

Advocates of dynamic systems have suggested that higher mental processes are based on continuous representations. In order to evaluate this claim, we first define the concept of representation, and rigorously distinguish between discrete representations and continuous representations. We also explore two important bases of representational content. Then, we present seven arguments that discrete representations are necessary for any system that must discriminate between two or more states. It follows that higher mental processes require discrete representations. We also argue that discrete (...) representations are more influenced by conceptual role than continuous representations. We end by arguing that the presence of discrete representations in cognitive systems entails that computationalism (i.e., the view that the mind is a computational device) is true, and that cognitive science should embrace representational pluralism. (shrink)

This paper considers the past and future of Psychology within Cognitive Science. In the history section, I focus on three questions: (a) how has the position of Psychology evolved within Cognitive Science, relative to the other disciplines that make up Cognitive Science; (b) how have particular Cognitive Science areas within Psychology waxed or waned; and (c) what have we gained and lost. After discussing what’s happened since the late 1970s, when the Society and the journal began, I speculate about where (...) the field is going. (shrink)

This paper puts forward a general framework for thought about human information processing. It is intended to avoid some of the problems of pipeline or stage models of function. At the same time it avoids the snare of supposing a welter of indefinitely many separate processes. The approach is not particularly original, but rather represents the common elements or presuppositions in a number of modern theories. These presuppositions are not usually explicit, however, and making them so reduces the danger of (...) slipping back into earlier modes of thought.The key point is to distinguish between persisting representations and the processes that translate one representation into another. Various classes or groups of persisting representations can be distinguished by the experimental treatments that interfere with them. In particular, there now seem to be several kinds of short-term or temporary storage, different from each other as well as from longterm memory; the translating processes also have several different modes or kinds. A particularly important aspect of the current position is that a model of this general type no longer requires some external agent to direct and control long sequences of behaviour. (shrink)

This paper puts forward a general framework for thought about human information processing. It is intended to avoid some of the problems of pipeline or stage models of function. At the same time it avoids the snare of supposing a welter of indefinitely many separate processes. The approach is not particularly original, but rather represents the common elements or presuppositions in a number of modern theories. These presuppositions are not usually explicit, however, and making them so reduces the danger of (...) slipping back into earlier modes of thought.The key point is to distinguish between persisting representations and the processes that translate one representation into another. Various classes or groups of persisting representations can be distinguished by the experimental treatments that interfere with them. In particular, there now seem to be several kinds of short-term or temporary storage, different from each other as well as from longterm memory; the translating processes also have several different modes or kinds. A particularly important aspect of the current position is that a model of this general type no longer requires some external agent to direct and control long sequences of behaviour. (shrink)

Contemporary epistemology has assumed that knowledge is represented in sentences or propositions. However, a variety of extensions and alternatives to this view have been proposed in other areas of investigation. We review some of these proposals, focusing on (1) Ryle's notion of knowing how and Hanson's and Kuhn's accounts of theory-laden perception in science; (2) extensions of simple propositional representations in cognitive models and artificial intelligence; (3) the debate concerning imagistic versus propositional representations in cognitive psychology; (4) recent treatments of (...) concepts and categorization which reject the notion of necessary and sufficient conditions; and (5) parallel distributed processing (connectionist) models of cognition. This last development is especially promising in providing a flexible, powerful means of representing information nonpropositionally, and carrying out at least simple forms of inference without rules. Central to several of the proposals is the notion that much of human cognition might consist in pattern recognition rather than manipulation of rules and propositions. (shrink)

This article critically analyses the notion of intentionality from several philosophical cognitive points of view. The authors argue that the notion of mental representation in the wider sense and intentionality in the narrower sense remains elusive despite accommodated paradoxes, improved semantic precision and more sophisticated strategies in dealing with intentionality. We will argue that different approaches to intentionality appear to be coherent in their inferences. However, most of them become contradictory and mutually exclusive when juxtaposed and applied to borderline questions. (...) While the explanatory value of both philosophy of mind as well as cognitive psychology should not be underestimated, we must note that not even hard-core neuroscience has been able to pin point what is going on in our minds, let alone come up with a clear cut explanation how it works or a definition of what thought really is. To date, however, intentionality is the best of all explanatory models regarding mental representations. (shrink)

Prior to the twentieth century, theories of knowledge were inherently perceptual. Since then, developments in logic, statis- tics, and programming languages have inspired amodal theories that rest on principles fundamentally different from those underlying perception. In addition, perceptual approaches have become widely viewed as untenable because they are assumed to implement record- ing systems, not conceptual systems. A perceptual theory of knowledge is developed here in the context of current cognitive science and neuroscience. During perceptual experience, association areas in the (...) brain capture bottom-up patterns of activation in sensory-motor areas. Later, in a top-down manner, association areas partially reactivate sensory-motor areas to implement perceptual symbols. The stor- age and reactivation of perceptual symbols operates at the level of perceptual components – not at the level of holistic perceptual expe- riences. Through the use of selective attention, schematic representations of perceptual components are extracted from experience and stored in memory (e.g., individual memories of green, purr, hot). As memories of the same component become organized around a com- mon frame, they implement a simulator that produces limitless simulations of the component (e.g., simulations of purr). Not only do such simulators develop for aspects of sensory experience, they also develop for aspects of proprioception (e.g., lift, run) and introspec- tion (e.g., compare, memory, happy, hungry). Once established, these simulators implement a basic conceptual system that represents types, supports categorization, and produces categorical inferences. These simulators further support productivity, propositions, and ab- stract concepts, thereby implementing a fully functional conceptual system. Productivity results from integrating simulators combinato- rially and recursively to produce complex simulations. Propositions result from binding simulators to perceived individuals to represent type-token relations. Abstract concepts are grounded in complex simulations of combined physical and introspective events. Thus, a per- ceptual theory of knowledge can implement a fully functional conceptual system while avoiding problems associated with amodal sym- bol systems. Implications for cognition, neuroscience, evolution, development, and artificial intelligence are explored. (shrink)