A perfectly matched layer (PML) absorbing material composed of a uniaxial anisotropic material is presented for the truncation of finite-difference time-domain (FDTD) lattices. It is shown that the uniaxial PML material formulation is mathematically equivalent to the perfectly matched layer method published by Berenger (see J. Computat. Phys., Oct. 1994). However, unlike Berenger's technique, the uniaxial PML absorbing medium presented in this paper is based on a Maxwellian formulation. Numerical examples demonstrate that the FDTD implementation of the uniaxial PML medium (...) is stable, equal in effectiveness as compared to Berenger's PML medium, while being more computationally efficient. (shrink)

Brian O'Shaughnessy puts forward a bold and original theory of consciousness, one of the most fascinating but puzzling aspects of human existence. He analyses consciousness into purely psychological constituents, according pre-eminence to its epistemological power; the result is an integrated picture of the conscious mind in its natural physical setting. Consciousness and the World is a rich and exciting book, a major contribution to our understanding of the mind.

The development of robots that closely resemble human beings can contribute to cognitive research. An android provides an experimental apparatus that has the potential to be controlled more precisely than any human actor. However, preliminary results indicate that only very humanlike devices can elicit the broad range of responses that people typically direct toward each other. Conversely, to build androids capable of emulating human behavior, it is necessary to investigate social activity in detail and to develop models of the cognitive (...) mechanisms that support this activity. Because of the reciprocal relationship between android development and the exploration of social mechanisms, it is necessary to establish the field of android science. Androids could be a key testing ground for social, cognitive, and neuroscientific theories as well as platform for their eventual unification. Nevertheless, subtle flaws in appearance and movement can be more apparent and eerie in very humanlike robots. This uncanny phenomenon may be symptomatic of entities that elicit our model of human other but do not measure up to it. If so, very humanlike robots may provide the best means of pinpointing what kinds of behavior are perceived as human, since deviations from human norms are more obvious in them than in more mechanical-looking robots. In pursuing this line of inquiry, it is essential to identify the mechanisms involved in evaluations of human likeness. One hypothesis is that, by playing on an innate fear of death, an uncanny robot elicits culturally-supported defense responses for coping with death’s inevitability. An experiment, which borrows from methods used in terror management research, was performed to test this hypothesis. [Thomson Reuters Essential Science Indicators: Fast Breaking Paper in Social Sciences, May 2008]. (shrink)

Recent studies of emotion mindreading reveal that for three emotions, fear, disgust, and anger, deficits in face-based recognition are paired with deficits in the production of the same emotion. What type of mindreading process would explain this pattern of paired deficits? The simulation approach and the theorizing approach are examined to determine their compatibility with the existing evidence. We conclude that the simulation approach offers the best explanation of the data. What computational steps might be used, however, in simulation-style emotion (...) detection? Four alternative models are explored: a generate-and-test model, a reverse simulation model, a variant of the reverse simulation model that employs an “as if” loop, and an unmediated resonance model. (shrink)

Mimesis as Make-Believe is important reading for everyone interested in the workings of representational art.

Recent accounts of pretense have been underdescribed in a number of ways. In this paper, we present a much more explicit cognitive account of pretense. We begin by describing a number of real examples of pretense in children and adults. These examples bring out several features of pretense that any adequate theory of pretense must accommodate, and we use these features to develop our theory of pretense. On our theory, pretense representations are contained in a separate mental workspace, a Possible (...) World Box which is part of the basic architecture of the human mind. The representations in the Possible World Box can have the same content as beliefs. Indeed, we suggest that pretense representations are in the same representational ``code'' as beliefs and that the representations in the Possible World Box are processed by the same inference and UpDating mechanisms that operate over real beliefs. Our model also posits a Script Elaborator which is implicated in the embellishment that occurs in pretense. Finally, we claim that the behavior that is seen in pretend play is motivated not from a ``pretend desire'', but from a real desire to act in a way that ®ts the description being constructed in the Possible World Box. We maintain that this account can accommodate the central features of pretense exhibited in the examples of pretense, and we argue that the alternative accounts either can't accommodate or fail to address entirely some of the central features of pretense. q 2000 Elsevier Science B.V. All rights reserved. (shrink)

The renowned philosopher Jerry Fodor, a leading figure in the study of the mind for more than twenty years, presents a strikingly original theory on the basic constituents of thought. He suggests that the heart of cognitive science is its theory of concepts, and that cognitive scientists have gone badly wrong in many areas because their assumptions about concepts have been mistaken. Fodor argues compellingly for an atomistic theory of concepts, deals out witty and pugnacious demolitions of rival theories, and (...) suggests that future work on human cognition should build upon new foundations. This lively, conversational, and superbly accessible book is the first volume in the Oxford Cognitive Science Series, where the best original work in this field will be presented to a broad readership. Concepts will fascinate anyone interested in contemporary work on mind and language. Cognitive science will never be the same again. (shrink)

Altruism has both an evolutionary and a psychological meaning. As the term is used in evolutionary theory, a trait is deemed altruistic if it reduces the fitness of the actor and enhances the fitness of someone else. In its psychological sense, the thesis that we have altruistic ultimate motives asserts that we care about the welfare of others, not just as a means of enhancing our own well-being, but as an end in itself. In Unto Others (hereafter UO), we consider (...) both evolutionary altruism (Part I) and psychological altruism (Part II) from an evolutionary perspective. We propose a multilevel selection theory to explain how altruism can evolve from group selection, based on Darwin’s solution to the problem. Our presentation of multilevel selection theory expands the range of topics beyond altruism in other respects as well. In Part I1 of UO, we evaluate the arguments, both conceptual and empirical, that philosophers and psychologists have advanced in an attempt to choose between psychological egoism and motivational pluralism. We conclude that these arguments are inconclusive. (shrink)

Drawing from religion and the human sciences, particularly psychology after Freud, the author attempts to demonstrate that the fear of death is man's central ...

Hybrid accounts of folk psychology maintain that we sometimes theorize and sometimes simulate in order to understand others. An important question is why this is the case. In this paper, I present a view according to which simulation, but not theory, plays a central role in empathy. In contrast to others taking a similar approach to simulation, I do not focus on empathy’s cognitive aspect, but stress its affective-motivational one. Simulating others’ emotions usually engages our motivations altruistically. By vicariously feeling (...) what others are feeling, we directly come to be motivated by their projects and concerns. Simulation contrasts with more theoretical approaches to psychological attribution that help us understand and explan others, but that do not move us altruistically. This helps us see why we would posit two different folk psychological approaches instead of merely one. (shrink)

In this chapter, I outline and defend a version of concept empiricism. The theory has four central tenets: Concepts represent categories by reliable causal relations to category instances; conceptual representations of category vary from occasion to occasion; these representations are perceptually based; and these representations are all learned, not innate. The last two tenets on this list have been central to empiricism historically, and the first two have been developed in more recent years. I look at each in turn, and (...) then I discuss the most obvious objection to empiricism. According to that objection, some concepts cannot be perceptually based because they represent things that are abstract, and hence unperceivable. I discuss two standard examples: democracy and moral badness. I argue that both can be explained using resources available to the empiricist. (shrink)

Conceptual integration—“blending”—is a general cognitive operation on a par with analogy, recursion, mental modeling, conceptual categorization, and framing. It serves a variety of cognitive purposes. It is dynamic, supple, and active in the moment of thinking. It yields products that frequently become entrenched in conceptual structure and grammar, and it often performs new work on its previously entrenched products as inputs. Blending is easy to detect in spectacular cases but it is for the most part a routine, workaday process that (...) escapes detection except on technical analysis. It is not reserved for special purposes, and is not costly.In blending, structure from input mental spaces is projected to a separate, “blended” mental space. The projection is selective. Through completion and elaboration, the blend develops structure not provided by the inputs. Inferences, arguments, and ideas developed in the blend can have effect in cognition, leading us to modify the initial inputs and to change our view of the corresponding situations.Blending operates according to a set of uniform structural and dynamic principles. It additionally observes a set of optimality principles. (shrink)

What is the relationship between phenomenology and intentionality? A common picture in recent philosophy of mind has been that the phenomenal aspects and the intentional aspects of mentality are independent of one another. According to this view, the phenomenal character of certain mental states or processes”states for which there is "something it is like" to undergo them—is not intentional. Examples that are typically given of states with inherent phenomenal character are sensations, such as pains, itches, and color sensations. This view (...) also asserts, on the other hand, that the intentionality of certain mental states and processes their "being about something" is not phenomenal. Beliefs and desires are the paradigm cases of intentional mental states. Although they are intentionally directed (i.e., they have aboutness) these mental states are not inherently phenomenal. There is nothing that it is like to be in such a state by virtue of which it is directed toward what it is about. We will call this picture separatism, because it treats phenomenal aspects of mentality and intentional aspects of mentality as mutually independent, and thus separable. Although there may be complex states that are both phenomenal and intentional, their phenomenal aspects and their intentional aspects are separable. Many philosophers who hold this picture have thought that these two aspects of mentality lead to quite different sorts of problems with respect to the project of “naturalizing the mental.†Proponents of separatism often hold that while the problem of naturalizing phenomenology poses great difficulties, the problem of naturalizing intentionality is much. (shrink)