Why does performing certain tasks cause the aversive experience of mental effort and concomitant deterioration in task performance? One explanation posits a physical resource that is depleted over time. We propose an alternative explanation that centers on mental representations of the costs and benefits associated with task performance. Specifically, certain computational mechanisms, especially those associated with executive function, can be deployed for only a limited number of simultaneous tasks at any given moment. Consequently, the deployment of these computational mechanisms carries (...) an opportunity cost – that is, the next-best use to which these systems might be put. We argue that the phenomenology of effort can be understood as the felt output of these cost/benefit computations. In turn, the subjective experience of effort motivates reduced deployment of these computational mechanisms in the service of the present task. These opportunity cost representations, then, together with other cost/benefit calculations, determine effort expended and, everything else equal, result in performance reductions. In making our case for this position, we review alternative explanations for both the phenomenology of effort associated with these tasks and for performance reductions over time. Likewise, we review the broad range of relevant empirical results from across sub-disciplines, especially psychology and neuroscience. We hope that our proposal will help to build links among the diverse fields that have been addressing similar questions from different perspectives, and we emphasize ways in which alternative models might be empirically distinguished. (shrink)

Neuropsychological dissociations between regular and irregular English past-tense morphology have been reported using a lexical decision task in which past-tense primes immediately precede present-tense targets. We present N400 event-related potential data from healthy participants using the same design. Both regular and irregular past-tense forms primed corresponding present-tense forms, but with a longer duration for irregular verbs. Phonological control conditions suggested that differences in formal overlap between prime and target contribute to, but do not account for, this difference, suggesting a link (...) between irregular morphology and semantics. Further analysis dividing the irregular verbs into two categories (weak irregular and strong) revealed that priming for strong verbs was reliably stronger than that for weak irregular and regular verbs, which were statistically indistinguishable from one another. We argue that, although we observe a regular-irregular dissociation, the nature of this dissociation is more consistent with single- than with dual-system models of inflectional morphology. (shrink)

Ecology is indispensable to understanding the biological world and addressing the environmental problems humanity faces. Its philosophy has never been more important. In this book, James Justus introduces readers to the philosophically rich issues ecology poses. Besides its crucial role in biological science generally, climate change, biodiversity loss, and other looming environmental challenges make ecology's role in understanding such threats and identifying solutions to them all the more critical. When ecology is applied and its insights marshalled to address these (...) problems and guide policy formation, interesting philosophical issues emerge. Justus sets them out in detail, and explores the often ethically charged dimensions of applied ecological science, using accessible language and a wealth of scientifically-informed examples. (shrink)

Robustness concepts are often invoked to manage two obstacles confronting models of ecological systems: complexity and uncertainty. The intuitive idea is that any result derived from many idealized but credible models is thereby made more reliable or is better confirmed. An appropriate basis for this inference has proven elusive. Here, several representations of robustness analysis are vetted, paying particular attention to complex models of ecosystems and the global climate. The claim that robustness is itself confirmatory because robustness analysis employs a (...) Bayesian variety-of-evidence argument is criticized, but recent overwhelming pessimism about robustness may have a silver lining. (shrink)

Therefore, the difference between the natural and the non or supernatural would not be an ontological one. The identification of kinds of complexes or ...

This book gives a detailed treatment of functional interpretations of arithmetic, analysis, and set theory. The subject goes back to Gödel's Dialectica interpretation of Heyting arithmetic which replaces nested quantification by higher type operations and thus reduces the consistency problem for arithmetic to the problem of computability of primitive recursive functionals of finite types. Regular functional interpretations, i.e. Dialectica and Diller-Nahm interpretation as well as Kreisel's modified realization, together with their Troelstra-style hybrids, are applied to constructive as well as classical (...) systems of arithmetic, analysis, and set theory. They yield relative consistency and conservativity results and closure under relevant rules of the theories in question as well as axiomatic characterizations of the functional translations. Prerequisites are: familiarity with classical and intuitionistic predicate logic, basics of computability theory, Gödel's incompleteness theorems. (shrink)

Gottfried Keller's “A Village Romeo and Juliet” contains an astonishing number of neuter terms that are of key importance to this novella. This observation is in line with Keller's predilection for miniaturized worlds and diminutives, played out in this narrative through two basic traits: the reduction of the Shakespearean tragedy to a novella that is a “village story” and the nicknames given to its female protagonist. Around one pole of neutrality the story assembles a cluster of terms that convey things (...) in an abstract, generalized manner. Other neutral nouns make deeply personal concerns look as if they were governed by some overriding, a-personal force. In this vein, the text tends to de-personalize human actions by expressing them in the grammatical form of nominalized infinitives. Inconspicuous idiomatic phrases seem to hide, as in the Freudian Id, the menacing power of the drives. Precisely by revealing that the narrative's sphere is constructed of neutral elementary particles, the text transforms and transubstantiates what it represents into the neutrality of the script. It does so solely, it seems, to make palpable that this literature is charged with the sensuality of the genders. (shrink)

Most epistemologists hold that knowledge entails belief. However, proponents of this claim rarely offer a positive argument in support of it. Rather, they tend to treat the view as obvious and assert that there are no convincing counterexamples. We find this strategy to be problematic. We do not find the standard view obvious, and moreover, we think there are cases in which it is intuitively plausible that a subject knows some proposition P without—or at least without determinately—believing that P. Accordingly, (...) we present five plausible examples of knowledge without (determinate) belief, and we present empirical evidence suggesting that our intuitions about these scenarios are not atypical. (shrink)

Ecologists have proposed several incompatible definitions of ecological stability. Emulating physicists, mathematical ecologists commonly define it as Lyapunov stability. This formalizes the problematic concept by integrating it into a well‐developed mathematical theory. The formalization also seems to capture the intuition that ecological stability depends on how ecological systems respond to perturbation. Despite these advantages, this definition is flawed. Although Lyapunov stability adequately characterizes perturbation responses of many systems studied in physics, it does not for ecological systems. This failure reveals a (...) limitation of its underlying mathematical theory, and an important difference between dynamic systems modeling in physics and ecology. *Received March 2006; revised June 2008. †To contact the author, please write to: Philosophy Department, 151 Dodd Hall, Florida State University, Tallahassee, FL 32306; e‐mail: [email protected]. (shrink)

Context: Although ethics consultation is commonplace in United States (U.S.) hospitals, descriptive data about this health service are lacking. Objective: To describe the prevalence, practitioners, and processes of ethics consultation in U.S. hospitals. Design: A 56-item phone or questionnaire survey of the "best informant" within each hospital. Participants: Random sample of 600 U.S. general hospitals, stratified by bed size. Results: The response rate was 87.4%. Ethics consultation services (ECSs) were found in 81% of all general hospitals in the U.S., and (...) in 100% of hospitals with more than 400 beds. The median number of consults performed by ECSs in the year prior to survey was 3. Most individuals performing ethics consultation were physicians (34%), nurses (31%), social workers (11%), or chaplains (10%). Only 41% had formal supervised training in ethics consultation. Consultation practices varied widely both within and between ECSs. For example, 65% of ECSs always made recommendations, whereas 6% never did. These findings highlight a need to clarify standards for ethics consultation practices. (shrink)

Perhaps no concept has been thought more important to ecological theorizing than the niche. Without it, technically sophisticated and well-regarded accounts of character displacement, ecological equivalence, limiting similarity, and others would seemingly never have been developed. The niche is also widely considered the centerpiece of the best candidate for a distinctively ecological law, the competitive exclusion principle. But the incongruous array and imprecise character of proposed definitions of the concept square poorly with its apparent scientific centrality. I argue this definitional (...) diversity and imprecision reflects a problematic conceptual indeterminacy that challenges its putative indispensability in ecology. (shrink)

Freedom interpreted as absence of restraints, as such, is a vacuous ideal. It requires reference to some setting and course of action in order to distinguish those restraints that block human effort from those, say, that support it. More broadly, this notion of freedom has little meaning and less value without some external criterion for evaluating human action and its conditions. Many thinkers have argued that the. criterion must be the absolute Truth ? truth that is unconditioned, indubitable, and imperative. (...) They have often argued that there is no freedom of error, and that the many persons who do not know such Truth are free only in obeying the few who do. This concept of freedom is often regarded as intolerable. A third possibility is to interpret freedom as a name for a range of significant alternatives for thought and action. Freedom, here, is compatible with truth interpreted in terms of the process of inquiry, rather than as substantive possession. It is a necessary condition for judging which restraints are real obstacles and which courses of action may be harmless, legitimate or good. The third meaning, especially, is illustrated with reference to the freedoms of utterance (expression) and speech (communication). (shrink)

Evolutionary psychology often does not sufficiently document the innate constraint and domain specificity required for strong adaptationist argument. We develop these criteria within the domain of music. First, we advocate combining computational, developmental, cross-cultural, and neuroscience research to address the ways in which a domain is innately constrained. Candidate constraints in music include the importance of the octave and other simple pitch ratios, the categorization of the octave into tones, the importance of melodic contour, tonal hierarchies, and principles of grouping (...) and meter. Second, we advocate combining psychological, neuroscience, and genetic research across cognitive domains to address the domain specificity of such constraints. Currently available evidence suggests that the innate constraints in music are not specific to that domain, making it unclear which domain(s) provided the relevant selection pressures. (shrink)

Methodological individualism has a long, successful, and controversial track record in the social sciences. Its record in ecology is much shorter but proving as successful and controversial with so-called individual-based models. Distinctions and debates about methodological individualism in social sciences clarify the commitments of this general, individualistic approach to modeling ecological phenomena and show that there is a lot recommending it. In particular, a representational priority on individual organisms yields a cogent albeit deflationary account of ecological emergence and helps reveal (...) how quite disparate models and theories in ecology might be unified. (shrink)

First published in 2000. Routledge is an imprint of Taylor & Francis, an informa company.