2,268 research outputs found

    Concepts and concreteness in psycholinguistics

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    This thesis is about the concrete-abstract distinction (‘concreteness’) as it applies in psycholinguistic research and theories of concepts. Concreteness is one of the most-investigated psycholinguistic variables, and is also the basis for major disputes about the nature of the human conceptual system. However, I argue that concreteness is not actually a useful construct, and that the units of the conceptual system do not neatly match up with words of natural language, as is often assumed in the experimental and theoretical literatures. I dispute evidence for ‘concreteness effects’, whereby words with high concreteness ratings exhibit processing differences relative to words with low concreteness ratings. The concreteness measure itself has statistical properties that invalidate it as a psycholinguistic tool. I report four new experiments designed to take into account these troublesome statistical properties, and maximise the chances of finding a concreteness effect. Counterintuitively, in three out of four experiments, the effect disappeared, and in the fourth it was extremely small. I suggest that evidence for concreteness effects is not as strong as it appears to be. Furthermore, even if the effects are real, current explanations of them still fail in various ways. I also consider how the concrete-abstract distinction intersects with popular theories of concepts and cognition, with an emphasis on two in particular (a Fodorian Language of Thought, and a Barsalou-ian Simulator theory). Using the alleged ‘abstract’ concept JUSTICE as an example, I argue that from the point of view of these theories, some abstract concepts are explanatorily vacuous: they do not actually offer any insight into behaviour or cognition. I conclude that although many ‘concrete’ items belong in our theories of concepts, some alleged ‘abstract’ concepts aren’t concepts at all. I explore some positive implications of this conclusion for theories of word meaning, and for theories of concepts in general

    Is there a reliability challenge for logic?

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    There are many domains about which we think we are reliable. When there is prima facie reason to believe that there is no satisfying explanation of our reliability about a domain given our background views about the world, this generates a challenge to our reliability about the domain or to our background views. This is what is often called the reliability challenge for the domain. In previous work, I discussed the reliability challenges for logic and for deductive inference. I argued for four main claims: First, there are reliability challenges for logic and for deduction. Second, these reliability challenges cannot be answered merely by providing an explanation of how it is that we have the logical beliefs and employ the deductive rules that we do. Third, we can explain our reliability about logic by appealing to our reliability about deduction. Fourth, there is a good prospect for providing an evolutionary explanation of the reliability of our deductive reasoning. In recent years, a number of arguments have appeared in the literature that can be applied against one or more of these four theses. In this paper, I respond to some of these arguments. In particular, I discuss arguments by Paul Horwich, Jack Woods, Dan Baras, Justin Clarke-Doane, and Hartry Field

    ICP polishing of silicon for high quality optical resonators on a chip

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    Miniature concave hollows, made by wet etching silicon through a circular mask, can be used as mirror substrates for building optical micro-cavities on a chip. In this paper we investigate how ICP polishing improves both shape and roughness of the mirror substrates. We characterise the evolution of the surfaces during the ICP polishing using white-light optical profilometry and atomic force microscopy. A surface roughness of 1 nm is reached, which reduces to 0.5 nm after coating with a high reflectivity dielectric. With such smooth mirrors, the optical cavity finesse is now limited by the shape of the underlying mirror

    The Uses of Argument in Mathematics

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    Stephen Toulmin once observed that `it has never been customary for philosophers to pay much attention to the rhetoric of mathematical debate'. Might the application of Toulmin's layout of arguments to mathematics remedy this oversight? Toulmin's critics fault the layout as requiring so much abstraction as to permit incompatible reconstructions. Mathematical proofs may indeed be represented by fundamentally distinct layouts. However, cases of genuine conflict characteristically reflect an underlying disagreement about the nature of the proof in question.Comment: 10 pages, 5 figures. To be presented at the Ontario Society for the Study of Argumentation Conference, McMaster University, May 2005 and LOGICA 2005, Hejnice, Czech Republic, June 200

    Counteridenticals

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    A counteridentical is a counterfactual with an identity statement in the antecedent. While counteridenticals generally seem non-trivial, most semantic theories for counterfactuals, when combined with the necessity of identity and distinctness, attribute vacuous truth conditions to such counterfactuals. In light of this, one could try to save the orthodox theories either by appealing to pragmatics or by denying that the antecedents of alleged counteridenticals really contain identity claims. Or one could reject the orthodox theory of counterfactuals in favor of a hyperintensional semantics that accommodates non-trivial counterpossibles. In this paper, I argue that none of these approaches can account for all the peculiar features of counteridenticals. Instead, I propose a modified version of Lewis’s counterpart theory, which rejects the necessity of identity, and show that it can explain all the peculiar features of counteridenticals in a satisfactory way. I conclude by defending the plausibility of contingent identity from objections

    Serum 25-Hydroxyvitamin D and Intact Parathyroid Hormone Influence Muscle Outcomes in Children and Adolescents

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    Increases in 25-hydroxyvitamin D concentrations are shown to improve strength in adults; however, data in pediatric populations are scant and equivocal. In this ancillary study of a larger-scale, multi-sited, double-blind, randomized, placebo-controlled vitamin D intervention in US children and adolescents, we examined the associations between changes in vitamin D metabolites and changes in muscle mass, strength, and composition after 12 weeks of vitamin D3 supplementation. Healthy male and female, black and white children and adolescents between the ages of 9 and 13 years from two US states (Georgia 34°N and Indiana 40°N) were enrolled in the study and randomly assigned to receive an oral vitamin D3 dose of 0, 400, 1000, 2000, or 4000 IU/d for 12 weeks between the winter months of 2009 to 2011 (N = 324). Analyses of covariance, partial correlations, and regression analyses of baseline and 12-week changes (post-baseline) in vitamin D metabolites (serum 25(OH)D, 1,25(OH)2 D, intact parathyroid hormone [iPTH]), and outcomes of muscle mass, strength, and composition (total body fat-free soft tissue [FFST], handgrip strength, forearm and calf muscle cross-sectional area [MCSA], muscle density, and intermuscular adipose tissue [IMAT]) were assessed. Serum 25(OH)D and 1,25(OH)2 D, but not iPTH, increased over time, as did fat mass, FFST, forearm and calf MCSA, forearm IMAT, and handgrip strength (p < 0.05). Vitamin D metabolites were not associated with muscle strength at baseline nor after the 12-week intervention. Changes in serum 25(OH)D correlated with decreases in forearm IMAT, whereas changes in serum iPTH predicted increases in forearm and calf MCSA and IMAT (p < 0.05). Overall, increases in 25(OH)D did not influence muscle mass or strength in vitamin D-sufficient children and adolescents; however, the role of iPTH on muscle composition in this population is unknown and warrants further investigation

    Groundwater study of the Pingrup townsite

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    A groundwater study was carried out in the townsite of Pingrup. It aimed to accelerate the implementation of effective salinity risk management. The study consisted of a drilling investigation and expansion of a piezometer network, a pumping test, groundwater flow modelling and a flood risk analysis
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