Against the Additive View of Imagination

According to the additive view of sensory imagination, mental imagery often involves two elements. There is an image-like element, which gives the experiences qualitative phenomenal character akin to that of perception. There is also a non-image element, consisting of something like suppositions about the image's object. This accounts for extra-sensory features of imagined objects and situations: for example, it determines whether an image of a grey horse is an image of Desert Orchid, or of some other grey horse. The view promises to give a simple and intuitive explanation of some puzzling features of imagination, and, further, to illuminate imagination's relation to modal knowledge. I contend that the additive view does not fulfil these two promises. The explanation of how images come to be determinate is redundant: the content constituting the indeterminate mental images on which the view relies is sufficient to deliver determinate images too, so the extra resources offered by the view are not required. When applied to modal epistemology, the view either delivers implausible results or offers no distinctive insight. Since the view is sold on its explanatory merits, and since these are dubious, the additive view should be rejected.     

“转换-坚持”对低阶层健康的保护作用及其机制

低社会阶层是不良健康状况最可靠的社会决定因素之一。然而, 很少有人理解为什么同样处于低阶层, 有些个体却能保持良好的健康状况。在大量实证研究的基础上, 研究者们发现“转换-坚持”策略这一心理因素能有效保护处于逆境中的低阶层者的健康, 使其免于受到疾病的侵扰。当个体面临持续或频繁的压力时, “转换-坚持”策略减轻了下丘脑-垂体-肾上腺轴的急性生理激活, 有效抑制了低阶层面临逆境时的生理应激反应, 随着时间的推移, 阻止了致病过程的发展; 同时, 该策略还减少了低阶层者的不良健康行为, 进而对健康起到保护作用。未来研究应在深入探索核心机制基础上开发出有效的干预方案, 为解决我国相对贫困问题中的健康贫困提供新的路径。     

Bipedal Hopping Reveals Evidence of Advanced Neuromuscular Aging Among People With Mild Multiple Sclerosis

Measures of walking such as the timed 25-ft walk test (T25FWT) may not be able to detect subtle impairment in lower limb function among people with multiple sclerosis (MS). We examined bipedal hopping to determine to what extent people with mild (Expanded Disease Severity Scale ≤ 3.5) MS (n = 13) would differ compared to age-, gender-, and education-matched controls (n = 9) and elderly participants (n = 13; ≥ 70 years old). We estimated lower limb power (e.g., hop length, velocity), consistency (e.g., variability of hop length, time), and symmetry (ratio of left to right foot). Participants completed the T25FWT and, after a rest, they then hopped using both feet 4 times along the walkway. We found that although all groups scored below the 6 -s cutoff for T25FWT, the elderly group had significantly shorter hop lengths, more variability, and more asymmetry than the controls. The results of the MS group were not significantly different from the elderly or controls in most measures and most of their values fell between the control and elderly groups. Hop length, but not measures of walking predicted Expanded Disease Severity Scale score (R² = .38, p = .02). Bipedal hopping is a potentially useful measure of lower limb neuromuscular performance.     

Axiomatizing hybrid products: How can we reason many-dimensionally in hybrid logic?

The aim of this paper is to propose a two-dimensional hybrid logic in order to formalize inferences containing both spatial and temporal propositions. The semantic idea behind the proposal is to name both horizontal and vertical lines in a 2D-plane by two kinds of nominals. This is a generalization of the idea of naming a point in one-dimensional hybrid logic. I give an axiomatization of the proposed two-dimensional hybrid logic and show that it enjoys a general completeness result (called pure completeness) with respect to product Kripke frames. Moreover, in order to capture $T\times W$-frames studied by R.H. Thomason (1984), I introduce the notion of a dependent product frame, which enables us to represent the dependence of space over time. I also give a complete axiomatization of this dependent two-dimensional hybrid logic, and, as a corollary, reveal that a hybridization of $T\times W$-logic enjoys strong completeness.     

5～7岁儿童类比系统性效应的实验研究

本研究利用Gentner的理论,参考Robins的研究方法自己编制材料,以故事呈现的方式研究了5岁、6岁和7岁三个年龄组儿童的类比系统性效应。结果表明,5岁年龄组的儿童不容易进行结构映射,而6岁和7岁两个年龄组的儿童表现出比较明显的类比系统性效应。这表明在合适的年龄阶段,儿童可以理解故事中的因果关系。     

On Dynamic Topological and Metric Logics

We investigate computational properties of propositional logics for dynamical systems. First, we consider logics for dynamic topological systems (W.f), fi, where W is a topological space and f a homeomorphism on W. The logics come with ‘modal’ operators interpreted by the topological closure and interior, and temporal operators interpreted along the orbits {w, f(w), f² (w), ˙˙˙} of points w ε W. We show that for various classes of topological spaces the resulting logics are not recursively enumerable (and so not recursively axiomatisable). This gives a ‘negative’ solution to a conjecture of Kremer and Mints. Second, we consider logics for dynamical systems (W, f), where W is a metric space and f and isometric function. The operators for topological interior/closure are replaced by distance operators of the form ‘everywhere/somewhere in the ball of radius a, ‘for a ε Q ⁺. In contrast to the topological case, the resulting logic turns out to be decidable, but not in time bounded by any elementary function.     

Gentzen Calculi for the Existence Predicate

We introduce Gentzen calculi for intuitionistic logic extended with an existence predicate. Such a logic was first introduced by Dana Scott, who provided a proof system for it in Hilbert style. We prove that the Gentzen calculus has cut elimination in so far that all cuts can be restricted to very simple ones. Applications of this logic to Skolemization, truth value logics and linear frames are also discussed.     

Identical Twins,Deduction Theorems,and Pattern Functions: Exploring the Implicative BCSK Fragment of S5

We recapitulate (Section 1) some basic details of the system of implicative BCSK logic, which has two primitive binary implicational connectives, and which can be viewed as a certain fragment of the modal logic S5. From this modal perspective we review (Section 2) some results according to which the pure sublogic in either of these connectives (i.e., each considered without the other) is an exact replica of the material implication fragment of classical propositional logic. In Sections 3 and 5 we show that for the pure logic of one of these implicational connectives two – in general distinct – consequence relations (global and local) definable in the Kripke semantics for modal logic turn out to coincide, though this is not so for the pure logic of the other connective, and that there is an intimate relation between formulas constructed by means of the former connective and the local consequence relation. (Corollary 5.8. This, as we show in an Appendix, is connected to the fact that the ‘propositional operations’ associated with both of our implicational connectives are close to being what R. Quackenbush has called pattern functions.) Between these discussions Section 4 examines some of the replacement-of-equivalents properties of the two connectives, relative to these consequence relations, and Section 6 closes with some observations about the metaphor of identical twins as applied to such pairs of connectives.