Undisturbed Upright Stance Control in the Elderly: Part 1. Age-Related Changes in Undisturbed Upright Stance Control

The authors investigated age-related changes in postural control in 33 healthy young adults (18-31 years), 29 seniors (62-75 years), and 22 elderly people (75-96 years). A force platform recorded the results. The horizontal motions of the center of gravity (CG_h) and their difference in the plane of support CP - CG_v were deduced from the complex center of pressure (CP) trajectories. With fractional Brownian modeling, one can establish that the aging process seems to induce a transition phase in which seniors take more time to initiate the corrective process in the mediolateral (ML) axis than do younger people. The elderly develop a new strategy characterized by the mobilization of higher neuromuscular energy to maintain equilibrium. In the ML axis, the larger displacements could be caused mainly by a hip strategy that could facilitate step initiation. In the anteroposterior (AP) axis, seniors and elderly individuals maintain a relative ability to stabilize their CG into the base of support compared with younger people.     

Changes of Gait Kinematics in Different Simulators of Reduced Gravity

Gravity reduction affects the energetics and natural speed of walking and running. But, it is less clear how segmental coordination is altered. Various devices have been developed in the past to study locomotion in simulated reduced gravity. However, most of these devices unload only the body center of mass. The authors reduced the effective gravity acting on the stance or swing leg to 0.16g using different simulators. Locomotion under these conditions was associated with a reduction in the foot velocity and significant changes in angular motion. Moreover, when simulated reduced gravity directly affected the swing limb, it resulted in significantly slower swing and longer foot excursions, suggesting an important role of the swing phase dynamics in shaping locomotor patterns.     

不同类型音乐对悲伤情绪舒缓作用的EEG研究

该研究采用EEG法探究音乐对悲伤情绪舒缓作用。选取中国古典、流行、摇滚及班得瑞音乐及悲伤影片。播放影片诱发悲伤情绪后,用音乐进行舒缓,同步采集脑电,分析得脑电功率谱(PS)及重心频率(GF)。结果表明,影片显著降低了GF及α频段PS;古典音乐GF最高,且诱发的α段PS最高,摇滚乐最低;脑对音乐加工的性别差异显著,半球差异不显著;主观体验悲伤度与α波PS显著负相关。所选音乐均具情绪舒缓作用,中国古典音乐最佳;α波PS,可作为反映悲伤-快乐情绪体验变化的脑电指标。     

护士工作应激与倦怠的关系

依据Maslach等的理论构想,利用中式工作倦怠量表和工作应激问卷,通过对175名护士的调查,考察工作应激与倦怠之间的关系。结果表明,奖赏不足和价值观冲突对耗竭具有显著的预测作用;工作负荷、缺乏控制和共同体瓦解对人格解体具有显著的预测作用;共同体瓦解对成就感降低具有显著的预测作用。     

Characterization Classes Defined without Equality

In this paper we mainly deal with first-order languages without equality and introduce a weak form of equality predicate, the so-called Leibniz equality. This equality is characterized algebraically by means of a natural concept of congruence; in any structure, it turns out to be the maximum congruence of the structure. We show that first-order logic without equality has two distinct complete semantics (fll semantics and reduced semantics) related by the reduction operator. The last and main part of the paper contains a series of Birkhoff-style theorems characterizing certain classes of structures defined without equality, not only full classes but also reduced ones.     

工作倦怠结构的验证性因素分析

用所编制的工作倦怠问卷,先后对541名被试的调查,对工作倦怠的结构进行探讨。结果表明,工作倦怠由耗竭、人格解体和成就感降低三个因素构成。工作倦怠的三因素结构模型在三个职业样本的验证性因素分析中都得到了支持。工作倦怠问卷的信度与效度指标也都达到了心理测量学的要求。     

ARGUMENTS FROM NOTHING: GOD AND QUANTUM COSMOLOGY

This essay explores a simple argument for a Ground of Being, objections to it, and limitations on it. It is nonsensical to refer to Nothing in the sense of utter absence, hence nothing can be claimed to come from Nothing. If, as it seems, the universe, or any physical ensemble containing it, is past‐finite, it must be caused by an uncaused Ground. Speculative many‐worlds, pocket universes and multiverses do not affect this argument, but the quantum cosmologies of Alex Vilenkin, and J. B. Hartle and Stephen Hawking, which claim that the universe came from literally nothing, would. I argue that their novel project cannot work for reasons both physical (their “nothing” is actually a vacuum state governed by eternal physical laws) and methodological (physical theory cannot explain the emergence of the physical per se). Thus my argument stands. However, as David Hume showed, a posteriori arguments like mine infer a creation, and Creator, of a certain character, namely, a stochastic concept of creation and a panentheistic, partly physical Creator lacking omniscience and omnipotence. Rather than undermining the cosmological argument, as Hume intended, these limitations liberate the concept of the Ground from unnecessary problems, as Hartshorne suggested.     

Vestibular stimulation interferes with the dynamics of an internal representation of gravity

The remembered vanishing location of a moving target has been found to be displaced downward in the direction of gravity (representational gravity) and more so with increasing retention intervals, suggesting that the visual spatial updating recruits an internal model of gravity. Despite being consistently linked with gravity, few inquiries have been made about the role of vestibular information in these trends. Previous experiments with static tilting of observers’ bodies suggest that under conflicting cues between the idiotropic vector and vestibular signals, the dynamic drift in memory is reduced to a constant displacement along the body’s main axis. The present experiment aims to replicate and extend these outcomes while keeping the observers’ bodies unchanged in relation to physical gravity by varying the gravito-inertial acceleration using a short-radius centrifuge. Observers were shown, while accelerated to varying degrees, targets moving along several directions and were required to indicate the perceived vanishing location after a variable interval. Increases of the gravito-inertial force (up to 1.4G), orthogonal to the idiotropic vector, did not affect the direction of representational gravity, but significantly disrupted its time course. The role and functioning of an internal model of gravity for spatial perception and orientation are discussed in light of the results.     

Geometric representation of association between categories

Categories can be counted, rated, or ranked, but they cannot be measured. Likewise, persons or individuals can be counted, rated, or ranked, but they cannot be measured either. Nevertheless, psychology has realized early on that it can take an indirect road to measurement: What can be measured is the strength of association between categories in samples or populations, and what can be quantitatively compared are counts, ratings, or rankings made under different circumstances, or originating from different persons. The strong demand for quantitative analysis of categorical data has thus created a variety of statistical methods, with substantial contributions from psychometrics and sociometrics. What is the common basis of these methods dealing with categories? The basic element they share is that the sample space has a special geometry, in which categories (or persons) are point masses forming a simplex, while distributions of counts or profiles of ratings are centers of gravity, which are also point masses. Rankings form a discrete subset in the interior of the simplex, known as the permutation polytope, and paired comparisons form another subset on the edges of the simplex. Distances between point masses form the basic tool of analysis. The paper gives some history of major concepts, which naturally leads to a new concept: the shadow point. It is then shown how loglinear models, Luce and Rasch models, unfolding models, correspondence analysis and homogeneity analysis, forced classification and classification trees, as well as other models and methods, fit into this particular geometrical framework.     

可以兼顾策略、认知状态和能力的CD-CAT选题方法

当CD-CAT测验需要同时诊断被试的解题策略、认知状态并评估被试的宏观能力时,就需要在选题过程中兼顾这三个测量目标。用两种不同方式将多策略香农熵(MSSHE)指标与Fisher信息量相结合,提出多策略情境中的DWI指标MSDWI)选题法与“先用MSSHE后用Fisher信息量”的两步选题法。基于多策略RRUM模型(MS-RRUM),将这两种方法与随机选题法在不同属性数量条件下进行模拟比较,结果表明：当属性数量为4个或6个时,两步选题法在策略判准率、认知状态判准率和能力估计三个方面都有最佳的效果。