Power Spectral Density Analysis of Lateral Human Standing Sway

A number of investigators have used power spectral density (PSD) analysis to try to identify and quantify various sensory systems which are involved in upright standing. Using PSD analysis, over a frequency range from 0.02-2.5 Hz, the present study examined two trials of lateral sway in each of 80 men. The results showed that little change occurred in PSD values between the first and second trials. Exponential curves were fit to the averaged trials data of each subject. The values of the parameter estimates obtained from the curve-fitting were regressed on the values of various direct, and derived anthropometric variables to try to explain the variance of the parameter estimates in terms of the anthropometrics. The subject’s center of gravity location accounted for no more than 15.8% of the parameter variance, whereas the remaining anthropometrics explained even less. The overall averaged data suggest that three functions (related to visual, vestibular, and proprioceptive processes) may underlie the sway pattern over this frequency range. PSD curves of individuals with a history of high-level athletic activity clearly differed from those of sedentary subjects.     

执政伦理的属性、主旨与基本论域

执政伦理关涉到执政党对执政正当性的关注与思考以及对执政未来性的预期判断,具有宽容性、制衡性和有序性等伦理属性。执政党对公权力的遵循与服从不是出于阶级意志,而是受制于正义的约束,正义理应成为执政伦理的主旨。从学科的定位看,执政伦理属于政治伦理,但是它并不是着重研究政党伦理的道德构成及其培养的方式,而是对执政的制度构成、性质及其建构所依赖的伦理价值进行研究。因此,执政伦理还应是一种制度伦理和公共伦理。     

Inverse duration effects in partial report.

In partial-report experiments, an array of stimuli is displayed briefly, followed by a probe indicating the items to be reported. When exposure duration of the array is increased, 2 contrasting outcomes have been found: Some experiments find that performance improves (direct-duration effect); others find that it deteriorates (inverse-duration effect). The objective here was to identify the reasons for the discrepant results. This was done by investigating the roles played by 5 factors that differed between the 2 sets of contrasting studies. An inverse-duration effect was obtained in each of 6 experiments; its magnitude was affected by retinal eccentricity and by the number of items denoted by the probe. The effect was independent of array configuration and of number of items in the array. The direct-duration effect was shown to arise from a confounding of exposure duration and brightness.     

Analytical Inverse Optimization in Two-Hand Prehensile Tasks

The authors explored application of analytical inverse optimization (ANIO) method to the normal finger forces in unimanual and bimanual prehensile tasks with discrete and continuously changing constraints. The subjects held an instrumented handle vertically with one or two hands. The external torque and grip force changed across trials or within a trial continuously. Principal component analysis showed similar percentages of variance accounted for by the first two principal components across tasks and conditions. Compared to unimanual tasks, bimanual tasks showed significantly more frequent inability to find a cost function leading to a stable solution. In cases of stable solutions, similar second-order polynomials were computed as cost functions across tasks and condition. The bimanual tasks, however, showed significantly worse goodness-of-fit index values. The authors show that ANIO can be used in tasks with slowly changing constraints making it an attractive tool to study optimality of performance in special populations. They also show that ANIO can fail in multifinger tasks, likely due to irreproducible behavior across trials, more likely to happen in bimanual tasks compared to unimanual tasks.     

Categoricity Spectra for Polymodal Algebras

We investigate effective categoricity for polymodal algebras (i.e., Boolean algebras with distinguished modalities). We prove that the class of polymodal algebras is complete with respect to degree spectra of nontrivial structures, effective dimensions, expansion by constants, and degree spectra of relations. In particular, this implies that every categoricity spectrum is the categoricity spectrum of a polymodal algebra.     

Inverse Images of Box Formulas in Modal Logic

We investigate, for several modal logics but concentrating on KT, KD45, S4 and S5, the set of formulas B for which ${\square B}$ is provably equivalent to ${\square A}$ for a selected formula A (such as p, a sentence letter). In the exceptional case in which a modal logic is closed under the (‘cancellation’) rule taking us from ${\square C \leftrightarrow \square D}$ to ${C \leftrightarrow D}$ , there is only one formula B, to within equivalence, in this inverse image, as we shall call it, of ${\square A}$ (relative to the logic concerned); for logics for which the intended reading of “ ${\square}$ ” is epistemic or doxastic, failure to be closed under this rule indicates that from the proposition expressed by a knowledge- or belief-attribution, the propositional object of the attitude in question cannot be recovered: arguably, a somewhat disconcerting situation. More generally, the inverse image of ${\square A}$ may comprise a range of non-equivalent formulas, all those provably implied by one fixed formula and provably implying another—though we shall see that for several choices of logic and of the formula A, there is not even such an ‘interval characterization’ of the inverse image (of ${\square A}$ ) to be found.     

Inverse relations between preference and contrast

Pigeons were trained on a multiple schedule in which two target components with identical reinforcement schedules were followed by either the same-valued schedule or by extinction. Response rate increased in both target components but was higher in the target component followed by extinction, replicating previous findings of positive anticipatory contrast. A similar design was used to study negative contrast, in that the two target components were followed either by the same-valued schedule or by a higher valued schedule. Negative contrast occurred equally, on average, in both target components, thus failing to demonstrate negative contrast that is specifically anticipatory in nature. When the stimuli correlated with the two target components were paired in choice tests, the pattern of preference was in the opposite direction. For the positive contrast procedure, no significant preference between the two target stimuli was evident. But for the negative contrast procedure, preference favored the stimulus followed by the higher valued schedule. The results demonstrate a functional dissociation between positive and negative contrast in relation to stimulus value. More generally, the results demonstrate an inverse relation between response rate and preference and challenge existing accounts of contrast in terms of the concept of relative value.     

Inverse statistics and misperception of exponential growth

Exponential growth presented by numerical series or graphs is grossly underestimated by human subjects. This misperception was considerably lessened by presenting decreasing functions; this conclusion holds for both numeric and graphic stimuli. In the numerical conditions, about 25% of the subjects performed according to the statistical norm. In contrast with previous results, considerable individual differences with respect to sensitivity for rate of growth were observed. This finding was interpreted in terms of task difficulty: Extrapolation of ascending series is too difficult a task to be discriminative. Extrapolation of descending series is much easier, and may therefore better discriminate among subjects.     

海洛因成瘾者的脑灰质密度下降

本研究对海洛因成瘾者（n=34）和无毒品依赖的正常被试（n=34）进行磁共振脑结构扫描,用基于体素的形态学测量（VBM）方法分析被试间灰质密度的差异,并考察了海洛因成瘾者用药时间与灰质密度之间的关系。结果表明,同正常对照组相比,海洛因成瘾者其额叶和颞叶下部的灰质密度显著下降。进一步分析显示,用药时间短于5年的成瘾者其灰质密度下降不明显,而用药时间5年以上的患者其灰质密度下降非常显著。本文讨论了上述结果的潜在临床价值和理论意义。     

Assessing Mathematics Misunderstandings via Bayesian Inverse Planning

Online educational technologies offer opportunities for providing individualized feedback and detailed profiles of students' skills. Yet many technologies for mathematics education assess students based only on the correctness of either their final answers or responses to individual steps. In contrast, examining the choices students make for how to solve the equation and the ways in which they might answer incorrectly offers the opportunity to obtain a more nuanced perspective of their algebra skills. To automatically make sense of step-by-step solutions, we propose a Bayesian inverse planning model for equation solving that computes an assessment of a learner's skills based on her pattern of errors in individual steps and her choices about what sequence of problem-solving steps to take. Bayesian inverse planning builds on existing machine learning tools to create a generative model relating (mis)-understandings to equation solving choices. Two behavioral experiments demonstrate that the model can interpret people's equation solving and that its assessments are consistent with those of experienced teachers. A third experiment uses this model to tailor guidance for learners based on individual differences in misunderstandings, closing the loop between assessing understanding, and using that assessment within an educational technology. Finally, because the bottleneck in applying inverse planning to a new domain is in creating the model of possible student misunderstandings, we show how to combine inverse planning with an existing production rule model to make inferences about student misunderstandings of fraction arithmetic.     

Inverse target- and cue-priming effects of masked stimuli

The processing of a visual target that follows a briefly presented prime stimulus can be facilitated if prime and target stimuli are similar. In contrast to these positive priming effects, inverse priming effects (or negative compatibility effects) have been found when a mask follows prime stimuli before the target stimulus is presented: Responses are facilitated after dissimilar primes. Previous studies on inverse priming effects examined target-priming effects, which arise when the prime and the target stimuli share features that are critical for the response decision. In contrast, 3 experiments of the present study demonstrate inverse priming effects in a nonmotor cue-priming paradigm. Inverse cue-priming effects exhibited time courses comparable to inverse target-priming effects. Results suggest that inverse priming effects do not arise from specific processes of the response system but follow from operations that are more general.     

群体印象形成与个体印象形成：反基准比率效应

采用 “反基准比率效应”范式考察在群体印象形成与个体印象形成两种认知加工过程中, 基准比率对印象形成过程及其结果的影响。被试分别为39名19~25岁大学生(实验1：男生17名, 女生22名, 均为右利手)以及46名19~25岁大学生(实验2：男生21名, 女生25名, 均为右利手)。结果发现：无论是群体印象形成还是个体印象形成, 在学习阶段, 知觉者都能准确认知各类事件间的关系, 但会优先建构高频事件间的联结。而在测试阶段, 当低频事件与高频事件同时出现时, 知觉者发生明显关系误判, 即以反基准比率的倾向高估低频事件间的联结强度。实验表明群体与个体印象形成过程中都会产生反基准比率效应这样的加工偏差, 进而初步揭示反基准比率现象在社会信息加工领域具有一定的普遍性。     

Information Density and Syntactic Repetition

In noun phrase (NP) coordinate constructions (e.g., NP and NP), there is a strong tendency for the syntactic structure of the second conjunct to match that of the first; the second conjunct in such constructions is therefore low in syntactic information. The theory of uniform information density predicts that low‐information syntactic constructions will be counterbalanced by high information in other aspects of that part of the sentence, and high‐information constructions will be counterbalanced by other low‐information components. Three predictions follow: (a) lexical probabilities (measured by N‐gram probabilities and head‐dependent probabilities) will be lower in second conjuncts than first conjuncts; (b) lexical probabilities will be lower in matching second conjuncts (those whose syntactic expansions match the first conjunct) than nonmatching ones; and (c) syntactic repetition should be especially common for low‐frequency NP expansions. Corpus analysis provides support for all three of these predictions.     

Inverse reference in subtraction performance: An analysis from arithmetic word problems

Studies of elementary calculation have shown that adults solve basic subtraction problems faster with problems presented in addition format (e.g., 6?+?_?=?13) than in standard subtraction format (e.g., 13 – 6?=?_). Therefore, it is considered that adults solve subtraction problems by reference to the inverse operation (e.g., for 13 – 6?=?7, “I know that 13 is 6?+?7”) because presenting the subtraction problem in addition format does not require the mental rearrangement of the problem elements into the addition format. In two experiments, we examine whether adults' use of addition to solve subtractions is modulated by the arrangement of minuend and subtrahend, regardless of format. To this end, we used arithmetic word problems since single-digit problems in subtraction format would not allow the subtrahend to appear before the minuend. In Experiment 1, subtractions were presented by arranging minuend and subtrahend according to previous research. In Experiment 2, operands were reversed. The overall results showed that participants benefited from word problems where the subtrahend appears before the minuend, including subtractions in standard subtraction format. These findings add to a growing body of literature that emphasizes the role of inverse reference in adults' performance on subtractions.