The Fictionalist’s Attitude Problem

According to John Mackie, moral talk is representational (the realists go that bit right) but its metaphysical presuppositions are wildly implausible (the non-cognitivists got that bit right). This is the basis of Mackie’s now famous error theory: that moral judgments are cognitively meaningful but systematically false. Of course, Mackie went on to recommend various substantive moral judgments, and, in the light of his error theory, that has seemed odd to a lot of folk. Richard Joyce has argued that Mackie’s approach can be vindicated by a fictionalist account of moral discourse. And Mark Kalderon has argued that moral fictionalism is attractive quite independently of Mackie’s error-theory. Kalderon argues that the Frege–Geach problem shows that we need moral propositions, but that a fictionalist can and should embrace propositional content together with a non-cognitivist account of acceptance of a moral proposition. Indeed, it is clear that any fictionalist is going to have to postulate more than one kind of acceptance attitude. We argue that this double-approach to acceptance generates a new problem – a descendent of Frege–Geach – which we call the acceptance–transfer problem. Although we develop the problem in the context of Kalderon’s version of non-cognitivist fictionalism, we show that it is not the non-cognitivist aspect of Kalderon’s account that generates the problem. A closely related problem surfaces for the more typical variants of fictionalism according to which accepting a moral proposition is believing some closely related non-moral proposition. Fictionalists of both stripes thus have an attitude problem.

Error analysis of digital filters using HOL theorem proving

When a digital filter is realized with floating-point or fixed-point arithmetics, errors and constraints due to finite word length are unavoidable. In this paper, we show how these errors can be mechanically analysed using the HOL theorem prover. We first model the ideal real filter specification and the corresponding floating-point and fixed-point implementations as predicates in higher-order logic. We use valuation functions to find the real values of the floating-point and fixed-point filter outputs and define the error as the difference between these values and the corresponding output of the ideal real specification. Fundamental analysis lemmas have been established to derive expressions for the accumulation of roundoff error in parametric Lth-order digital filters, for each of the three canonical forms of realization: direct, parallel, and cascade. The HOL formalization and proofs are found to be in a good agreement with existing theoretical paper-and-pencil counterparts.     

心理测量本身及其在应用中的问题

从三个维度对心理测量进行了探讨：由理论基础上的缺陷所导致的局限性、在应用中所带来的问题以及由于运用统计相关分析所带来的弊端。最后对克服这些局限性的其它方法做简单介绍。     

考试抄袭识别的心理测量学研究回顾

考试抄袭是最难识别的作弊方式。抄袭统计量（ACS）和人员拟合统计量（PFS）是识别抄袭的两类主要统计方法。ACS是根据被怀疑抄袭者与被抄袭者实际得分模式相似的概率来识别抄袭者。PFS 则把一个观察的项目得分模式与一定的测量模型相对比,来检验被试得分模式是否与测量模型预测的模式相吻合。其中,PFS由于在识别异常得分模式时存在一些干扰因素,所以对结果的解释存在多样性,应用较少。ACS是专门用于识别抄袭的统计方法,研究表明其识别率更高。目前ACS指标在美国的SAT和一些资格认证考试中已经得到广泛应用     

多目标觉知范式检验视觉意识容量

采用一种新的多目标觉知范式检验视觉意识容量。实验中首先迅速呈现包含8个刺激的圆形阵列（刺激位置随机分布）,然后所有刺激被灰色的圆覆盖,并随机选取阵列中的一个刺激作为目标,要求被试用尽可能少的点击次数找到目标。结果发现,即使被试不能一次击中目标,其也可能拥有对目标不精确的视觉信息。这些不精确的视觉信息能够帮助被试用更少的点击次数和更短的点击距离找到目标,且被试对这些不精确的视觉信息是有意识的。研究结果表明视觉意识能够以概率性的表征存在,并支持视觉整体统计假说,也能够进一步解释视觉意识容量的主观测量和客观测量之间存在的冲突。     

Parameter Inference for Computational Cognitive Models with Approximate Bayesian Computation

This paper addresses a common challenge with computational cognitive models: identifying parameter values that are both theoretically plausible and generate predictions that match well with empirical data. While computational models can offer deep explanations of cognition, they are computationally complex and often out of reach of traditional parameter fitting methods. Weak methodology may lead to premature rejection of valid models or to acceptance of models that might otherwise be falsified. Mathematically robust fitting methods are, therefore, essential to the progress of computational modeling in cognitive science. In this article, we investigate the capability and role of modern fitting methods—including Bayesian optimization and approximate Bayesian computation—and contrast them to some more commonly used methods: grid search and Nelder–Mead optimization. Our investigation consists of a reanalysis of the fitting of two previous computational models: an Adaptive Control of Thought—Rational model of skill acquisition and a computational rationality model of visual search. The results contrast the efficiency and informativeness of the methods. A key advantage of the Bayesian methods is the ability to estimate the uncertainty of fitted parameter values. We conclude that approximate Bayesian computation is (a) efficient, (b) informative, and (c) offers a path to reproducible results.     

Perception of ensemble statistics requires attention

To overcome inherent limitations in perceptual bandwidth, many aspects of the visual world are represented as summary statistics (e.g., average size, orientation, or density of objects). Here, we investigated the relationship between summary (ensemble) statistics and visual attention. Recently, it was claimed that one ensemble statistic in particular, color diversity, can be perceived without focal attention. However, a broader debate exists over the attentional requirements of conscious perception, and it is possible that some form of attention is necessary for ensemble perception. To test this idea, we employed a modified inattentional blindness paradigm and found that multiple types of summary statistics (color and size) often go unnoticed without attention. In addition, we found attentional costs in dual-task situations, further implicating a role for attention in statistical perception. Overall, we conclude that while visual ensembles may be processed efficiently, some amount of attention is necessary for conscious perception of ensemble statistics.     

On the asymptotic distribution of Pearson’s X 2 in cross-validation samples

In categorical data analysis, two-sample cross-validation is used not only for model selection but also to obtain a realistic impression of the overall predictive effectiveness of the model. The latter is of particular importance in the case of highly parametrized models capable of capturing every idiosyncracy of the calibrating sample. We show that for maximum likelihood estimators or other asymptotically efficient estimators Pearson's X ² is not asymptotically chi-square in the two-sample cross-validation framework due to extra variability induced by using different samples for estimation and goodness-of-fit testing. We propose an alternative test statistic, X _xval ², obtained as a modification of X ² which is asymptotically chi-square with C−1 degrees of freedom in cross-validation samples. Stochastically, X _xval ² ≤ X ². Furthermore, the use of X ² instead of X _xval ² with a χ _C −1² reference distribution may provide an unduly poor impression of fit of the model in the cross-validation sample. This paper is dedicated to the memory of Michael V. Levine. Requests for reprints should be sent to Albert Maydeu-Olivares, Faculty of Psychology, University of Barcelona, P. Valle de Hebrón, 171, 0835 Barcelona, Spain.     

Initial development and validity evidence for the processes of change in Psychological Skills Training Questionnaire

ObjectivesThe purpose of this study was to create and provide validity evidence for the Processes of Change in Psychological Skills Training Questionnaire (PCPSTQ).DesignThe current study used a cross-sectional research design.MethodsFive hundred fifty nine NCAA Division I, professional, and Olympic level athletes participated in the current study. To create the PCPSTQ, an initial pool of 114 items was generated by the research team. After a content validity process, 65 items were retained for analysis. Exploratory structural equation modeling was used as an analytic strategy to identify the most appropriate factor structure for the PCPSTQ. Decisions about the most appropriate model were made using multiple fit indices. To examine the construct validity of the PCPSTQ, a series of one-way ANOVAs were conducted to examine differences in processes of change use across stage of change.ResultsIn the current study, validity evidence provided support for a 7-factor process of change measure (χ² = 325.84, p < .001; Comparative Fit Index = .971; Tucker Lewis Index = .945; Root Mean Square Error of Approximation = .037; Standard Root Mean Square Residual = .020). Results also supported the construct validity of the scale as a significant difference in process of change use across stage of change was reported for all seven processes.ConclusionsResults of the current study support the factor structure and construct validity of the PCPSTQ. It appears that the processes of behavior change reported across multiple behavior change domains might also be viable for sport psychology professionals.