Recovering a Probabilistic Knowledge Structure by Constraining its Parameter Space

In the Basic Local Independence Model (BLIM) of Doignon and Falmagne (Knowledge Spaces, Springer, Berlin, 1999), the probabilistic relationship between the latent knowledge states and the observable response patterns is established by the introduction of a pair of parameters for each of the problems: a lucky guess probability and a careless error probability. In estimating the parameters of the BLIM with an empirical data set, it is desirable that such probabilities remain reasonably small. A special case of the BLIM is proposed where the parameter space of such probabilities is constrained. A simulation study shows that the constrained BLIM is more effective than the unconstrained one, in recovering a probabilistic knowledge structure.     

用信息函数法对标准参照测验作质量分析

根据项目反应理论的信息函数法,以自主开发的“现代教育和心理测量通用分析系统”为工具,对两个大规模实施的标准参照测验进行了测验质量分析。结果说明,信息函数分析法比经典真分数理论分析法,可以获得更丰富、深刻、有针对性的资料,能对项目筛选修订、测验编制开发给出有力的指导,值得大力引进、推广。     

3~5岁幼儿一位数大小比较的信息加工模式

主要探讨我国幼儿对数量大小比较的信息加工模式。实验1探讨幼儿对一位数大小比较的发展状况及其心理表征特点,被试为3岁、4岁与5岁幼儿各20人,要求被试对1-9两两进行大小比较,然后对不同年龄幼儿对比成绩进行比较与聚类分析。实验2进一步探讨幼儿对数字的语义编码情况及其与数的大小比较的关系,被试与实验1相同,要求被试对1-9每个数字作出大、中或小的编码,然后分析数字的语义编码成绩与大小比较成绩的关系。实验3采用因果设计,探讨幼儿关于数字的语义编码对他们关于数的大小判断的影响,被试为30名4岁幼儿,随机分成训练组与控制组,对训练组被试进行数字语义编码训练,然后比较两组被试大小比较的成绩。结果表明：(1)幼儿一位数大小比较直接受其对数的语义表征的影响;(2)随着年龄的增长,幼儿对数的表征逐步表现出离散聚类模式,相应地,对一位数大小比较的信息加工过程就表现为由无序的、随机的过程逐步发展成为层次编码比较的过程。     

Statistical models of syntax learning and use

This paper shows how to define probability distributions over linguistically realistic syntactic structures in a way that permits us to define language learning and language comprehension as statistical problems. We demonstrate our approach using lexical‐functional grammar (LFG), but our approach generalizes to virtually any linguistic theory. Our probabilistic models are maximum entropy models. In this paper we concentrate on statistical inference procedures for learning the parameters that define these probability distributions. We point out some of the practical problems that make straightforward ways of estimating these distributions infeasible, and develop a “pseudo‐likelihood” estimation procedure that overcomes some of these problems. This method raises interesting questions concerning the nature of the data available to a language learner and the modularity of language learning and processing.     

不同干扰刺激对成人数量估计的影响

研究采用自行设计的图形材料,考察了不同干扰刺激(纯靶刺激;干扰刺激与靶刺激数量相同;干扰刺激是靶刺激数量的2倍)对成人完成数量估计任务的影响.30名硕士生参加了本实验.行为数据和口头报告资料分析显示:1)反应时随数量估计任务难度的增加而不断增长;2)干扰刺激越多,任务越复杂,成人估计的误差率越高,准确性越低;3)成人存在多重数字表征形式,完成数量估计任务时主要采用线性表征,但随着干扰刺激物的增加,运用对数表征的趋势愈加明显.     

Implications of accuracy, sensitivity, and variability of body size estimations to disordered eating

The current study was conducted to investigate the relationships between body size estimations and disordered eating symptomatology. The method of constant stimuli was used to derive three measures of self-perceived body size in 93 women: (1) accuracy of body size estimations (body image distortion); (2) sensitivity in discriminating body size within blocks of trials (body image sensitivity); and (3) variability in making body size estimations between blocks of trials (body image variability). Participants also completed measures of disordered eating. Although body image distortion correlated with dietary restraint and eating concern, body image variability accounted for additional variance in these variables, as well as variance in binge eating. The relationships involving body image variability were found to be mediated by body dissatisfaction and internalization of the thin ideal. Together, these results are consistent with the proposition that body image variability is a significant factor in disordered eating.     

Facteur d’impact et mondialisation culturelle

In the present article, we recall the principle of articles consummation as defined by the ISI creator (Institute for Scientific Information). That principle justifies the impact factor (IF) used as a measure of a journal scientific value, of a researcher or of a researcher group… We expose some assumptions that support the IF validity. Further we demonstrate that, on the one hand, these assumptions are not very well established and, on the other hand, that principle and the IF success bias the scientific activity. We consider next two shapes that this bias could take: at best a phenomenon of fashions, at worst, an ideological war having as purpose the American way of thinking domination.     

Experiencing past and future personal events: functional neuroimaging evidence on the neural bases of mental time travel

Functional MRI was used in healthy subjects to investigate the existence of common neural structures supporting re-experiencing the past and pre-experiencing the future. Past and future events evocation appears to involve highly similar patterns of brain activation including, in particular, the medial prefrontal cortex, posterior regions and the medial temporal lobes. This result seems to support the view of a common neurocognitive system, which would allow humans to mentally travel through time. Past events recollection was associated with greater amplitude of hippocampal and anterior medial prefrontal hemodynamic responses. This result is discussed in terms of the involvement of the self in the conscious experience of past and future events representations. More generally, our data provide new evidence in favour of the idea that re- and pre-experiencing past and future events may rely on similar cognitive capacities.     

The SNARC effect does not imply a mental number line

In this study, we directly contrast two approaches that have been proposed to explain the SNARC effect. The traditional direct mapping account suggests that a direct association exists between the position of a number on the mental number line and the location of the response. On the other hand, accounts are considered that propose an intermediate step in which numbers are categorized as either small or large between the number magnitude and the response representations. In a magnitude comparison task, we departed from the usual bimanual left/right response dimension and instead introduced the unimanual close/far dimension. A spatial-numerical association was observed: small numbers were associated with a close response, while large numbers were associated with a far response, regardless of the movement direction (left/right). We discuss why these results cannot be explained by assuming a direct mapping from the representation of numbers on a mental number line to response locations and discuss how the results can be explained by the alternative accounts.     

Reinforcement magnitude: an evaluation of preference and reinforcer efficacy

Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current study was to evaluate the relations among reinforcer magnitude, preference, and efficacy by drawing on the procedures and results of basic experimentation in this area. Three children who engaged in problem behavior that was maintained by social positive reinforcement (attention, access to tangible items) participated. Results indicated that preference for different magnitudes of social reinforcement may predict reinforcer efficacy and that magnitude effects may be mediated by the schedule requirement.