One or two dimensions in spontaneous classification: a simplicity approach

When participants are asked to spontaneously categorize a set of items, they typically produce unidimensional classifications, i.e., categorize the items on the basis of only one of their dimensions of variation. We examine whether it is possible to predict unidimensional vs. two-dimensional classification on the basis of the abstract stimulus structure, by employing Pothos and Chater's simplicity model of spontaneous categorization [Pothos, E. M., & Chater, N. (2002). A simplicity principle in unsupervised human categorization. Cognitive Science, 26, 303-343]. The simplicity model provides a quantitative measure of how intuitive a particular classification is. With objects represented in two dimensions, we propose that a unidimensional classification will be preferred if it is more intuitive than all possible two-dimensional ones, and vice versa. Empirical results supporting this proposal are reported. Implications for Goodman's paradox are discussed.     

Self-other similarity judgment asymmetries reverse for people to whom you want to be similar

People typically judge themselves to be less similar to others than others are to themselves. The selective accessibility model [Mussweiler, T. (2003). Comparison process in social judgement: mechanical consequences. Psychological Review, 110, 472-489.] suggests that the direction of this self-other similarity asymmetry could reverse for comparison others to whom people want to be more similar. Motivation to be more similar is thought to prompt a focal hypothesis of similarity as opposed to dissimilarity, which influences the amount and kind of information accessed when making the judgment. A study found a typical asymmetry for comparison others to whom participants did not wish to be more similar, and a reversed asymmetry for comparison others to whom participants did wish to be more similar. The direction of the asymmetry was not dependent on whether participants knew a lot or a little about the comparison other.     

Similarity based approximate reasoning: fuzzy control

This paper presents an approach to similarity based approximate reasoning that elucidates the connection between similarity and existing approaches to inference in approximate reasoning methodology. A set of axioms is proposed to get a reasonable measure of similarity between two fuzzy sets. The similarity between the fact(s) and the antecedent of a rule is used to modify the relation between the antecedent and the consequent of the rule. An inference is drawn using the well-known projection operation on the domain of the consequent. Zadeh's compositional rule of inference and existing similarity based reasoning techniques are considered for a new similarity based approximate reasoning technique. The proposed mechanism is used to develop a modified fuzzy control system. A new defuzzification scheme is proposed. Simulation results are presented for the well-known inverted pendulum problem.     

Role of prior knowledge in implicit and explicit learning of artificial grammars

Artificial grammar learning (AGL) performance reflects both implicit and explicit processes and has typically been modeled without incorporating any influence from general world knowledge. Our research provides a systematic investigation of the implicit vs. explicit nature of general knowledge and its interaction with knowledge types investigated by past AGL research (i.e., rule- and similarity-based knowledge). In an AGL experiment, a general knowledge manipulation involved expectations being either congruent or incongruent with training stimulus structure. Inconsistent observations paradoxically led to an advantage in structural knowledge and in the use of general world knowledge in both explicit (conscious) and implicit (unconscious) cases (as assessed by subjective measures). The above findings were obtained under conditions of reduced processing time and impaired executive resources. Key findings from our work are that implicit AGL can clearly be affected by general knowledge, and implicit learning can be enhanced by the violation of expectations.     

大连地区健康人群体重指数分布状况的调查分析

调查分析大连地区健康人群中体重指数(BMI)、腰臀围比(WHR)的分布状况。对630例长期居住大连地区的21岁～60岁汉族健康成人的BMI、WHR进行调查分析,检测受检者身高、体重、腰围、臀围,按不同年龄段、不同性别分析BMI、WHR的性别及年龄分布。大连地区健康人群总体的平均BMI为(23.66±3.12)kg/m~2,其中男性为(24.66±2.88)kg/m~2。女性为(22.41±2.97)kg/m~2,经t检验有显著差异(t=11.85,P＜0.001)。BMI≥25的人群比例为24.1%,BMI≥30的为3.0%。BMI随年龄变化的曲线为斜线,从21岁～60岁,随着年龄的增长而显著升高,51岁～60岁达到最高峰;WHR随年龄变化的曲线为斜线,随着年龄的增长而显著升高,51岁～60岁达到最高峰。随着社会生活水平的提高,人群中BMI、WHR结构发生了明显的变化,肥胖者日趋增多,应重视超重和肥胖的防治工作。     

2型糖尿病一级亲属代谢相关指标分布规律的研究

为了研究2型糖尿病(DM)家系一级亲属的代谢相关指标变化规律,选择55个2型糖尿病家系中糖尿病患者的一级亲属为研究对象,按照糖耐量试验结果分组,比较组间血压、血糖、血脂、C肽、胰岛素等指标。结果显示,2型糖尿病家系一级亲属各组血脂水平的变化差异无显著性,而血糖、胰岛素抵抗等指标差异有显著性。由此得出结论,2型DM家系一级亲属血脂、血糖、血压、胰岛素等指标均有一定程度的异常,且各组间的血糖、血压、胰岛素抵抗等差异显著于血脂水平的变化。     

On the law of Regular Minimality: Reply to Ennis

Ennis's critique touches on issues important for psychophysics, but the points he makes against the hypothesis that Regular Minimality is a basic property of sensory discrimination are not tenable.(1) Stimulus variability means that one and the same apparent stimulus value (as measured by experimenter) is a probabilistic mixture of true stimulus values. The notion of a true stimulus value is a logical necessity: variability and distribution presuppose the values that vary and are distributed (even if these values are represented by processes or sets rather than real numbers). Regular Minimality is formulated for true stimulus values. That a mixture of probabilities satisfying Regular Minimality does not satisfy this principle (unless it also satisfies Constant Self-Similarity) is an immediate consequence of my 2003 analysis. Stimulus variability can be controlled or estimated: the cases when observed violations of Regular Minimality can be accounted for by stimulus variability corroborate rather than falsify this principle. In this respect stimulus variability is no different from fatigue, perceptual learning, and other factors creating mixtures of discrimination probabilities in an experiment.(2) Could it be that well-behaved Thurstonian-type models are true models of discrimination but their parameters are so adjusted that the violations of Regular Minimality they lead to (due to my 2003 theorems) are too small to be detected experimentally? This is possible, but this amounts to admitting that Regular Minimality is a law after all, albeit only approximate: nothing in the logic of the Thurstonian-type representations per se prevents them from violating Regular Minimality grossly rather than slightly. Moreover, even very small violations predicted by a given class of Thurstonian-type models can be tested in specially designed experiments (perhaps under additional, independently testable assumptions). The results of one such experiment, in which observers were asked to alternately adjust to each other the values of stimuli in two observation areas, indicate that violations of Regular Minimality, if any, are far below limits of plausible interpretability.     

Sample size and bentler and Bonett's nonnormed fit index

Bentler and Bonett's nonnormed fit index is a widely used measure of goodness of fit for the analysis of covariance structures. This note shows that contrary to what has been claimed the nonnormed fit index is dependent on sample size. Specifically for a constant value of a fitting function, the nonnormed index is inversely related to sample size. A simple alternative fit measure is proposed that removes this dependency. In addition, it is shown that this new measure as well as the old nonnormed fit index can be applied to any fitting function that measures the deviation of the observed covariance matrix from the covariance matrix implied by the parameter estimates for a model.     

城市老年人生活满意度及其影响因素的研究

生活满意指数是衡量老年人心理健康状况的一项重要指标,而许多因素都可能会对老年人的生活满意指数产生影响。我们采用生活满意指数A(LSIA)量表对355名城市老年人进行了有关研究,结果表明:城市老年人的LSIA平均得分为13.07±3.43(M±SD);老年人中对经济状况满意、对个人健康状况自我评价好、抑郁症状轻、原无职业及有较多亲密朋友者,其生活满意指数就高,反之则低。     

Open-field nidus and pullusindices in Mus Musculus L.

Swiss albino mice ( Mus Musculus L. ) were studied in an open field (OF). The question whether laboratory rodents were more attracted to a nest equipped with familiar odoriferous cues from the home-cage bedding or to signals of an unfamiliar newborn pup inserted in the OF was addressed. The results of the three quantitatively recorded OF behaviors, ambulation, retrieval and radial latency , indicated that in females both ambulation and retrieval were enhanced by the presence of a pup in a nestless field; in males locomotion was suppressed by a nest in a pupless OF. In the case of both sexes radial latency was determined by the OF position of a nest. A comparison between the two qualitative assessments, the nidus and pullus indices, yielded that the sex of the adult and the OF positions of both targets equally impacted attraction towards both nest and pup.