Local Optima in Mixture Modeling

It is common knowledge that mixture models are prone to arrive at locally optimal solutions. Typically, researchers are directed to utilize several random initializations to ensure that the resulting solution is adequate. However, it is unknown what factors contribute to a large number of local optima and whether these coincide with the factors that reduce the accuracy of a mixture model. A real-data illustration and a series of simulations are presented that examine the effect of a variety of data structures on the propensity of local optima and the classification quality of the resulting solution. We show that there is a moderately strong relationship between a solution that has a high proportion of local optima and one that is poorly classified.     

Do multicultural experiences facilitate global processing style?

The current research explores whether multicultural experiences facilitate global processing style. We conducted two experiments in which participants were exposed to either a multicultural experience or a monocultural experience. They were required to either perform the Navon letter task (Experiment 1) or search for similarities or differences between two videos (Experiment 2). The experimental results showed that, compared to the participants exposed to a monocultural experience, those exposed to a multicultural experience had faster reaction times to global letters (Experiment 1) and tended to search for similarities (Experiment 2). This indicates that individuals with multicultural experiences facilitate a global processing style. © 2016 John Wiley & Sons Australia, Ltd, Asian Association of Social Psychology and Beijing Normal University     

Causes of Allais common consequence paradoxes: An experimental dissection

The common consequence paradox of Allais can be decomposed into three simpler principles: transitivity, coalescing, and restricted branch independence. Different theories attribute such paradoxes to violations of restricted branch independence only, to coalescing only, or to both. This study separates tests of these two properties in order to compare these theories. Although rank-dependent utility (RDU) theories, including cumulative prospect theory (CPT), violate branch independence, the empirical pattern of violations is opposite that required by RDU theories to account for Allais paradoxes. Data also show systematic violations of coalescing, which refute RDU theories. The findings contradict both original and CPTs with or without their editing principles of combination and cancellation. Modal choices were well predicted by Birnbaum's RAM and TAX models with parameters estimated from previous data. The effects of event framing on these tests were also assessed and found to be negligible.     

生物运动加工特异性：整体结构和局部运动的作用

人类具有很强的识别生物体运动信息的能力, 甚至当运动信息仅是由附着在头部和一些重要关节上的光点的运动组成时, 观察者对该信息检测和编码的优势依然存在。光点生物运动信息包含整体信息(如整体形状)和局部信息(如各个点的运动轨迹)。先前的绝大部分研究强调整体形状在生物运动知觉中的作用。最近有研究表明去除了整体结构信息的局部生物运动仍然存在加工优势, 揭示了局部生物运动本身可能包含了一些特异性信息。因此生物运动知觉并非单一现象, 而是一种具有不同加工机制(基于整体结构和基于局部运动)的多水平现象。     

Influence analysis of ranking data

This paper develops diagnostic measures to identify those observations in Thurstonian models for ranking data which unduly influence parameter estimates that are obtained by the partition maximum likelihood approach of Chan and Bentler (1998). Diagnostic measures are constructed by employing the local influence approach that uses geometric techniques to assess the effect of small perturbations on a postulated statistical model. Very little additional effort is required to compute the proposed diagnostic measures, because all of the necessary building blocks are readily available after a usual fit of the model. The work described in this paper was partially supported by the grants from the Research Grants Council of the Hong Kong Special Administrative Region, China (RGC Ref. No. CUHK4186/98P and RGC Direct Grant ID2060178). The authors are grateful to the Editor and four anonymous referees for their helpful comments.     

人脑眶额皮质表征奖赏信息的进展

文章围绕人脑眶额皮质在表征奖赏信息上的核心作用展开,分别从人脑眶额皮质表征奖赏信息的共同神经表征和特异性神经表征特点,奖赏加工和该脑区局部形态特征之间的关系以及眶额皮质表征奖赏信息的时间动态性等角度对最近的重要研究进展进行了一定的梳理和概括。最后,文章讨论了未来研究需要解决的由奖赏类型多样性和脑区间奖赏信息整合复杂性带来的系列问题。     

干扰材料的熟悉性和认知方式对语篇阅读的影响

采用熟悉词和不熟悉词为干扰材料,考察了干扰材料的熟悉性对语篇阅读的影响.实验第一阶段要求不同认知方式被试朗读插入熟悉度不同干扰材料的短文,考查被试的阅读效率;第二阶段采用学习—自由回忆任务考查不同提示条件下在短文中使用过的干扰词和新词的学习效果.结果发现:(1)对场独立者而言,熟悉词的干扰作用明显大于不熟悉词,而对场依存者而言,熟悉词和不熟悉词的干扰作用无差异;(2)在提示条件下,被试对干扰词的回忆量大于对新词的回忆量.研究结果表明,在语篇阅读过程中,与场依存者相比,熟悉的干扰材料对场独立者的影响更大;熟悉词比不熟悉词产生更大干扰的原因可能是由于其激活了读者更多的经验,而非具有加工的优势.     

心理疲劳对射击运动员整体局部加工的不同影响

采用整体—局部任务范式,通过事件相关电位技术（ERPs）同时结合问卷测量,考察心理疲劳对射击运动员整体加工和局部加工产生的影响。12名射击运动员参加实验。首先通过目标追踪任务诱发心理疲劳,然后使用心理疲劳问卷评估心理疲劳程度,再让被试进行整体—局部加工任务。结果发现：（1）目标追踪任务能够有效地诱发心理疲劳;（2）射击运动员完成整体知觉任务的反应时更快,准确率更高;（3）在心理疲劳状态下,射击运动员对整体知觉任务中一致条件的反应更快,准确率更高,在额区和中央区引发的N2、P3波幅更高;但是,对局部知觉任务中一致和不一致条件的反应时和准确率以及N2、P3波幅之间的差异不显著。这些结果表明,心理疲劳对整体和局部加工有着不同的影响。整体加工相对自动化,受心理疲劳的影响较小,而局部加工依赖于有意搜索,受心理疲劳的影响较大。研究揭示了心理疲劳对于注意的局部加工的影响及其神经关联,对未来射击运动员特定干预措施设计具有启发意义。     

双文化经验对整体加工方式的影响*

已有研究表明,与个体主义文化相比,集体主义文化易引发整体加工方式。但是,文化不仅可以按照东西方文化划分为个体主义和集体主义,还可以依据个体的文化经验划分为多元文化和单一文化。那么,与单一文化经验相比,多元文化经验,尤其是最常见的双文化经验是否也有利于整体加工方式呢?在两个实验中,我们将被试分为两组,让其中一组被试暴露在双文化情境下,另外一组被试暴露在单一文化情境下。然后让这两组被试要么寻找两段视频间的相似点或者差异点（实验1）,要么回忆与老年人刻板印象一致或不一致的信息（实验2）。结果发现,与暴露在单一文化情境下相比,暴露在双文化情境下的被试倾向于寻找事物间的相似点（实验1）,并且不易形成刻板印象（实验2）。这表明,双文化经验有利于整体加工方式。