Working memory demands of exact and approximate addition

We compared the working memory requirements of two forms of mental addition: exact calculation (e.g., 63 + 49 = 112) and approximation (e.g., 63 + 49 is about 110). In two experiments, participants solved two-digit addition problems (e.g., 63 + 49) alone and in combination with a working memory task (i.e., remembering four consonants). In Experiment 1, participants chose an answer from two alternatives (e.g., exact: 112 vs. 122; approximate: 110 vs. 140). In Experiment 2, participants responded verbally with exact or approximate answers. In both experiments, the working memory load impaired exact and approximate addition performance, but exact addition was affected more. Load also impaired performance on problems with a carry operation in the units (e.g., 28 + 59 or 76 + 57) more than on problems without a unit carry (e.g., 24 + 53 or 76 + 52). These results identify the carry operation as the source of the working memory demands in multidigit addition.     

Processing negative numbers by transforming negatives to positive range and by sign shortcut

Numerals are processed by a phylogenetically old analogue magnitude system. Can culturally new negative numerals be processed using this same representation? To find out whether magnitude representation could be used, we contrasted three possible processing mechanisms: an extended magnitude system for both positive and negative numbers, a mirroring mechanism that could transform negative values to the positive range to be processed on the positive magnitude system, and a sign shortcut strategy that can process the signs of numbers independently of the absolute values of numerals. To test these three hypotheses, a comparison task was used and the reaction time pattern, numerical distance, and Spatial-Numerical Association of Response Codes (SNARC) effect was analysed. The results revealed a mirroring process along with a sign shortcut mechanism. The SNARC effect was observed only when positive numbers were compared.     

Solving distant analogies reduces belief-based responding in transitive inference

ABSTRACT

Previous research demonstrated that relational processing in transitive inference problems can be disrupted by belief-based content. Given the premises, The horse is larger than the goat, and The goat is larger than the elephant, accepting the valid conclusion, The horse is larger than the elephant suggests use of relational processing whereas accepting the invalid conclusion The elephant is larger than the horse indicates belief-based responding. This research examined whether solving analogies influenced participants’ reliance on belief-based or relational processing. Participants generated solutions to either distant analogies (e.g. nose:scent::antenna: ______) or near analogies (e.g. nose:scent::tongue:______) before evaluating the conclusions of transitive inference problems that were valid (V) or invalid (I) and believable (B), unbelievable (U) or neutral (N). Solving distant analogies eliminated belief-based responding (possibly reflecting improved inhibitory control) and facilitated relational responding on VU problems.     

Guidelines for Writing Letters to Patients

Patient letters provide a permanent record of the genetic counseling that was provided and are unique in medical care; rarely do other health care providers send summaries written specifically to their patients and families. We surveyed genetic counseling training program directors and found that while the acquisition of patient letter-writing skills was considered important, there were no specific guidelines made available to students. To develop letter-writing guidelines, we evaluated patient letters, reviewed references on professional correspondence, surveyed the medical literature, and worked with a writing consultant. The guidelines we subsequently developed and present here include a format for writing patient letters, suggestions on presenting medical information in understandable terms, and wording considerations. These patient letter-writing guidelines are intended to serve as a guide for teaching students this important skill and as a resource for practicing health care professionals.     

Executive Heads and the Role of Intergovernmental Organizations: Expansionist Leadership in the United Nations and the European Union

Despite considerable advances in methods to examine leaders' personal characteristics using at–a–distance assessment, few studies have applied such techniques outside of the national level. This study reveals that such approaches can provide analytical leverage for examining executive heads of intergovernmental organizations (IGOs). The personal characteristics of six United Nations Secretaries–General and four European Union Commission Presidents were measured via content analysis of their responses to questions. Separately, their behavior in office was measured via historical accounts and analyses. In general, executive heads with higher expansionist leadership style scores displayed a greater willingness to try to enhance the status of their organizations.     

符号数量和非符号数量的空间表征:5岁儿童的SNARC效应和距离效应

对物理刺激的数量信息表征是符号数字表征的前提和基础,据此假设在儿童的SNARC效应发生的时序问题上,非符号数量(如面积)的空间表征早于符号数量(如阿拉伯数字)的空间表征。本研究邀请5岁幼儿完成数字比较和面积比较两类任务,结果发现在数字比较任务中没有出现SNARC效应,但却存在距离效应;在面积比较任务中出现了SNARC效应和距离效应。可以推断,在阿拉伯数字的空间表征出现之前,儿童已经能够对非符号数量信息进行空间表征。     

领导对建言反应的动机感知作用机制:基于归因理论的阐释

基于归因理论,从领导对建言行为动机的认知视角,解释领导对建言差异反应的原因。当领导认为员工建言基于组织关心动机、亲社会动机时,会给予表扬/认可、奖赏、执行等积极反应;当领导认为员工建言是基于挑战动机、疏离动机、印象管理动机或自我保护动机时,会给予批评/惩罚、忽视、报复等消极反应。此外,权力距离能够调节领导对建言动机的感知,即低权力距离领导,对建言行为更为接纳、支持,会增强专业性、建言氛围与积极动机感知的关系,减弱挑战性建言与消极动机感知的关系;而高权力距离领导,倾向于绝对优势的权力和对下属的控制,会减弱专业性、可信性及建言氛围与积极动机感知的关系,增强挑战性建言与消极动机感知的关系。最后,建议未来的研究关注以下几个方面:(1)将建言作为一个过程来探讨,研究领导对建言的反应如何影响员工后续的态度和行为;(2)研究建言氛围形成的原因及其作用;(3)关注情绪在建言行为中的功能机制等。     

Common magnitude representation of fractions and decimals is task dependent

Although several studies have compared the representation of fractions and decimals, no study has investigated whether fractions and decimals, as two types of rational numbers, share a common representation of magnitude. The current study aimed to answer the question of whether fractions and decimals share a common representation of magnitude and whether the answer is influenced by task paradigms. We included two different number pairs, which were presented sequentially: fraction–decimal mixed pairs and decimal–fraction mixed pairs in all four experiments. Results showed that when the mixed pairs were very close numerically with the distance 0.1 or 0.3, there was a significant distance effect in the comparison task but not in the matching task. However, when the mixed pairs were further apart numerically with the distance 0.3 or 1.3, the distance effect appeared in the matching task regardless of the specific stimuli. We conclude that magnitudes of fractions and decimals can be represented in a common manner, but how they are represented is dependent on the given task. Fractions and decimals could be translated into a common representation of magnitude in the numerical comparison task. In the numerical matching task, fractions and decimals also shared a common representation. However, both of them were represented coarsely, leading to a weak distance effect. Specifically, fractions and decimals produced a significant distance effect only when the numerical distance was larger.     

A new rank correlation coefficient with application to the consensus ranking problem

The consensus ranking problem has received much attention in the statistical literature. Given m rankings of n objects the objective is to determine a consensus ranking. The input rankings may contain ties, be incomplete, and may be weighted. Two solution concepts are discussed, the first maximizing the average weighted rank correlation of the solution ranking with the input rankings and the second minimizing the average weighted Kemeny–Snell distance. A new rank correlation coefficient called τ_x is presented which is shown to be the unique rank correlation coefficient which is equivalent to the Kemeny‐Snell distance metric. The new rank correlation coefficient is closely related to Kendall's tau but differs from it in the way ties are handled. It will be demonstrated that Kendall's τ_b is flawed as a measure of agreement between weak orderings and should no longer be used as a rank correlation coefficient. The use of τ_x in the consensus ranking problem provides a more mathematically tractable solution than the Kemeny–Snell distance metric because all the ranking information can be summarized in a single matrix. The methods described in this paper allow analysts to accommodate the fully general consensus ranking problem with weights, ties, and partial inputs. Copyright © 2002 John Wiley & Sons, Ltd.