The Idea of an Exact Number: Children's Understanding of Cardinality and Equinumerosity

Understanding what numbers are means knowing several things. It means knowing how counting relates to numbers (called the cardinal principle or cardinality); it means knowing that each number is generated by adding one to the previous number (called the successor function or succession), and it means knowing that all and only sets whose members can be placed in one‐to‐one correspondence have the same number of items (called exact equality or equinumerosity). A previous study (Sarnecka & Carey, 2008) linked children's understanding of cardinality to their understanding of succession for the numbers five and six. This study investigates the link between cardinality and equinumerosity for these numbers, finding that children either understand both cardinality and equinumerosity or they understand neither. This suggests that cardinality and equinumerosity (along with succession) are interrelated facets of the concepts five and six, the acquisition of which is an important conceptual achievement of early childhood.     

不同特质焦虑水平的选择性注意偏向

高特质焦虑个体常表现出对威胁性刺激的选择性注意偏向的特点。然而其潜在的神经机制目前仍不清楚。通过记录高、低特质焦虑者各17名进行情绪加工时的ERP,比较了两组个体在选择性注意偏向发生的时间进程和相关的神经反应的差异。结果发现,高特质焦虑者诱发出更大的N1,进一步发现恐惧图片比中性图片诱发更大的N1;而低特质焦虑者诱发了更大的N2,特质焦虑得分越低, N2波幅越大。结果初步说明高特质焦虑者加工早期对恐惧图片分配了较多的注意资源,并且其抑制执行功能可能受损;而低特质焦虑者较晚开始区分恐惧图片和中性图片。这些结果提供了支持认知-动机模型的新证据。     

不同线索下特质焦虑个体的返回抑制

焦虑与注意偏向的研究是近年来情绪与认知领域的热点。为探讨特质焦虑个体的注意偏向特点及其返回抑制能力是否受不同线索的调节, 采用特质焦虑量表筛选高特质焦虑大学生29名, 低特质焦虑大学生28名完成线索-靶子任务。要求被试在提示线索消失后, 对位置进行快而准地辨别反应, 分别探索中性和情绪性提示线索下被试的返回抑制。结果发现：(1)在中性线索条件下, 高焦虑个体平均反应时慢于低焦虑个体。(2) 在情绪线索条件下, 高焦虑个体在负性线索下的反应时小于在正性线索下的反应时; 高、低焦虑个体在各种SOA条件下均出现了返回抑制, 但各组返回抑制量受到情绪线索的调节：在正性情绪线索条件下, 两组返回抑制量没有显著差异; 在负性情绪线索下, 高焦虑个体返回抑制量显著小于低焦虑个体。这表明, (1)焦虑个体的注意偏向受到刺激信息的影响：只对负性情绪线索出现注意警觉; (2)只有在涉及负性情绪信息时高、低焦虑个体返回抑制能力才有差异, 高焦虑个体存在对负性情绪线索的抑制困难。     

What do people think about changes in health behaviors? Differential perceptions of consequences of increases and decreases in health behaviors

Most health decision-making models posit that cost-benefit analyses underlie decisions to make changes in health-related behavioral practices. In a series of studies, participants imagined either increasing or decreasing the frequency of a variety of health behaviors and estimated the consequences of those changes. In Studies 1 and 2, individuals consistently estimated that increasing a health behavior produced greater consequences than did decreasing the behavior by an equivalent amount. The results of Study 3 demonstrated that this effect is due to differences in how individuals judge the impact of health behavior changes which involve not engaging in the behavior at all versus other types of changes. Taken together, these findings suggest that perceptions of the outcomes afforded by health behavior changes depend on both the behavioral frequency and direction of changes in behavior an individual is considering. This asymmetry has the potential to help explain patterns of behavior in a range of important health domains and may impact the effectiveness of behavior change interventions.     

Interpreting cross-sectional data on stages of change

Abstract

The vast majority of studies investigating stage theories of health behaviour such as the transtheoretical model have used a cross-sectional research design. Participants are classified into stages and compared on theoretically relevant variables. This paper discusses the proper interpretation of cross-sectional data on stages of change. Linear patterns are not consistent with the stage model assumption that different causal factors are important at different stages but discontinuity patterns (patterns that do not show consistent increments or decrements across stages) can be diagnostic of a stage model. Researchers who use cross-sectional designs should specify predictions concerning the patterns to be expected under a stage model and under possible rival models, and interpret their data accordingly. Wherever possible, they should conduct prospective longitudinal and experimental studies which enable stronger inferences to be drawn.     

Counter-Closure

The focus of this paper is the prima facie plausible view, expressed by the principle of Counter-Closure, that knowledge-yielding competent deductive inference must issue from known premises. I construct a case that arguably falsifies this principle and consider five available lines of response that might help retain Counter-Closure. I argue that three are problematic. Of the two remaining lines of response, the first relies on non-universal intuitions and forces one to view the case I construct as exhibiting a justified, true belief to which none of the usual diagnoses of knowledge failure in Gettier cases apply. The second line involves claiming that Fake Barns and its ilk are misdiagnosed by epistemological orthodoxy as Gettier cases. We are thus confronted by a trilemma: either the case I discuss undermines the first-blush plausible principle of Counter-Closure; or the case I discuss instantiates a novel kind of Gettier case; or a popular conception of a key range of alleged Gettier cases must be rejected. No matter which horn we choose, the case points to a philosophically curious conclusion.     

Anxiety reactivity and anxiety perseveration represent dissociable dimensions of anxiety vulnerability: A replication and extension

Trait anxiety is a unitary construct reflecting individual differences in the tendency to experience anxious symptomatology, typically measured with questionnaires such as the Spielberger Trait Anxiety Inventory (STAI‐T). Recent research by Rudaizky, Page, and MacLeod has found evidence that two different dimensions of trait anxiety account for independent variance in trait anxiety scores. These dimensions are anxiety reactivity (AR), reflecting the probability of experiencing an anxious reaction, and anxiety perseveration (AP), reflecting the persistence of anxious symptoms once elicited. There are two key issues addressed in this study: first, the replicability of Rudaizky et al.'s findings and second, the ability of the measures of AR and AP developed by Rudaizky et al. to predict independent variance in STAI‐T scores after statistically controlling for variance shared with a measure of depression. Regression analysis determined that AR and AP do account for independent variance in STAI‐T trait anxiety scores even after statistically controlling for depression. The implications of these findings for the understanding of anxiety vulnerability are discussed.     

Physicians' Silent Decisions: Because Patient Autonomy Does Not Always Come First

Physicians make some medical decisions without disclosure to their patients. Nondisclosure is possible because these are silent decisions to refrain from screening, diagnostic or therapeutic interventions. Nondisclosure is ethically permissible when the usual presumption that the patient should be involved in decisions is defeated by considerations of clinical utility or patient emotional and physical well-being. Some silent decisions—not all—are ethically justified by this standard. Justified silent decisions are typically dependent on the physician's professional judgment, experience and knowledge, and are not likely to be changed by patient preferences. We condemn the inappropriate exclusion of the patient from the decision-making process. However, if a test or treatment is unlikely to yield a net benefit, disclosure and discussion are at times unnecessary. Appropriate silent decisions are ethically justified by such considerations as patient benefit or economy of time.