Two core systems of numerical representation in infants

Two nonverbal representation systems, the analog magnitude system (AMS) and the object tracking system (OTS), have been proposed to explain how humans and nonhuman animals represent numerosities. There has long been debate about which of the two systems is responsible for representing small numerosities (<4). This review focuses on findings with human infants to inform that debate. We argue that the empirical data cannot all be explained by a single system, and in particular, infants’ failures to compare small and large numerosities – the boundary effect – undermines the claim that the AMS can account for infants’ numerical abilities in their entirety. We propose that although the two systems coexist throughout the lifespan, competition between the systems is primarily a developmental phenomenon. Potential factors that drive the engagement of each system in infancy, such as stimulus features and task demands, are discussed, and directions for future research are suggested.     

Comparing adaptive procedures for estimating the psychometric function for an auditory gap detection task

A subject’s sensitivity to a stimulus variation can be studied by estimating the psychometric function. Generally speaking, three parameters of the psychometric function are of interest: the performance threshold, the slope of the function, and the rate at which attention lapses occur. In the present study, three psychophysical procedures were used to estimate the three-parameter psychometric function for an auditory gap detection task. These were an up–down staircase (up–down) procedure, an entropy-based Bayesian (entropy) procedure, and an updated maximum-likelihood (UML) procedure. Data collected from four young, normal-hearing listeners showed that while all three procedures provided similar estimates of the threshold parameter, the up–down procedure performed slightly better in estimating the slope and lapse rate for 200 trials of data collection. When the lapse rate was increased by mixing in random responses for the three adaptive procedures, the larger lapse rate was especially detrimental to the efficiency of the up–down procedure, and the UML procedure provided better estimates of the threshold and slope than did the other two procedures.     

Interpersonal self‐support and attentional bias on negative and positive interpersonal information

Interpersonal self‐support is an indigenous Chinese personality concept. It represents the idealized notion of the kind of personality traits that help individuals deal with interpersonal problems and develop and maintain the harmonic and appropriate social relationships required in China's collectivistic and interdependent culture. It also was assumed to be a protective personality factor with regard to mental health and was found to be negatively related to psychosomatic symptoms. In the current study, cognitive processing of interpersonal information is assumed to be an underlying mechanism that connects interpersonal self‐support with interpersonal relationships and mental health. To test this hypothesis, we conducted two experiments to investigate whether attentional bias on positive and negative interpersonal information was related to high and low interpersonal self‐support. A spatial cueing task and the emotional Stroop task were administered to two samples of high and low interpersonal self‐support Chinese undergraduate students to measure attentional bias. The results from both experiments suggested that high interpersonal self‐support students had an attentional bias toward positive interpersonal information, while low interpersonal self‐support students preferentially attended to negative interpersonal information. Study 1 indicated that attentional bias toward positive interpersonal information was easily engaged in the high interpersonal self‐support group, while attentional bias toward negative interpersonal information was both easy to engage and difficult to disengage in the low interpersonal self‐support students. These results support our hypotheses that high interpersonal self‐support people engage in positive processing of interpersonal information, whereas low interpersonal self‐support people engage in negative processing of interpersonal information. The differential balance between positive and negative processing on interpersonal information may explain why interpersonal self‐support predicts both mental health and interpersonal relationships. In addition, the relational schema may explain why interpersonal self‐support is associated with an attentional bias toward interpersonal information.     

Both Sides of the Coin: Randomization from the Perspectives of Physician-Investigators and Patient-Subjects

Randomization is the “gold standard” design for clinical research trials and is accepted as the best way to reduce bias. Although some controversy remains over this matter, we believe equipoise is the fundamental ethical requirement for conducting a randomized clinical trial. Despite much attention to the ethics of randomization, the moral psychology of this study design has not been explored. This article analyzes the ethical tensions that arise from conducting these studies and examines the moral psychology of this design from the perspectives of physician-investigators and patient-subjects. We conclude with a discussion of the practical implications of this analysis.     

阅读研究中的主要眼动指标评述

眼跳和注视是阅读过程中的两种基本眼动现象.目前在对阅读的眼动研究中分析指标主要包括两类,一类是与眼睛何时移动有关的时间维度的眼动指标,具体包括以字或词为兴趣区的眼动指标,如单一注视时间、首次注视时间、第二次注视时间、凝视时间、离开目标后的首次注视时间、回视时间和总注视时间等,以及以短语或句子为兴趣区的眼动指标,如第一遍阅读时间、向前阅读时间、第二遍阅读时间、回视路径阅读时间、重读时间等.另一类是与眼睛移动位置有关的空间维度的眼动指标,具体包括眼跳距离、注视位置、注视次数、跳读率、再注视比率和回视次数等.在使用眼动指标时,需要注意眼动指标的分类、原始数据的删除标准以及眼动指标的选择等问题.     

类别学习中的认知学习机制

采用归类任务,比较不同知识条件、不同特征呈现方式下,对非定义特征维度的掌握,验证类别学习的认知学习机制。结果发现对非定义特征维度的掌握,在样例特征固定位置呈现条件下较多,而在样例特征随机呈现条件下较少;在知识定义特征维度条件下较多,而在机械定义特征维度条件下较少。研究结果支持了类别学习的认知学习机制。     

空间转换在记叙文阅读情境模型建构中的作用

采用探测词和事件分割范式探讨了空间转换与事件转换分离的情况下, 空间转换在记叙文情境模型建构中的作用。实验1a重复前人研究, 探讨空间转换对阅读时间和情境模型更新的影响, 并验证在空间转换对情境模型的影响的研究中, 采用多指标探测范式的合理性。实验1b探讨在空间转换与事件转换相分离的条件下, 空间转换对情境模型更新的影响; 实验2a探讨空间转换对事件分割的影响, 并验证在空间转换对情境模型的影响的研究中, 采用事件分割范式的合理性; 实验2b探讨空间转换与事件转换相分离的条件下, 空间转换对事件分割的影响, 从而验证空间转换对情境模型更新的影响。结果表明, 当空间转换与事件转换相分离时, 不引起情境模型的更新, 事件单元是建构记叙文心理表征的核心单元, 空间转换只有在标识事件转换的情况下, 才能引发读者更新情境模型。     

Dissociating position and heading estimations: Rotated visual orientation cues perceived after walking reset headings but not positions

This project examined the roles of idiothetic cues due to individuals’ movement and allothetic cues independent of individuals’ movement in individuals’ estimations of their position and heading during locomotion. In an immersive virtual environment, participants learned the locations of five objects and then moved along two legs of a path before positioning the origin and the objects. Participants’ estimations of their test position and their test heading were calculated based on the responded objects’ locations, using a method of dissociating position estimation and heading estimation developed in this project. Results showed that when a conflicting visual orientation cue was presented after walking, participants relied on the allothetic cues (i.e., the visual orientation cue) for their heading estimation, but on idiothetic cues for their position estimation. These results indicate that after participants updated their position in terms the origin of the path (homing vector) via path integration, they estimated their heading. These results are inconsistent with the theoretical models stipulating that homing vectors are specified in terms of participants’ body coordinate systems, but are consistent with the models stipulating that both homing vectors and participants’ heading are specified in terms of a fixed reference direction in the environment.     

Now for Me,Later for Us? Effects of Group Context on Temporal Discounting

Delayed rewards are less valuable than immediate rewards. This well‐established finding has focused almost entirely on individual outcomes. However, are delayed rewards similarly discounted if they are shared by a group? The current article reports on three experiments exploring the effect of group context on delay discounting. Results indicate that discount rates of individual and group rewards were highly correlated, but that respondents were more willing to wait (decreased discounting) for shared outcomes than for individual outcomes. An explanatory model is proposed suggesting that decreased discount rates in group contexts may be due to the way the effects of both delay and social discounting are combined. That is, in a group context, a person values both a future reward (discounted by delay) and a present reward to another person (discounted by the social distance between them). The results are explained by a combined discount function containing a delay factor and a factor representing the social distance between the decision maker and group members. Practical implications of the fact that shared consequences can increase individual self‐control are also discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Mechanism of formation of aligned two-phase microstructure in a Fe-0.25wt%C alloy under high magnetic field gradients

The effect of a magnetic force on creating an aligned two-phase microstructure in a Fe-0.25wt%C alloy under magnetic field gradients has been investigated. Through the changes in the heating temperature, both dipolar interactions and magnetic forces work together during the austenite to ferrite transformation. The results showed that the aligned two-phase microstructure is not observed under the influence of the magnetic force alone. The ferrite grains are elongated due to dipole interactions at the early stages of their nucleation and growth and then the magnetic force turns the elongated ferrite grains, whose major axis is not parallel to the direction of magnetic force, to the direction of the field in the presence of magnetic field gradients.