Estimation of the Coefficient of Variation with Minimum Risk: A Sequential Method for Minimizing Sampling Error and Study Cost

The coefficient of variation is an effect size measure with many potential uses in psychology and related disciplines. We propose a general theory for a sequential estimation of the population coefficient of variation that considers both the sampling error and the study cost, importantly without specific distributional assumptions. Fixed sample size planning methods, commonly used in psychology and related fields, cannot simultaneously minimize both the sampling error and the study cost. The sequential procedure we develop is the first sequential sampling procedure developed for estimating the coefficient of variation. We first present a method of planning a pilot sample size after the research goals are specified by the researcher. Then, after collecting a sample size as large as the estimated pilot sample size, a check is performed to assess whether the conditions necessary to stop the data collection have been satisfied. If not an additional observation is collected and the check is performed again. This process continues, sequentially, until a stopping rule involving a risk function is satisfied. Our method ensures that the sampling error and the study costs are considered simultaneously so that the cost is not higher than necessary for the tolerable sampling error. We also demonstrate a variety of properties of the distribution of the final sample size for five different distributions under a variety of conditions with a Monte Carlo simulation study. In addition, we provide freely available functions via the MBESS package in R to implement the methods discussed.     

Simple actions influence pop-out search

Recent research has revealed that a simple action (pressing a computer key) produced in response to a visual object prioritizes features of that object in subsequent visual search. The effects of simple action, however, have only been studied with search displays that required serial search. Here we explored whether simple actions have an effect when the target in visual search is always a salient singleton. Participants viewed a coloured shape at the beginning of each trial, and sometimes they acted (pressed the space bar) in response to it. In the subsequent search task, after acting (but not after viewing), the previously-seen colour affected search performance even though the target was always a salient singleton and the colour was uninformative. The results reveal that prior action can interact with bottom-up salience during search. Implications for our understanding of both visual search and repetition priming are discussed.     

Is gaze behaviour in a laboratory context similar to that in real-life? A study in bicyclists

Numerous laboratory-based studies recorded eye movements in participants with varying expertise when watching video projections in the lab. Although research in the lab offers the advantage of internal validity, reliability and ethical considerations, ecological validity is often questionable. Therefore the current study compared visual search in 13 adult cyclists, when cycling a real bicycle path and while watching a film clip of the same road. Dwell time towards five Areas of Interest (AOIs) is analysed. Dwell time (%) in the lab and real-life was comparable only for the low quality bicycle path. Both in real-life and the lab, gaze is predominantly driven towards the road. Since gaze behaviour in the lab and real-life tends to be comparable with increasing task-complexity (road quality), it is concluded that under certain task constraints laboratory experiments making use of video clips might provide valuable information regarding gaze behaviour in real-life.     

Visual search for emotional expressions: Effect of stimulus set on anger and happiness superiority

Prior reports of preferential detection of emotional expressions in visual search have yielded inconsistent results, even for face stimuli that avoid obvious expression-related perceptual confounds. The current study investigated inconsistent reports of anger and happiness superiority effects using face stimuli drawn from the same database. Experiment 1 excluded procedural differences as a potential factor, replicating a happiness superiority effect in a procedure that previously yielded an anger superiority effect. Experiments 2a and 2b confirmed that image colour or poser gender did not account for prior inconsistent findings. Experiments 3a and 3b identified stimulus set as the critical variable, revealing happiness or anger superiority effects for two partially overlapping sets of face stimuli. The current results highlight the critical role of stimulus selection for the observation of happiness or anger superiority effects in visual search even for face stimuli that avoid obvious expression related perceptual confounds and are drawn from a single database.     

Probabilistic Inferences Under Emotional Stress: How Arousal Affects Decision Processes

Many models of decision making neglect emotional states that could affect individuals' cognitive processes. The present work explores the effect of emotional stress on people's cognitive processes when making probabilistic inferences. Two contrasting hypotheses are tested against one another: the uncertainty‐reduction and attention‐narrowing hypotheses of how emotional stress affects decision making. In the experimental study, emotional stress was induced through the use of highly aversive pictures immediately before each decision. Emotional state was assessed by both subjective (state anxiety, arousal, and pleasantness ratings) and objective (skin conductance) measures. The results show that emotional stress impacts decision making; in particular, emotionally aroused participants seem to have focused on the most important information and selected simpler decision strategies relative to participants in a control condition. The results are in line with the attention‐narrowing hypothesis and suggest that emotional stress can impact decision making through limited predecisional information search and the selection of simpler decision strategies. Copyright © 2015 John Wiley & Sons, Ltd.     

社会心理学中的启动研究:范式与挑战

启动效应被严格界定为先前刺激对后续无关情境中的行为反应产生的无意识影响,而且启动对象应是某种认知表征或思维过程。启动研究最早源于认知心理学领域,后被用于社会心理学研究中,并逐渐发展出概念启动、心理定势启动和序列启动三大启动范式及诸多新技术。已有研究存在启动术语混淆和实验者效应等内外部效度问题,其中最大的争议为启动研究结果的可重复性问题。未来研究应致力于解决这些问题,并探讨启动的作用机制。     

不同背景下不同频率闪烁的突显工效研究

本实验对黑、白背景下高频、中频、低频三种闪烁的突显工效进行了比较研究。实验结果表明：闪烁作为突显类型可以提高视觉搜索的绩效,而且,在闪烁的频率较高时（２７Ｈｚ以上）,这种闪烁的突显工效更为明显。视觉材料的呈现背景对闪烁突显视觉搜索绩效没有明显的影响,但在白背景下采用闪烁效果较好。     

All on the Same Side: Reflections on the Dialogue Between Science and Religion

The 'war' between religion and science is winding down, creating new opportunities for fruitful dialogue. The foundations of indirect religion-science dialogue, where the perspectives of the two disciplines illuminate some third subject, are not well established. A detailed comparison of the Roman Catholic bishops' dialogues and a similar program within the American Association for the Advancement of Science illustrates the variety in formalscience-religion interactions and reveals much about the promise, achievements, and limitations of different approaches. Success depends in large part on controlling the diversity of the dialogue group, choosing topics carefully, and adopting positive and cooperative attitudes.     

生命意义的内涵、测量及功能

研究者通常用目的和含义来定义生命意义,或者把它定义为多维度的结构。认知、动机和情感是被提及最多的生命意义的组成维度。动机和认知维度得到了较多研究者的认可,而情感维度存在较大争议。生命意义是幸福不可或缺的元素,它能够影响许多与幸福有关的变量。目前的研究对生命意义的动机维度(生命意义寻求)及如何获得和提高生命意义研究较少,今后的研究可针对这两方面开展。