One and Done? Optimal Decisions From Very Few Samples

In many learning or inference tasks human behavior approximates that of a Bayesian ideal observer, suggesting that, at some level, cognition can be described as Bayesian inference. However, a number of findings have highlighted an intriguing mismatch between human behavior and standard assumptions about optimality: People often appear to make decisions based on just one or a few samples from the appropriate posterior probability distribution, rather than using the full distribution. Although sampling‐based approximations are a common way to implement Bayesian inference, the very limited numbers of samples often used by humans seem insufficient to approximate the required probability distributions very accurately. Here, we consider this discrepancy in the broader framework of statistical decision theory, and ask: If people are making decisions based on samples—but as samples are costly—how many samples should people use to optimize their total expected or worst‐case reward over a large number of decisions? We find that under reasonable assumptions about the time costs of sampling, making many quick but locally suboptimal decisions based on very few samples may be the globally optimal strategy over long periods. These results help to reconcile a large body of work showing sampling‐based or probability matching behavior with the hypothesis that human cognition can be understood in Bayesian terms, and they suggest promising future directions for studies of resource‐constrained cognition.     

Judgment Difficulty and the Moral Intensity of Unethical Acts: A Cognitive Response Analysis of Dual Process Ethical Judgment Formation

This study analyzes cognitive responses to explore a dual processing perspective of ethical judgment formation. Specifically, the study investigates how two factors, judgment task difficulty and moral intensity, influence the extent of deontological and teleological processing and their effects on ethical judgments. A single experiment on 110 undergraduate research participants found that judgment task difficulty affected the extent of deontological and teleological processing. Although moral intensity affected ethical judgments, it did not produce effects on either deontological or teleological cognitive responses. Results did not support the hypotheses that deontological and teleological cognitive responses would mediate the relationships between the experimental factors and ethical judgments. Overall, the results support continued research of factors that affect the nature of information processing in ethical decision situations and the use of cognitive response analysis as a tool for conducting this research.     

Implicit visual learning: How the task set modulates learning by determining the stimulus–response binding

Implicit learning is one of the most fundamental learning mechanisms that enables humans to adapt to regularities inherent in the environment. Despite its high flexibility, it depends on constraints, such as selective attention. Here, we focused on the stimulus-to-response binding which defines the dimensions of the stimuli and the responses participants attend to. In a serial reaction time task with a visual sequence, we investigated whether this stimulus–response binding influences the amount of sequence learning. The results of Experiments 1 and 2 showed that visual sequence learning is reduced when participants do not attend to the relevant response dimension. Furthermore, the findings of Experiment 3 suggest that attention to the relevant response dimension increased the development of explicit knowledge without affecting implicit knowledge. This latter finding is difficult to reconcile with the assumption that explicit learning results from the gradual strengthening of sequence representations.     

不同认知方式对词—面孔任务Stroop效应的影响

该研究采用词—面孔Stroop任务,以76名大学生为被试,探讨了不同认知方式（场独立、场依存）对情绪冲突Stroop效应的影响。结果发现：（1）情绪冲突的Stroop效应显著,即,在词—面孔Stroop任务中,当词和面孔的情绪效价一致时,被试的反应时更短,正确率更高。（2）认知方式对情绪冲突Stroop任务的影响显著,表现为无论是一致还是不一致条件下,场独立者比场依存者的反应时都更短。（3）场依存者的情绪冲突Stroop效应更大,表现为其在词—面孔情绪效价一致和不一致条件下的反应时差异更大。     

高趋近动机积极情绪对注意灵活性的影响

该研究通过两个实验探讨不同趋近动机强度的积极情绪对注意灵活性的影响。实验一中40名大学生被试分别在高趋近和低趋近动机积极情绪条件下完成隐性注意朝向任务;实验二以35名大学生为被试,考察高趋近动机积极情绪和中性情绪条件下的注意灵活性。两项实验结果表明,与低趋近动机积极情绪和中性情绪条件相比,高趋近动机积极情绪下个体的注意灵活性降低,实验结果支持情绪的动机维度模型。     

经颅直流电刺激对健康人群反应抑制的影响

反应抑制是指抑制不恰当的或不符合当前需要的行为的能力, 研究表明反应抑制主要与额下回、背外侧前额叶和前辅助运动区的功能有关。经颅直流电刺激(tDCS)是一种非侵入式脑刺激技术, 近年来对健康人群使用tDCS刺激相应脑区从而影响反应抑制功能的研究日益增多, 但主要研究结果不一致。阐明tDCS影响反应抑制具体的神经机制、减少tDCS研究的异质性、探索更有效的tDCS刺激方式和确定tDCS效果的年龄依赖性差异已成为目前亟待解决的问题。     

任务切换理论争议新证据

任务切换是研究认知控制的主要范式之一。大量研究发现切换试次比重复试次的反应时更长,错误率更高,这种差异称为切换代价。任务切换时所产生切换代价的理论解释主要有惯性论、重构论和联结论。近十年来,这些理论均获得新的实验支持和发展,但其争议依旧,没有哪一理论能成功解释任务切换的所有效应。未来研究可以建立整合模型,以准确描述切换代价产生的认知机制。     

阈上阈下启动刺激在不同锻炼人群中引发自动评价的特点

双加工理论认为锻炼行为形成中自动加工（系统1）和熟虑加工（系统2）是两个相互作用但又截然不同的信息处理系统,其中自动评价通过触发系统1的自动加工过程激活运动记忆自发的心理联想,并对运动进行情感评价,从而影响锻炼行为。本研究的目的是检测锻炼相关刺激在不同锻炼人群中引发的自动评价特点。采用评价启动任务范式,实验1和实验2分别给予阈上和阈下锻炼词或非锻炼词作为启动刺激,之后要求被试对积极或者消极目标词进行按键反应。研究结果显示无论阈上还是阈下呈现锻炼启动词,均表现为锻炼组对积极目标词反应速度更快。结果表明：锻炼人群对于锻炼词具有积极自动评价。