奖赏预期调节局部注意干扰效应

局部注意干扰效应(Localized attentional interference, LAI)是指在视觉搜索任务中同时搜索在空间上分离的两个目标时, 或者目标周围存在一个无关奇异项时, 这两个关键刺激相距较近时产生的干扰现象。本实验采用视觉搜索范式, 探讨了奖赏预期对局部注意干扰效应的影响。实验1采用双目标搜索任务, 要求被试判断搜索画面中两个奇异项刺激的形状是否相同。结果显示奖赏条件和无奖赏条件都表现出显著的距离主效应, 随着目标间距离增大, 被试的正确率提高, 反应时下降。同时, 在远距离时, 奖赏条件下的正确率高于无奖赏条件, 而在近距离时, 奖赏条件下的正确率反而低于无奖赏条件, 即, 奖赏条件下局部注意干扰效应反而增大。高动机状态增强了两个目标的表征, 反而不利于解决局部注意干扰效应。实验2采用单目标搜索任务, 要求被试判断特定目标的方位并忽略另一无关奇异项刺激。与实验1不同的是, 实验2仅在无奖赏条件下观察到显著的距离主效应, 即被试行为表现在远距离时更好; 而在奖赏条件下, 被试在近距离和远距离的表现一样好, 即没有局部注意干扰效应。这说明在奖赏预期条件, 个体可以有效抑制分心物刺激的干扰, 将注意集中于目标刺激的加工, 从而对局部注意干扰效应产生调节。整个研究表明, 奖赏整体上能够提高对任务相关刺激的表征, 并抑制任务无关刺激, 虽然这并不总是能够提高任务表现。     

网络成瘾倾向者在视觉工作记忆引导下的注意捕获

采用工作记忆任务和视觉搜索任务相结合的双任务范式, 探讨网络成瘾倾向者在视觉工作记忆引导下的注意捕获。实验1考察了单一分心刺激视场中分心刺激的性质对网络成瘾倾向者选择性注意的影响, 实验2通过控制匹配试验出现的概率来诱发不同的抑制动机, 探讨多分心刺激视场中两种抑制动机下网络成瘾倾向者的注意表现。结果发现：(1)无论在单一分心刺激还是多分心刺激视场中, 网络成瘾倾向被试的目标搜索反应时均显著短于正常组被试, 且两组的搜索正确率没有差异。(2)在单一分心刺激视场中, 无论是与工作记忆项目匹配还是不匹配的分心刺激都会捕获正常组被试的注意, 但不会捕获网络成瘾倾向被试的注意。(3)在多分心刺激视场中, 当抑制动机水平较低时, 两组被试均对匹配分心物产生注意捕获效应, 且网络成瘾倾向被试受工作记忆引导的注意捕获效应小于正常组被试; 当抑制动机较高时, 两组被试均对匹配分心物产生注意抑制效应, 且没有差异。研究结果表明, 面对非网络相关视觉刺激时, 网络成瘾倾向者受工作记忆引导的注意捕获效应小于正常组, 并表现出了知觉加工上的优势。     

工作记忆内容对不同学业水平学生自上而下注意控制的影响

该研究采用视觉搜索任务范式,以小学五年级学优生与学困生为被试,探讨了工作记忆内容对不同学业水平学生自上而下注意控制的影响。结果发现:(1)学优生与学困生的自上而下注意控制能力存在显著差异,学优生的反应时显著短于学困生;(2)工作记忆内容影响自上而下注意控制,靶相关信息能促进对靶刺激的搜索,而靶无关信息却会干扰对靶刺激的搜索。     

道路交通标志中对称结构效应的眼动研究

本研究考察了道路交通标志中路名信息对称结构效应的眼动模式。实验采用眼动跟踪技术和视觉搜索范式,共有16名被试参加。实验结果表明：（1）在对称结构路名信息的视觉搜索中,被试的反应正确率明显优于非对称结构条件下的正确率;（2）对称结构条件下,被试的注视点和回扫次数明显较少,凝视时间明显较短;（3）在以道路交通标志为视觉搜索材料时,搜索区有无路名目标对视觉搜索绩效没有影响。可以认为：在道路交通标志中存在对称结构效应;眼动模式的差异是引起对称结构效应的认知机制。     

认知控制在工作记忆表征引导注意中的作用:来自眼动的证据

研究同时采用首次注视点百分率与行为反应时指标,探讨了认知控制在无关工作记忆表征引导视觉注意选择过程中的作用。实验1发现:当视觉搜索容易时,首次注视点百分率和反应时指标都出现了注意引导效应;而当视觉搜索困难时,在反映早期注意定向的首次注视点百分率指标上,搜索快的被试组的注意引导效应显著大于搜索慢的被试组,而在行为反应时指标上,搜索快的被试组表现出注意引导效应,但搜索慢的被试组则表现出相反的注意拒绝效应。实验2发现当采用更为突显的靶子刺激时,首次注视点百分率指标上表现出的注意引导效应并未受到视觉搜索靶子显著性的影响,甚至还表现出一定的优先性。这些结果表明认知控制在工作记忆表征引导视觉注意的过程中所起的作用是动态变化的,视觉搜索早期注意定向阶段的注意引导效应比较稳健,认知控制只能减弱其效应的量值,而在随后的视觉搜索过程中,当视觉搜索比较缓慢时,认知控制可能会将注意引导效应反转为相反的注意拒绝效应。     

音乐训练与抑制控制的关系：来自ERPs的证据

抑制控制是人类非常重要的认知功能之一, 它对个体适应环境具有重要的意义。本研究将抑制控制细分为反应抑制和冲突控制, 采用Go/No-go和Stroop任务从行为和脑电层面, 考察了音乐训练与抑制控制能力的关系及其认知神经机制。结果发现：在行为指标上, 音乐训练组比控制组的Stroop干扰效应更小, 但两组被试在Go/No-go任务表现上没有差异。在脑电指标上, 在Go/No-go任务中音乐训练组的N2差异波和P3差异波波幅(No-go减Go条件)显著大于控制组, 在Stroop任务中音乐训练组的N450差异波波幅(不一致减一致条件)也显著大于控制组, 但两组被试的SP差异波波幅(不一致减一致条件)无显著差异。结果表明：音乐训练组被试在反应抑制任务中可能具有更强的冲突监控和运动抑制能力, 在冲突控制任务中也具有更强的冲突监控能力。本研究从电生理的层面反映了音乐训练与抑制控制能力的提升具有一定的关联。     

任务相关性对数量感序列依赖效应的影响

序列依赖效应反映了当前的知觉体验不仅取决于当下的刺激输入,还受到近期历史的影响。这一效应对于我们在动态变化的环境中形成相对稳定的知觉至关重要。本研究使用点阵作为刺激材料,在数量/面积(实验1)或数量/大小(实验2)两个维度上进行正交设计,旨在通过估计任务探索任务相关性如何影响线性分布特征的序列依赖效应。结果显示无论特征是否与任务相关,前一试次与当前试次同一特征总会对当前试次的知觉产生相反的影响。对于任务相关特征,前一试次产生的序列依赖始终为排斥效应。而对于任务无关特征,如果在当前试次中无关特征对被试的知觉反应有正向预测作用,则前一试次无关特征产生排斥的序列依赖效应;反之,如果在当前试次中无关特征对被试的知觉反应有负向预测,则前一试次无关特征产生吸引的序列依赖效应。任务相关性对序列依赖效应的影响主要体现在效应幅值的降低。这些发现揭示了线性分布特征的序列依赖效应受任务相关性以及特征本身特性的共同影响,而无关特征的序列依赖效应则暗示在客体水平也可以产生序列依赖效应。     

复杂图形表象产生的认知加工机制

采用Kosslyn双任务分离的研究范式,通过两个实验考察了复杂图形表象产生的认知加工机制。实验1提出了当要求被试在产生动物的部分表象时,大脑左半球明显反应更快;而当要求被试产生客体整体特征的表象时,并没有出现大脑半球的优势效应。实验2采用控制任务进一步证实大脑两半球不同的优势效应,研究发现当同样的任务以知觉形式完成时,没有大脑半球的优势效应。实验结果表明,在复杂图形表象产生的过程中,当产生部分表象时,大脑左半球有显著优势;而当产生整体表象时,两半球起同样作用。此结果进一步拓展了Kosslyn提出的大脑半球专门化假说。     

侗歌经验对侗族中学生执行功能的影响

音乐训练对认知能力具有广泛的促进效应。本研究结合执行功能的三个成分(抑制控制、工作记忆和认知灵活性), 在我国民族音乐背景下, 匹配实验任务的视觉和听觉形式, 探讨侗歌经验对侗族中学生执行功能的影响。结果表明, 侗歌组被试在抑制能力和刷新能力上显著好于侗族非侗歌组被试和汉族被试, 这一优势在视觉任务中和听觉任务中均存在, 说明侗歌经验产生的认知优势具有跨感觉通道的普遍性。侗歌组被试和侗族非侗歌组被试的转换能力差异不显著。侗族非侗歌组被试的抑制能力和转换能力好于汉族被试, 这体现了语言和音乐的交互作用。     

视知觉无意识对局部形状和颜色特征加工的注意调节

研究了视知觉无意识对局部几何特征加工中的整体优势效应.被试为天津师范大学本科生60名.仪器为pentium III高分辨率计算机,程序用E-prime心理实验软件系统编制而成.被试的任务是判断靶图形中央线条的方向或颜色.用MANOVA分析了启动图形对靶图形局部特征加工的启动效应,发现了视知觉对无意识呈现的图形加工具有形状优势效应,启动图形与靶图形的整体形状相同可以抑制对靶图形局部形状特征的判断.当被试的任务变成判断靶线条的颜色或启动图形的边由连通状态变成不连通时,视知觉无意识对启动图形加工的整体优势效应消失.该结果提示整体优势效应很可能与任务涉及的信息通道密切相关,对局部形状特征的注意很可能涉及对周围整体形状信息加工自动抑制的过程.     

Spatial and temporal separation fails to counteract the effects of low prevalence in visual search

Recent research has shown that, in visual search, participants can miss 30–40% of targets when they only appear rarely (i.e., on 1–2% of trials). Low target prevalence alters the behaviour of the searcher. It can lead participants to quit their search prematurely (Wolfe, Horowitz, & Kenner, 2005), to shift their decision criteria (Wolfe et al., 2007), and/or to make motor or response errors (Fleck & Mitroff, 2007). In this paper we examine whether the low prevalence (LP) effect can be ameliorated if we split the search set in two, spreading the task out over space and/or time. Observers searched for the letter “T” among “L”s. In Experiment 1, the left or right half of the display was presented to the participants before the second half. In Experiment 2, items were spatially intermixed but half of the items were presented first, followed by the second half. Experiment 3 followed the methods of Experiment 2 but allowed observers to correct perceived errors. All three experiments produced robust LP effects with higher errors at 2% prevalence than at 50% prevalence. Dividing up the display had no beneficial effect on errors. The opportunity to correct errors reduced but did not eliminate the LP effect. Low prevalence continues to elevate errors even when observers are forced to slow down and permitted to correct errors.     

Spatial and temporal separation fails to counteract the effects of low prevalence in visual search

Recent research has shown that, in visual search, participants can miss 30-40% of targets when they only appear rarely (i.e. on 1-2% of trials). Low target prevalence alters the behavior of the searcher. It can lead participants to quit their search prematurely (Wolfe et al., 2005), to shift their decision criteria (Wolfe et al., 2007) and/or to make motor or response errors (Fleck & Mitroff, 2007). In this paper we examine whether the LP Effect can be ameliorated if we split the search set in two, spreading the task out over space and/or time. Observers searched for the letter "T" among "L"s. In Experiment 1, the left or right half of the display was presented to the participants before the second half. In Experiment 2, items were spatially intermixed but half of the items were presented first, followed by the second half. Experiment 3 followed the methods of Experiment 2 but allowed observers to correct perceived errors. All three experiments produced robust low prevalence (LP) effects with higher errors at 2% prevalence than at 50% prevalence. Dividing up the display had no beneficial effect on errors. The opportunity to correct errors reduced but did not eliminate the LP effect. Low prevalence continues to elevate errors even when observers are forced to slow down and permitted to correct errors.     

Even in correctable search, some types of rare targets are frequently missed

Socially important visual search tasks, such as airport baggage screening and tumor detection, place observers in situations where the targets are rare and the consequences of failed detection are substantial. Recent laboratory studies have demonstrated that low target prevalence yields substantially higher miss errors than do high-prevalence conditions, in which the same targets appear frequently (Wolfe, Horowitz, & Kenner, 2005; Wolfe et al., 2007). Under some circumstances, this \ldprevalence effect\rd can be eliminated simply by allowing observers to correct their last response (Fleck & Mitroff, 2007). However, in three experiments involving search of realistic X-ray luggage images, we found that the prevalence effect is eliminated neither by giving observers the choice to correct a previous response nor by requiring observers to confirm their responses. This prevalence effect, obtained when no trial-by-trial feedback was given, was smaller than the effect obtained when observers searched through the same stimuli but were given trial-by-trial feedback about accuracy. We suggest that low prevalence puts pressure on observers in any search task, and that the diverse symptoms of that pressure manifest themselves differently in different situations. In some relatively simple search tasks, misses may result from motor or response errors. In other, more complex tasks, shifts in decision criteria appear to be an important contributor.     

“… the art of shaping a democratic reality and being directed by it …”—philososophy of science in turbulent times

This article has three objectives: First, it revises the history of the reception of Ludwik Fleck??s monograph Entstehung und Entwicklung einer wissenschaftlichen Tatsache (1935, Genesis and Development of a Scientific Fact). Contrary to the established picture, Fleck??s book was largely discussed in the years before the outbreak of World War II. What becomes clear when reading these early reviews and especially Fleck??s comments to those written by representatives of Nazi Germany is, second, the political dimension of his epistemology. In this respect, Fleck??s emphasis on the genuinely democratic character of science will be discussed in some detail. And third, Fleck??s notion of ??Denkstil????thought-style??shall be examined more closely since, as we will claim, it can be understood as a notion indicating where the democratic dimension of science encounters its limits.     

Features,as well as space and time,guide object persistence

What role do surface features (e.g., color) play in the establishment and maintenance of episodic representations of objects (object files)? Mitroff and Alvarez (2007) showed that stimuli that were linked by a continuous spatiotemporal history yielded object-specific preview benefits—a standard index of object files—whereas stimuli linked only by shared surface features did not. Here, it is shown that abruptly changing the features of an object that has been established on the basis of spatiotemporal history can disrupt object-specific preview benefits (Experiments 1 and 2). Moreover, under some conditions, feature match alone can give rise to the preview benefits (Experiment 3). These results indicate that surface features, as well as spatiotemporal factors, play an important role in establishing and maintaining episodic object representations.     

Low target prevalence is a stubborn source of errors in visual search tasks

In visual search tasks, observers look for targets in displays containing distractors. Likelihood that targets will be missed varies with target prevalence, the frequency with which targets are presented across trials. Miss error rates are much higher at low target prevalence (1%-2%) than at high prevalence (50%). Unfortunately, low prevalence is characteristic of important search tasks such as airport security and medical screening where miss errors are dangerous. A series of experiments show this prevalence effect is very robust. In signal detection terms, the prevalence effect can be explained as a criterion shift and not a change in sensitivity. Several efforts to induce observers to adopt a better criterion fail. However, a regime of brief retraining periods with high prevalence and full feedback allows observers to hold a good criterion during periods of low prevalence with no feedback.     

The effects of local prevalence and explicit expectations on search termination times

In visual search tasks, the relative proportions of target-present and -absent trials have important effects on behavior. Miss error rates rise as target prevalence decreases (Wolfe, Horowitz, & Kenner, Nature 435, 439-440, 2005). At the same time, search termination times on target-absent trials become shorter (Wolfe & Van Wert, Current Biology 20, 121-124, 2010). These effects must depend on some implicit or explicit knowledge of the current prevalence. What is the nature of that knowledge? In Experiment 1, we conducted visual search tasks at three levels of prevalence (6%, 50%, and 94%) and analyzed performance as a function of "local prevalence," the prevalence over the last n trials. The results replicated the usual effects of overall prevalence but revealed only weak or absent effects of local prevalence. In Experiment 2, the overall prevalence in a block of trials was 20%, 50%, or 80%. However, a 100%-valid cue informed observers of the prevalence on the next trial. These explicit cues had a modest effect on target-absent RTs, but explicit expectation could not explain the full prevalence effect. We conclude that observers predict prevalence on the basis of an assessment of a relatively long prior history. Each trial contributes a small amount to that assessment, and this can be modulated but not overruled by explicit instruction.     

Rates and correlates of undetermined deaths among African Americans: results from the National Violent Death Reporting System

Little is known about the factors associated with undetermined death classifications among African Americans. In this study, the rates of undetermined deaths were assessed, the prevalence of missing information was estimated, and whether the circumstances preceding death differ by race were examined. Data were derived from the 2005-2008 National Violent Death Reporting System. African Americans had higher prevalence of missing information than Whites. African Americans classified as undetermined deaths were more likely to be older, women, never married/single, to have had a blood alcohol content at or above the legal limit, and to have had a substance abuse problem. The results suggest that racial differences in the preponderance and the type of evidence surrounding the death may affect death classification.     

认知诊断缺失数据处理方法的比较：零替换、多重插补与极大似然估计法

数据缺失在测验中经常发生, 认知诊断评估也不例外, 数据缺失会导致诊断结果的偏差。首先, 通过模拟研究在多种实验条件下比较了常用的缺失数据处理方法。结果表明：(1)缺失数据导致估计精确性下降, 随着人数与题目数量减少、缺失率增大、题目质量降低, 所有方法的PCCR均下降, Bias绝对值和RMSE均上升。(2)估计题目参数时, EM法表现最好, 其次是MI, FIML和ZR法表现不稳定。(3)估计被试知识状态时, EM和FIML表现最好, MI和ZR表现不稳定。其次, 在PISA2015实证数据中进一步探索了不同方法的表现。综合模拟和实证研究结果, 推荐选用EM或FIML法进行缺失数据处理。     

Comparison of Modern Methods for Analyzing Repeated Measures Data With Missing Values

Missing data are a pervasive problem in many psychological applications in the real world. In this article we study the impact of dropout on the operational characteristics of several approaches that can be easily implemented with commercially available software. These approaches include the covariance pattern model based on an unstructured covariance matrix (CPM-U) and the true covariance matrix (CPM-T), multiple imputation-based generalized estimating equations (MI-GEE), and weighted generalized estimating equations (WGEE). Under the missing at random mechanism, the MI-GEE approach was always robust. The CPM-T and CPM-U methods were also able to control the error rates provided that certain minimum sample size requirements were met, whereas the WGEE was more prone to inflated error rates. In contrast, under the missing not at random mechanism, all evaluated approaches were generally invalid. Our results also indicate that the CPM methods were more powerful than the MI-GEE and WGEE methods and their superiority was often substantial. Furthermore, we note that little or no power was sacrificed by using CPM-U method in place of CPM-T, although both methods have less power in situations where some participants have incomplete data. Some aspects of the CPM-U and MI-GEE methods are illustrated using real data from 2 previously published data sets. The first data set comes from a randomized study of AIDS patients with advanced immune suppression, the second from a cohort of patients with schizotypal personality disorder enrolled in a prevention program for psychosis.