无关工作记忆表征的负性情绪信息能否捕获视觉注意?一项眼动研究

研究通过分析视觉搜索任务的首次注视点和行为反应时, 探讨无关工作记忆表征的负性情绪信息对视觉注意选择的影响。实验1发现在反映早期注意选择的首次注视点百分率指标上, 不管工作记忆表征的情绪效价如何, 均出现了显著的注意捕获效应; 实验2发现当采用中性情绪靶子刺激时, 首次注视点百分率指标上仍表现出了稳健的注意捕获效应; 在首次注视点持续时间指标上, 实验1和实验2均发现记忆匹配条件的干扰刺激显著小于控制条件的干扰刺激, 表现出注意的快速脱离; 而在行为反应时指标上, 早期的注意捕获效应消失(实验1), 甚至被反转为注意抑制效应(实验2)。这些结果表明在早期注意选择阶段, 记忆驱动的注意捕获效应不受工作记忆表征情绪效价的影响, 但认知控制会在早期注意捕获之后促使注意快速脱离记忆匹配的干扰刺激, 其作用效果受靶子刺激情绪效价的调节。     

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。     

注意捕获效应受知觉负载及目标与干扰项距离的共同影响

研究考察了无关干扰项引发的注意捕获效应如何受到任务知觉负载以及目标与干扰项距离的共同影响。被试在视觉搜索集中搜索目标并做辨别反应。通过控制搜索集的大小来控制任务知觉负载, 同时在搜索集中存在一个用颜色标定的无关干扰项(奇异项), 该奇异项与当前的搜索目标存在一致、中性或不一致的关系, 该奇异项的位置与当前目标相邻或相距较远。结果发现, 被试在低负载条件下出现显著的干扰效应(不一致条件的反应时减中性条件的反应时), 而在高负载条件下干扰效应减小。此外, 在高负载条件下, 当目标与干扰项相距较近时没有出现干扰效应, 而当目标与干扰项相距较远时存在显著的干扰效应。干扰效应受到任务知觉负载和目标与无关干扰项距离的共同影响。这些结果说明, 与任务无关的刺激是否捕获注意取决于当前任务总体上是否存在可用的剩余注意资源, 也受到其周围临近区域的局部注意资源是否充足的影响。     

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。     

知觉负载影响注意选择和冲突解决的系列效应

研究考察了无关侧抑制项引起的侧抑制效应如何受到当前试次知觉负载和先前试次知觉负载与目标?侧抑制项关系的交互影响。被试在视觉搜索集中搜索目标朝向刺激(水平或竖直朝向)并作辨别反应, 非目标项在低负载条件下彼此朝向一致, 在高负载条件下彼此朝向不一致。在搜索集的左侧或右侧存在一个与当前目标一致或不一致的无关侧抑制项(flanker)。结果发现, 整体上, 在当前试次低负载条件下会产生较大的干扰效应, 而在当前试次高负载下无干扰效应。此外, 先前试次(trial n-1)为高负载条件时, 当前试次(trial n)出现了典型的知觉负载效应, 即低负载条件干扰效应较大, 高负载条件无干扰效应。但是, 先前试次为低负载条件时, 当前试次的干扰效应大小受到先前试次冲突解决状态的影响。先前试次为低负载条件且目标?无关侧抑制项不一致时, 下一试次低负载条件的侧抑制效应显著减小, 与高负载条件没有差异; 反之, 先前试次为低负载且目标?侧抑制项一致条件时, 下一试次低负载条件的侧抑制效应显著增大。先前试次为低负载条件时, 完成了知觉加工的侧抑制项或者引发了冲突效应(不一致条件), 或者促进了对目标的反应(一致条件), 造成不同的注意选择和冲突解决状态, 显著影响了下一试次的行为表现。这说明, 注意选择与冲突控制过程是动态变化的, 除了受到当前试次知觉负载的影响, 也受到先前试次注意选择和冲突解决状态的调节。     

情绪性记忆的定向遗忘效应

刺激的情绪性具有增强记忆的效果,那么,带有情绪信息的刺激对遗忘又会产生怎样的影响？已有研究从行为及认知神经机制层面探讨了情绪性刺激对定向遗忘效应的影响,但结果并不一致。总结已有文献发现,以情绪性刺激的材料类型、情绪效价、唤醒度和熟悉度为主的客观因素和以被试的情绪状态为主的主观因素均为影响定向遗忘效应产生及其稳定性的重要原因。这类研究是对有意遗忘研究领域的重要补充,也加深了人们对有意遗忘机制的理解。     

中英双语者情绪注意偏向中的双语优势效应

采用改进的点–探测范式,考察熟练双语者在情绪注意偏向中对情绪信息加工的优势效应及该效应产生的原因。采用2（熟练双语者和非熟练双语者）×3（靶刺激与消极词汇出现的位置一致、不一致和中性条件）×2（线索呈现时间为100 ms和400 ms）的混合实验设计,记录被试对靶子的按键反应时和错误率。结果发现：线索呈现100 ms和400 ms时,两组被试在注意定向分数上无显著差异;线索呈现100 ms时,两组被试的注意解除分数无显著差异;线索呈现400 ms时,熟练双语者的注意解除分数显著小于非熟练双语者。结果表明,在情绪注意偏向任务中,熟练双语者比非熟练双语者表现出了对情绪词汇信息更好的注意抑制控制能力,体现出对情绪信息加工的双语优势效应,产生这一优势效应的原因是熟练双语者在注意的晚期阶段比非熟练双语者具有更好的情绪信息注意解除能力。     

工作记忆表征引导视觉注意选择的眼动研究

工作记忆表征能否引导视觉注意选择？目前实验结果尚不一致。有研究者认为能否观察到注意引导效应取决于视觉搜索类型。研究采用工作记忆任务与视觉搜索任务相结合的双任务范式, 结合眼动追踪技术, 对不同视觉搜索类型下的注意引导效应进行验证。实验1结果发现, 不管视觉搜索任务的靶子是否变化, 在早期的眼动指标上都发现了显著的注意引导效应, 但注意引导效应在靶子固定的视觉搜索任务下表现得更强。实验2在平衡两种视觉搜索任务中的工作记忆负载后发现, 两种视觉搜索任务下都出现了显著的注意引导效应, 但没有发现实验1中所出现的任务间差异。实验结果否定了视觉搜索类型对注意引导效应的决定性影响, 同时也提示工作记忆负载可能在注意引导效应中起重要作用。     

工作记忆内容驱动完全无关刺激捕获注意

研究通过三个实验以检验工作记忆内容能否自动引导注意选择视场中与之匹配的任务完全无关刺激。实验一要求被试在工作记忆保持阶段完成一个视觉搜索任务，结果发现当搜索序列外的无关干扰刺激与工作记忆内容匹配时搜索绩效显著降低；实验二结果表明该干扰效应不能归因于自下而上的启动机制，因为对颜色刺激仅仅进行知觉辨认而没有工作记忆加工时并没有产生启动效应；实验三通过缩短搜索任务刺激的呈现时间以使得被试在完成搜索任务前没有足够时间眼跳至无关干扰刺激，结果发现了与实验一类似的干扰效应，说明在没有眼跳的情况下与工作记忆内容匹配的完全无关刺激可以捕获注意。这些结果表明保持在工作记忆中的信息表征可以自动引导注意选择视场中与之匹配的任务完全无关刺激，为基于工作记忆内容的注意捕获提供了新证据支持。     

知觉与表象过程中不同线索表情的启动效应研究

探讨情绪性面孔的知觉和表象过程中,不同类型线索表情的启动效应,并关注不同类型表情表象难易的差异。选取NimStim数据库中20位演员的愉快、愤怒和中性表情作为启动刺激,随后呈现同一演员不同表情的图片,或通过颜色提示被试对不同表情进行表象,并同时进行表情类型判断。研究发现,情绪性面孔知觉与表象任务中均存在启动效应,之前呈现的线索面孔将会对接下来呈现的相同效价的面孔产生启动效应,对相反效价及中性面孔产生抑制; 在平衡不同类型面孔可能存在的启动效应后,正性、负性及中性表情是同样易于表象的。     

Aging and visual search: automatic and controlled attentional bias to threat faces

Using a visual search paradigm, we investigated how age affected attentional bias to emotional facial expressions. In Experiments 1 and 2, participants searched for a discrepant facial expression in a matrix of otherwise homogeneous faces. Both younger and older adults showed a more effective search when the discrepant face was angry rather than happy or neutral. However, when the angry faces served as non-target distractors, younger adults' search was less effective than happy or neutral distractor conditions. In contrast, older adults showed a more efficient search with angry distractors than happy or neutral distractors, indicating that older adults were better able to inhibit angry facial expressions. In Experiment 3, we found that even a top-down search goal could not override the angry face superiority effect in guiding attention. In addition, RT distribution analyses supported that both younger and older adults performed the top-down angry face search qualitatively differently from the top-down happy face search. The current research indicates that threat face processing involves automatic attentional shift and a controlled attentional process. The current results suggest that age only influenced the controlled attentional process.     

Emotional priming of pop-out in visual search

When searching for a discrepant target along a simple dimension such as color or shape, repetition of the target feature substantially speeds search, an effect known as feature priming of pop-out (V. Maljkovic and K. Nakayama, 1994). The authors present the first report of emotional priming of pop-out. Participants had to detect the face displaying a discrepant expression of emotion in an array of four face photographs. On each trial, the target when present was either a neutral face among emotional faces (angry in Experiment 1 or happy in Experiment 2), or an emotional face among neutral faces. Target detection was faster when the target displayed the same emotion on successive trials. This effect occurred for angry and for happy faces, not for neutral faces. It was completely abolished when faces were inverted instead of upright, suggesting that emotional categories rather than physical feature properties drive emotional priming of pop-out. The implications of the present findings for theoretical accounts of intertrial priming and for the face-in-the-crowd phenomenon are discussed.     

Task-irrelevant angry faces capture attention in visual search while modulated by resources

We investigated the attentional capture effect of emotional faces under sufficient or restricted attentional conditions. In a modified visual search paradigm, three kinds of schematic faces (angry, happy, and neutral) served as stimuli. Participants were instructed to search for a target face indicated by a dot and to respond to the dot's position. In this design, the emotional content of the face is task-irrelevant and does not need to be attended. The results of Experiment 1 demonstrate that having an angry face as the target face elicited a faster response than did the neutral target face, and when the angry face is used as a distractor, the response to the target was delayed compared to the response with no such distractor. Experiment 2 included inverted faces to decrease emotional content; results showed that inversion of the faces reduced the effect of angry faces on the search performance. When attention was cued to a specific area in Experiment 3, the effect of angry faces outside of the cued area became weaker. In conclusion, the results indicate that a task-irrelevant angry face can capture attention beyond top-down control, but this effect is modulated by the availability of attentional resources. (PsycINFO Database Record (c) 2011 APA, all rights reserved).     

Perceptual grouping, not emotion, accounts for search asymmetries with schematic faces

Several different explanations have been proposed to account for the search asymmetry (SA) for angry schematic faces (i.e., the fact that an angry face target among friendly faces can be found faster than vice versa). The present study critically tested the perceptual grouping account, (a) that the SA is not due to emotional factors, but to perceptual differences that render angry faces more salient than friendly faces, and (b) that the SA is mainly attributable to differences in distractor grouping, with angry faces being more difficult to group than friendly faces. In visual search for angry and friendly faces, the number of distractors visible during each fixation was systematically manipulated using the gaze-contingent window technique. The results showed that the SA emerged only when multiple distractors were visible during a fixation, supporting the grouping account. To distinguish between emotional and perceptual factors in the SA, we altered the perceptual properties of the faces (dented-chin face) so that the friendly face became more salient. In line with the perceptual account, the SA was reversed for these faces, showing faster search for a friendly face target. These results indicate that the SA reflects feature-level perceptual grouping, not emotional valence.     

Age-related differences in the distractor previewing effect with schematic faces of emotions

Young and older adults searched for a unique face in a set of three schematic faces and identified a secondary feature of the target. The faces could be negative, positive, or neutral. Young adults were slower and less accurate in searching for a negative face among neutral faces when they had previewed a display of negative faces than when they had previewed neutral faces, indicating an emotional distractor previewing effect (DPE), but this effect was eliminated with inverted faces. The DPE is an index of inter-trial inhibition to keep attention away from previewed, non-target information. Older adults also showed such an emotional DPE, but it was present with both upright and inverted faces. These results show that, in general, both young and old participants are sensitive to trial history, yet the different patterns of results suggest that these two groups remember and use different types of perceptual information when searching through emotional faces.     

Visual search is not blind to emotion

A series of three visual search tasks revealed more efficient search for hostile than for peaceful faces among neutral face distractors. Given that this effect has been observed inconsistently in prior literature, meta-analytic methods were employed for evaluating data across three experiments in order to develop a more valid estimate of the potentially small effect size. Furthermore, in the present experiments, different emotional meanings were conditioned to identical faces across observers, thus eliminating confounds between the physical characteristics and the emotional valences of the face stimuli. On the basis of the present findings, we argue that the visual system is capable of determining a face's emotional valence before the face becomes the focus of attention, and that emotional valence can be used by the visual system to determine subsequent attention allocation. However, meta-analytic results indicate that emotional valence makes a relatively small contribution to search efficiency in the present search context.     

Angry faces are tracked more easily than neutral faces during multiple identity tracking

We investigated whether and how emotional facial expressions affect sustained attention in face tracking. In a multiple-identity and object tracking paradigm, participants tracked multiple target faces that continuously moved around together with several distractor faces, and subsequently reported where each target face had moved to. The emotional expression (angry, happy, and neutral) of the target and distractor faces was manipulated. Tracking performance was better when the target faces were angry rather than neutral, whereas angry distractor faces did not affect tracking. The effect persisted when the angry faces were presented upside-down and when surface features of the faces were irrelevant to the ongoing task. There was only suggestive and weak evidence for a facilitatory effect of happy targets and a distraction effect of happy distractors in comparison to neutral faces. The results show that angry expressions on the target faces can facilitate sustained attention on the targets via increased vigilance, yet this effect likely depends on both emotional information and visual features of the angry faces.     

Task-irrelevant direct gaze facilitates visual search for deviant facial expression

The detection of emotional expression is important particularly when the expression is directed towards the viewer. Therefore, we conjectured that the efficiency in visual search for deviant emotional expression is modulated by gaze direction, which is one of the primary clues for encoding the focus of social attention. To examine this hypothesis, two visual search tasks were conducted. In Emotional Face Search, the participants were required to detect an emotional expression amongst distractor faces with neutral expression; in Neutral Face Search they were required to detect a neutral target among emotional distractors. The results revealed that target detection was accelerated when the target face had direct gaze compared to averted gaze for fearful, angry, and neutral targets, but no effect of distractor gaze direction was observed. An additional experiment including multiple display sizes has shown a shallower search slope in search for a target face with direct gaze than that with averted gaze, indicating that the advantage of a target face with direct gaze is attributable to efficient orientation of attention towards target faces. These results indicate that direct gaze facilitates detection of target face in visual scenery even when gaze discrimination is not the primary task at hand.     

A tale of two negatives: differential memory modulation by threat-related facial expressions

Facial expressions serve as cues that encourage viewers to learn about their immediate environment. In studies assessing the influence of emotional cues on behavior, fearful and angry faces are often combined into one category, such as "threat-related," because they share similar emotional valence and arousal properties. However, these expressions convey different information to the viewer. Fearful faces indicate the increased probability of a threat, whereas angry expressions embody a certain and direct threat. This conceptualization predicts that a fearful face should facilitate processing of the environment to gather information to disambiguate the threat. Here, we tested whether fearful faces facilitated processing of neutral information presented in close temporal proximity to the faces. In Experiment 1, we demonstrated that, compared with neutral faces, fearful faces enhanced memory for neutral words presented in the experimental context, whereas angry faces did not. In Experiment 2, we directly compared the effects of fearful and angry faces on subsequent memory for emotional faces versus neutral words. We replicated the findings of Experiment 1 and extended them by showing that participants remembered more faces from the angry face condition relative to the fear condition, consistent with the notion that anger differs from fear in that it directs attention toward the angry individual. Because these effects cannot be attributed to differences in arousal or valence processing, we suggest they are best understood in terms of differences in the predictive information conveyed by fearful and angry facial expressions.