情绪诱发视盲任务中的情绪注意控制机制：来自脑电ERP和时频分析的证据

采用脑电时频分析技术,对情绪诱发视盲任务中的情绪控制机制进行了分析。实验设置负性图片、中性图片及填充图片三种干扰刺激条件,关注被试正确完成目标识别时的干扰刺激加工过程。实验结果发现,负性与中性干扰刺激在注意加工阶段均较控制性的填充图片条件诱发前额中央分布的theta同步化效应,而且负性刺激所诱发的此效应又较中性情绪刺激更多分布在左侧前额和颞枕部。实验结果表明：（1）情绪诱发视盲任务下被试确实存在对于情绪干扰刺激的自上而下控制;（2）相比中性干扰刺激,负性干扰刺激在EIB中的情绪注意控制机制不仅包括前人所发现的后部颞枕区对刺激识别的注意控制,而且包括前额叶参与下的负性情绪控制。     

任务无关情绪刺激对工作记忆信息更新的影响:来自ERP的证据

任务无关的情绪刺激如何对工作记忆的信息更新过程产生影响还不清楚。本研究采用情绪N-back任务,结合事件相关电位技术调查情绪对工作记忆信息更新的影响。ERP结果显示,在0-back任务中,负性分心物诱发的P3显著小于中性分心物,表明其干扰了工作记忆信息更新过程;而在2-back任务中,负性分心物诱发的P3与中性分心物没有显著差异,表明其未对信息更新表现出干扰效应。该结果支持了情绪与认知加工的双竞争模型。     

Differential response patterns to disgust-related pictures

ABSTRACT

In the present study, attentional bias was investigated as a potential predisposing mechanism for the contamination-related subtype of obsessive-compulsive disorder (C-OC disorder). Fifty healthy participants with varying degrees of subclinical C-OC symptoms performed a visual search task to measure differential attentional biases elicited by neutral, disgust-, and fear-specific pictorial material. Participants had to find a target picture within five neutral distractor pictures randomly presented on different locations in an array. The task was to decide whether the array contained an unpleasant target picture or not. In randomly-selected emotional trials, participants were further asked about the content of the picture and the confidence of their answer. The results show that the reaction times significantly differed between the emotional and neutral pictures. Participants were significantly more confident in answering questions referring to fear compared to disgust pictures. This effect was marginally amplified in participants with higher C-OC symptoms. We discuss the results within the framework of the cost and benefit hypothesis, which postulates that disgust evolutionarily elicits stronger uncertainty compared to fear, owing to the ambiguous nature of the stimuli. Increased uncertainty might be an important but underestimated factor for pathological disgust experience, such as in obsessive-compulsive disorder.     

Prior cognitive activity implicitly modulates subsequent emotional responses to subliminally presented emotional stimuli

It has been reported that engagement in several kinds of cognitive activity can successfully inhibit unpleasant emotions. In this study, we tried to replicate the previous finding that cognitive activity can modulate subsequent psychological and physiological emotional processes and to investigate whether prior cognitive activity can attenuate implicit emotional processes triggered by subliminal emotional stimuli. Sixty students were randomly divided into three groups (cognitive task group, noncognitive task group, control group). The cognitive task group was asked to engage in an n-back task, while the control group was asked to stay calm. The noncognitive task group was asked to do a handgrip-squeezing task. All participants then engaged in a version of a subliminal affective priming task where they were unconsciously exposed to affectively negative pictures. The cognitive task group showed lower negative experiences after the subliminal affective priming task and a substantial reduction in their heart rate responses, as compared with the other groups. These results provide evidence that engagement in cognitive activity can attenuate emotional processes in an automatic and unconscious manner.     

Differential interference effects of negative emotional states on subsequent semantic and perceptual processing

Past studies have revealed that encountering negative events interferes with cognitive processing of subsequent stimuli. The present study investigates whether negative events affect semantic and perceptual processing differently. Presentation of negative pictures produced slower reaction times than neutral or positive pictures in tasks that require semantic processing, such as natural or man-made judgments about drawings of objects, commonness judgments about objects, and categorical judgments about pairs of words. In contrast, negative picture presentation did not slow down judgments in subsequent perceptual processing (e.g., color judgments about words, size judgments about objects). The subjective arousal level of negative pictures did not modulate the interference effects on semantic or perceptual processing. These findings indicate that encountering negative emotional events interferes with semantic processing of subsequent stimuli more strongly than perceptual processing, and that not all types of subsequent cognitive processing are impaired by negative events.     

Affective stimuli capture attention regardless of categorical distinctiveness: An emotion-induced blindness study

Affective stimuli capture attention, whether their affective value stems from emotional content or a history of reward. The uniqueness of such stimuli within their experimental contexts might imbue them with an enhanced categorical distinctiveness that accounts for their impact on attention. Indeed, in emotion-induced blindness, categorically distinctive neutral pictures disrupt target perception, albeit to a lesser degree than do emotional pictures. Here, we manipulated the categorical distinctiveness of distractors in an emotion-induced blindness task. Participants searched within RSVP streams for a target that followed an emotional or a neutral distractor picture. In a categorically homogenous condition, all non-distractor items were exemplars from a uniform category, thus enhancing the distractor's categorical distinctiveness. In a categorically heterogeneous condition, each non-distractor item represented a distinct category. Neutral distractors disrupted target perception only in the homogenous condition, but emotional distractors did so regardless of their categorical distinctiveness.     

Effects of emotional content on working memory capacity

Emotional events tend to be remembered better than neutral events, but emotional states and stimuli may also interfere with cognitive processes that underlie memory performance. The current study investigated the effects of emotional content on working memory capacity (WMC), which involves both short term storage and executive attention control. We tested competing hypotheses in a preregistered experiment (N?=?297). The emotional enhancement hypothesis predicts that emotional stimuli attract attention and additional processing resources relative to neutral stimuli, thereby making it easier to encode and store emotional information in WMC. The emotional impairment hypothesis, by contrast, predicts that emotional stimuli interfere with attention control and the active maintenance of information in working memory. Participants completed a common measure of WMC (the operation span task; Turner, M. L., &; Engle, R. W. [1989]. Is working memory capacity task dependent? Journal of Memory and Language, 28, 127–154) that included either emotional or neutral words. Results revealed that WMC was reduced for emotional words relative to neutral words, consistent with the emotional impairment hypothesis.     

Enhanced recognition of emotional stimuli in the chimpanzee (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)

Humans often have a better memory of emotional events than neutral events. From the comparative-cognitive perspective, we explored the enhancement of recognition memory by emotion in chimpanzees (Pan troglodytes) using a serial probe recognition task. In this task, we sequentially presented a list of pictures to subjects and then tested their recognition of specific pictures from within the list. We selected pictures of aggressive chimpanzees as emotional stimuli and less tensed, relaxed chimpanzees as neutral stimuli. In Experiment 1, we gave four-item lists to two young chimpanzees; one showed significantly greater recognition of pictures depicting aggressive chimpanzees than neutral ones. In Experiment 2, this chimpanzee was further tested using a recognition task with eight-item lists. The subject again showed better recognition of emotional stimuli than neutral. Furthermore, the presence of an emotional stimulus in the list also facilitated recognition of the neutral item immediately following it. Overall, although only one of the two chimpanzees showed enhanced recognition memory by emotional stimuli, this is the first demonstration of such a response in the chimpanzee. The findings are discussed in comparison with those of human studies.     

情绪场景图片的注意偏向：眼动研究

注意实验中,与不带情绪色彩的刺激相比,具有情绪意义的刺激可引起注意偏向。本研究以情绪场景图片为材料,通过眼动技术分别记录被试在反向眼跳任务和Go/No-go任务中的眼动数据,考察了情绪图片的注意偏向。结果发现：反向眼跳任务中,对情绪图片的眼跳潜伏期比中性图片更长,眼跳错误率也更高;在Go任务中,相对于呈现在中央的中性图片,情绪图片引起的对靶子的眼跳潜伏期更长;在No-go任务中,相对于呈现在中央的中性图片,情绪图片引起的眼跳错误率更低。实验结果说明,情绪图片可引起注意偏向,表现为更快的捕获注意并且注意更难从情绪图片上转移。     

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。     

图词间隔时间影响口语词汇产生中语义效应的机制：图词干扰范式研究

口语词汇产生过程中存在语义抑制和语义促进效应, 可能发生在概念准备和词汇选择或者后词汇水平阶段。本研究采用图画-词汇干扰实验任务, 变化图画与词汇出现点之间的时间间隔(stimulus onset asynchrony, SOA), 运用脑电技术考察口语词汇产生中语义效应发生的时间进程。结果显示, 当SOA为0 ms时表现出语义抑制效应, 语义效应发生在词汇选择阶段(344~418 ms); 当SOA为-400 ms时, 语义效应发生在概念准备阶段(0~76 ms)和词汇选择阶段(274~390 ms); 460~594 ms时间窗口内的语义效应可能表明讲话者对语义信息的自我监测。词汇产生中存在语义促进效应和抑制效应的权衡, 影响了行为结果中语义效应的方向, 上述发现支持了口语词汇产生的词汇竞争假说。     

Fear-related pictures deteriorate the performance of university students with high fear of snakes or spiders

Despite research regarding emotional processing, it is still unclear whether fear-evoking stimuli are processed when they are irrelevant and when attention is oriented elsewhere. In this study, 63 healthy university students with high fear from snakes or spiders participated in two different experiments. In an emotional modification of the spatial cueing task, 31 subjects (5 males) were asked to detect a target letter while ignoring a neutral or fear-related distracting picture. The distribution of attention was independently manipulated by a spatial cue that preceded the appearance of the picture and the target letter. In an emotional modification of the cognitive load paradigm, 32 subjects (4 males) were asked to discriminate between two target letters, while ignoring a central neutral or fear-related picture, and additional 1, 3, or 5 distracting letters that created a varied attentional load. Fear-related pictures interfered with the performance of highly fearful participants, even when the pictures were presented outside the focus of attention and when the task taxed attentional resources. We suggest that highly fearful individuals process fear-related information automatically, either inattentively or with prioritized attention capture over competing items, leading to deteriorated cognitive performance. Different results were shown in healthy individuals while processing negative--but not phobic--pictures, suggesting that emotional processing depends on the fear value of the stimulus for a specific observer.     

记忆编码中目标与背景的情绪一致性对记忆提取的影响

摘 要 本研究将经典情绪启动范式和学习-再认范式相结合,探讨学习时启动与目标的情绪一致性对目标再认的影响。在记忆编码阶段,以情绪面孔图片为启动刺激、一般情绪图片为目标刺激,要求被试对目标图片的效价进行判断;在提取阶段向被试呈现一般情绪图片,要求被试判断是否在前一阶段见过。结果表明,编码阶段的加工背景对记忆提取产生了显著影响。一致启动促进了认知加工与记忆编码,提高了再认正确率。ERP结果也表明,在目标刺激呈现后300-500ms,编码时的情绪一致性对再认阶段消极目标诱发的ERP产生了显著影响。     

Positive emotion impedes emotional but not cognitive conflict processing

Cognitive control enables successful goal-directed behavior by resolving a conflict between opposing action tendencies, while emotional control arises as a consequence of emotional conflict processing such as in irony. While negative emotion facilitates both cognitive and emotional conflict processing, it is unclear how emotional conflict processing is affected by positive emotion (e.g., humor). In 2 EEG experiments, we investigated the role of positive audiovisual target stimuli in cognitive and emotional conflict processing. Participants categorized either spoken vowels (cognitive task) or their emotional valence (emotional task) and ignored the visual stimulus dimension. Behaviorally, a positive target showed no influence on cognitive conflict processing, but impeded emotional conflict processing. In the emotional task, response time conflict costs were higher for positive than for neutral targets. In the EEG, we observed an interaction of emotion by congruence in the P200 and N200 ERP components in emotional but not in cognitive conflict processing. In the emotional conflict task, the P200 and N200 conflict effect was larger for emotional than neutral targets. Thus, our results show that emotion affects conflict processing differently as a function of conflict type and emotional valence. This suggests that there are conflict- and valence-specific mechanisms modulating executive control.     

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.     

Is Phonological Encoding in Naming Influenced by Literacy?

We examined phonological priming in illiterate adults, using a cross-modal picture-word interference task. Participants named pictures while hearing distractor words at different Stimulus Onset Asynchronies (SOAs). Ex-illiterates and university students were also tested. We specifically assessed the ability of the three populations to use fine-grained, phonemic units in phonological encoding of spoken words. In the phoneme-related condition, auditory words shared only the first phoneme with the target name. All participants named pictures faster with phoneme-related word distractors than with unrelated word distractors. The results thus show that phonemic representations intervene in phonological output processes independently of literacy. However, the phonemic priming effect was observed at a later SOA in illiterates compared to both ex-illiterates and university students. This may be attributed to differences in speed of picture identification.     

Manipulations of distractor frequency do not mitigate emotion-induced blindness

Emotional distractors can impair perception of subsequently presented targets, a phenomenon called emotion-induced blindness. Do emotional distractors lose their power to disrupt perception when appearing with increased frequency, perhaps due to desensitisation or enhanced recruitment of proactive control? Non-emotional tasks, such as the Stroop, have revealed that high frequency distractors or conflict lead to reduced interference, and distractor frequency appears to modulate attentional capture by emotional distractors in spatial attention tasks. But emotion-induced blindness is thought to reflect perceptual competition between targets and emotional distractors, and it is unclear whether high frequency emotional stimuli cause less disruption at this relatively early stage of processing. In four experiments, participants searched streams of images for a rotated target image. A negative or neutral distractor appeared before the target, and their relative frequency was manipulated. Across all experiments, the frequency of emotional distractors did not modulate emotion-induced blindness even when participants were explicitly informed that they would appear often or seldom. Thus, increased distractor frequency does not appear to mitigate the priority allotted to emotional distractors during perceptual competition.     

Attentional capture by irrelevant emotional distractor faces

We establish attentional capture by emotional distractor faces presented as a "singleton" in a search task in which the emotion is entirely irrelevant. Participants searched for a male (or female) target face among female (or male) faces and indicated whether the target face was tilted to the left or right. The presence (vs. absence) of an irrelevant emotional singleton expression (fearful, angry, or happy) in one of the distractor faces slowed search reaction times compared to the singleton absent or singleton target conditions. Facilitation for emotional singleton targets was found for the happy expression but not for the fearful or angry expressions. These effects were found irrespective of face gender and the failure of a singleton neutral face to capture attention among emotional faces rules out a visual odd-one-out account for the emotional capture. The present study thus establishes irrelevant, emotional, attentional capture.     

Event-related induced frontal alpha as a marker of lateral prefrontal cortex activation during cognitive reappraisal

Electrocortical activity, typically used to track the effects of cognitive reappraisal on the processing of emotional stimuli, has not been used to index the prefrontal-cortex-mediated regulatory mechanisms responsible for these effects. In the present study, we examined the novel possibility that induced frontal alpha (i.e., 8?C13?Hz), shown to reflect the inhibition and disengagement of task-relevant cortical regions, may be quantified to explore cortical activation that is specifically enhanced during cognitive reappraisal. For this purpose, 44 participants viewed unpleasant and neutral pictures followed by auditory instructions to either continue viewing the picture or reduce their emotional response to the picture by making the picture seem less emotional (i.e., cognitive reappraisal). In line with previous work, unpleasant pictures elicited a larger late positive potential (LPP) than did neutral pictures. Also corroborating previous work, the mid-latency LPP was reduced when pictures were cognitively reappraised. However, the present study showed for the first time that whereas unpleasant pictures elicited higher frontal alpha power bilaterally than did the neutral pictures, frontal alpha power was reduced (indicative of more activation and cognitive control) during cognitive reappraisal of both picture types over the left hemisphere. Taken together, the LPP and event-related induced frontal-alpha findings contribute unique information about the distinct neural substrates and cognitive processes underlying reappraisal.     

Divided attention enhances the recognition of emotional stimuli: evidence from the attentional boost effect

The present study examined predictions of the early-phase-elevated-attention hypothesis of the attentional boost effect (ABE), which suggests that transient increases in attention at encoding, as instantiated in the ABE paradigm, should enhance the recognition of neutral and positive items (whose encoding is mostly based on controlled processes), while having small or null effects on the recognition of negative items (whose encoding is primarily based on automatic processes). Participants were presented a sequence of negative, neutral and positive stimuli (pictures in Experiment 1, words in Experiment 2) associated to target (red) squares, distractor (green) squares or no squares (baseline condition). They were told to attend to the pictures/words and simultaneously press the spacebar of the computer when a red square appeared. In a later recognition task, stimuli associated to target squares were recognised better than stimuli associated to distractor squares, replicating the standard ABE. More importantly, we also found that: (a) the memory enhancement following target detection occurred with all types of stimuli (neutral, negative and positive) and (b) the advantage of negative stimuli over neutral stimuli was intact in the DA condition. These findings suggest that the encoding of negative stimuli depends on both controlled (attention-dependent) and automatic (attention-independent) processes.