The effects of emotional stimuli on target detection: indirect and direct resource costs

The present study was designed to explore the performance costs of negative emotional stimuli in a vigilance task. Forty participants (20 women) performed a vigilance task in two conditions: one with task-irrelevant negative-arousing pictures and one with task-irrelevant neutral pictures. In addition to performance, we measured subjective state (energetic arousal, tense arousal, task-related and task-unrelated thoughts) and frontal cerebral activity with near infrared spectroscopy. Overall performance in the negative picture condition was lower than in the neutral picture condition and the negative picture condition had elevated levels of energetic arousal, tense arousal and task-related thoughts. Moreover, there was a significant relationship between the impact of the negative pictures on tense arousal and task-related thoughts and the impact of the negative pictures on performance (in comparison to the neutral picture stimuli task). These results provide support for indirect cost models of negative emotional stimuli on target detection performance.     

Affective and cognitive modulation of performance monitoring: Behavioral and ERP evidence

This study investigates the effects of negative affect on performance monitoring. EEG was acquired during a lateralized, numeric Stroop working memory task that featured task-irrelevant aversive and neutral pictures between stimuli. Performance accuracy showed a right-hemisphere advantage for stimuli that followed aversive pictures. Response-locked event-related potentials (ERPs) from accurate trials showed an early negative component (CRN; correct response/conflict-related negativity) followed by a positive wave comparable to the Pe (error positivity). The CRN was bi-peaked with an earlier peak that was sensitive to aversive pictures during early portions of the experiment and a later peak that increased with error likelihood later in the experiment. Pe amplitude was increased with aversive pictures early in the experiment and was sensitive to picture type, Stroop interference, and hemisphere of stimulus delivery during later trials. This suggests that ERP indices of performance monitoring, the CRN and Pe, are dynamically modulated by both affective and cognitive demands.     

Sequential modulations of valence processing in the emotional Stroop task

This study investigated trial-to-trial modulations of the processing of irrelevant valence information. Participants (N = 126) responded to the frame color of pictures with positive, neutral, or negative affective content--a procedure known as an emotional Stroop task (EST). As is typically found, positive and negative pictures delayed responses as compared to neutral pictures. However, the type and extent of this valence-based interference depended on the irrelevant picture valence in the preceding trial. Whereas preceding exposure to negative valence prompted interference from positive and negative pictures, such interference was removed after neutral trials. Following positive pictures, interference from negative but not from positive pictures was observed. We suggest that these sequential modulations reflect automatic self-regulatory selection processes that help to keep the balance between attending to task-relevant information and task-irrelevant information that signals important changes in the environment.     

认知负荷对疼痛共情的影响:来自ERP研究的证据

先前研究表明,对他人的疼痛共情受到多种因素的调节。认知负荷对疼痛共情的调节作用尚无研究。本研究使用事件相关电位技术探究高低认知负荷对疼痛共情神经加工过程的影响。实验通过不同长度的数字串记忆任务,形成高/低两种认知负荷,要求被试在不同认知负荷条件下观看他人处于疼痛/不疼痛情境下的图片,同时记录被试的在观看图片时的EEG数据。通过比较不同条件下观看图片诱发的ERP成分发现:早期成分P2和N2上认知负荷水平与图片类型出现了显著的交互作用,即在高认知负荷下疼痛图片诱发的波幅与非疼痛图片诱发的波幅差异显著,而低认知负荷下两种图片诱发的波幅差异不显著。这表明认知负荷主要影响疼痛共情加工的早期、自动化加工阶段。相比较于低认知负荷条件下,在高认知负荷下他人的疼痛获得了更好的加工。     

Sustained and transient modulation of performance induced by emotional picture viewing

We investigated how viewing task-irrelevant emotional pictures affects the performance of a subsequent nonemotional visual detection task. Subjects performed target-detection trials following the offset of individual unpleasant, pleasant, and neutral pictures. Sustained interference occurred when subjects viewed unpleasant pictures (mutilated bodies) in a sequential, "blocked" fashion. Such slowing down of reaction time appeared to build up with time, consistent with the instatement of a defensive emotional state. With a randomized picture presentation, only a transient interference effect was observed, consistent with increased attentional demands during the processing of unpleasant pictures. During blocked presentation of affiliative pleasant pictures, reaction times were faster, suggesting the activation of appetitive motivational systems. Ultimately, both attentional and motivational systems are intricately tied in the brain and, together, determine behavior.     

Can bottom-up processes of attention be a source of ‘interference’ in situations where top-down control of attention is crucial?

In this study, we investigate whether emotionally engaged bottom-up processes of attention can be a source of ‘interference’ in situations where top-down control of attention is necessary. Participants were asked to monitor and report on a video of a war scenario showing a developing battle in two conditions: emotionally positive and emotionally negative. Half of the participants (n = 15) were exposed to task-irrelevant pictures of positive emotional valence embedded within the scenario; the other half were exposed to task-irrelevant pictures of negative emotional valence. Sensitivity and Bias scores were calculated using signal detection theory. Overall, task accuracy scores were dependent upon the valence; negative pictures had an adverse effect on performance, whereas positive pictures improved performance. We concluded that negative emotional pictures interfered with top-down control of attention by attracting competing bottom-up processes of attention. We found the opposite effect for positive emotional stimuli.     

Semantic negative priming in picture categorization and naming

Ignoring a particular stimulus can hamper subsequent attended processing of the same stimulus, a phenomenon known as 'negative priming'. Previous research has yielded partial support for the claim that the effect results from the attentional inhibition of central representations, as suggested by the fact that it appears to extend to semantic associates of ignored stimuli. In the current experiment, participants categorized or named pictorial stimuli with superimposed distractor pictures; the effect of unrelated, identical, or categorically related previously ignored pictures was investigated. Furthermore, visual similarity between categorically related picture pairs was manipulated in the naming task. The results indicated negative priming from identical ignored pictures irrespective of task. However, semantic negative priming was observed in the categorization task only. In the naming task, even visual overlap between categorically related picture pairs failed to induce negative priming. These findings argue against a central locus of the negative priming effect.     

The effects of perceptual load on semantic processing under inattention

Inattentional blindness refers to a failure to consciously detect an irrelevant object that appears without any expectation when attention is engaged with another task. The perceptual load theory predicts that task-irrelevant stimuli will reach awareness only when the primary task is of low load, which allows processing resources to spill over to processing task-irrelevant stimuli as well. We studied whether perceptual load has an effect on inattentional blindness for a task-irrelevant stimulus whose meaning is or is not relevant to the attentional goals of the observer. In the critical trial, a word appeared without any expectation in the center of a display of attended pictures. The results showed that, under both high and low load, unexpected words belonging to the attended semantic category were detected more often than semantically unrelated words. These results imply that task-irrelevant stimuli, whose meanings are relevant to the observer’s task, enter awareness irrespective of perceptual load.     

Distinguishing between automaticity and attention in the processing of emotionally significant stimuli

There is contradicting evidence as to whether irrelevant but significant emotional stimuli can be processed outside the focus of attention. In the current study, participants were asked to ignore emotional and neutral pictures while performing a competing task. In Experiment 1, orienting of attention to distracting pictures was manipulated via a peripheral cue. In Experiment 2, attentional load was varied, either leaving spare attention to process the distracting pictures or, alternatively, depleting attentional resources. Although all pictures were task irrelevant, negative pictures were found to interfere more with performance in comparison to neutral pictures. This finding suggests that processing of negative stimuli is automatic in the sense that it does not require execution of conscious monitoring. However, interference occurred only when sufficient attention was available for picture processing. Hence, processing of negative pictures was dependent on sufficient attentional resources. This suggests that processing of emotionally significant stimuli is automatic yet requires attention.     

The locus of the emotional Stroop effect: A study with the PRP paradigm

Stimuli that are clearly positive or negative (hence valence-laden stimuli) have the potential to interrupt unrelated task processing. A typical example is the emotional Stroop effect (ESE) in which responding to a certain task feature (e.g., color) is delayed by the presentation of task-irrelevant valent stimuli (e.g., negative pictures) compared to valence-neutral stimuli. Here we scrutinize which processes are slowed down by irrelevant but valent stimulation. In Experiment 1, participants performed in a Psychological Refractory Period (PRP) experiment with tone discrimination as Task 1 and color discrimination as Task 2. Importantly, colors in Task 2 were accompanied by valent or neutral pictures. Valent pictures delayed responding in Task 2 (thus an ESE) and this delay was additive to the time interval between tasks. In Experiment 2, task order was reversed and the ESE in Task 1 fully propagated to the Task 2 tone discrimination. These results imply that irrelevant valence-laden stimulation delays capacity-limited processes, and we suggest that this is a late perceptual process acting on stimulus categorization.     

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。     

Short-term retention of pictures and words: evidence for dual coding systems.

The recall of picture and word triads was examined in three experiments that manipulated the type of distraction in a Brown-Peterson short-term retention task. In all three experiments recall of pictures was superior to words under auditory distraction conditions. Visual distraction produced high performance levels with both types of stimuli, whereas combined auditory and visual distraction significantly reduced picture recall without further affecting word recall. The results were interpreted in terms of the dual coding hypothesis and indicated that pictures are encoded into separate visual and acoustic processing systems while words are primarily acoustically encoded.     

Anticipatory modulation of interference induced by unpleasant pictures

In a series of experiments participants were asked to make speeded judgments regarding the correctness of arithmetic equations (arithmetic verification task) that were presented in front of pictures that are assumed to elicit neutral, positive, or strong negative emotional responses. In some conditions, precues predicted the affective valence of the next picture, whereas in other conditions the precues were uncorrelated with the type of picture. The main question was in which way the opportunity to anticipate a forthcoming negatively valenced stimulus would modulate its impact on cognitive performance. Anticipation generally enhanced the interfering effect of unpleasant pictures. This effect was largely independent of the arousal induced by the pictures. The findings suggest that informative precues led participants to integrate the valence of the pictures into their task representation, which in the case of negative pictures resulted in a somewhat paradoxical intensification of emotional interference.     

Bilingualism influences inhibitory control in auditory comprehension

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among four pictures while their eye-movements were tracked. Each target picture (e.g., hamper) appeared together with a similar-sounding within-language competitor picture (e.g., hammer) and two neutral pictures. Following each eye-tracking trial, priming probe trials indexed residual activation of target words, and residual inhibition of competitor words. Eye-tracking showed similar within-language competition across groups; priming showed stronger competitor inhibition in monolinguals than in bilinguals, suggesting differences in how inhibitory control was used to resolve within-language competition. Notably, correlation analyses revealed that inhibition performance on a nonlinguistic Stroop task was related to linguistic competition resolution in bilinguals but not in monolinguals. Together, monolingual-bilingual comparisons suggest that cognitive control mechanisms can be shaped by linguistic experience.     

Nonspatial attentional capture by previously rewarded scene semantics

Recent research has shown that reward influences visual perception and cognition in a way that is distinct from the well-documented goal-directed mechanisms. In the current study we explored how task-irrelevant stimulus-reward associations affect processing of stimuli when attention is constrained and reward no longer delivered. During a training phase, participants performed a choice game, exposing them to different reward schedules for different semantic categories of natural scene pictures. In a separate test session in which no additional reward was provided, the differentially rewarded scene categories were used as task-irrelevant non-targets in a rapid serial visual presentation (RSVP) task. Participants performed a detection task on a previously non-rewarded target category. Results show that participants' sensitivity index (d′) for target detection decreased as a function of whether the reward was coupled to the distractor category during training. The semantic category of natural scenes associated with high reward caused more interference in target detection than the semantic category associated with a low reward. The same was found when new, unseen distractor pictures of the same semantic categories were used. The present findings suggest that reward can be selectively associated with high level scene semantics. We argue that learned stimulus-reward associations persistently bias perceptual processing independently of spatial shifts in attention and the immediate prospect of reward.     

Picture superiority in conceptual memory: Dissociative effects of encoding and retrieval tasks

We examined the role of encoding processes for picture superiority in explicit and conceptual-implicit memory. The nature of encoding instruction (naming or semantic categorization) yielded dissociative effects on picture and word memory on one explicit test, category-cued recall, and two conceptual-implicit tests, category-cued generation and category-cued verification. Category-cued recall was greater for pictures than for words following naming, but it did not differ for pictures and words following semantic categorization. Category-cued generation priming was greater for pictures than for words following naming, but it was greater for words than for pictures following semantic categorization. In contrast, category-cued verification priming did not differ for pictures and words following either naming or semantic categorization. Thus, picture superiority can be eliminated or reversed depending on the type of conceptual encoding task and conceptual-retrieval test.     

厌恶情绪加工特点的事件相关电位研究

厌恶作为一种威胁相关情绪有着帮助人们躲避有害刺激的进化意义。近年来的研究表明, 厌恶加工能拥有独特的神经机制, 主要表现为在感觉刺激输入早期起抑制作用。本研究使用高时间分辨率的事件相关电位技术(event-related potential, ERP)作为研究手段, 探究正常被试观看厌恶图片时脑电活动变化。采用视觉搜索范式作为实验任务, 考察不同加工阶段注意资源消耗特点。脑电结果表明, 厌恶加工确实存在独特的加工机制, 表现为皮层活动先抑制后增强。行为结果呈显著交互作用：情绪图呈现时间较短时(0/300 ms), 被试任务表现受负性情绪加工干扰; 情绪图呈现时间较长时(600/900 ms), 被试任务表现不受负性情绪干扰。研究结果支持负性情绪两阶段加工模型, 即厌恶加工也存在先自动化后控制化的两个阶段, 并且在自动化加工完全消失之前存在两种加工进程并存的过度阶段。     

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。     

Conditions of directed attention inhibit recognition performance for explicitly presented target-aligned irrelevant stimuli

The fate of irrelevant and overtly presented stimuli that was temporally aligned with an attended target in a separate task was explored. Seitz and Watanabe (2003) demonstrated that if an irrelevant motion stimulus was implicit (i.e., subthreshold), a later facilitation for the same motion direction was observed if the previously presented implicit motion (of the same direction) was temporally aligned with the presence of an attended target. Later research, however, demonstrated that if the motion stimulus aligned with the attended target was explicit (i.e., suprathreshold), a later inhibition was observed (Tsushima, Seitz, & Watanabe, 2008). The current study expands on this by using more salient stimuli (words and pictures) in an inattentional blindness paradigm, and suggests that when attention is depleted, recognition for target-aligned task-irrelevant items is impaired in a subsequent recognition task. Participants were required to respond to either immediate picture, or word, repetitions in a stream of simultaneously presented line drawings and written words, and later given a surprise recognition test that measured recognition for the words or the pictures. When analyzing word recognition performance after attention had been directed to the pictures, words that had appeared simultaneously with a picture repetition in the repetition detection task were recognized at levels significantly below chance. The same inhibition was mirrored when testing for picture recognition after having attended to the words in the repetition detection task. These data suggest an inhibitory mechanism that is exhibited in later recognition tests for salient information that was previously unattended and had been simultaneously being presented with an attended target in a different task.     

Processing of task-irrelevant natural scenes in social anxiety

In this study, by manipulating perceptual load, we investigated whether socially anxious people process task-irrelevant, non-emotional, natural scenes. When attention was directed to letters and perceptual load was low, task-irrelevant natural scenes were processed, as evidenced by repetition priming effects, in both high and low socially anxious people. In the high perceptual load condition, repetition-priming effects decreased in participants with low social anxiety, but not in those with high social anxiety. The results were the same when attention was directed to pictures of animals: even in the high perceptual load condition, high socially anxious participants processed task-irrelevant natural scenes, as evidenced by flanker effects. However, when attention was directed to pictures of people, task-irrelevant natural scenes were not processed by participants in either anxiety group, regardless of perceptual load. These results suggest that high socially anxious individuals could not inhibit task-irrelevant natural scenes under conditions of high perceptual load, except when attention was focused on people.