Trade-offs in visual attention and the enhancement of memory specificity for positive and negative emotional stimuli

Emotional influences on memory can lead to trade-offs in memory for gist or detail and trade-offs in memory for central or peripheral aspects of an event. Attentional narrowing has often been proposed as a theoretical explanation for this pattern of findings with negative emotion. These trade-offs have been less extensively investigated with positive emotion. In three experiments, we investigate memory for specific visual details of positive and negative stimuli, examine central–peripheral trade-offs in memory, and assess the hypothesis that attentional narrowing contributes to emotional enhancement of memory specificity. We found that memory for details was enhanced by negative and positive emotion. Central–peripheral trade-offs were found in memory for negative emotional stimuli but not in memory for positive emotional stimuli. These trade-offs with negative emotion were associated with attentional narrowing at the time of encoding, as measured by eye movements. There were no attentional effects at the time of encoding found with positive emotional stimuli. Evidence was found for the attentional narrowing hypothesis of memory specificity and central–peripheral trade-offs in memory for negative emotional events. Alternative explanations for the positive emotional enhancement of memory specificity are required.     

Effect of negative emotional pictures on associative memory for peripheral information

We investigated the influence of negative emotional pictures on associative memory. A visual object was embedded in the periphery of negative emotional or neutral pictures. Memory was assessed for central item (pictorial) information, peripheral (object) information, and the association between item and peripheral information. On tests of item information, negative emotional pictures were remembered better than neutral pictures. However, associative memory between item and peripheral information was less accurate when the pictures were negative compared to neutral. This occurred despite equivalent recall (Experiments 1 and 2) and recognition (Experiment 2) for the peripheral objects themselves. Further experiments confirmed that performance on the associative test was not influenced by testing order (Experiment 3). These findings suggest that negative emotional arousal can particularly disrupt the associative binding of peripheral information to a central emotional event.     

Memory for contextual details: effects of emotion and aging

When individuals are confronted with a complex visual scene that includes some emotional element, memory for the emotional component often is enhanced, whereas memory for peripheral (nonemotional) details is reduced. The present study examined the effects of age and encoding instructions on this effect. With incidental encoding instructions, young and older adults showed this pattern of results, indicating that both groups focused attention on the emotional aspects of the scene. With intentional encoding instructions, young adults no longer showed the effect: They were just as likely to remember peripheral details of negative images as of neutral images. The older adults, in contrast, did not overcome the attentional bias: They continued to show reduced memory for the peripheral elements of the emotional compared with the neutral scenes, even with the intentional encoding instructions.     

情绪记忆的鲜活性和准确性的关系*

采用记得/知道范式,以正性、负性和中性图片为实验材料,以32名大学本科生为被试,考察情绪记忆鲜活性和准确性的关系。结果发现,情绪记忆的记得成绩好于中性记忆,说明情绪记忆较中性记忆更具鲜活性;情绪记忆的鲜活性和准确性存在较大的关联,在正性、负性和中性图片上相关都达到了显著,表明情绪记忆的鲜活性与刺激中心细节的恢复相联系。     

Enhanced memory for emotional pictures: A product of increased attention to affective stimuli?

The current experiment addressed the question, is enhanced memory for emotional pictures due to increased attention to affective stimuli? Participants viewed pairs of pictures (emotional-neutral or neutral-neutral) whilst their eye movements were recorded; participants had to decide which picture out of each pair they preferred. There was increased attention to positive pictures and decreased attention to negative images during picture viewing. Despite this, when a recognition test was given 1 week later, memory enhancements were found for negative pictures only. Moreover, although there was a general correlation between total inspection time and memory performance, this reliability was clear only for neutral pictures, and not for emotional images. The results suggest that memory advantages for emotional pictures can occur without increased attention to such images.     

Hormonal contraception usage is associated with altered memory for an emotional story

Substantial evidence now documents sex-related influences on the neurobiology of emotional memory. Robust sex influences exist, for example, on the amygdala’s role in emotional memory formation, as well as on retention of central information (gist) and detail for an emotional event. Evidence also suggests that the well-documented effects of stress hormones on memory depend upon sex hormone levels. Since hormonal contraception alters sex hormone levels, and must by extension alter sex/stress hormone interactions in memory, we examined whether the use of hormonal contraception also alters memory for an emotional story. Two groups of healthy female subjects—one naturally cycling, one using hormonal contraception—viewed either a brief, emotionally arousing story, or a closely matched, but more emotionally neutral story. Each subject’s eye movements and pupil dilation changes were recorded as they viewed the story. Additionally, saliva samples were taken throughout the experimental session to examine salivary alpha-amylase, a biomarker for norepinephrine. A surprise free recall test one week later measured story memory in all subjects. Naturally cycling women exhibited enhanced memory of story details, but not of central information (gist), in the emotional compared with neutral story conditions. In contrast, women using hormonal contraception exhibited enhanced memory of gist, but not story details, in the emotional compared with neutral story conditions. Analysis of eye movements made while watching the stories indicated that the differences in memory could not be attributed either to a differential attention focus or to the degree of arousal induced by the stories in the two groups. These findings suggest that the use of hormonal contraception alters memory for an emotional event, perhaps by altering sex/stress hormone interactions in memory formation. They also suggest that further investigation of the mnemonic effects of these very widely used treatments is warranted.     

Effect of negative emotional content on working memory and long-term memory

In long-term memory, negative information is better remembered than neutral information. Differences in processes important to working memory may contribute to this emotional memory enhancement. To examine the effect that the emotional content of stimuli has on working memory performance, the authors asked participants to perform working memory tasks with negative and neutral stimuli. Task accuracy was unaffected by the emotional content of the stimuli. Reaction times also did not differ for negative relative to neutral words, but on an n-back task using faces, participants were slower to respond to fearful faces than to neutral faces. These results suggest that although emotional content does not have a robust effect on working memory, in some instances emotional salience can impede working memory performance.     

Emotion enhances the subjective feeling of remembering, despite lower accuracy for contextual details

Emotion strengthens the subjective experience of recollection. However, these vivid and confidently remembered emotional memories may not necessarily be more accurate. We investigated whether the subjective sense of recollection for negative stimuli is coupled with enhanced memory accuracy for contextual details using the remember/know paradigm. Our results indicate a double-dissociation between the subjective feeling of remembering, and the objective memory accuracy for details of negative and neutral scenes. "Remember" judgments were boosted for negative relative to neutral scenes. In contrast, memory for contextual details and associative binding was worse for negative compared to neutral scenes given a "remember" response. These findings show that the enhanced subjective recollective experience for negative stimuli does not reliably indicate greater objective recollection, at least of the details tested, and thus may be driven by a different mechanism than the subjective recollective experience for neutral stimuli.     

Memory for time and place contributes to enhanced confidence in memories for emotional events

Emotion strengthens the subjective sense of remembering. However, these confidently remembered emotional memories have not been found be more accurate for some types of contextual details. We investigated whether the subjective sense of recollecting negative stimuli is coupled with enhanced memory accuracy for three specific types of central contextual details using the remember/know paradigm and confidence ratings. Our results indicate that the subjective sense of remembering is indeed coupled with better recollection of spatial location and temporal context, but not higher memory accuracy for colored dots placed in the conceptual center of negative and neutral scenes. These findings show that the enhanced subjective recollective experience for negative stimuli reliably indicates objective recollection for spatial location and temporal context, but not for other types of details, whereas for neutral stimuli, the subjective sense of remembering is coupled with all the types of details assessed. Translating this finding to flashbulb memories, we found that, over time, more participants correctly remembered the location where they learned about the terrorist attacks on 9/11 than any other canonical feature. Likewise, participants' confidence was higher in their memory for location versus other canonical features. These findings indicate that the strong recollective experience of a negative event corresponds to an accurate memory for some kinds of contextual details but not for other kinds. This discrepancy provides further evidence that the subjective sense of remembering negative events is driven by a different mechanism than the subjective sense of remembering neutral events.     

Paying attention to emotional images with impact

Emotional stimuli receive high processing priority in attention and memory. This processing "advantage" is generally thought to be predominantly mediated by arousal. However, recent data suggest that ratings of an image's affective "impact" may be a better predictor of recollection than arousal or valence. One interpretation of these findings is that high-impact images may draw an individual's attention, thus facilitating subsequent processing. We investigated the allocation of visual attention to negative emotional images that differed in impact but were matched for valence, arousal, and other characteristics. Participants viewed a central image flanked by 2 neutral indoor or outdoor scenes and made speeded judgments about whether the neutral scenes matched. In Experiment 1, responses were slower on high-impact relative to low-impact or neutral trials. In Experiment 2, responses on high-arousal relative to low-arousal trials did not differ significantly. These data provide evidence for differential allocation of attention to distinct sets of negative, equally arousing images, and argue against the prevailing view that heightened attention to and processing of emotional stimuli relate simply to arousal or valence.     

The emotion-induced memory trade-off: More than an effect of overt attention?

Although it has been suggested that many effects of emotion on memory are attributable to attention, in the present study we addressed the hypothesis that such effects may relate to a number of different factors during encoding or postencoding. One way to look at the effects of emotion on memory is by examining the emotion-induced memory trade-off, whereby enhanced memory for emotional items often comes at the cost of memory for surrounding background information. We present evidence that this trade-off cannot be explained solely by overt attention (measured via eyetracking) directed to the emotional items during encoding. Participants did not devote more overt attention to emotional than to neutral items when those items were selectively remembered (at the expense of their backgrounds). Only when participants were asked to answer true/false questions about the items and the backgrounds—a manipulation designed to affect both overt attention and poststimulus elaboration—was there a reduction in selective emotional item memory due to an increase in background memory. These results indicate that the allocation of overt visual attention during encoding is not sufficient to predict the occurrence of selective item memory for emotional items.     

No emotional "pop-out" effect in natural scene viewing

It has been shown that attention is drawn toward emotional stimuli. In particular, eye movement research suggests that gaze is attracted toward emotional stimuli in an unconscious, automated manner. We addressed whether this effect remains when emotional targets are embedded within complex real-world scenes. Eye movements were recorded while participants memorized natural images. Each image contained an item that was either neutral, such as a bag, or emotional, such as a snake or a couple hugging. We found no latency difference for the first target fixation between the emotional and neutral conditions, suggesting no extrafoveal "pop-out" effect of emotional targets. However, once detected, emotional targets held attention for a longer time than neutral targets. The failure of emotional items to attract attention seems to contradict previous eye-movement research using emotional stimuli. However, our results are consistent with studies examining semantic drive of overt attention in natural scenes. Interpretations of the results in terms of perceptual and attentional load are provided.     

Eyewitness memory for arousing events: putting things into context

If attention is focused on central details at high levels of arousal, memory for peripheral details should be diminished (Easterbrook, 1959 ). If this is the case, contextual reinstatement (CR) procedures should not enhance memory because these procedures specifically use peripheral information to cue memory. The present experiment tested how arousal influenced eyewitness memory for an event and how it interacts with CR procedures. Participants first viewed one of three series of slides (neutral, arousal, or unusual/control). Memory for central and peripheral details was tested via photo lineups and recognition tests. Although CR procedures enhanced recognition memory for non‐arousing and unusual events, they did not affect recognition memory for arousing events. Analyses of the peripheral photo lineup and peripheral recognition test data revealed that CR enhanced the hit rate for the neutral and unusual conditions but not for the arousal condition. Although CR procedures tended to enhance recognition of central information (increasing the hit rate and decreasing the false alarm rate), CR had a smaller enhancement effect in the arousal condition relative to the neutral and unusual conditions. The present experiment also replicates the Christianson and Loftus ( 1991 ) finding that peripheral information is not remembered as well in an arousing event, as compared to memory of neutral and unusual events. The theoretical and applied implications of these results are discussed. Copyright © 2002 John Wiley & Sons, Ltd.     

Emotional memory for central and peripheral details in children with callous-unemotional traits

A limited number of studies have shown that adults and adolescents with psychopathic traits suffer from emotional memory impairment. The present study examined whether this finding could be replicated in a sample of children between 8 and 12?years of age with callous-unemotional (CU) traits. Children with high CU traits (n?=?24) were compared with children with low CU traits (n?=?18) with regard to performance on a peripheral memory recognition test that examined memory for central and peripheral components of neutral and negative pictures. Results showed that overall recognition rates did not differ between the high- and low-CU groups. For negative pictures, both groups demonstrated better recognition of the central component at the expense of the peripheral component, while for neutral pictures, the peripheral component was better recognized than the central component. This study is the first to demonstrate that children with high CU traits do not suffer from an impaired emotional memory. Copyright ? 2012 John Wiley & Sons, Ltd.     

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。     

Effects of repeated retrieval of central and peripheral details in complex emotional slides

Research has demonstrated that repeated retrieval enhances memory for practised verbal information, but undermines correct recall of unpractised related verbal information, a phenomenon known as retrieval-induced forgetting (RIF). This paper addresses the question of what happens with memory for unrehearsed aspects of an emotional picture when retrieval of other aspects of that picture is practised. In two experiments we investigated whether repeated retrieval of certain details of negative emotional slides undermines recall of unrehearsed details of such slides. In Experiment 1 retrieval of peripheral details was practised. The results demonstrated that recall for peripheral details was enhanced. However, correct recall of unpractised central details remained unaffected. Furthermore, retrieval practice did not alter the number of commission errors. Experiment 2 revealed that repeated retrieval of central details enhanced memory for these details. Although more commission errors were produced, again correct recall was not impaired for the unrehearsed central and peripheral details. This failure to find retrieval-induced forgetting effects for complex visual material is at odds with the RIF literature, and potential reasons for this are discussed. The data also extend previous studies in demonstrating that extensive retrieval can increase the number of commission errors.     

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。     

How arousal modulates memory: Disentangling the effects of attention and retention

Emotion may influence memory both by altering attention and perception during encoding and by affecting memory retention. To date, studies have focused on the enhancement of memory consolidation by arousal. However, they have failed to rule out a role for attention. To specifically link memory enhancement of arousing material to modulation of memory retention, we examined recognition of neutral and arousing words at two time points and under conditions that manipulate attention during encoding. Participants were briefly presented with an arousing or neutral word at the periphery, while fixating on a central word. Recognition of peripheral words was assessed either immediately or after 24 h. Whereas recognition of neutral words became worse over time, recognition of arousing words remained the same and was better than neutral word recognition at delay. The results indicate that arousal supports slower forgetting even when the difference in attentional resources allocated to stimuli is minimized.     

Effects of level of processing on memory for affectively valenced words

In this study we tested whether subjects remember affectively valenced stimuli better than neutral stimuli when their attention is not focused on the affective charge of the stimuli during encoding. We tested memory for positive, negative, and neutral words in three memory tasks and using two encoding conditions (physical and semantic). Our results show that subjects remember affectively valenced stimuli better than neutral stimuli when they encode them according to their emotional content as well as to other features of the stimuli. However, although both positive and negative words are better remembered than neutral ones when semantically encoded, only positive words are better remembered than neutral ones when physically encoded. These results suggest that the affective charge of a stimulus (especially when positive) can affect retention even when a subject's attention has not focused on it during encoding.     

Intact emotion–cognition interaction in schizophrenia patients and first-degree relatives: Evidence from an emotional antisaccade task

Schizophrenia patients have deficits in cognitive control as well as in a number of emotional domains. The antisaccade task is a measure of cognitive control that requires the inhibition of a reflex-like eye movement to a peripheral stimulus. Antisaccade performance has been shown to be modulated by the emotional content of the peripheral stimuli, with emotional stimuli leading to higher error rates than neutral stimuli, reflecting an implicit emotion processing effect. The aim of the present study was to investigate the impact on antisaccade performance of threat-related emotional facial stimuli in schizophrenia patients, first-degree relatives of schizophrenia patients and healthy controls. Fifteen patients, 22 relatives and 26 controls, matched for gender, age and verbal intelligence, carried out an antisaccade task with pictures of faces displaying disgusted, fearful and neutral expressions as peripheral stimuli. We observed higher antisaccade error rates in schizophrenia patients compared to first-degree relatives and controls. Relatives and controls did not differ significantly from each other. Antisaccade error rate was influenced by the emotional nature of the stimuli: participants had higher antisaccade error rates in response to fearful faces compared to neutral and disgusted faces. As this emotional influence on cognitive control did not differ between groups we conclude that implicit processing of emotional faces is intact in patients with schizophrenia and those at risk for the illness.