When the half-full glass is appraised as half empty and memorised as completely empty: mood-congruent true and false recognition in depression is modulated by salience

Since the 1980s a large body of empirical effort has been devoted to mood-congruent memory (MCM) biases in clinical depression. Whereas there is broad, albeit not unequivocal, evidence that depressive patients retain negative-valenced memory items better than neutral material, few studies have investigated false memories in depression. In a pilot study we gathered support for both enhanced true and false memory for emotional material in depression. The present study aimed to extend these preliminary findings. In view of investigations suggesting that arousing and meaningful stimuli have facilitated access to memory, personal salience was considered a moderator for MCM. In the present study 21 depressed and 22 healthy participants were presented six false memory lists dealing with neutral, negative, and positive themes. At recognition, each item had to be appraised for its degree of valence subsequent to an old-new judgement. Pre-categorised and subjective valence did not discriminate groups. However, relative to controls depressed patients showed both more veridical as well as false recognition for items that concurrently elicited higher salience ratings in patients. In contrast, group differences in recognition performance did not significantly affect salience ratings. Results indicate that salience modulates MCM and may account for discrepancies in the literature.     

Valence and the development of immediate and long-term false memory illusions

Across five experiments we examined the role of valence in children's and adults’ true and false memories. Using the Deese/Roediger-McDermott paradigm and either neutral or negative-emotional lists, both adults’ (Experiment 1) and children's (Experiment 2) true recall and recognition was better for neutral than negative items, and although false recall was also higher for neutral items, false recognition was higher for negative items. The last three experiments examined adults’ (Experiment 3) and children's (Experiments 4 and 5) 1-week long-term recognition of neutral and negative-emotional information. The results replicated the immediate recall and recognition findings from the first two experiments. More important, these experiments showed that although true recognition decreased over the 1-week interval, false recognition of neutral items remained unchanged whereas false recognition of negative-emotional items increased. These findings are discussed in terms of theories of emotion and memory as well as their forensic implications.     

Emotional content enhances true but not false memory for categorized stimuli

Past research has shown that emotion enhances true memory, but that emotion can either increase or decrease false memory. Two theoretical possibilities—the distinctiveness of emotional stimuli and the conceptual relatedness of emotional content—have been implicated as being responsible for influencing both true and false memory for emotional content. In the present study, we sought to identify the mechanisms that underlie these mixed findings by equating the thematic relatedness of the study materials across each type of valence used (negative, positive, or neutral). In three experiments, categorically bound stimuli (e.g., funeral, pets, and office items) were used for this purpose. When the encoding task required the processing of thematic relatedness, a significant true-memory enhancement for emotional content emerged in recognition memory, but no emotional boost to false memory (Exp. 1). This pattern persisted for true memory with a longer retention interval between study and test (24 h), and false recognition was reduced for emotional items (Exp. 2). Finally, better recognition memory for emotional items once again emerged when the encoding task (arousal ratings) required the processing of the emotional aspect of the study items, with no emotional boost to false recognition (Exp. 3). Together, these findings suggest that when emotional and neutral stimuli are equivalently high in thematic relatedness, emotion continues to improve true memory, but it does not override other types of grouping to increase false memory.     

Working memory affects false memory production for emotional events

Whereas a link between working memory (WM) and memory distortions has been demonstrated, its influence on emotional false memories is unclear. In two experiments, a verbal WM task and a false memory paradigm for negative, positive or neutral events were employed. In Experiment 1, we investigated individual differences in verbal WM and found that the interaction between valence and WM predicted false recognition, with negative and positive material protecting high WM individuals against false remembering; the beneficial effect of negative material disappeared in low WM participants. In Experiment 2, we lowered the WM capacity of half of the participants with a double task request, which led to an overall increase in false memories; furthermore, consistent with Experiment 1, the increase in negative false memories was larger than that of neutral or positive ones. It is concluded that WM plays a critical role in determining false memory production, specifically influencing the processing of negative material.     

No deficits in nonverbal memory, metamemory and internal as well as external source memory in obsessive-compulsive disorder (OCD)

A large body of literature suggests that some symptoms of obsessive-compulsive disorder (OCD) result from mnemonic dysfunctions. The present study tested various formulations of the memory deficit hypothesis considering important moderators, such as depression and response slowing. Thirty-two OCD patients and 32 healthy controls were presented verbal or nonverbal instructions for actions (e.g. simple gestures). These actions should either be performed or imagined. For recognition, previously presented as well as novel actions were displayed. Decisions had to be made whether an action was previously displayed (verbally vs. nonverbally) or not and whether an action was performed or imagined (internal source memory). Moreover, both judgments required confidence ratings. Groups did not differ in memory accuracy and metamemory for verbally presented material. Patients displayed some impairment for nonverbally presented material and imagined instructions, which, however, could be fully accounted for by response slowing and depressive symptoms. The study challenges the view that primary memory deficits underlie OCD or any of its subtypes. We claim that research should move forward from the mere study of objective impairment to the assessment of cognitive performance in conjunction with personality traits such as inflated responsibility.     

The effect of limited attention and delay on negative arousing false memories

ABSTRACT

Previous research has shown that, in comparison to neutral stimuli, false memories for high arousing negative stimuli are greater after very fast presentation and limited attention at study. However, full compared to limited attention conditions still produce comparably more false memories for all stimuli types. Research has also shown that emotional stimuli benefit from a period of consolidation. What effect would such consolidation have on false memory formation even when attention is limited at study? The aim of the present study was to investigate the effect of fast presentation on false memory production for negatively-arousing and neutral items over time using the DRM paradigm. Sixty-eight participants studied Negative and neutral DRM lists with fast or slow presentation conditions. Half completed a recognition test immediately and half completed a recognition test after one-week. Results revealed that, for fast presentation, negative critical lures increased after one week and were comparable to negative critical lures in the slow presentation encoding conditions. Neutral critical lures in the fast presentation condition did not change and remained lower compared to the slow presentation condition. These findings are the first demonstration that arousing negative false memories can increase over time when attention at encoding is limited.     

不同情绪效价的DRM词表对错误记忆的影响

请49名在校大学生对自编的36个具有不同情绪效价的DRM词表进行评定,再以60名在校大学生为实验对象考察不同情绪效价的DRM词表对错误记忆的影响。结果发现,(1) 负性和中性DRM词表产生的错误记忆量显著高于正性DRM词表;(2) 被试在“记得/知道/猜测”判断上对负性和中性词表的关键诱饵倾向于“知道”,而对正性词表的关键诱饵更倾向于“记得”。结果表明,DRM词表本身所具有的情绪与人为诱发的情绪,对错误记忆的影响具有不同的性质和特点。     

False memory in aging: effects of emotional valence on word recognition accuracy

Memory is susceptible to distortions. Valence and increasing age are variables known to affect memory accuracy and may increase false alarm production. Interaction between these variables and their impact on false memory was investigated in 36 young (18-28 years) and 36 older (61-83 years) healthy adults. At study, participants viewed lists of neutral words orthographically related to negative, neutral, or positive critical lures (not presented). Memory for these words was subsequently tested with a remember-know procedure. At test, items included the words seen at study and their associated critical lures, as well as sets of orthographically related neutral words not seen at study and their associated unstudied lures. Positive valence was shown to have two opposite effects on older adults' discrimination of the lures: It improved correct rejection of unstudied lures but increased false memory for critical lures (i.e., lures associated with words studied previously). Thus, increased salience triggered by positive valence may disrupt memory accuracy in older adults when discriminating among similar events. These findings likely reflect a source memory deficit due to decreased efficiency in cognitive control processes with aging.     

The effects of emotional content and aging on false memories

After studying a list of words related to a nonpresented lure word, people often falsely recall or recognize the nonpresented lure. Older adults are particularly susceptible to these forms of false memories. The age-related false memory enhancement likely occurs because older adults do not encode, or later retrieve, items in enough detail to allow them to discriminate between presented words and other associated but nonpresented items. Pesta, Murphy, and Sanders (2001) suggested that the emotional salience of the lures may provide distinctiveness, so that individuals would be less likely to endorse an emotional lure as a studied item than to endorse a neutral lure. In the present investigation, young and older adults were less likely to falsely recall or recognize emotional, as compared with neutral, lures. Both age groups appeared capable of using the distinctiveness of the emotional lures to reduce, although not to eliminate, false recall and recognition.     

Source memory that encoding was self-referential: the influence of stimulus characteristics

Decades of research suggest that encoding information with respect to the self improves memory (self-reference effect, SRE) for items (item SRE). The current study focused on how processing information in reference to the self affects source memory for whether an item was self-referentially processed (a source SRE). Participants self-referentially or non-self-referentially encoded words (Experiment 1) or pictures (Experiment 2) that varied in valence (positive, negative, neutral). Relative to non-self-referential processing, self-referential processing enhanced item recognition for all stimulus types (an item SRE), but it only enhanced source memory for positive words (a source SRE). In fact, source memory for negative and neutral pictures was worse for items processed self-referentially than non-self-referentially. Together, the results suggest that item SRE and source SRE (e.g., remembering an item was encoded self-referentially) are not necessarily the same across stimulus types (e.g., words, pictures; positive, negative). While an item SRE may depend on the overall likelihood the item generates any association, the enhancing effects of self-referential processing on source memory for self-referential encoding may depend on how embedded a stimulus becomes in one’s self-schema, and that depends, in part, on the stimulus’ valence and format. Self-relevance ratings during encoding provide converging evidence for this interpretation.     

错误记忆的自我参照效应：易化的作用

采用DRM范式,设置三种参照对象条件（自我、他人和中性参照）,考察错误记忆是否存在自我参照效应。结果发现：（1）与正确记忆一样,错误记忆中亦存在自我参照效应;（2）无论是正确记忆还是错误记忆,自我参照条件下的回忆成分均显著多于他人参照和中性参照,但熟悉性成分在三种不同参照对象条件下没有显著差异;（3）当词表中学习项目由分组呈现变为随机呈现时,错误记忆的自我参照效应仍稳定存在。结果揭示,自我参照效在促进正确记忆的同时,亦可易化错误记忆效应。     

抑郁症状中学生自我相关生活事件的回忆、再认和启动效应特点

采用Tversky的实验设计,对非抑郁和抑郁症状中学生的回忆、再认和启动效应进行了探讨。实验发现,抑郁症状中学生对自我相关生活事件信息加工存在负性回忆、负性再认、负性启动和负性加工偏向;抑郁症状中学生对自我相关生活事件信息加工的回忆具有情境一致性;对再认材料的不同加工深度影响抑郁症状中学生自我相关生活事件信息加工的再认;抑郁症状中学生对自我相关生活事件信息加工的负性启动主要是由于对负性条目、中性条目的负性偏向加工引起     

A single bout of resistance exercise can enhance episodic memory performance

Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise.     

Variation in individuals' semantic networks for common knowledge is associated with false memory

Three experiments assessed the relationships between false memories of words and their degree of connectedness within individual semantic networks. In the first two experiments, participants studied associated word lists (e.g., hot, winter, ice), completed a recognition test that included related nonstudied words (e.g., cold, snow), and then rated the semantic relatedness of all word pairs including studied and nonstudied words. In the third experiment, the task order was reversed; participants completed pairwise ratings and then, two weeks later, completed the false memory task. The relatedness ratings were analysed using the Pathfinder scaling algorithm. In all experiments, items that an individual falsely recognized had higher semantic Pathfinder node densities than those items correctly rejected.     

The robustness of false memory for emotional pictures

Emotional material is commonly reported to be more accurately recognised; however, there is substantial evidence of increased false alarm rates (FAR) for emotional material and several reports of stronger influences on response bias than accuracy. This pattern is more frequently reported for words than pictures. Research on the mechanisms underlying bias differences has mostly focused on word lists under short retention intervals. This article presents four series of experiments examining recognition memory for emotional pictures while varying arousal and the control over the content of the pictures at two retention intervals, and one study measuring the relatedness of the series picture sets. Under the shorter retention interval, emotion increased false alarms and reduced accuracy. Under the longer retention interval emotion increased hit rates and FAR, resulting in reduced accuracy and/or bias. At both retention intervals, the pattern of valence effects differed based on the arousal associated with the picture sets. Emotional pictures were found to be more related than neutral pictures in each set; however, the influence of relatedness alone does not provide an adequate explanation for all emotional differences. The results demonstrate substantial emotional differences in picture recognition that vary based on valence, arousal and retention interval.     

Mood-congruent true and false memory: Effects of depression

The Deese/Roediger-McDermott paradigm was used to investigate the effect of depression on true and false recognition. In this experiment true and false recognition was examined across positive, neutral, negative, and depression-relevant lists for individuals with and without a diagnosis of major depressive disorder. Results showed that participants with major depressive disorder falsely recognised significantly more depression-relevant words than non-depressed controls. These findings also parallel recent research using recall instead of recognition and show that there are clear mood congruence effects for depression on false memory performance.     

The effect of mood on false memory for emotional DRM word lists

In the present study, we investigated the effect of participants’ mood on true and false memories of emotional word lists in the Deese–Roediger–McDermott (DRM) paradigm. In Experiment 1, we constructed DRM word lists in which all the studied words and corresponding critical lures reflected a specified emotional valence. In Experiment 2, we used these lists to assess mood-congruent true and false memory. Participants were randomly assigned to one of three induced-mood conditions (positive, negative, or neutral) and were presented with word lists comprised of positive, negative, or neutral words. For both true and false memory, there was a mood-congruent effect in the negative mood condition; this effect was due to a decrease in true and false recognition of the positive and neutral words. These findings are consistent with both spreading-activation and fuzzy-trace theories of DRM performance and have practical implications for our understanding of the effect of mood on memory.     

外显与内隐记忆的情绪一致性效应

基于Yonelinas等双加工信号检测模型对再认记忆测验中外显记忆与内隐记忆分离的方法,以96名大学生为被试,考察了诱发抑郁与非临床抑郁状态下外显和内隐记忆的情绪一致性效应。结果表明诱发抑郁组和非临床抑郁组对抑郁词的外显记忆成绩显著高于对中性词和愉快词;对抑郁词的内隐记忆成绩亦显著高于对中性词和愉快词,且显著高于控制组对抑郁词的内隐记忆成绩。情绪一致性记忆效应在非临床抑郁个体和诱发抑郁个体的外显和内隐记忆中均存在。     

错误记忆影响因素的实验研究

本研究采用DRM范式,考察了关联性、学习程度和时间间隔对错误记忆的影响,结果表明:(1)低学习程度和中学习程度下的再认错误率显著高于高学习程度下的再认错误率,说明错误记忆随着学习程度的增加而降低;(2)低关联程度下的再认错误率显著低于中关联程度和高关联程度下的再认错误率,说明关联性高低是引发错误记忆的重要变量;(3)时间间隔对错误再认率没有影响,说明错误记忆不具有时间上的衰退效应,一旦产生后极其顽固,不容易消退,可能更多地受无意识加工的影响。实验结果揭示了错误记忆与真实记忆之间存在着较为复杂的关系。真实记忆可能是错误记忆的根源,而二者的关系在不同影响因素条件下则既有共变又有分离。