Aging and recognition memory for emotional words: A bias account

The present study investigated age-related differences in the locus of the emotional enhancement effect in recognition memory. Younger and older adults studied an emotion-heterogeneous list followed by a forced choice recognition memory test. Luce’s (1963) similarity choice model was used to assess whether emotional valence impacts memory sensitivity or response bias. Results revealed that the emotional enhancement effect in both age groups was due to a more liberal response bias for emotional words. However, the pattern of bias differed, with younger adults more willing to classify negative words as old and older adults more willing to classify positive words as old. The results challenge the conclusion that emotional words are more memorable than neutral words.     

Effects of sleep on positive,negative and neutral valenced story and image memory

During sleep, emotional memories are preferentially strengthened. However, most studies on sleep and emotional memory focus on comparing negative valence with neutral valence stimuli. This study compared the sleep-dependent memory effects for stories and images, each comprising negative, neutral, and positive stimuli. It was hypothesized that a sleep effect would be seen for negatively and positively valenced stimuli. A novel story memory task (comprising three stories), and photographs from the Nencki Affective Picture database were presented for learning to 61 healthy adults (ages 18–25). They were tested for memory on the two tasks immediately, and then again after either a 2-hr nap (n = 31; 17 women, 14 men) or 2-hr wake period (n = 30; 13 women, 17 men). At second testing, the sleep condition had significantly better recall compared to the wake condition on both tasks. There was a relationship with valence only for the story task, with better performance for the sleep condition on the negatively and positively valenced texts, but not on the neutral text. There were no significant relationships between memory measures and sleep-stage duration and EEG power variables. The story memory findings support the hypothesis that memory consolidation prioritizes emotional memory, whether positively or negatively valenced.     

The effect of emotion-focused orientation at retrieval on emotional memory in young and older adults

This study examines how emotion-focused orientation at retrieval affects memory for emotional versus neutral images in young and older adults. A total of 44 older adults (ages 61–84 years, M=70.00, SD=5.54) and 43 young adults (ages 17–33 years, M=20.58, SD=3.72) were tested on their free recall and forced-choice recognition of images. At retrieval the emotion-focused orientation was manipulated by instructing participants to focus on emotion-related information (i.e., emotional content of images and the emotional reactions evoked by the images). In the control conditions participants were either instructed to focus on visual information or not provided any specific orientation instruction. In free recall but not forced-choice recognition, the emotion-focused orientation increased young adults’ positivity bias and thus wiped out their superior negativity bias. However, the emotion-focused orientation did not affect older adults’ emotional memory. The data suggest that young adults activate and prioritise emotional goals in response to external demand during intentional information processing whereas older adults seem to spontaneously tune themselves to emotional goals.     

简化的联合再认范式中情绪对错误记忆影响的年龄差异

以康奈尔情绪DRM词表为主要实验材料, 使用简化的联合再认范式(DRM范式的变式), 结合多项式加工树建模的统计手段, 对34名年轻人(23 ± 2岁)和28名老年人(68 ± 5岁)的再认记忆进行比较, 以考察不同年龄组中情绪效价对错误记忆的作用机制。结果发现材料的情绪效价对错误记忆的影响存在显著年龄差异：(1) 积极情绪能够有效降低老年人的错误记忆, 其作用机制为积极情绪增强了老年人的字面痕迹而减弱了要点痕迹提取; (2) 消极情绪能够有效地降低年轻人的错误记忆, 其作用机制为消极情绪使年轻人反应偏向降低, 但不影响其记忆痕迹的提取。结果表明, 简化的联合再认范式下, 情绪效价对错误记忆的效应存在明显的年龄差异：老年人表现出积极情绪降低错误记忆的积极偏向; 年轻人表现出消极情绪降低错误记忆的消极偏向; 情绪效应对错误记忆的认知机制存在年龄差异。     

Sleep facilitates consolidation of emotional declarative memory

Both sleep and emotion are known to modulate processes of memory consolidation, yet their interaction is poorly understood. We examined the influence of sleep on consolidation of emotionally arousing and neutral declarative memory. Subjects completed an initial study session involving arousing and neutral pictures, either in the evening or in the morning. Twelve hours later, after sleeping or staying awake, subjects performed a recognition test requiring them to discriminate between these original pictures and novel pictures by responding "remember,"know" (familiar), or "new." Selective sleep effects were observed for consolidation of emotional memory: Recognition accuracy for know judgments of arousing stimuli improved by 42% after sleep relative to wake, and recognition bias for remember judgments of these stimuli increased by 58% after sleep relative to wake (resulting in more conservative responding). These findings hold important implications for understanding of human memory processing, suggesting that the facilitation of memory for emotionally salient information may preferentially develop during sleep.     

Local context effects during emotional item directed forgetting in younger and older adults

This paper explored the differential sensitivity young and older adults exhibit to the local context of items entering memory. We examined trial-to-trial performance during an item directed forgetting task for positive, negative, and neutral (or baseline) words each cued as either to-be-remembered (TBR) or to-be-forgotten (TBF). This allowed us to focus on how variations in emotional valence (independent of arousal) and instruction (TBR vs. TBF) of the previous item (trial n-1) impacted memory for the current item (trial n) during encoding. Different from research showing impairing effects of emotional arousal, both age groups showed a memorial boost for stimuli when preceded by items high in positive or negative valence relative to those preceded by neutral items. This advantage was particularly prominent for neutral trial n items that followed emotional items suggesting that, regardless of age, neutral memories may be strengthened by a local context that is high in valence. A trending age difference also emerged with older adults showing greater sensitivity when encoding instructions changed between trial n-1 and n. Results are discussed in light of age-related theories of cognitive and emotional processing, highlighting the need to consider the dynamic, moment-to-moment fluctuations of these systems.     

Sleep disruption explains age-related prospective memory deficits: implications for cognitive aging and intervention

The high prevalence of sleep disruption among older adults may have implications for cognitive aging, particularly for higher-order aspects of cognition. One domain where sleep disruption may contribute to age-related deficits is prospective memory—the ability to remember to perform deferred actions at the appropriate time in the future. Community-dwelling older adults (55–93 years, N = 133) undertook assessment of sleep using actigraphy and participated in a laboratory-based prospective memory task. After controlling for education, sleep disruption (longer awakenings) was associated with poorer prospective memory. Additionally, longer awakenings mediated the relationship between older age and poorer prospective memory. Other metrics of sleep disruption, including sleep efficiency and wake after sleep onset, were not related to prospective memory, suggesting that examining the features of individual wake episodes rather than total wake time may help clarify relationships between sleep and cognition. The mediating role of awakening length was partially a function of greater depression and poorer executive function (shifting) but not retrospective memory. This study is among the first to examine the association between objectively measured sleep and prospective memory in older adults. Furthermore, this study is novel in suggesting sleep disruption might contribute to age-related prospective memory deficits; perhaps, with implications for cognitive aging more broadly. Our results suggest that there may be opportunities to prevent prospective memory decline by treating sleep problems.     

Memory for faces with emotional expressions in Alzheimer’s disease and healthy older participants: positivity effect is not only due to familiarity

Young individuals better memorize initially seen faces with emotional rather than neutral expressions. Healthy older participants and Alzheimer’s disease (AD) patients show better memory for faces with positive expressions. The socioemotional selectivity theory postulates that this positivity effect in memory reflects a general age-related preference for positive stimuli, subserving emotion regulation. Another explanation might be that older participants use compensatory strategies, often considering happy faces as previously seen. The question about the existence of this effect in tasks not permitting such compensatory strategies is still open. Thus, we compared the performance of healthy participants and AD patients for positive, neutral, and negative faces in such tasks. Healthy older participants and AD patients showed a positivity effect in memory, but there was no difference between emotional and neutral faces in young participants. Our results suggest that the positivity effect in memory is not entirely due to the sense of familiarity for smiling faces.     

Ageing and autobiographical memory for emotional and neutral events

We investigated age-related effects in recall of emotional and neutral autobiographical memories. Protocols were scored according to episodic and non-episodic detail categories using the Autobiographical Interview. Young adults recalled a greater number of episodic details compared to older adults, whereas older adults recalled more semantic details, replicating previous findings. Both young and older adults' emotional memories contained more overall detail than neutral ones, with the enhancement from emotion-specific to episodic details, but this did not alter the effect of age group on the pattern of episodic and semantic details. However, the age effect on episodic details was attenuated for neutral autobiographical memories. The findings suggest that age differences for emotional autobiographical recollection might reflect a more general pattern of age-related changes in memory, with impaired recall of episodic components and relative sparing of semantic aspects of autobiographical memory in older adults when compared to young adults.     

Remembering specific features of emotional events across time: The role of REM sleep and prefrontal theta oscillations

When an episode of emotional significance is encountered, it often results in the formation of a highly resistant memory representation that is easily retrieved for many succeeding years. Recent research shows that beyond generic consolidation processes, rapid eye movement (REM) sleep importantly contributes to this effect. However, the boundary conditions of consolidation processes during REM sleep, specifically whether these extend to source memory, have not been examined extensively. The current study tested the effects of putative consolidation processes emerging during REM sleep and slow wave sleep (SWS) on item and source memory of negative and neutral images, respectively. Results demonstrate superior emotional relative to neutral item memory retention after both late night REM sleep and early night SWS. Emotional source memory, on the other hand, exhibited an attenuated decline following late night REM sleep, whereas neutral source memory was selectively preserved across early night SWS. This pattern of results suggests a selective preservation of emotional source memory during REM sleep that is functionally dissociable from SWS-dependent reprocessing of neutral source memory. This was further substantiated by a neurophysiological dissociation: Postsleep emotional source memory was selectively correlated with frontal theta lateralization (REM sleep), whereas postsleep neutral item memory was correlated with SWS spindle power. As such, the present results contribute to a more comprehensive characterization of sleep-related consolidation mechanisms underlying emotional and neutral memory retention. Subsidiary analysis of emotional reactivity to previously encoded material revealed an enhancing rather than attenuating effect of late night REM sleep on emotional responses.     

Age differences in the automatic accessibility of emotional words from semantic memory

Using a speeded word fragment completion task, we assessed age differences in the automatic accessibility of emotional versus neutral words from semantic memory. Participants were instructed to complete a series of single-solution word fragments as quickly as possible. The results demonstrate that older adults are biased against accessing both positive and negative words relative to neutral words, whereas young adults are biased against accessing positive words only. These findings suggest an arousal-based accessibility bias favouring neutral stimuli in older adults coupled with a valence-based bias accessing negative and neutral stimuli for young adults.     

Sleep in children enhances preferentially emotional declarative but not procedural memories

Although the consolidation of several memory systems is enhanced by sleep in adults, recent studies suggest that sleep supports declarative memory but not procedural memory in children. In the current study, the influence of sleep on emotional declarative memory (recognition task) and procedural memory (mirror tracing task) in 20 healthy children (10-13 years of age) was examined. After sleep, children showed an improvement in declarative memory. Separate analysis with respect to the emotional stimulus content revealed that sleep enhances the recognition of emotional stimuli (p > .001) rather than neutral stimuli (p = .084). In the procedural task, however, no sleep-enhanced memory improvement was observed. The results indicate that sleep in children, comparable to adults, enhances predominantly emotional declarative memory; however, in contrast to adults, it has no effect on the consolidation of procedural memory.     

Age-related differences in medial prefrontal activation in response to emotional images

Research has suggested that aging results in a "positivity effect," with young adults dwelling on negative information, and older adults attending to positive information. In order to understand age-related changes in emotional processing underlying this effect, the present fMRI study compared neural activity in young and older adults as they viewed positive, negative, and neutral images. Results indicated a striking age-related reversal in the valence of information eliciting activity within the ventromedial prefrontal cortex (VMPFC). Negative in comparison with positive images activated the VMPFC more for young adults, whereas positive in comparison with negative images activated the VMPFC more for the older adults. The VMPFC is a region associated with the processing of emotional information, and more specifically, with emotion generation and emotion regulation. Therefore, the present results suggest that age-related changes in these processes implemented by the VMPFC contribute to older adults' "positivity effect."     

Phenomenological characteristics of emotional memories in younger and older adults

Older adults sometimes show a “positivity effect” in memory, remembering proportionally more positive information than younger adults. Using a modified Memory Characteristics Questionnaire, this study examined whether emotional valence impacts the phenomenological qualities of young and older adults’ memories. Ageing did not impact the effect of valence on the qualities of high-arousal memories. However, ageing sometimes impacted subjective memory for details of low-arousal memories: In Experiment 2, older adults reported remembering more thoughts, feelings, and temporal order details about positive low-arousal stimuli, while young adults’ ratings for those dimensions were higher for negative low-arousal stimuli. These findings suggest that valence most readily affects the qualities of young and older adults’ emotional memories when those memories are low in arousal.     

The differential effects of mood on age differences in the correspondence bias

The present study found that age-related differences in the correspondence bias were differentially influenced by induced mood. Young and older adults completed an attitude-attribution task after having been induced to experience a positive, neutral, or negative mood. Although negative moods intensified age-related differences in the correspondence bias, young and older adults were equally susceptible to the correspondence bias when in a positive mood. In addition, induced mood differentially influenced the attributional confidence of young and older adults. Whereas negatively induced young adults were less confident than positively induced young adults in their attributions, negatively induced older adults were more confident than positively induced older adults in their attributions. Findings are discussed in terms of how positive and negative moods operate differently in motivating young and older adults' attributional judgments.     

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.     

The effects of emotion on younger and older adults’ monitoring of learning

Age-related differences in memory monitoring appear when people learn emotional words. Namely, younger adults’ judgments of learning (JOLs) are higher for positive than neutral words, whereas older adults’ JOLs do not discriminate between positive versus neutral words. In two experiments, we evaluated whether this age-related difference extends to learning positive versus neutral pictures. We also evaluated the contribution of two dimensions of emotion that may impact younger and older adults’ JOLs: valence and arousal. Younger and older adults studied pictures that were positive or neutral and either high or low in arousal. Participants made immediate JOLs and completed memory tests. In both experiments, the magnitude of older adults’ JOLs was influenced by emotion, and both younger and older adults demonstrated an emotional salience effect on JOLs. As important, the magnitude of participants’ JOLs was influenced by valence, and not arousal. Emotional salience effects were also evident on participants’ free recall, and older adults recalled as many pictures as did younger adults. Taken together, these data suggest that older adults do not have a monitoring deficit when learning positive (vs. neutral) pictures and that emotional salience effects on younger and older adults’ JOLs are produced more by valence than by arousal.     

Age effects in emotional prospective memory: cue valence differentially affects the prospective and retrospective component

While first studies suggested that emotional task material may enhance prospective memory performance in young and older adults, the extent and mechanisms of this effect are under debate. The authors explored possible differential effects of cue valence on the prospective and retrospective component of prospective memory in young and older adults. Forty-five young and 41 older adults performed a prospective memory task in which emotional valence of the prospective memory cue was manipulated (positive, negative, neutral). The multinomial model of event-based prospective memory was used to analyze effects of valence and age on the two prospective memory components separately. Results revealed an interaction indicating that age differences were smaller in both emotional valence conditions. For older adults positive cues improved the prospective component, while negative cues improved the retrospective component. No main effect of valence was found for younger adults on an overt accuracy measure, but model-based analyses showed that the retrospective component was enhanced in the positive compared with the negative cue condition. The study extends the literature in demonstrating that processes underlying emotional effects on prospective memory may differ depending on valence and age.     

老化对睡眠依赖性记忆巩固的影响

随着老化的发生和发展, 老年人的睡眠和记忆问题变得越来越突出。研究显示老年人针对程序性记忆的睡眠依赖性巩固能力受损, 而针对陈述性记忆的睡眠依赖性巩固研究结果尚存分歧。此外, 患有神经退行性疾病的老年人在正常老化的基础上伴有情景记忆睡眠依赖性巩固能力受损。未来研究应考虑同步采集脑电和脑成像数据, 探索增龄通过睡眠影响记忆的神经通路, 尝试搭建老化、睡眠以及记忆三因素的交互模型, 并从睡眠对记忆巩固影响的角度提出针对老年人记忆问题的干预措施。     

Effects of Aging on Functional Connectivity of the Amygdala for Subsequent Memory of Negative Pictures: A Network Analysis of Functional Magnetic Resonance Imaging Data

ABSTRACT— Aging is associated with preserved enhancement of emotional memory, as well as with age-related reductions in memory for negative stimuli, but the neural networks underlying such alterations are not clear. We used a subsequent-memory paradigm to identify brain activity predicting enhanced emotional memory in young and older adults. Activity in the amygdala predicted enhanced emotional memory, with subsequent-memory activity greater for negative stimuli than for neutral stimuli, across age groups, a finding consistent with an overall enhancement of emotional memory. However, older adults recruited greater activity in anterior regions and less activity in posterior regions in general for negative stimuli that were subsequently remembered. Functional connectivity of the amygdala with the rest of the brain was consistent with age-related reductions in memory for negative stimuli: Older adults showed decreased functional connectivity between the amygdala and the hippocampus, but increased functional connectivity between the amygdala and dorsolateral prefrontal cortices. These findings suggest that age-related differences in the enhancement of emotional memory might reflect decreased connectivity between the amygdala and typical subsequent-memory regions, as well as the engagement of regulatory processes that inhibit emotional responses.