Emotion-induced modulation of recognition memory decisions in a Go/NoGo task: Response bias or memory bias?

In recognition memory tests for words, items with negative emotional meaning are more often classified as “old” compared to neutral items, whether or not they are in fact old. Two accounts for this bias have been offered: One proposes that emotions disrupt retrieval and response monitoring processes (executive control account), the other proposes that emotions cause illusory feelings of remembering (memory bias account). We addressed this issue by varying the target signal in a Go/NoGo variant of a recognition memory task for negative, neutral, and positive words and faces: One group of participants was asked to respond to old items whereas the other group was asked to respond to new items. Results showed that the “Go-for-old” group showed the typical emotion-induced response bias shift for both positive and negative words, while the “Go-for-new” group showed the opposite pattern. Results were nonsignificant for faces, but went into the same direction. The findings are clearly inconsistent with the executive control account and speak for a genuine memory illusion induced by emotional arousal.     

编码任务对来源记忆的影响:一项事件相关电位研究

本研究采用ERPs技术,探讨编码任务对来源记忆的影响及其神经机制。在学习阶段,被试进行两种编码操作：匹配判断任务和大小判断任务;在测验阶段,让被试进行来源判断任务。行为结果发现：在编码阶段,匹配判断任务比大小判断任务需要更长的时间;在测验阶段,匹配判断任务在“项目旧/背景旧”和“部分旧”条件的正确率显著高于大小判断任务,匹配判断任务在“项目旧/背景旧”条件的反应时显著短于大小判断任务。测验阶段ERPs结果发现：两种编码任务的新旧效应在200~700ms均有较广泛的头皮分布,而在700~1100ms呈前额皮层最大化分布;匹配判断任务的新旧效应比大小判断任务更大,表现在600~700ms的FPz电极以及700~800ms的Pz、P4电极。由此可见,在来源记忆中,编码任务影响来源记忆,主要表现在后部顶区位置;晚期前额皮层新旧效应不受任务难度因素的影响。     

Effects of Domain,Retention Interval,and Information Load on Young and Older Adults’ Visuospatial Working Memory

Age-related differences in visuospatial working memory were examined in 69 young adults and 49 older adults exposed to three pairs of tasks. Each pair consisted of one task involving information about the form or appearance of items and another task involving information about item locations. The first pair of tasks manipulated retention interval and required maintaining information about one item. The second pair also manipulated retention interval and required maintaining information about multiple items presented simultaneously. The third pair manipulated the number of sequentially presented items. Analyses of the first two pairs of tasks revealed significant age deficits in working memory for spatial locations but not in working memory for visual features. Notably, there were no age differences in the effect of retention interval on any of the four tasks, suggesting that visuospatial information is lost at similar rates in older and young adults. Analyses of the third pair of tasks revealed that, regardless of domain, increasing the amount of information impaired older adults’ memory performance to a greater extent than young adults’ performance. Thus, the present results suggest differences in basic working memory capacity in both domains, but a lack of age differences in rates of forgetting from working memory, and greater age-related deficits in the spatial domain than in the object domain.     

Directed forgetting of complex pictures in an item method paradigm

An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect—that is, better recognition of “to-be-remembered” than of “to-be-forgotten” pictures—was observed, although its size was smaller than previously reported for words or line drawings. The magnitude of the directed forgetting effect correlated negatively with participants’ depression and dissociation scores. The results indicate that, at least in an item method, directed forgetting occurs for complex pictures as well as words and simple line drawings. Furthermore, people with higher levels of dissociative or depressive symptoms exhibit altered memory encoding patterns.     

Decline in working memory updating through ageing: Intrusion error analyses

The present research examines the decline in working memory updating through age. Two experiments compared groups of participants in different age ranges (young‐old, 55–65 years, old, 66–75 years and old‐old, more than 75 years and, in Experiment 2 only, young, 20–30 years). Memory updating tasks were administered, which required participants to remember the smallest items in each list. To perform the task correctly, participants had to update information efficiently, reducing interference from items no longer relevant. Intrusion errors were computed and in the first experiment these were described as “intrusions of irrelevant items” (immediate exclusion) and “intrusions of once relevant items” (delayed exclusion). The oldest adults performed worse in memory updating and made a greater number of intrusion errors of once relevant information. In the second experiment results showed that increases in memory load (number of items that had to be remembered) and updating demand (number of potentially relevant items) impaired performance. The oldest adults had greater difficulty when the task demand was increased. Furthermore, they produced a higher number of intrusion errors, particularly when the updating demand was increased. It therefore appears that elderly people have specific difficulty in updating information in working memory by excluding irrelevant information.     

The effects of encoding task on age-related differences in the functional neuroanatomy of face memory

Age-related differences in brain activity mediating face recognition were examined using positron emission tomography. Participants encoded faces using a pleasant-unpleasant judgment, a right-left orientation task, and intentional learning. Scans also were obtained during recognition. Both young and old groups showed signficant effects of encoding task on recognition accuracy, but older adults showed reduced accuracy overall. Increased brain activity in older adults was similar to that seen in young adults during conditions associated with deeper processing, but was reduced during the shallow encoding and recognition conditions. Left prefrontal activity was less in older adults during encoding, but greater during recognition. Differential correlations of brain activity and behavior were found that suggest older adults use unique neural systems to facilitate face memory.     

Directed remembering: Subliminal cues alter nonconscious memory strategies

Much research on memory function has focused on changes in recognition performance brought about by differences in the processes engaged during encoding. In most of this work, participants either receive explicit instructions to remember particular items or they perform orienting (i.e., encoding) tasks that support different levels of memory performance. In daily life, however, the retention or dismissal of information often occurs without conscious intent, thereby suggesting an alternative, nonconscious route through which purposive remembering and forgetting can occur. Based on this line of reasoning, we speculated that recognition performance in a standard item-based forgetting paradigm may be moderated by subliminal cues that trigger the automatic activation of different mnemonic strategies. We report the results of two experiments that supported this prediction. In each experiment, the basic item-based forgetting effect was replicated, but via the subliminal presentation of “remember” and “forget” cues. In addition, cue-dependent differences in memory performance were traced to the operation of a covert rehearsal mechanism during encoding. We consider the implications of these findings for the non-conscious operation of memory processes in everyday life.     

Secondary memory and very rapid forgetting

Studies of recall in the absence of expectancy (e.g., Muter, 1980) have suggested that forgetting from primary memory is much more rapid than previously assumed. Two experiments examined the role of secondary memory, as reflected by encoding strategies, in determining this rate of forgetting. Experiment 1 demonstrated that the type of encoding specified by orienting tasks can influence recall in a traditional Brown-Peterson task. Experiment 2 demonstrated a similar pattern of effects of orienting task in the Muter task when recall was not expected, despite much more rapid forgetting. The type of encoding engaged by the orienting tasks did not account for Muter's results. Expectancy and orienting task appear to have separable influences on resource allocation during encoding. The presence of secondary memory influences at even the shortest retention interval indicates that forgetting from primary memory may be even more rapid than has been proposed.     

Recognition in a visuospatial memory task: The effect of presentation

The influence of the mode of presentation (simultaneous vs. sequential) on accuracy and latency of visuospatial recognition was explored in three experiments. In Experiment 1, two groups were administered a visuospatial task in which a number of positions were shown either simultaneously or sequentially (in a random order); memory was tested using a recognition procedure of visuospatial patterns, either identical or different (a single cell displaced). The results showed that (1) performance was higher in the simultaneous than in the sequential presentation, and (2) decision time increased with complexity in the sequential presentation but not in the simultaneous presentation. In Experiment 2, the same task was used in three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test, a single location, rather than a pattern, was presented for recognition. The results showed that (1) performance was higher in the simultaneous and in the ordered sequential presentations than in the random sequential one, and (2) decision time increased with complexity. In Experiment 3, the same task was used in the same three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test either an identical or a “displaced” pattern was presented for recognition. The results showed that (1) performance was equivalent in the three types of presentation, and (2) decision time increased with complexity for “hit” items; different patterns of linear relations were observed for “correct rejections” items. The results are interpreted in terms of the organisation of visuospatial working memory, and three types of encoding—extrafigural spatial encoding, visual pattern encoding, and spatial path encoding—were proposed.     

Limitations of episodic memory for highly similar auditory stimuli

Two experiments investigated participants’ recognition memory for word content, while varying vocal characteristics, and for vocal characteristics alone. In Experiment 1, participants performed an auditory recognition task in which they identified whether a spoken word was “new”, “old” (repeated word, repeated voice), or “similar” (repeated word, new voice). Results showed that word recognition accuracy was lower for similar trials than old trials. In Experiment 2, participants performed an auditory recognition task in which they identified whether or not a phrase was spoken in an old or new voice, with repetitions occurring after a variable number of intervening stimuli. Results showed that recognition accuracy was lower when old voices spoke an alternate message than a repeated message and accuracy decreased as a function of number of intervening items. Overall, the results suggest that speech recognition is better for lexical content than vocal characteristics alone.     

情绪一致性对有意遗忘的影响

有意遗忘是强调遗忘的有意性和指向性。对负性情绪的有意遗忘有利于个体的身心健康。本研究采用单字范式,实验一以正性、负性和中性情绪词为材料,探讨了情绪材料对有意遗忘的影响。结果发现,三类词语均表现出了显著的有意遗忘效应;实验二在实验一的基础上加入了情绪状态,探讨了情绪状态和情绪材料对有意遗忘的影响,结果发现,在积极情绪状态下,被试更多地遗忘负性情绪词;在消极情绪状态下,被试更多地遗忘中性词。表明个体对情绪信息的有意遗忘既受信息的情绪性影响,又受个体情绪状态的影响。     

Differential attentional allocation and subsequent recognition for young and older adult faces

Studies examining own-age recognition biases report inconsistent results and often utilize paradigms that present faces individually and in isolation. We investigated young and older adults' attention towards young and older faces during learning and whether differential attention influences recognition. Participants viewed complex scenes while their eye movements were recorded; each scene contained two young and two older faces. Half of the participants formed scene impressions and half prepared for a memory test. Participants then completed an old/new face recognition task. Both age groups looked longer at young than older faces; however, only young adults showed an own-age recognition advantage. Participants in the memory condition looked longer at faces but did not show enhanced recognition relative to the impressions condition. Overall, attention during learning did not influence recognition. Our results provide evidence for a young adult face bias in attentional allocation but suggest that longer looking does not necessarily indicate deeper encoding.     

Self-referencing enhances recollection in both young and older adults

Processing information in relation to the self enhances subsequent item recognition in both young and older adults and further enhances recollection at least in the young. Because older adults experience recollection memory deficits, it is unknown whether self-referencing improves recollection in older adults. We examined recollection benefits from self-referential encoding in older and younger adults and further examined the quality and quantity of episodic details facilitated by self-referencing. We further investigated the influence of valence on recollection, given prior findings of age group differences in emotional memory (i.e., “positivity effects”). Across the two experiments, young and older adults processed positive and negative adjectives either for self-relevance or for semantic meaning. We found that self-referencing, relative to semantic encoding, increased recollection memory in both age groups. In Experiment 1, both groups remembered proportionally more negative than positive items when adjectives were processed semantically; however, when adjectives were processed self-referentially, both groups exhibited evidence of better recollection for the positive items, inconsistent with a positivity effect in aging. In Experiment 2, both groups reported more episodic details associated with recollected items, as measured by a memory characteristic questionnaire, for the self-reference relative to the semantic condition. Overall, these data suggest that self-referencing leads to detail-rich memory representations reflected in higher rates of recollection across age.     

The aftermath of memory retrieval for recycling visual working memory representations

We examined the aftermath of accessing and retrieving a subset of information stored in visual working memory (VWM)—namely, whether detection of a mismatch between memory and perception can impair the original memory of an item while triggering recognition-induced forgetting for the remaining, untested items. For this purpose, we devised a consecutive-change detection task wherein two successive testing probes were displayed after a single set of memory items. Across two experiments utilizing different memory-testing methods (whole vs. single probe), we observed a reliable pattern of poor performance in change detection for the second test when the first test had exhibited a color change. The impairment after a color change was evident even when the same memory item was repeatedly probed; this suggests that an attention-driven, salient visual change made it difficult to reinstate the previously remembered item. The second change detection, for memory items untested during the first change detection, was also found to be inaccurate, indicating that recognition-induced forgetting had occurred for the unprobed items in VWM. In a third experiment, we conducted a task that involved change detection plus continuous recall, wherein a memory recall task was presented after the change detection task. The analyses of the distributions of recall errors with a probabilistic mixture model revealed that the memory impairments from both visual changes and recognition-induced forgetting are explained better by the stochastic loss of memory items than by their degraded resolution. These results indicate that attention-driven visual change and recognition-induced forgetting jointly influence the “recycling” of VWM representations.     

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.     

Item-specific processing reduces false recognition in older and younger adults: Separating encoding and retrieval using signal detection and the diffusion model

Our study examined processing effects in improving memory accuracy in older and younger adults. Specifically, we evaluated the effectiveness of item-specific and relational processing instructions relative to a read-only control task on correct and false recognition in younger and older adults using a categorized-list paradigm. In both age groups, item-specific and relational processing improved correct recognition versus a read-only control task, and item-specific encoding decreased false recognition relative to both the relational and read-only groups. This pattern was found in older adults despite overall elevated rates of false recognition. We then applied signal-detection and diffusion-modeling analyses, which separately utilized recognition responses and the latencies to those responses to estimate contributions of encoding and monitoring processes on recognition decisions. Converging evidence from both analyses demonstrated that item-specific processing benefits to memory accuracy were due to improvements of both encoding (estimates of d′ and drift rate) and monitoring (estimates of lambda and boundary separation) processes, and, importantly, occurred similarly in both younger and older adults. Thus, older and younger adults showed similar encoding-based and test-based benefits of item-specific processing to enhance memory accuracy.     

Decomposing item-method directed forgetting of emotional pictures: Equivalent costs and no benefits

Using an item-method directed forgetting task, we presented negative, neutral, and positive photographic pictures, one at a time, each followed by an instruction to remember or forget. We determined that the directed forgetting effect, defined as better subsequent recognition of to-be-remembered (TBR) items than to-be-forgotten (TBF) items, was equivalent across negative, neutral, and positive pictures. To disentangle the underlying costs (i.e., decrease in memory for TBF items) and benefits (i.e., increase in memory for TBR items), we compared recognition memory performance in the directed forgetting task to that of a novel within-subjects remember-all control condition (Experiment 1) and to a between-subjects remember-all control group (Experiment 2). We observed costs without benefits across all three emotions—negative, neutral, and positive—in both experiments. These results demonstrate that equivalent directed forgetting effects for emotional stimuli are not attributable to different underlying component processes. Instead, our results suggest that selection for encoding is accomplished in similar ways, regardless of emotional content.     

Repeated study of items with and without repeated context: aging effects on memory discriminability

Presenting items multiple times during encoding is a common way to enhance recognition accuracy. Under such conditions, older adults often show an increase in false recognition that counteracts benefits of repeated study. Using a false-memory paradigm with related study items and related lures, we tested whether repetition within the same encoding task or repetition across two different encoding tasks would be more beneficial to older adults’ memory discriminability. Results showed that, compared to items not repeated at study, items repeated in the same context and items repeated across different contexts showed improvements in memory discriminability in both young and older adults. This improvement was primarily reflected in improved recollection responses for both age groups across both repeat study conditions, as compared to no repetition. Importantly, the results demonstrated that repetition can be used to successfully mitigate age-related deficits by increasing memory discriminability and without incurring a cost of false recognition specific to any one age group.     

Age-Related Differences in Memory Illusions: Revelation Effect

Older adults are often more susceptible to various illusions and distortions of memory than young adults. In the experiments reported here, we explored the question of whether normal aging was associated with a larger revelation effect, an illusion of memory in which items that are revealed gradually during a recognition test are more likely to be called old than unrevealed items that are shown in their entirety. Contrary to expectations, older adults were not susceptible to this memory illusion. A revelation effect occurred for young but not older adults, even when older adults were similar to young adults on measures of recognition and repetition priming. When data across experiments were combined, there was evidence for a negative revelation effect in older adults in which revealed items were less likely called old than unrevealed items. These results place boundary conditions on the claim that older adults are more susceptible than young adults to memory illusions, and imply that one or more mechanisms underlying the revelation effect are age sensitive.     

Retrieval-induced forgetting in young children

A prominent theory of cognitive development attributes the poor performance that children show in many cognitive tasks to a general lack of inhibitory control. We tested this theory by examining children’s inhibitory capabilities in retrieval-induced forgetting (RIF), a memory task in which selective retrieval of previously studied material causes forgetting of related, nonretrieved material. Such forgetting is often attributed to inhibitory control processes, which supposedly suppress the nonretrieved items’ memory representation. We examined RIF in kindergartners, second graders, and adults, using both recall and recognition testing. Although all three age groups showed significant RIF in recall, only adults and second graders, but not kindergartners, showed RIF in recognition. Because inhibition-based RIF should be present in recall and recognition, these findings indicate that in adults and second graders, but not in kindergartners, RIF is mediated by inhibition. The results support the view of inefficient inhibitory processes in young children’s cognition.