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.     

Effect of distinctive encoding on false recognition,discrimination, and decision criteria in young and elderly adults

In order to examine the effects of distinctive encoding on age-related differences in false memory and decision criteria, we used a standard recognition paradigm and manipulated three encoding conditions: control, general, and distinctive. The results revealed main effects of age and encoding condition on hits and false recognition, and interactions between these variables, with elderly adults benefiting more than young adults from the encoding tasks. In the distinctive encoding condition, the age-related difference on false recognition was eliminated. These findings are discussed in terms of an age-related deficit in self-initiated distinctive processing. Further analyses showed that elderly adults used a more lenient decision criterion than young adults. Distinctive encoding led all subjects to use stringent decision criteria, but did not eliminate age differences.     

The production of false recognition and the associated state of consciousness following encoding in a naturalistic context in aging

Using virtual reality, we implemented a naturalistic variant of the DRM paradigm in young and older adults to evaluate false recall and false recognition. We distinguished false recognition related to the highest semantic association (the critical lures), semantic similarity (i.e. items that belong to the same semantic category), and perceptual similarity (i.e. items that are similar, but not identical in terms of shape or color). The data revealed that younger adults recalled and recognized more correct elements than older adults did while the older adults intruded more critical items than younger adults. Both age groups produced false recognition related to the critical items, followed by perceptually and then semantically related items. False recognitions were highly recollective as they were mainly associated with a sense of remembering, even more so in older adults than in young adults. The decline of executive functions and working memory predicted age-related increases in false memories.     

Memory for objects in real scenes: The development of recognition and recall

Subjects examined crowded semirealistic layouts of toy objects, or photographs of these layouts, and then tried to identify added, moved or deleted items. The main study, involving 1st-, 3rd, 6th-graders, and adults, showed that although successful recognition of added items was superior to both recall of deleted items and recognition of moved ones, all three scores improved with age. In addition, false reports of “new” items decreased markedly in the older groups. The results argue against the widely held view that recognition memory undergoes little or no developmental improvement. No significant difference between real layouts and photographs appeared either in the main experiment or in replications involving shorter exposure (Experiment 2) or retarded subjects (Experiment 3).     

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.     

The ironic effect of guessing: increased false memory for mediated lists in younger and older adults

Younger and older adults studied lists of words directly (e.g., creek, water) or indirectly (e.g., beaver, faucet) related to a nonpresented critical lure (CL; e.g., river). Indirect (i.e., mediated) lists presented items that were only related to CLs through nonpresented mediators (i.e., directly related items). Following study, participants completed a condition-specific task, math, a recall test with or without a warning about the CL, or tried to guess the CL. On a final recognition test, warnings (vs. math and recall without warning) decreased false recognition for direct lists, and guessing increased mediated false recognition (an ironic effect of guessing) in both age groups. The observed age-invariance of the ironic effect of guessing suggests that processes involved in mediated false memory are preserved in aging and confirms the effect is largely due to activation in semantic networks during encoding and to the strengthening of these networks during the interpolated tasks.     

Older adults encode--but do not always use--perceptual details: intentional versus unintentional effects of detail on memory judgments

Investigations of memory deficits in older individuals have concentrated on their increased likelihood of forgetting events or details of events that were actually encountered (errors of omission). However, mounting evidence demonstrates that normal cognitive aging also is associated with an increased propensity for errors of commission-shown in false alarms or false recognition. The present study examined the origins of this age difference. Older and younger adults each performed three types of memory tasks in which details of encountered items might influence performance. Although older adults showed greater false recognition of related lures on a standard (identical) old/new episodic recognition task, older and younger adults showed parallel effects of detail on repetition priming and meaning-based episodic recognition (decreased priming and decreased meaning-based recognition for different relative to same exemplars). The results suggest that the older adults encoded details but used them less effectively than the younger adults in the recognition context requiring their deliberate, controlled use.     

False recognition of abstract versus common objects in older and younger adults: testing the semantic categorization account

Older adults often demonstrate higher levels of false recognition than do younger adults. However, in experiments using novel shapes without preexisting semantic representations, this age-related elevation in false recognition was found to be greatly attenuated. Two experiments tested a semantic categorization account of these findings, examining whether older adults show especially heightened false recognition if the stimuli have preexisting semantic representations, such that semantic category information attenuates or truncates the encoding or retrieval of item-specific perceptual information. In Experiment 1, ambiguous shapes were presented with or without disambiguating semantic labels. Older adults showed higher false recognition when labels were present but not when labels were never presented. In Experiment 2, older adults showed higher false recognition for concrete but not abstract objects. The semantic categorization account was supported.     

Age differences in veridical and false recall are not inevitable: The role of frontal lobe function

The relationship of neuropsychological measures of frontal lobe function to age differences in false recall was assessed using the Deese/Roediger-McDermott associative false memory paradigm (Deese, 1959; Roediger & McDermott, 1995). As other studies have found, older adults were less likely to correctly recall studied items and more likely to falsely recall highly related but nonpresented items than were younger adults. When older adults were divided based on a composite measure of frontal lobe functioning, this age difference was found only for low frontal lobe functioning individuals. High frontal lobe functioning older adults and young adults had equivalent levels of false recall, as well as equivalent levels of veridical recall. These results suggest that age differences in memory may be due to declines in frontal lobe function. More important, our findings indicate that declines in veridical recall and increases in false recall are not an inevitable consequence of aging.     

范畴变量对虚假记忆的影响

以中文词为材料,考察范畴样例重复,样例熟悉性、典型性和范畴大小对虚假再认的影响。实验1表明,随着范畴样例增加,虚假再认也增加。实验2表明,对高熟悉的样例虚假再认多。实验3表明,对高典型样例更易虚假再认。实验4表明,和大范畴样例比,对小范畴样例有更多的虚假再认。整个结果可以用激活扩散理论统一地加以解释     

Recall and recognition of self-performed acts

Summary In Experiment 1, recall and recognition of 80 action phrases were compared under two encoding conditions: verbal and motor (performing the denoted acts). Memory performance was better under motor encoding than under verbal encoding, and more so in recognition than in recall. We assume that this finding is due to the item-specific effect of a specific motor component in the memory trace after enacting. In Experiments 2 and 3 we further investigated whether false-alarm rates are dependent on the motoric similarity of distractor items. The rate of false alarms was lower under motor encoding than under verbal encoding, but the motoric similarity of distractor items to list items did not influence the false alarms. The results were interpreted as support for the assumption that motor encoding enhances item-specific information in relation to verbal encoding, but that during verbal recognition the motoric quality of the depicted movement is not processed.     

跨视听通道的相继错误记忆效应

本研究以12名大学生为被试采用DRM范式,考察了视觉与听觉通道在编码阶段的错误记忆ERP效应,以从更深层面认识错误记忆的内在加工机制。研究结果表明,在编码阶段,在300-500ms及500-700ms的时间窗视觉通道均存在相继错误记忆效应（DIM）,比听觉通道表现出较强的DIM效应,这不仅说明视觉通道与听觉通道在编码阶段具有不同的脑机制,而且表明DIM效应与学习项目的语义加工有着密切的关系。     

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.     

Age differences in memory span

Five-year-olds recalled fewer items than adults in memory-span tasks involving both familiar and unfamiliar faces. This occurred even though the use of rehearsal and recoding strategies was minimized for adults. This residual age difference may be partially accounted for by two further processing limitations in children. The five-year-olds needed more time than adults to name a face (Experiment 1) and to encode a face (Experiment 2). In order to test whether limitations in children's initial recognition and stimulus-identification processes could account for recall performance, Experiment 3 reduced adults' exposure duration in the memory-span task. This led to a drastic reduction in the age difference. Other factors contributing to remaining age differences included adults' adaptability in using various alternative encoding and retrieval strategies which elevated their recall performance.     

What underlies the deficit in reported recollective experience in old age?

In recognition memory, older adults report fewer occasions on which recognition is accompanied by recollection of the original encoding context. This study asks why this occurs. Two main hypotheses were tested: (1) Older adults fail to encode the items sufficiently when first they experience them. (2) Older adults have a retrieval deficit that prevents efficient reintegration of target and context. In addition, the hypothesis that frontal lobe integrity is essential for recollective experience was examined. Twenty older (mean age 70.7 years) and 20 younger (mean age 22.9 years) adults were asked to study a list of items and to verbalize the strategies they were using to remember. A further 20 older adults (mean age 70.0 years) were tested without the think-aloud protocol. Subsequently, subjects completed a battery of psychometric tests before completing a recognition test. As expected, older adults showed less recollective experience. They differed from the young in how they encoded the material, and once this difference was accounted for, no age differences in recollective experience remained. There was little evidence to support the hypothesis that frontal lobe integrity plays a role in the reduction of recollective experience with age.     

Reduced effects of pictorial distinctiveness on false memory following dynamic visual noise

High levels of false recognition for non-presented items typically occur following exposure to lists of associated words. These false recognition effects can be reduced by making the studied items more distinctive by the presentation of pictures during encoding. One explanation of this is that during recognition, participants expect or attempt to retrieve distinctive pictorial information in order to evaluate the study status of the test item. If this involves the retrieval and use of visual imagery, then interfering with imagery processing should reduce the effectiveness of pictorial information in false memory reduction. In the current experiment, visual-imagery processing was disrupted at retrieval by the use of dynamic visual noise (DVN). It was found that effects of DVN dissociated true from false memory. Memory for studied words was not influenced by the presence of an interfering noise field. However, false memory was increased and the effects of picture-induced distinctiveness was eliminated. DVN also increased false recollection and remember responses to unstudied items.     

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.     

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.     

Aging and the Accessibility of Performed and To-Be-Performed Actions

In young adults information designated for future enactment is more readily accessible from memory than information not intended for enactment (e.g. Goschke & Kuhl, 1993). We examined whether this advantage for to-be-enacted material is reduced in older adults and thus whether attenuated action accessibility could underlie age-associated declines in prospective remembering. Young and older adults showed an equivalent increase in accessibility (faster recognition latencies) for to-be-enacted items over items intended for verbal report. Both age groups also showed increased accessibility for actions performed at encoding compared with verbally encoded items. Moreover, these effects were non-additive, suggesting similarities in the representation of completed and to-be-completed actions.     

Pictorial encoding reduces false recognition of semantic associates

High levels of false recognition can be observed after people study lists of semantic associates that all converge on a nonpresented lure word. To test the idea that encoding distinctive perceptual information would help to reduce false recognition, we presented a line drawing representing each associated word during study list presentation and later tested recognition of studied words and lure words. Two experiments revealed marked reductions in false recognition after pictorial encoding, relative after to word encoding. Results suggest that people reject related and unrelated lures because these items lack the distinctive qualities associated with remembered pictures.