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PubMedDate not supplied

Memory self-efficacy and memory performance among black and white elders.

BACKGROUND: The ability to differentiate between normal functioning and pathologic changes in cognitive aging will be enhanced by descriptive studies providing data from diverse samples of older adults. METHODS: In this study, demographics, depression, health, memory self-efficacy, and metamemory were studied in relation to the memory performance of Black and White American older adults. Community-living adults participated in face-to-face interviews in their apartments or homes. Trained registered nurse interviewers administered all structured questionnaires (subjective) and performance tests (objective), including the Rivermead Behavioural Memory Test. Descriptive statistics, independent sample t-tests, Pearson correlations, and hierarchical regression were used in the analyses. RESULTS: The sample consisted of 89 Black and 83 White adults (mean age, 76.52 years), and their Mini-Mental State Examination scores were in the nonimpaired range. The memory self-efficacy scores of the entire sample were low (M = 31.95 +/- 18.20). The Black elders scored lower on memory self-efficacy and memory performance. Memory self-efficacy predicted memory performance in the White group (r [83] =.41; p < or =.05), but the correlation for the Black group was nonsignificant (r [89] =.16). However, when the entire sample was combined for the regression analyses, the relation was significant (r [173] =.30; p < or =.05). Age, education, and memory self-efficacy accounted for 13% of the variance in memory performance. CONCLUSIONS: Objective and subjective memory scores were decreased, and both measures provided insight into the participants' everyday memory function. The sample had low confidence in their memory ability, and this negatively influenced their everyday memory performance. The recruitment of minority elders into cognitive aging studies will continue to challenge researchers.

Black or African American↗

PubMed1995

Wada memory asymmetries predict verbal memory decline after anterior temporal lobectomy.

We examined Wada memory and neuropsychological memory function in 34 nonlesional patients who underwent anterior temporal lobectomy (ATL) and who were seizure free at 1-year follow-up. Patients who displayed a decline on verbal memory measures that exceeded 1 SD after left ATL had significantly smaller left/right Wada memory asymmetries than left ATL patients without a significant verbal memory decline. When Wada memory asymmetries were used to predict verbal memory decline after left ATL in individual patients, similar statistically significant effects were present. No significant relationship between Wada memory and postoperative memory was present in right ATL patients, and postoperative memory function was not related to Wada memory performance after either left hemisphere or right hemisphere injection alone. We conclude that Wada memory asymmetries provide one measure of the risk to material-specific decline in verbal memory after left ATL.

Analysis of Variance↗

PubMed2005

The effects of working memory demands on the neural correlates of prospective memory.

Event-related brain potentials (ERPs) were used to examine the reciprocal costs of working and prospective memory loads on the neural correlates of the realization of delayed intentions and the detection of target stimuli. The electrophysiological data revealed several interesting results: (1) distinct modulations of the ERPs were elicited by working memory targets and prospective memory cues, (2) working memory load modulated the amplitude of the N300 elicited by prospective memory cues, (3) prospective memory load was associated with a broadly distributed sustained modulation that began shortly after stimulus onset, and (4) brain-behavior correlations between the neural correlates of prospective memory and working memory varied with the working memory demands of the ongoing activity. These findings appear to indicate that attentional processes associated with the detection of prospective memory cues are sensitive to the working memory demands of the ongoing activity and that different processes may support prospective memory depending on the working memory demands of the ongoing activity.

Adolescent↗

PubMed2005

Successful declarative memory formation is associated with ongoing activity during encoding in a distributed neocortical network related to working memory: a magnetoencephalography study.

The aim of the present study was to investigate the spatio-temporal characteristics of the neural correlates of declarative memory formation as assessed by the subsequent memory effect, i.e. the difference in encoding activity between subsequently remembered and subsequently forgotten items. Different operations could account for these effects. In particular, it has been proposed that successful memory formation depends on the organization of the information at the time of encoding, an operation accomplished by the working memory system. Consequently, functional magnetic resonance imaging studies have already shown that the very same regions that are involved in certain working memory processes are also involved in declarative memory formation. Here, we used magnetoencephalography to investigate whether the subsequent memory effects in these regions are present throughout picture stimulus presentation, postulating ongoing working memory operations as an effective factor. The results showed that subsequent memory effects began to appear after about 300 ms post stimulus onset over bilateral temporal areas and left parietal regions and were sustained throughout the recording epoch (1000 ms). Roughly parallel to these effects, we identified a left frontal subsequent memory effect, which, however, was less sustained than the other effects. In addition, we revealed a late subsequent memory effect over the right occipital region, which has not been described previously in the event-related potential literature. These sustained subsequent memory effects are suggestive of working memory processes that may enable deep semantic and perceptual processing. Additionally, contextually constrained visual perception after top-down modulation may account for a more efficient encoding of the complex scene.

Adult↗

PubMed2000

Antigen-specific B cell memory: expression and replenishment of a novel b220(-) memory b cell compartment.

The mechanisms that regulate B cell memory and the rapid recall response to antigen remain poorly defined. This study focuses on the rapid expression of B cell memory upon antigen recall in vivo, and the replenishment of quiescent B cell memory that follows. Based on expression of CD138 and B220, we reveal a unique and major subtype of antigen-specific memory B cells (B220(-)CD138(-)) that are distinct from antibody-secreting B cells (B220(+/)-CD138(+)) and B220(+)CD138(-) memory B cells. These nonsecreting somatically mutated B220(-) memory responders rapidly dominate the splenic response and comprise >95% of antigen-specific memory B cells that migrate to the bone marrow. By day 42 after recall, the predominant quiescent memory B cell population in the spleen (75-85%) and the bone marrow (>95%) expresses the B220(-) phenotype. Upon adoptive transfer, B220(-) memory B cells proliferate to a lesser degree but produce greater amounts of antibody than their B220(+) counterparts. The pattern of cellular differentiation after transfer indicates that B220(-) memory B cells act as stable self-replenishing intermediates that arise from B220(+) memory B cells and produce antibody-secreting cells on rechallenge with antigen. Cell surface phenotype and Ig isotype expression divide the B220(-) compartment into two main subsets with distinct patterns of integrin and coreceptor expression. Thus, we identify new cellular components of B cell memory and propose a model for long-term protective immunity that is regulated by a complex balance of committed memory B cells with subspecialized immune function.

Animals↗

PubMed2006

Secondary memory CD8+ T cells are more protective but slower to acquire a central-memory phenotype.

The formation of memory CD8 T cells is an important goal of vaccination. However, although widespread use of booster immunizations in humans generates secondary and tertiary CD8 T cell memory, experimental data are limited to primary CD8 T cell memory. Here, we show that, compared with primary memory CD8 T cells, secondary memory CD8 T cells exhibit substantially delayed conversion to a central-memory phenotype, as determined by CD62L expression and interleukin (IL)-2 production. This delayed conversion to a central-memory phenotype correlates with reduced basal proliferation and responsiveness to IL-15, although in vitro coculture with a high concentration of IL-15 is capable of inducing proliferation and CD62L upregulation. Functionally, secondary memory CD8 T cells are more protective in vivo on a per cell basis, and this may be explained by sustained lytic ability. Additionally, secondary memory CD8 T cells are more permissive than primary memory CD8 T cells for new T cell priming in lymph nodes, possibly suggesting a mechanism of replacement for memory T cells. Thus, primary and secondary memory CD8 T cells are functionally distinct, and the number of encounters with antigen influences memory CD8 T cell function.

Animals↗

PubMed1984

Memory demands and the development of young children's memory.

The primary purposes of this study were to determine the nature of and changes in early memory demands and to assess the relationship between memory demands and memory performance. 10 children at each of 2 ages--30 and 42 months--were observed in their homes for 4 2-hour sessions. Conversations between mothers and children were recorded and mother's memory-demand questions were coded for form and content from these conversations. Question form referred to whether recall or recognition was required and question content to the type of information requested--event or knowledge. Children also participated in 2 long-term memory tasks--production and verification. They were shown a dollhouse and asked to produce the names of objects that would belong in 2 rooms of the house and to verify whether particular miniature replicas of household objects belonged in the rooms. Although memory demands were frequently made, there were few changes between age 2 and 3 in the incidence or types of questions children were asked. At age 3, positive correlations were found between children's production and verification performance and content rather than form of mothers' memory-demand questions. At age 2 no overall relationships were found. Children were retested a year later on memory tasks, and for both age groups memory demands and performance were positively correlated even when initial memory-performance level was controlled. These results, along with other patterns in the data, suggested that mothers' memory demands have an impact on children's memory performance that provides at least partial support for Vygotsky's sociohistorical model of memory development.

Child Development↗

PubMed1994

Naive versus memory CD4 T cell response to antigen. Memory cells are less dependent on accessory cell costimulation and can respond to many antigen-presenting cell types including resting B cells.

Secondary responses to Ag in vivo are characterized by more rapid kinetics and greatly enhanced magnitude compared with primary responses. For CD4+ T cells, this is in part due to a greater frequency of Ag-specific memory cells, and may also reflect differences in responsiveness of memory vs naive cells to stimulation. To compare activation requirements and the role of accessory cells, naive and memory cells were stimulated with immobilized anti-CD3 in the presence or absence of APC. With anti-CD3 alone, naive cells proliferated slightly but produced no detectable IL-2, whereas memory cells proliferated well with significant IL-2 production. Increasing numbers of T-depleted APC greatly enhanced responses of naive cells to levels equivalent to those of memory cells, whereas for memory cells only IL-2 production increased slightly. The response of naive cells was equivalent in magnitude and kinetics to that of memory cells when low density APC, enriched in dendritic cells and depleted of resting B cells, were used with anti-CD3. To directly compare naive and memory responses in an Ag-specific model, we examined CD4+ cells specific for a peptide of pigeon cytochrome c fragment isolated from TCR-alpha beta transgenic mice. Naive cells were compared with 4-day activated blasts (effectors) and memory cells generated by adoptive transfer of effectors to adult thymectomized bone marrow reconstituted mice, in which the cells return to a resting state but still respond to recall Ag. Naive cells responded to Ag on dendritic cells and activated B cells but not on resting B cells or macrophages. In contrast, both memory cells and effectors were stimulated by all APCs, including resting B cells and macrophage to a limited extent. The ability of memory cells to respond to all APC types was confirmed using Ag-specific cells generated by in vivo priming with keyhole limpet hemocyanin. These results suggest that memory cells are considerably less dependent on accessory cell costimulation than naive cells, but that naive cells can respond equivalently in both magnitude and kinetics if Ag is presented on costimulatory APCs such as dendritic cells. In addition, these studies suggest that the enhanced secondary T cell response is due to a combination of the increased frequency of Ag-specific cells and their ability to react to Ag presented on a wider range of APC types, rather than an inherent capacity of memory T cells to respond better and faster.

Animals↗

PubMed2001

Relations between subjective evaluations of memory and objective memory performance.

Several explanations for the weak relations between subjective memory judgements and objective memory performance were investigated in two groups of normal older adults. Group 1 sampled a general population (mean age 61.6 yr., range 46-89), while Group 2 sampled subjects who were on a waiting list for memory training (mean age 63.0 yr., range 45-85 years). In both groups, subjective memory judgments were assessed with global ratings of memory capacity and with ratings of frequency of forgetting in specific memory situations. Memory performance was assessed with several well-known tests and with recently developed tests for domain-specific aspects of memory. Most tests concerned episodic memory. Study 1 also included measures of semantic, incidental and working memory. Study 2 further examined the influence of the domain-specificity of objective and subjective measures for remembering names, intentions, and texts. Relations between memory self-reports and performance were weak in both groups and for all kinds of tests. Against expectations, the low correlations could not be explained by differences between ecological and laboratory tests or incidentally and intentionally remembered information, or by differences between specific failures compared to global, stereotyped judgments. Surprisingly, correlations did not increase when subjective and objective measures assessed the same ability, like remembering names. Also noncognitive variables (mood and lifestyle) did not influence the relations. The (weak) relations between subjective and objective memory measures were comparable for subjects over and under 65 years of age. Furthermore, relations were comparable for the general population sample and the memory compliant group.

Aged↗

PubMed2006

Is overgeneral autobiographical memory an isolated memory phenomenon in major depression?

The present study explored the relation between overgeneral autobiographical memory (AM) and other aspects of memory functioning in depression. A total of 26 patients with major depressive disorder completed a set of memory tasks measuring AM specificity (AMT; Williams & Broadbent, 1986), working memory, semantic memory, verbal learning, delayed verbal recall, recognition memory, and source memory. Reduced specificity of AM was related to poor working memory (central executive functioning) and poor source memory. The former finding conforms to the idea that the voluntary retrieval of specific autobiographical memories (AMs) involves central executive processes (e.g., Conway & Pleydell-Pearce, 2000). The latter finding replicates and extends recent findings suggesting that overgeneral AM is part of a broader memory deficit in retrieving the specific details of the context in which information was acquired (Ramponi, Barnard, & Nimmo-Smith, 2004). Furthermore, in line with Ramponi et al. (2004), rumination was found to be related to both overgeneral AM and poor source memory.

Adult↗

PubMed2002

Everyday memory and laboratory memory tests: general function predictors in schizophrenia and remitted depression.

This study was designed to compare neuropsychological memory measures ("laboratory memory tests") and an everyday memory measure in patients with schizophrenia, patients with major depression, and normal controls. Patients with schizophrenia ( N= 68) treated with typical (N = 33) or atypical ( N= 35) neuroleptics, patients with major depression (N = 30), and a control group (N = 36) were evaluated with clinical measures (Positive and Negative Syndrome Scale and Hamilton Depression Rating Scale), laboratory memory tests (Digit-Span, Paired-Associates, Rey Complex Figure Test, and Digit-Symbol), everyday memory test (RMBT), and the Global Assessment of Functioning (GAF). The schizophrenia group had a significantly lower level of performance in everyday memory and general function but not in laboratory memory tests. Verbal and everyday memory measures were correlated with general function. The diagnosis rather than current symptoms (in remission) contributed to test variance and was correlated with performance on everyday memory and general function tests. Everyday memory and verbal memory were good predictors of general function in schizophrenic and depressive patients in the remitted phase. However, the advantages of these tests over laboratory memory tests need to be further investigated in larger and more representative samples.

Adolescent↗

PubMed1998

Episodic memory, semantic memory, and amnesia.

Episodic memory and semantic memory are two types of declarative memory. There have been two principal views about how this distinction might be reflected in the organization of memory functions in the brain. One view, that episodic memory and semantic memory are both dependent on the integrity of medial temporal lobe and midline diencephalic structures, predicts that amnesic patients with medial temporal lobe/diencephalic damage should be proportionately impaired in both episodic and semantic memory. An alternative view is that the capacity for semantic memory is spared, or partially spared, in amnesia relative to episodic memory ability. This article reviews two kinds of relevant data: 1) case studies where amnesia has occurred early in childhood, before much of an individual's semantic knowledge has been acquired, and 2) experimental studies with amnesic patients of fact and event learning, remembering and knowing, and remote memory. The data provide no compelling support for the view that episodic and semantic memory are affected differently in medial temporal lobe/diencephalic amnesia. However, episodic and semantic memory may be dissociable in those amnesic patients who additionally have severe frontal lobe damage.

Amnesia↗

PubMed2004

Semantic memory and verbal working memory correlates of N400 to subordinate homographs.

N400 is an event-related brain potential that indexes operations in semantic memory conceptual space, whether elicited by language or some other representation (e.g., drawings). Language models typically propose three stages: lexical access or orthographic- and phonological-level analysis; lexical selection or word-level meaning and associate activation; and lexical integration, sentence- and discourse-level operations. The exact stage that N400 reflects is unknown, although opinion favors lexical integration over lexical selection. Surprisingly, little research has assessed relationships between neuropsychological measures of semantic memory fund of information or verbal working memory capacity and N400. Subjects performed a homograph disambiguation comprehension task with minimal working memory load. Short sentences read: The noun was adjective/verb. The nouns were either homographs or unambiguous. The adjective/verb was disambiguating for the homograph, and congruent or incongruent for the unambiguous noun. The primary noun of interest was the subordinate homograph. Comprehension of the subordinate meaning should correlate with semantic memory stores, reflecting greater knowledge. If N400 primarily reflects lexical access operations, it should also correlate with measures of semantic knowledge. If N400 reflects lexical integration, it should correlate with measures of working memory capacity. Comprehension errors were associated with semantic memory stores, but not working memory capacity. N400 was related to working memory capacity, but not semantic knowledge, suggesting that N400 primarily reflects late-stage working memory operations. N400 to subordinate disambiguating words was larger with greater working memory capacity, and thus may index the absolute capacity of working memory rather than difficulty in contextual integration.

Adult↗

PubMed2004

Re-experiencing old memories via hippocampus: a PET study of autobiographical memory.

The time-scale of medial temporal lobe (MTL) involvement in storage and retrieval of episodic memory is keenly debated. To test competitive theories of long-term memory consolidation, the present work aimed at characterizing which cerebral regions are involved during retrieval of recent and remote strictly episodic autobiographical memory. Using positron emission tomography (PET), we examined mental retrieval of recent (0-1 year) and remote (5-10 years) autobiographical memories, controlling for the nature of the autobiographical memories (i.e., specificity, state of consciousness, vividness of mental visual imagery, emotion) retrieved during scanning by behavioral measures assessed at debriefing for each event recalled. Cognitive results showed that specificity and emotion did not change with time interval although both autonoetic consciousness and mental image quality were significantly higher for recent memories, suggesting an underlying shift in the phenomenal experience of remembering with the passage of time. The SPM analysis revealed common activations during the recollection of recent and remote memories that involved a widespread but mainly left-sided cerebral network, consistent with previous studies. Subtraction analysis demonstrated that the retrieval of recent (relative to remote) autobiographical memories principally activated the left dorsolateral prefrontal cortex whereas the retrieval of remote (relative to recent) autobiographical memories activated the inferior parietal cortex bilaterally. ROIs analysis revealed more hippocampal activity for remote memories than for recent ones and a preferentially right-sided involvement of the hippocampal responses whatever the remoteness of autobiographical memories. New insights based on higher hippocampal response to the remoteness of episodic autobiographical memories challenge the standard model and are less discrepant with the multiple trace theory.

Adult↗

PubMedDate not supplied

Phonological short-term memory contributions to sentence processing in young children.

Two experiments investigated the contribution of phonological short-term memory to the processing of spoken sentences by 4- and 5-year-old children. In Experiment 1, sentences contained either short or longer words, and varied in syntactic structure. Overall, repetition but not comprehension of the sentences was significantly influenced by word length. In Experiment 2. children selected on the basis of their high phonological short-term memory ability were founded to be superior at repeating sentences to children of lower phonological short-term memory ability, although the two groups did not differ in their comprehension accuracy for the same sentences. In both experiments, comprehension and repetition performance were differently influenced by particular sentence structures. It is proposed that sentence repetition in children is constrained by phonological memory capacity, and is therefore directly influenced by memory-related factors that include the length and number of words in sentences, and individual differences in memory skills.

Child, Preschool↗

PubMed2005

Source memory in the real world: a neuropsychological study of flashbulb memory.

A flashbulb memory (FM) is a vivid, enduring memory for how one learned about a surprising, shocking event. It thus involves memory for the source of event information, as opposed to memory for the event itself. Which brain regions are involved in FM, however, is uncertain. Although medial temporal lobe/diencephalic (MTL/D) damage impairs content or item memory, frontal lobe (FL) damage has been associated with impaired source memory. One would therefore expect that FM should depend on the FLs, although two recent reports do not support this idea. In the current study, we examined memory for the events of September 11th, and memory for the source of that information, in MTL/D patients, FL patients, and healthy subjects. Only the MTL/D patients were impaired in long-term memory for the event itself, measured after a 6 month retention interval. The FL patients, on the other hand, showed a selective deficit in source memory, although their memory for the target event was unimpaired. MTL/D and FL structures appear to play different roles in memory for flashbulb events.

Adult↗

PubMed1996

Memory systems and the psychoanalytic retrieval of memories of trauma.

Increasingly, psychoanalysis has confronted the issue of recovered memories of childhood trauma. Based on trauma research, the concept of a special traumatic memory has evolved. Overwhelming psychic experience is thought to generate a defensively altered state of consciousness (specifically dissociation), which encodes memory in unassimilated visual, somatic, and behavioral, rather than linguistic modes. Analytic reevocation and interpretation of the original altered states of consciousness then permits the transformation of "early" traumatic memory into "later" explicit memory. Examined from the vantage point of contemporary cognitive research and theory, underlying flaws may be found in these propositions when they are extended to patients without explicit memory of trauma: first, dissociation is a chameleonlike process, perhaps as closely associated with suggestibility as with trauma; second, state-dependent learning does not adequately account for the absence of explicit memory; and third, implicit memory does not map onto explicit memory in any direct or simple fashion. Consequently, the clinical application of current propositions about traumatic memory to patients without explicit memory of trauma may warrant considerable caution. Provisional guidelines are offered for estimating the validity of retrieved memories of trauma.

Humans↗

PubMed1999

Memory suppressor genes: enhancing the relationship between synaptic plasticity and memory storage.

Memory suppressor genes encode proteins that act as inhibitory constraints to impede memory storage. The study of memory suppressor genes is important not only for understanding the link between synaptic plasticity and learning but also for identifying potential targets for future pharmaceuticals to treat memory disorders. This article first reviews the evidence for proteins that impede memory storage from work in invertebrates and then explores recent evidence for the existence of memory suppressor genes in vertebrates in the context of hippocampus-dependent forms of memory. In Aplysia, memory suppressor gene products act at each step in long-term facilitation: in the cytoplasm to regulate kinase activity, in the nucleus to alter the activity of transcriptional regulatory proteins, and on the cell surface to modulate cell-cell interactions. Studies of genetically modified Drosophila have provided behavioral evidence for the existence of memory suppressor genes. One of the best candidates for a neuronal mechanism underlying learning is long-term potentiation (LTP), which has been extensively studied in the mammalian hippocampus. Recent work has identified a number of putative memory suppressor gene products that act in the hippocampus at the levels of LTP induction, regulation of intracellular signaling cascades, and transcriptional control. Using these gene products as tools to study enhancements rather than deficits in LTP and learning may generate more precise information about the relationship between synaptic plasticity and behavioral learning. The study of mammalian memory suppressor genes may provide insights into alleviating the learning and memory deficits that accompany both normal aging and a variety of human disorders.

Animals↗