SEARCH · PubMed Health

Results for “Memory”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

PubMed2001

Flashbulb memories in social groups: a comparative test-retest study of the memory of French President Mitterrand's death in a French and a Belgian group.

Flashbulb memories are vivid and long-lasting memories for the reception context of an important public event (Brown & Kulik, 1977). They are assumed to be triggered by emotional factors (i.e., intensity of emotional feeling, appraisal of the original event) and by social factors (i.e., social sharing of the news, following media debate about the event). The present study investigated the memory for the death of the former President of France F. Mitterrand in two social groups, i.e., French and Belgian people. This study tests whether the flashbulb memory attributes, the memory for the original event, and the impact of the emotional and social determinants of flashbulb memory differed across groups. The results indicated that the flashbulb memory for Mitterrand's death is affected by group provenance, as French people showed higher levels of recall for the flashbulb memory attributes and their determinants than Belgian people. Time impaired recollections in both groups, so that flashbulb memories appear prone to decay and share the same destiny as ordinary memories. The theoretical construct of concern--as the most basic antecedent of emotional experiences and its related appraisal (Frijda, 1994)--is discussed in order to explain the differences in memory of the two social groups.

Adult↗

PubMed1996

Memory complaints and memory impairment in older individuals.

OBJECTIVE: To examine whether subjective memory complaints, measured with a series of four questions, are associated with performance on cognitive tests. DESIGN: Cross-sectional study of individuals, 65 to 85 years of age, who lived in the community of Amsterdam. PARTICIPANTS: Individuals were selected randomly within 5-year age strata from the patient lists of 30 general practitioners. Of the 4051 participants, 2537 nondepressed and nondemented respondents were included in the analysis. MEASURES: Four categories of subjective memory complaints were developed on the basis of answers to questions about the presence or absence of memory complaints and memory-related problems in daily functioning. Tests of cognitive function were derived from the subscales of the CAMCOG. MAIN RESULTS: Individuals with complaints and memory-related problems performed more poorly on tests of memory and memory-related functions. This relationship was strengthened after adjusting for age, sex, and premorbid verbal intelligence, all of which were related to complaint status and to performance on cognitive tests. CONCLUSION: Simple questions about memory function are related to memory performance in nondepressed, nondemented community-dwelling older people. Subjective memory complaints may be a promising indicator of memory impairment that signals the need for follow-up.

Aged↗

PubMed2006

Long-term memory following transient global amnesia: an investigation of episodic and semantic memory.

BACKGROUND: Several studies noted persistence of memory impairment following an episode of transient global amnesia (TGA) with standard tests. AIM: To specify long-term memory impairments in a group of patients selected with stringent criteria. METHODS: Both retrograde and anterograde memory were investigated in 32 patients 13-67 months after a TGA episode with original tasks encompassing retrograde semantic memory (academic, public and personal knowledge), retrograde episodic memory (autobiographical events) and anterograde episodic memory. RESULTS: Patients had preserved academic and public knowledge. Pathological scores were obtained in personal verbal fluency for the two most recent periods, and patients produced less autobiographical events than controls. However, when they were provided time to detail, memories were as episodic as in controls regardless of their remoteness. Anterograde episodic tasks revealed a mild but significant impairment of the capacity of re-living the condition of encoding, i.e. the moment at which words were presented. CONCLUSIONS: Patients who have suffered from an episode of TGA manifest deficits of memory focused on the retrieval of both recent semantic information and episodic memories and especially the capacity of re-living. These deficits may not result from a deterioration of memory per se but rather from difficulties in accessing memories.

Aged↗

PubMed2000

The influence of memory load upon delay-interval activity in a working-memory task: an event-related functional MRI study.

We conducted two fMRI studies to investigate the sensitivity of delay-period activity to changes in memory load during a delayed-recognition task for faces. In Experiment 1, each trial began with the presentation of a memory array consisting of one, two, or three faces that lasted for 3 sec. A 15-sec delay period followed during which no stimuli were present. The delay interval concluded with a one-face probe to which subjects made a button press response indicating whether this face was part of the memory array. Experiment 2 was similar in design except that the delay period was lengthened to 24 sec, and the memory array consisted of only one or three faces. We hypothesized that memory maintenance processes that spanned the delay interval would be revealed by their sensitivity to memory load. Long delay intervals were employed to temporally dissociate phasic activity engendered by the memory array from sustained activity reflecting maintenance. Regions of interest (ROIs) were defined anatomically for the superior frontal gyri (SFG), middle frontal gyri (MFG), and inferior frontal gyri (IFG), intraparietal sulci (IPS), and fusiform gyri (FFG) on a subject-by-subject basis. The mean time course of activity was determined for all voxels within these regions and for that subset of voxels within each ROI that correlated significantly with an empirically determined reference waveform. In both experiments, memory load significantly influenced activation 6--9 sec following the onset of the memory array with larger amplitude responses for higher load levels. Responses were greatest within MFG, IPS, and FFG. In both experiments, however, these load-sensitive differences declined over successive time intervals and were no longer significant at the end of the delay interval. Although insensitive to our load manipulation, sustained activation was present at the conclusion of the delay interval within MFG and other prefrontal regions. IPS delay activity returned to prestimulus baseline levels prior to the end of the delay period in Experiment 2, but not in Experiment 1. Within FFG, delay activity returned to prestimulus baseline levels prior to the conclusion of the delay interval in both experiments. Thus, while phasic processes engendered by the memory array were strongly affected by memory load, no evidence for load-sensitive delay-spanning maintenance processes was obtained.

Adult↗

PubMedDate not supplied

Memory complaint, memory performance, and psychiatric diagnosis: a community study.

This study examined the prevalence of memory complaint and poor memory performance on brief screening measures within a community sample of 810 adults. All individuals received an extensive household interview and a clinical psychiatric evaluation. Overall, 22% indicated that they currently had trouble with their memory. This percentage increased with age, rising to 43% for those 65 to 74 years old, 51% for those 75 to 84 years old, and 88% for those 85 years of age and older; the percentage indicating memory problems decreased with educational attainment. The prevalence of poor memory performance was 11%, also increasing with less education and increased age, rising to 26% for those 65 to 74 years old and to 40% for those older then 75. Those who complained of memory trouble were twice as likely to show poor memory performance (29%) compared with those who did not complain (15%). Multivariate analysis found age, emotional distress, and physical illness to be independent predictors of memory complaint; age, functional disability, education, and physical illnesses proved to be independently associated with poor memory performance. A higher prevalence of complaints of memory trouble was found not only for those with affective disorders, as might be expected, but also among those with schizophrenic, cognitive, anxiety, and adjustment disorders. However, only individuals with cognitive disorders showed a higher prevalence of poor memory performance.

Adolescent↗

PubMed1990

Switching between memory and perception: moving attention or memory retrieval?

Weber, Burt, and Noll (1986) estimated that the time needed to switch attention between memory and perception was around 300 msec. The first two experiments in the present paper estimated switching time using a variation of their task. Subjects reported aloud lists of six items. The items were read off a computer screen (perception), recited from memory, or reported alternately from the two sources. The data show that the switching-time estimate is influenced by input/output compatibility, response-initiation times, and memory load. When these factors were controlled, estimated switching time dropped to around 100-150 msec. The data suggest, however, that the switch from perception to memory might be slower than the switch from memory to perception, which would invalidate the formula used to compute switching time. Experiment 3 tested the time for a single switch from perception to memory and a single switch from memory to perception by restricting report to one pair of items in the list. When the to-be-reported pair was precued, estimated switching time dropped to zero. When the pair was not precued, the memory-to-perception switching time remained at zero, but the perception-to-memory time was more than 400 msec. The pattern of results forced a reconceptualization of the task in terms of memory retrieval rather than attention switching. The attention-switching times appear to reflect processes required to select items from memory.

Adult↗

PubMed2004

Comprehensive early and lasting loss of memory CD8 T cells and functional memory during acute and persistent viral infections.

Viral infections have been shown to induce lymphopenias that lower memory CD8 T cell frequencies, and they also have been shown to cause a permanent loss of memory cells specific to previously encountered pathogens. In this study, the patterns and significance of virus-induced memory CD8 T cell depletion were examined in mice immune to heterologous (Pichinde, vesicular stomatitis, vaccinia) viruses and subsequently challenged with acute or persistent lymphocytic choriomeningitis virus infections. Memory CD8 T cell loss was comprehensive and occurred in both lymphoid and peripheral tissues of the immune host. The impact of the loss of memory T cells was reflected by in vivo cytotoxicity assays, which showed decreased clearance of epitope-expressing targets. Memory CD8 T cell loss occurred very early (day 2) after infection, and was thereafter sustained, consistent more with an active deletion model than with a competition model. Cross-reactive T cells, in contrast, increased in number, but memory cells were reduced whether or not there was competition from cross-reactive T cells. Memory T cell loss was more profound during persistent infection than after acute infection. Adoptive transfer studies showed that, unlike the resolved acute infection, in which the reduced memory frequencies became stable, memory T cell loss was a continuously ongoing process during persistent infection. This study therefore links an early virus-induced lymphopenia to a subsequent long-term loss of CD8 T cell memory and offers a new mechanism for immune deficiency during persistent viral infections.

Acute Disease↗

PubMed1998

Qualitative differences between naive and memory T cells make a major contribution to the more rapid and efficient memory CD8+ T cell response.

CD8+ T cells are present at a higher frequency following a primary response, and these memory cells exhibit qualitative differences from naive cells. The importance of these differences vs increased precursor frequency in making a memory response more rapid and efficient has been unclear. Adoptive transfer of 2C TCR transgenic CD8+ T cells into normal recipients, followed by i.p. challenge with allogeneic P815 tumor, results in a long-lived memory population that includes both endogenous host CD8+ T cells and 2C cells. The 2C cells can be identified, using 1B2 mAb specific for the TCR, and thus used as an indicator of the properties of the memory cells. The memory cells have a heterogeneous surface phenotype, and their distribution in lymphoid organs, blood, and peripheral sites is distinct from that of naive cells. Upon rechallenge with Ag, memory cells access the peritoneal cavity much more rapidly than do naive cells (12 h vs 5 days). This appears to result from a requirement for naive cells to interact with Ag before they can efficiently migrate to inflammatory sites, while this is not required for memory cells. In addition, memory cells exhibit some cytolytic activity before rechallenge with Ag, and potent cytolytic activity is present in the peritoneal cavity within 12 h of rechallenge. Comparison of primary and memory responses in mice having similar frequencies of Ag-specific precursors demonstrated that the more rapid migration and the immediate effector function of at least some memory cells contribute very substantially to making a memory response at a peripheral site more rapid and efficient.

Adoptive Transfer↗

PubMed1986

Clinical memory tests and everyday memory.

This study examined the relationship between clinical memory tests and everyday memory abilities. Fifty older adults were given clinical memory tests, a battery of everyday tasks and a self-report questionnaire of memory problems. The interrelationships among these groups of memory assessment measures were studied using Pearson correlations and multivariate canonical analysis. The resulting intercorrelations and canonical variate loadings were low to moderate in overall magnitude. The self-assessment of memory problems had a much lower relationship to everyday and clinical memory tasks. The self-assessment of memory for reading material had the strongest relationship to clinical memory tests. In general, these results moderately support the use of clinical memory tests to predict everyday memory ability.

Journal Article↗

PubMed1985

Memory span and long-term memory deficits in brain-impaired patients.

Measures of verbal and visuospatial memory span and long-term memory were obtained from 21 brain-impaired and 21 neurologically unimpaired Veterans Administration medical patients. Significant deficits in both memory span and long-term memory were observed in the brain-impaired patients. Contrary to predictions from the experimental literature, memory span tests that require more processing of item content and location were not superior in detecting the memory span deficits. Discriminant function analyses revealed that measures of verbal and visuospatial long-term memory provided unique discrimination between the brain-impaired and unimpaired patients. However, when memory span measures were analyzed alone, inclusion of more than one measure of memory span did not provide additional unique discrimination. Implications for the clinical assessment of memory functioning are discussed.

Brain Damage, Chronic↗

PubMed1996

Effects of dietary nucleoside-nucleotide mixture on memory in aged and young memory deficient mice.

Intestinal mucosa, bone marrow hematopoietic cells and brain have limited capacity for the de novo synthesis of nucleosides (NSs) and nucleotides (NTs). Whereas the role of dietary NS and NT in the former two tissues is known, it is not known in the brain. Therefore we studied the effect of dietary NS and NT mixture on memory in aged mice (Experiment 1) and young memory deficient mice (Experiment 2). Memory retention was studied by step-through type passive avoidance performance (maximum 180 seconds). In Experiment 1 aged (7 month old) senescence accelerated mice (SAM) were fed 20% casein diet (control) or this diet supplemented with 0.5% NS/NT mixture for 12 weeks. Memory was studied 1, 2 and 3 days after the electric shock (punishment). In Experiment 2, young (1 month old) memory deficient mice (Dull mice) and normal mice (ddY mice) were fed the same diets as those in Experiment 1 for 12 weeks. Memory retention was studied 1 and 3 days after the punishment. In the aged SAM the average time of avoidance and also the percentages of successful memory 2 and 3 days after the punishment were significantly higher in the NS/NT diet group than the control diet group (P < 0.05). In the Dull mice percentage of successful memory was higher in the NS/NT diet group than in the control group 3 days after the punishment, however, such an effect was not observed in the normal mice. These results suggest that insufficient endogenous supply of NSs and NTs may be responsible for the factor of memory deficiency with aging or of genetical memory deficiency, which can be improved by the dietary administration of NSs and NTs.

Aging↗

PubMed2005

Impaired memory for faces and social scenes in autism: clinical implications of memory dysfunction.

A clinical memory test, the Wechsler Memory Scale-III (WMS-III), was used to study the auditory and visual memory of 29 high-functioning adults with autism and 34 group-matched normal controls. The individuals with autism performed as well as the controls on immediate and delayed memory for word pairs and stories and on a verbal working memory task. The autism group was impaired on immediate and delayed recall of faces and of family scenes and had impaired spatial working memory. The integrity of verbal working memory and impaired spatial working memory is consistent with the findings of other studies and may reflect the greater computational demands of the spatial task. Most importantly, the deficits in memory for faces and common social scenes, complex visual/spatial stimuli, demonstrate the contribution of memory dysfunction in autism to deficits in real life function.

Adolescent↗

PubMedDate not supplied

Word length and phonological similarity effects in simple, complex, and delayed serial recall tasks: implications for working memory.

Some current models of working memory argue that a passive short-term store is not involved in more dynamic working memory tasks. Other models argue that standard short-term memory and working memory tasks rely on common storage facilities. We examine these issues by exploring two signature effects of passive short-term storage in simple span, complex span, and Brown-Peterson tasks. The finding that all three tasks show word length and phonological similarity effects suggests that common processes or storage mechanisms are involved in all tasks. The implications for models of working memory are discussed.

Humans↗

PubMed1985

Memory-skills training, memory complaints, and depression in older adults.

This study examined the effectiveness of a self-taught program of memory-skills training for older adults complaining of memory difficulties in an immediate-treatment/waiting-list design. Analyses of covariance of measures of memory performance, memory evaluation (complaints), and a self-rating depression scale revealed a significant impact of training on memory performance but not on memory complaints or symptoms of depression. Subsequent evaluation of the waiting-list group, which was provided training after participation in the initial portion of the study, provided a partial replication of the design. The pattern of results was remarkably consistent with that obtained in the controlled evaluation of the training program. Finally, those complaining of memory problems were compared with a group of noncomplaining older adults. The two groups were comparable in memory performance and depression scores. Thus, memory complaints do not appear to reflect, systematically, memory problems or depression.

Aged↗

PubMed2006

Prospective memory complaints can be predicted by prospective memory performance in older adults.

BACKGROUND/AIMS: The aim of this study was to explore if prospective memory complaints reflect actual prospective memory performance in older adults. METHODS: Three hundred and sixty-four older adults aged 65-80 years were investigated with regard to prospective memory complaints, prospective memory test performance, self-reported depressive symptoms, and self-reported memory capacity. RESULTS: Separate analyses revealed that about half of the participants showed a significant relation between subjective and objective prospective memory. CONCLUSION: Older adults appear to be heterogeneous with regard to the association between objective and subjective prospective memory. For older adults with relatively few depressive symptoms and memory concerns, prospective memory complaints may serve as a valid criterion in the assessment of prospective memory ability.

Aged↗

PubMed1997

Clinical correlates of memory in schizophrenia: differential links between depression, positive and negative symptoms, and two types of memory impairment.

OBJECTIVE: This study investigated clinical correlates of memory impairment in schizophrenic patients. In particular, the authors hypothesized that depressive symptoms would be linked to memory efficiency, as found in other clinical populations. In addition, they tested Frith's pathophysiological model predicting links between negative symptoms and failure to respond, as well as between positive symptoms and production of erroneous responses. METHOD: Thirty-one patients were given several memory tasks: long-term free recall of nonorganizable and organizable lists in immediate and delayed conditions, recognition in immediate and delayed conditions, implicit memory (stem completion task), and short-term memory (digit span). Superficial encoding of information was also assessed by the ability to recall the items sequentially; deep encoding was assessed by the ability to organize the items according to their semantic properties. Two types of memory measures were individualized: measures reflecting memory efficiency and measures reflecting production of erroneous memory responses (intrusions, perseverations, false alarms). RESULTS: Consistent correlations appeared between severity of depressive symptoms and measures reflecting deep but not superficial encoding; none, however, was correlated with negative symptoms. Two of the three types of erroneous memory responses were positively linked to positive symptoms. CONCLUSIONS: Efficiency of memory processes relying on deep encoding seemed linked to depressive symptoms. In addition, the two distinct types of impairment predicted by Frith's model were found. The expected link of one with positive symptoms was verified, but the link of the other with negative symptoms was not.

Adult↗

PubMed2003

Selective memory and memory deficits in depressed inpatients.

We investigated memory impairment and mood-congruent memory bias in depression, using an explicit memory test and an implicit one. Thirty-six severely depressed inpatients that fulfilled DSM-IV criteria for major depressive disorder and 36 healthy controls matched for sex, age, and educational level participated in the study. Explicit memory was assessed with a free recall task and implicit memory with an anagram solution task. Results showed that depressed and controls differed in explicit memory performance, depending on the amount of cognitive distraction between incidental learning and testing. Implicit memory was not affected. In addition, severely depressed patients showed a mood-congruent memory bias in implicit memory but not in explicit memory. The complex pattern of results is discussed with regard to relevant theories of depression.

Adult↗

PubMed2001

Working memory in another dimension: functional imaging of human olfactory working memory.

The majority of working memory research has been carried out within the visual and auditory modalities, leaving it unclear how other modalities would map onto currently proposed working memory models. In this study we examined the previously uninvestigated area of olfactory working memory. Our aim was to investigate if olfactory working memory would engage prefrontal regions known to be involved in working memory for other sensory modalities. Using positron emission tomography we measured cerebral blood flow changes in 12 volunteers during an olfactory working memory task and a comparison visual working memory task. Our findings indicate that both olfactory and face working memory engaged dorsolateral and ventrolateral frontal cortex when the task requirements were matched; a conjunction analysis indicated overlap in the distribution of activity in the two tasks. Similarities and differences in activity were noted in parietal lobe regions, with both tasks engaging inferior areas of 40/7, but only visual working memory showing increased activity within left superior parietal cortex. The findings support the idea that working memory processes engage frontal cortical areas independent of the modality of input, but do not rule out the possibility of modality-specific neural populations within dorsolateral or ventrolateral cortex.

Adult↗