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PubMed2000

Memory for drawings in locations: spatial source memory and event-related potentials.

Event-related potentials (ERPs) were recorded during recognition tasks for line drawings (items) or for both drawings and their spatial locations (sources). Recognized drawings elicited more positive ERPs than new drawings. Independent of accuracy in the spatial judgment, the old/new effect in the source recognition task was larger over the prefrontal scalp, and of longer temporal duration than in the item recognition task, suggesting that the source memory task engaged a qualitatively distinct memory process. More posterior scalp sites were sensitive to the accuracy of the source judgment, but this effect was delayed relative to the difference between studied and unstudied drawings, suggesting that source memory processes are completed after item recognition. Similarities and differences between spatial source memory and memory for conjunctions of other stimulus attributes are discussed, together with the role of prefrontal cortex in memory.

Adult↗
PubMed2005

Correlates of intrusive memories and avoidance of memories of the Holocaust.

Although intrusive memories and avoidance of memories are psychological phenomena frequently reported by Holocaust survivors, their correlates have not been systematically researched. The present cross-sectional study examined socio-demographic and health characteristics of elderly Holocaust survivors, as well as the survivors' experiences during the Holocaust. In addition, present distress related to the Holocaust and fear of dying were examined. Results showed that survivors frequently suffered from intrusive memories, but not often from avoidance of memories of the Holocaust. Intrusive memories were strongly associated with present distress from the Holocaust, as well as with self-perceived bad health and fear of dying. These findings suggest that intrusive memories influence survivors' perceptions of life and change the way in which they deal with aging.

Aged↗
PubMed2006

[A detection of very mild Alzheimer's disease and MCI by memory complaints and deterioration of IADL in a questionnaire for a memory clinic].

BACKGROUND AND PURPOSE: There have been very few studies trying to explain about daily life features of patients with very mild Alzheimer disease (AD) and of those with mild cognitive impairment (MCI). The purpose of this study was 1) to clarify characteristics of very mild AD and MCI in their daily life, and 2) to examine items in a questionnaire that can be useful for detecting subjects of suspected AD. SUBJECTS AND METHODS: Subjects were 111 patients of the memory clinic in National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Japan; 39 normal range, 28 MCI, and 44 very mild AD. On their first visits, they were asked to fill out a questionnaire consisted of 103 items. Thirty five items in a questionnaire were selected, 15 memory-complaint items and 20 items of instrumental activities of daily living (IADL), and examined retrospectively. At first we compared each set of groups using the chi-square test. Then a logistic regression analysis was used to observe which items contributed to judge a person to be suspected of AD. And further, sensitivity and specificity for discriminating between an AD suspected and a normal range were examined. RESULTS: None of the items showed statistical significance between MCI group and very mild AD group. Then, we combined these two groups into one group (n = 72), and made comparison between this new group and normal range group (n = 39). There were 18 items that showed statistical significance between the two groups. And five of them, 'dysfunction of memory: noticed by others', 'dysfunction of memory: getting worse', 'unable to utilize the memorandum', 'forget incidents occurred a few days ago' and 'unable to locate unfamiliar places' showed significantly high odds ratio in judgment on a person to be suspected of AD. In addition to preceding 5 items we adopted two items, 'dysfunction of memory: unnoticeable by her/himself' and 'unable to manage household expenses', which were not included in the logistic regression analysis, but were essential for the discrimination between the two groups. The sum of score of these 7 items showed high specificity and sensitivity for dividing between the two groups. CONCLUSION: These findings indicated that an exploration of memory complaints and deteriorations of IADL was useful for the detection of MCI and very mild AD, especially 7 items described above could be used as a simple questionnaire for the elderly.

Activities of Daily Living↗
PubMed1987

Neuroanatomy of memory and amnesia: a case for multiple memory systems.

Several different dissociable memory systems are considered in terms of their known or putative sites of pathology. In man, short-term memory can be selectively impaired by left hemisphere lesions near the acoustic projection area. There may be other modality-specific deficits. Long-term memory is considered in terms of a) knowledge systems, b) stable associative memory; c) priming, and d) event memory, with special reference to the amnesic syndrome. For each of these categories, clinical neuropathological and relevant animal evidence is reviewed. It is concluded that "memory" is not holistic, and the anatomical bases must be considered independently for each of the several dissociable (but normally interacting) systems. Some are likely to involve virtually all levels of the nervous system, while others are highly specific.

Amnesia↗
PubMed1981

The generation of memory cells. V. Preferential priming of IgG1 B memory cells by immunization with antigen IgG2 antibody complexes.

We have studied the effects of priming mice with complexes of dinitrophenylated (DNP)-haemocyanin (KLH) and anti-DNP antibody on the generation of DNP-specific B memory cells producing IgG1 or IgG2 antibodies. Immunization with DNP-KLH alone (with or without adjuvant) induced roughly equal proportions of IgG1 and IgG2 memory cells, at all times after priming. In sharp contrast, immunization with DNP-KLH polyclonal anti-DNP antibody complexes induced 80%--90% IgG1 memory cells, especially early after priming. Further studies using conventional and hybridoma anti-DNP antibodies showed that this effect was induced by complexes containing IgG2 antibodies, and not by those made with IgG1 antibodies. The latter induced roughly equal proportions of IgG1 and IgG2 memory cells. Priming for preferential IgG1 memory was not induced by complexes made with (Fab')2 fragments of IgG2a antibody, nor was it seen in T cell-deprived mice immunized with antigen IgG2a complexes. The mechanisms involved in this phenomenon are unknown, but presumably reflect the well established capacity of immune complexes to concentrate in lymphoid follicles, which seem to be sites of B memory-cell generation.

Animals↗
PubMed1993

[Impairment of learning and memory and the accessory symptom in aged rats as senile dementia model (2)--Learning and memory].

We attempted to investigate the ability of learning and memory of aged rats. Swimming speed of aged rats in Morris's water maze was slower compared with that of young rats. Therefore, we used goal distance to indicate ability of learning and memory. In training session, distance for both groups decreased with training, but in aged rats it was significantly longer than that in young rats. In retention test 24 d after the training, distance in aged rats was longer than that in young rats, although there was no difference in distance for both groups between acquisition and retention tests. The distance in the working memory tended to increase with aging. There was no difference in time spent within platform phase in probe trial, in percent movement of first trial in habituation test, and in step-through latency in passive avoidance, between young and aged rats. Drinking latency for aged rats in water finding task was significantly longer compared with that in young rats. These findings suggest that learning and memory were impaired by aging in spatial and latent learning tasks. Aged rats could acquire and maintain memory of simple tasks, but in spatial tasks they tended to show decreased ability of retention and working memory.

Aging↗
PubMed1995

[Working memory and work with memory: visual-spatial and further components of processing].

Empirical and theoretical evidence for the concept of working memory is considered. We argue that the major weakness of this concept is its loose connection with the knowledge about background perceptive and cognitive processes. Results of two relevant experiments are provided. The first study demonstrated the classical chunking effect in a speeded visual search and comparison task, the proper domain of a large-capacity very short term sensory store. Our second study was a kind of extended levels-of-processing experiment. We attempted to manipulate visual, phonological, and (different) executive components of long-term memory in the hope of finding some systematic relationships between these forms of processing. Indeed, the results demonstrated a high degree of systematicity without any apparent need for a concept such as working memory for the explanation. Accordingly, the place for working memory is at all the interfaces where our metacognitive strategies interfere with mostly domain-specific cognitive mechanisms. Working memory is simply our work with memory.

Adult↗
PubMedDate not supplied

[Study of correlations between self-estimation of memory, psychometric test (SM9) and test of memory in daily life].

Assessment of memory performance is now well established. However, the normal form of assessment does not evaluate memory problems encountered during daily activities, a situation relevant to the evaluation of drug effects on memory components. The present study examines the ecological validity of psychometric tests. 49 individuals, from 20 to 89 years old without any identified pathology were included in the study, with the aim of establishing correlations between an autoquestionnaire of memory, a standard memory battery (SM9) and a daily memory video test (DMV). No correlation was found between self-estimation and objective tests or DMV. A strong correlation (r = 0.81) was found between SM9 and DMV. Imaged information and verbal coding appear to be essential parameters of objective tests. These results confirm the ecological validity of the objective psychometric tests and in particular of SM9.

Adult↗
PubMed1996

Memory distortion and false memory creation.

The 1990s have brought to public attention thousands of cases that began when a grown-up daughter or son walked into a therapist's office seeking help for depression, low self-esteem, or any of a number of life's problems. Many of these cases grew to involve memories of childhood sexual abuse recovered while in therapy--memories that did not exist, or at least were not remembered, before therapy began. Many of these cases also involved families torn violently apart. What should we make of these new-found memories? Are they true memories that were successfully revived in therapy? Are they false memories that were unwittingly planted? Are they symbolic expressions--historically false but representing some deep underlying truth? Insights from cognitive psychology may shed some light. Much of the litigation that has resulted from the emergence of "repressed memories" has been hazardous to the patients, and their families, as well as to the therapists who treat them.

Adolescent↗
PubMed1998

[Memory complaints: what should be done? From consultation to the memory center].

Memory complaints are frequent and not always the result of a memory impairment. Such complaints must be taken into account since they always reflect some disorder, at least of attentional processes. Excepting primary psychiatric disorders, biological and imaging exams are required in addition to a neuropsychological and behavioral assessment. Finding the cause of the memory complaints is not an end in itself. The purpose is to cure or at least to relieve the consequences of this and related symptoms with pharmacological, neuropsychological and psychological therapies, social help, information and support. Patients (especially in case of dementia) and families need follow-up care by a multidisciplinary staff (neurologists, psychiatrists, psychologists, speech therapists, nurses, nurse's aids and social workers) who play a role of prevention for intercurrent diseases, social and legal counselling and help anticipate the future. Multidisciplinary memory units are dedicated to the diagnosis and care of memory complaints and disorders. We describe here the operative function of these centers which should be integrated into a health care network centered around patients with memory complaints and their families.

Ambulatory Care Facilities↗
PubMed1992

Memory complaints, memory disorders and focus localization in patients with partial epilepsy.

Our study aimed at analysing effects of epileptic foci on memory function in patients with partial epilepsy. Twenty-eight patients with spontaneous memory complaints and psychometrically established memory disorders were assessed by 21-channel electroencephalography recorded both during cognitive testing and during 99mTc-HMPAO single photon emission computed tomography (SPECT). Computed tomography (CT) was performed on the same day. None of the epilepsy-related factors (seizure type, seizure frequency, type of epilepsy, age at onset of the seizures, type of antiepileptic treatment) could be related directly to severity or type of memory impairment (classified into the categories 'global', 'verbal' and 'non-verbal'). Remarkably, this study found no significant relationship between EEG focus localization and severity of measured memory impairment. Most areas with hypoperfusion on the SPECT were found in the group with global (severe) amnesia, typically with a right frontal localization. Abnormalities on CT were predominantly found in the same group, however, with a right-sided parietal localization. An unanticipated finding was that the majority of temporal CT and SPECT lesions were found in the group with relatively better memory performance.

Adult↗
PubMed2006

Timing, memory for intervals, and memory for untimed stimuli: The role of instructional ambiguity.

Theories of animal timing have had to account for findings that the memory for the duration of a timed interval appears to be dramatically shorted within a short time of its termination. This finding has led to the subjective shortening hypothesis and it has been proposed to account for the poor memory that animals appear to have for the initial portion of a timed interval when a gap is inserted in the to-be-timed signal. It has also been proposed to account for the poor memory for a relatively long interval that has been discriminated from a shorter interval. I suggest here a simpler account in which ambiguity between the gap or retention interval and the intertrial interval results in resetting the clock, rather than forgetting the interval. The ambiguity hypothesis, together with a signal salience mechanism that determines how quickly the clock is reset at the start of the intertrial interval can account for the results of the reported timing experiments that have used the peak procedure. Furthermore, instructional ambiguity rather than memory loss may account for the results of many animal memory experiments that do not involve memory for time.

Journal Article↗
PubMed2006

Keeping memories at an arm's length: vantage point of trauma memories.

This study investigated the relationship between memory vantage point and avoidance following trauma. Sixty trauma survivors with differing levels of avoidance were interviewed about the vantage point of their memory for trauma, a positive memory, and a neutral memory. Avoidant individuals were more likely to remember their trauma from an observer perspective than individuals with a lower level of avoidance. Avoidance did not influence vantage point for positive or neutral memories. These data support the proposal that adoption of the observer vantage point for trauma memories may serve an avoidant function for people affected by trauma.

Adolescent↗
PubMed2005

Ecphory of autobiographical memories: an fMRI study of recent and remote memory retrieval.

Ecphory occurs when one recollects a past event cued by a trigger, such as a picture, odor, or name. It is a central component of autobiographical memory, which allows us to "travel mentally back in time" and re-experience specific events from our personal past. Using fMRI and focusing on the role of medial temporal lobe (MTL) structures, we investigated the brain bases of autobiographical memory and whether they change with the age of memories. Importantly, we used an ecphory task in which the remote character of the memories was ensured. The results showed that a large bilateral network supports autobiographical memory: temporal lobe, temporo-parieto-occipital junction, dorsal prefrontal cortex, medial frontal cortex, retrosplenial cortex and surrounding areas, and MTL structures. This network, including MTL structures, changed little with the age of the memories.

Adult↗
PubMed1997

Memory and confidence in memory judgements among individuals with obsessive compulsive disorder and non-clinical controls.

The present study investigated episodic memory functioning in: (1) obsessive compulsive disorder (OCD) patients with primarily checking symptoms (i.e. checkers); (2) OCD patients without checking symptoms (i.e. non-checkers); and (3) non-clinical control participants. On a measure of recall, all groups were statistically equivalent with respect to the proportion of words correctly recalled. Using a recognition measure, checkers were unimpaired in episodic memory, as compared to non-checkers and non-clinical controls. However, relative to the other groups, patients with checking symptoms showed decreased confidence in their correct and incorrect recognition memory judgements, according to their item-by-item self-report confidence ratings. When checkers correctly identified previously seen words, they were also slower to respond than were the other groups, supporting the view that they were less confident in their memory judgments relative to the other groups, which did not differ on this measure. The results of the present study suggest that OCD checking is not related to memory impairments per se but rather that checking in OCD is a symptom of decreased confidence in memory.

Adult↗
PubMed1998

Effects of ketamine on thought disorder, working memory, and semantic memory in healthy volunteers.

BACKGROUND: The N-methyl-D-aspartate receptor antagonist, ketamine, produces a clinical syndrome of thought disorder, perceptual distortion, and cognitive impairment. METHODS: We have administered ketamine to healthy volunteers to characterize the formal thought disorder and specific memory dysfunction associated with ketamine. Ten healthy volunteers underwent a double-blind, placebo-controlled, ketamine infusion (0.12 mg/kg bolus and 0.65 mg/kg/hour). Thought disorder was evaluated with the Scale for the Assessment of Thought, Language and Communication. Cognitive testing involved working and semantic memory tasks. RESULTS: Ketamine produced a formal thought disorder, as well as impairments in working and semantic memory. The degree of ketamine-induced thought disorder significantly correlated with ketamine-induced decreases in working memory and did not correlate with ketamine-induced impairments in semantic memory. CONCLUSIONS: This study characterizes the formal thought disorder associated with ketamine and may suggest that ketamine-induced deficits in working memory are associated with ketamine-induced thought disorder.

Adult↗
PubMed1997

Intact perceptual memory in the absence of conscious memory.

Declarative memory enables conscious recollection of the past and has been proposed to be distinct from priming, a perceptual form of memory that operates nonconsciously and improves the ability to detect or identify recently presented stimuli. Yet, it has been difficult to obtain unambiguous evidence for the independence of declarative memory and priming. The authors report the first demonstration, using matched tests, of fully intact perceptual memory (priming) in a profoundly amnesic patient (E.P.), despite at-chance recognition memory. The priming and recognition tests included tests that were matched with respect to test materials, length of the study and test lists, and the kind of cues available at test. Priming appears to reflect neural changes within perceptual processing systems that occur before information reaches the brain systems that transform visual perception into conscious visual memory.

Aged↗