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At least 253 records · Page 14Linked to original sources

PubMed2005

Memory function in patients with obsessive compulsive disorder and the problem of confidence in their memories: a clinical study.

AIM: To examine obsessive-compulsive patients for memory of obsessive-compulsive relevant material and confidence in their memory. METHODS: Memory function was examined by a recognition task using neutral and obsessive-compulsive relevant sentences in 32 patients with obsessive-compulsive disorder and 31 control subjects. We also investigated the participants' confidence in the accuracy of their recognition. The severity of obsessive-compulsive disorder was evaluated by using the Yale-Brown Obsessive Compulsive Scale. The Maudsley Obsessive Compulsive Questionnaire, the Hamilton Depression Rating Scale, and the State-Trait Anxiety Inventory were also administered to the two groups. RESULTS: Whereas obsessive-compulsive disorder patients were not significantly different from control subjects on measures of recognition memory for both obsessive-compulsive relevant and neutral material, they were significantly less confident in the memory for obsessive-compulsive relevant and neutral sentences. Also, the State-Trait Anxiety Inventory (STAI) scores were negatively correlated with the recognition performance of obsessive-compulsive disorder relevant sentences and the levels of confidence in memory in the obsessive-compulsive disorder group. The obsessive-compulsive patients with checking compulsions were not different from non-checking obsessive-compulsive patients. CONCLUSION: Our results suggest that obsessive-compulsive patients experience difficulties in confidence in their memory, possibly related to anxiety rather than primary memory deficits.

Adult↗

PubMed1983

Age-related changes in confusion between memories for thoughts and memories for speech.

The present experiments compared people's abilities to make decisions about the origin of their memories. Experiment 1 demonstrated that 6-year-olds were as good as 17-year-olds in discriminating memories originating from what they said earlier (self-generations) from memories of what another person said earlier (external presentations). However, in both experiments 1 and 2, 6-year-olds were not as good at discriminating what they had said earlier from what they had only thought. The possibility that younger children simply have more difficulty distinguishing between memories originating from the same class, internal or external, was ruled out because 6-year-olds performed as well as 9-year-olds when differentiating between memories from 2 external sources (experiment 2). Nor could their difficulty be attributed to a general problem in distinguishing memories for their thoughts from any other class of memories because they were at no disadvantage in discriminating their earlier thoughts (words they imagined themselves saying) from words someone else said (experiment 2). Our findings suggest that some distinctions, self versus other, emerge as cues in memory sooner than other distinctions, thoughts versus actions.

Adolescent↗

PubMed1995

Development of memory and the hippocampus: comparison of food-storing and nonstoring birds on a one-trial associative memory task.

Food-storing birds, for example, marsh tits, Parus palustris, use memory to retrieve stored food and have a larger hippocampus relative to the rest of the telencephalon than do species that store little or no food such as the blue tit, P. caeruleus. The difference between food storers and nonstorers in relative hippocampal volume occurs after the young birds have fledged from the nest and is dependent upon some aspect of memory for retrieving caches of stored food. To test whether or not species differences in memory and volumetric changes in the hippocampus could be triggered by experience of memory tasks other than retrieval of stored food, groups of hand-raised marsh tits and blue tits were tested between days 35 and 192 posthatch on a one-trial associative memory task in which they were rewarded in phase II for returning to the feeder where they had eaten part of a peanut 20 min earlier. No species differences were found when the peanut was visible in phase I, but when the peanut was hidden in phase I, marsh tits performed better than blue tits, irrespective of whether or not they had had previous experience of storing and retrieving food. In dissociation trials (transformed array of feeders), marsh tits with food-storing experience responded preferentially to spatial cues, whereas blue tits responded equally to both spatial position and object-specific cues. These species differences are also found in wild-caught adults. However, marsh tits without food-storing experience responded equally to both spatial position and object-specific cues, which suggests that experience of storing and/or retrieving caches is required in order for marsh tits to develop the spatial preference seen in adult food storers. Both marsh tits with experience of the one-trial associative memory task and those that had also had food-storing experience had larger relative hippocampal volumes than did controls, independent of age. Of the marsh tits trained on the one-trial associative memory task, there was no difference between those that had had food-storing experience and those that had not. However, in blue tits, there was no effect of experience on relative hippocampal volume. No volumetric differences were observed in ectostriatum, which served as a control brain region. The results suggest that some aspect of memory for retrieving food (whether or not stored by the bird) directly influences growth of the hippocampal region in marsh tits, the food-storing species, but not in blue tits, the nonstoring species.

Animals↗

PubMed2005

Dissociation related to subjective memory fragmentation and intrusions but not to objective memory disturbances.

The present study was a replication of Kindt and Van den Hout (Behaviour Research and Therapy 41 (2003) 167) with several methodological adaptations. Two experiments were designed to test whether state dissociation is related to objective memory disturbances, or whether dissociation is confined to the realm of subjective experience. High trait dissociative participants (N(exp.1)=25; N(exp.2)=25) and low trait dissociative participants (N(exp.1)=25; N(exp.2)=25) were selected from normal samples (N(exp.1)=372; N(exp.2)=341) on basis of scores on the Dissociative Experience Scale (DES). Participants watched an extremely aversive film, after which state dissociation was measured by the Peri-traumatic Dissociative Experience Questionnaire (PDEQ). Memory disturbances were assessed 4h later (Exp. 1) or 1 week later (Exp. 2). Objective memory disturbances were assessed by a sequential memory task, items tapping perceptual representations (Exp. 1), or an open question with respect to the remembrance of the film (Exp. 2). Subjective memory disturbances were measured by means of visual analogue scales assessing fragmentation and intrusions. The two experiments provided a fairly exact replication of an earlier experiment (Behaviour Research and Therapy 41 (2003) 167-178), indicating a relation between dissociation and memory disturbances that appeared to be confined to the subjective experience of memory.

Adult↗

PubMed2003

[Executive functions and prospective memory performance in old age: an analysis of event-based and time-based prospective memory].

The goal of the present study was to examine the role of executive functions in age-related differences in prospective memory. Therefore, in a sample of 40 young ( M=24.8; SD=2.0) and 40 old adults ( M=69.3; SD=5.6), event- and time-based prospective memory as well as five executive functions were assessed. Results show that age differences in prospective memory performance depend largely on age-related individual differences in executive functions. Furthermore, the results indicate several executive functions to differentially predict prospective memory performance. The event-based prospective memory task requires inhibition to avoid distraction from irrelevant items. The time-based prospective memory task requires the flexible shifting of cognitive sets. Overall, the data support the assumption that age differences in prospective memory performance are closely related to executive functioning. In addition, time- and event-based prospective memory seem to rely on different executive processes.

Adult↗

PubMed2005

Annual conversion to alzheimer disease among patients with memory complaints attending an outpatient memory clinic: the influence of amnestic mild cognitive impairment and the predictive value of neuropsychological testing.

OBJECTIVE: The goals of this study were to determine the annual conversion rate to Alzheimer disease (AD) among patients reporting memory problems, including a subgroup with amnestic mild cognitive impairment (aMCI), and to investigate the predictive value of neurocognitive testing for future dementia. METHODS: A prospective study was carried out in an outpatient memory clinic. One hundred and seven patients underwent a clinical examination and completed a battery of standard cognitive tests at study entry and two years later. The conversion rate to clinically manifested AD two years later was investigated and sensitivity, specificity, receiver operating characteristics (AUC), positive predictive value and negative predictive value for each neuropsychological test were determined. RESULTS: We found an annual rate of conversion to AD of 6.5% among patients reporting memory decline in the setting of our clinic. Specifically, patients with aMCI had an annual conversion rate of approximately 20%. The annual conversion rate for patients reporting memory problems but showing no memory deficit at memory testing was approximately 3%. Receiver operating characteristics (AUC) of the neuropsychological tests ranged from 0.60 to 0.94. CONCLUSIONS: Patients with aMCI have 8.6-fold higher odds of developing AD compared with patients without evident memory impairment on neuropsychological testing. Although the risk of developing AD among patients without objective memory decline is small, some patients in this group still convert to AD and therefore close clinical monitoring of patients is necessary.

Aged↗

PubMed1996

Repressed memory and false memory.

Both the popular media and professional literature have presented many accounts of repressed memory and false memory in the past 5 years. Repressed memory occurs when trauma is too severe to be kept in conscious memory, and is removed by repression or dissociation or both. At some later time it may be recalled, often under innocuous circumstances, and reappears in conscious memory. False memory occurs when a vulnerable patient with a history of overcompliant or highly suggestible behavior is unwittingly coached by a respected authority figure to create, as if in memory, an experience that never actually occurred. The creation of each phenomenon is explored in detail, as well as suggestions for avoiding the creation of false memories in our patients.

Adolescent↗

PubMed2002

The frontal lobe role in memory: a review of convergent evidence and implications for the Wada memory test.

Functional imaging studies have implicated the frontal lobe in many of the memory processes often thought to be the domain of medial temporal structures. Results from fMRI studies of normal subjects have suggested that some components of memory formation, including those components tested during the Wada memory test, may involve frontal lobe regions. Specific behavioral disruptions during carotid amytal injections support a model for frontal lobe anesthesia in explaining results of the Wada memory test. Cortical stimulation data suggest that frontal lobe disruption is sufficient to cause memory disturbances. The convergence of evidence suggests frontal lobe memory may limit the predictive value of the Wada memory test in defining the risk of memory loss following temporal lobectomy.

Journal Article↗

PubMed1992

Assessment of memory complaint in age-associated memory impairment: the MAC-Q.

Few brief self-report memory questionnaires are available, and non has been well validated. We designed a brief questionnaire, the MAC-Q, to assess age-related memory decline. Validity and reliability of the MAC-Q were assessed in 232 subjects meeting diagnostic criteria for age-associated memory impairment (AAMI). Concurrent validity of the MAC-Q was supported by a significant correlation (r = .41, p < .001) with a lengthy, well-validated memory questionnaire. Multiple regression analysis indicated that memory test scores were significant predictors of MAC-Q scores. MAC-Q scores were not predicted by Hamilton Depression Scale scores, suggesting that memory complaint in AAMI is not related to affective status. Internal consistency and test-retest reliability of the MAC-Q were satisfactory. Our data support the validity and reliability of the MAC-Q, a new brief memory questionnaire. The MAC-Q is of particular relevance to the assessment of AAMI, but should also prove useful in any clinical or research setting requiring a brief index of memory complaint.

Aged↗

PubMed2001

Sleep states and memory processes in humans: procedural versus declarative memory systems.

The present paper focuses on human studies attempting to relate sleep states to memory processes. These studies typically present learning material to participants and then examine their ability to recall this material after intervening post-training sleep or sleep deprivation. Most experiments utilize either sleep recording or sleep deprivation following task acquisition to reach their conclusions, although cueing and position emission tomography (PET) scan studies have also been done. Results strongly suggest that REM sleep is involved with the efficient memory processing of cognitive procedural material but not declarative material. Although there are some data to suggest that stage 3/4 or NREM sleep is necessary for declarative memory consolidation, NREM may in fact simply be occurring at the same time as another factor that is actually involved in the memory processing. Preliminary results suggest that the length of the NREM-REM sleep cycle may be important for declarative memory. Preliminary data also suggest that stage 2 sleep may be involved with the memory for motor procedural but not cognitive procedural tasks. Sleep researchers would do well to capitalize on the latest advancements in memory research by choosing tasks that represent special memory systems and examining their relationships to sleep states.

Journal Article↗

PubMed2001

Sensory-perceptual episodic memory and its context: autobiographical memory.

Episodic memory is reconceived as a memory system that retains highly detailed sensory perceptual knowledge of recent experience over retention intervals measured in minutes and hours. Episodic knowledge has yet to be integrated with the autobiographical memory knowledge base and so takes as its context or referent the immediate past of the experiencing self (or the 'I'). When recalled it can be accessed independently of content and is recollectively experienced. Autobiographical memory, in contrast, retains knowledge over retention intervals measured in weeks, months, years, decades and across the life span. Autobiographical knowledge represents the experienced self (or the 'me'), is always accessed by its content and, when accessed, does not necessarily give rise to recollective experience. Instead, recollective experience occurs when autobiographical knowledge retains access to associated episodic memories. In this reworking of the 'episodic memory' concept autobiographical memory provides the instantiating context for sensory-perceptual episodic memory.

Autobiographies as Topic↗

PubMed2001

Cellular imaging of zif268 expression in the hippocampus and amygdala during contextual and cued fear memory retrieval: selective activation of hippocampal CA1 neurons during the recall of contextual memories.

The neuroanatomical and molecular basis of fear memory retrieval was studied by analyzing the expression of the plasticity-associated immediate early gene zif268. Cellular quantitative in situ hybridization revealed that zif268 is expressed within specific regions of the hippocampus and amygdala during fear memory retrieval. Within the hippocampus, increased expression of zif268 was observed within CA1 neurons, but not dentate gyrus neurons, during the retrieval of contextual, but not cued, fear associations. In contrast, zif268 expression was increased within neurons of the amygdala (lateral, basal, and central nuclei) during the retrieval of both contextual and cued fear memories. These results demonstrate activation of hippocampal CA1 neurons in contextual fear memory retrieval that was not merely a correlate of the behavioral expression of fear itself, because it was limited to the retrieval of contextual, and not cued, fear memories. Further studies revealed that the selective increase in hippocampal CA1 zif268 expression seen after contextual fear memory retrieval was limited to the retrieval of recent (24 hr) but not older (28 d) memories. These experiments represent the first demonstration that zif268 expression in specific neuronal populations is associated with memory retrieval and suggest that this gene may contribute to plasticity and reconsolidation accompanying the retrieval process.

Acoustic Stimulation↗

PubMed1995

Concurrent blockade of beta-adrenergic and muscarinic receptors disrupts working memory but not reference memory in rats.

In order to clarify the interactions between monoaminergic and cholinergic systems in working and reference memory functions, the effects of administration of the alpha, beta-adrenergic, D1-, D2-dopaminergic or serotonergic receptor antagonist together with the muscarinic receptor antagonist scopolamine on this behavior were examined using a three-panel runway task. Both in working and reference memory tasks, the number of errors (attempts to pass through two incorrect panels of the three panel-gates at four choice points) was significantly increased by 0.32 mg/kg scopolamine, but not by the doses up to 0.18 mg/kg. The beta-adrenergic antagonist propranolol at 10 mg/kg had no effect on the number of working memory errors. Combined administration of 10 mg/kg propranolol and scopolamine at 0.1 and 0.18 mg/kg significantly increased the number of working memory errors. However, in a reference memory task, propranolol at 10 mg/kg did not affect the number of errors, whether administered alone or together with 0.1 mg/kg scopolamine. Other monoaminergic receptor antagonists, including the alpha-adrenergic antagonist phentolamine (3.2 and 10 mg/kg), D1-antagonist SCH23390 (0.032 and 0.056 mg/kg). D2-antagonist sulpiride (100 mg/kg) and serotonin antagonist cinanserin (10 and 32 mg/kg) had no significant effect on working or reference memory errors, whether they were administered independently or in combination with scopolamine at 0.1 mg/kg. These results suggest that beta-adrenergic/muscarinic interactions play an important role in mediating processes involved in working memory performance of rats.

Adrenergic beta-Antagonists↗

PubMed2005

Chronic intracerebroventricular NGF administration improves working memory in young adult memory deficient rats.

Although the beneficial effects of nerve growth factor (NGF) in age-related memory deficits are well documented, the therapeutic role of this neurotrophin in memory deficits occurring in young subjects remains unclear. In the present study, the effect of chronic NGF administration on spatial working memory was investigated in young adult memory deficient Wistar rats. Memory deficient rats were selected on the basis of their preoperative performance in delayed matching-to-position task (DMTP) carried out in the eight-arm radial maze. The delay between sample and test choices was prolonged stepwise from 10s, to 1, 5, and eventually 15 min. Rats that performance at the longest 15-min delay was at least 3 S.E.M. above the group mean were classified as "poor learners". They were randomly assigned to either Control or NGF group, and treated with either vehicle solution (artificial cerebrospinal fluid) or NGF at the total dose of 40 microg/rat. Intracerebroventricular (icv) drug infusion was made continuously over 28 days at the rate of 0.25 microl/h using Alzet 2004 osmotic mini-pump. The postoperative training included the same stages as the preoperative one. No significant between-group difference in the postoperative performance was noted at the shortest delay of 10s that could be bridged by the immediate memory. Conversely, at all three longer delays, postoperative performance in the NGF group was significantly better compared to control rats. The present study thus shows that NGF may have beneficial effects in memory-deficient young adults.

Animals↗

PubMed1999

Working memory is more sensitive than declarative memory to the acute effects of corticosteroids: a dose-response study in humans.

The effects of various doses (40 microg/kg/hr, 300 microg/kg/hr, 600 microg/kg/hr or placebo) of hydrocortisone on tasks assessing working and declarative memory function were measured in 4 groups of 10 young men. During the infusion, participants were given an item-recognition working memory task, a paired-associate declarative memory task, and a continuous performance task used to control possible concomitant effects of corticosteroids on vigilance. The results revealed significant acute effects of the highest dose of hydrocortisone on working memory function, without any significant effect on declarative memory function or arousal-vigilance performance. These results suggest that working memory is more sensitive than declarative memory to the acute elevations of corticosteroids, which could explain the detrimental effects of corticosteroids on acquisition and consolidation of information, as reported in the literature.

Adrenocorticotropic Hormone↗

PubMed2002

Verbal short-term memory in Down syndrome: a problem of memory, audition, or speech?

The current study explored three possible explanations of poor verbal short-term memory performance among individuals with Down syndrome in an attempt to determine whether the condition is associated with a fundamental verbal short-term memory deficit. The short-term memory performance of a group of 19 children and young adults with Down syndrome was contrasted with that of two control groups matched for level of receptive vocabulary. The specificity of a deficit was assessed by comparing memory for verbal and visuo-spatial information. The effect of auditory problems on performance was examined by contrasting memory for auditorily presented material with that for material presented both auditorily and visually. The influence of speech-motor difficulties was investigated by employing both a traditional recall procedure and a serial recognition procedure that reduced spoken response demands. Results confirmed that individuals with Down syndrome do show impaired verbal short-term memory performance for their level of receptive vocabulary. The findings also indicated that this deficit is specific to memory for verbal information and is not primarily caused by auditory or speech-production difficulties.

Adolescent↗

PubMed2004

Inferior temporal, prefrontal, and hippocampal contributions to visual working memory maintenance and associative memory retrieval.

Higher order cognition depends on the ability to recall information from memory and hold it in mind to guide future behavior. To specify the neural mechanisms underlying these processes, we used event-related functional magnetic resonance imaging to compare brain activity during the performance of a visual associative memory task and a visual working memory task. Activity within category-selective subregions of inferior temporal cortex reflected the type of information that was actively maintained during both the associative memory and working memory tasks. In addition, activity in the anterior prefrontal cortex and hippocampus was specifically enhanced during associative memory retrieval. These data are consistent with the view that the active maintenance of visual information is supported by activation of object representations in inferior temporal cortex, but that goal-directed associative memory retrieval additionally depends on top-down signals from the anterior prefrontal cortex and medial temporal lobes.

Adolescent↗

PubMed1994

Involvement of auditory cortical and hippocampal neurons in auditory working memory and reference memory in the rat.

The goal of the present study was to see whether one neuron is involved exclusively in one type of memory or in different types of memory. Single-unit activity was recorded from rat hippocampal CA1, CA3, dentate gyrus, and auditory cortex (AC) during performances of auditory working memory (WM) and reference memory (RM) tasks. Both the memory tasks employed identical apparatus and stimuli and differed only in the type of memory required for correct performance. Around 10% and 43% of the units from the four brain regions showed sensory correlates (differences in activity due to the type of sensory stimulus) only in the WM or RM task, respectively. Only the AC had units showing different kinds of sensory correlates between the WM and RM tasks. About 30% of the units from the four regions had sensory-retention correlates (sustained differential activity during the delay) only in the RM task, whereas the AC had units with sensory-retention correlates only in the WM task or in both the WM and RM tasks. Approximately 35% of the units from the hippocampal regions showed motor correlates (increments of activity immediately prior to responses) only in the WM task. Another 30% of the hippocampal units showed such correlates both in the WM and RM tasks. About 22% of the hippocampal CA1 and CA3 units showed comparison-motor correlates (increases of activity prior to correct responses) only in the WM task. These results indicate that some neurons are involved solely in WM or RM, whereas other neurons are involved in both WM and RM. The results also suggest that more neurons are involved in sensory and retention processing for RM than for WM, and that the AC alone has flexible neurons involved in the processes for both types of memory. More hippocampal neurons are involved in the motor and comparison processes for WM than for RM.

Acoustic Stimulation↗