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PubMed1998

Predictors of perceived memory impairment: do they differ in Alzheimer's disease versus normal aging?

Predictors of perceived memory impairment were investigated in 40 elderly normal adults and 28 individuals with Alzheimer's disease. Measures of perceived memory impairment, global cognitive functioning, memory, use of memory strategies, memory strategy efficacy, and depressive symptomatology were obtained for all participants. The elderly normal and Alzheimer's disease groups did not differ in the extent to which they reported perceived memory impairment. For both participant groups, more frequent use of memory strategies and lower perceived memory strategy efficacy were significant predictors of perceived memory impairment. Depressive symptomatology was an additional, significant determinant of perceived memory impairment for the elderly normal group.

Aged↗

PubMed2003

Comparison between three memory tests: cued recall, priming and saving closed-head injured patients and controls.

Twenty closed-head injured (CHI) patients and 20 matched controls were tested with three different memory tasks: cued recall, word stem completion (WSC), and saving. Saving is defined as the advantage of relearning of a list of word pairs, in terms of the number of learning trials to the criterion of one errorless trial, over the original learning of the same list. It was predicted that CHI patients' explicit memory (i.e., cued recall), but not implicit memory (i.e., WSC), would be impaired. The question addressed in this study is whether the memory of CHI patients will be impaired when memory is tested with a saving task, with 2 weeks delay between original learning and relearning. The findings confirm impairment of CHI patients in explicit memory, although the learning rate is preserved. Implicit memory is preserved in CHI patients only when based on reactivation of preexisting knowledge, but not when dependent on forming new associations. Finally, the CHI patients, even after 2 weeks delay, demonstrated a significant saving in relearning old, as compared to new, pairs of words. The clinical contribution of this study is the delineation of those aspects of memory that are impaired and those that are preserved in CHI patients. The theoretical implications of the finding that memory could be preserved in CHI patients when measured by saving, are discussed in terms of the relationship between implicit memory and saving.

Adult↗

PubMed1993

Prospective memory impairment as an early indicator of dementia.

Theoretical accounts of the cognitive processes involved in prospective memory imply that performance on such tasks will be more vulnerable than retrospective memory tests to the early stages of dementia. This hypothesis is examined in elderly subjects from a general population sample which includes demented subjects. We report the findings on three tests of prospective memory from the Rivermead Behavioural Memory Test (Wilson et al., 1985) and compare it with measures of retrospective memory for recently acquired information. In contrast to retrospective memory where subjects with minimal dementia perform at a level intermediate between normals and more demented subjects, the subjects with minimal dementia perform as poorly as more demented subjects on the prospective memory tests. These findings provide evidence that prospective memory tasks are particularly sensitive to the early stages of dementia. Covariance analysis and the pattern of intercorrelations found between prospective and retrospective memory lead to alternative hypotheses about the cognitive processes involved in prospective memory and the way in which they break down.

Aged↗

PubMed2004

Evaluating computer-assisted memory retraining programmes for people with post-head injury amnesia.

OBJECTIVE: The present study was designed to perform theory-driven empirical work that might contribute to a better understanding of computer-assisted training effects adopting theoretically different memory retraining strategies for people who had amnesia as a result of a brain injury. RESEARCH DESIGN: A pre-test and post-test control group quasi-experimental design was adopted to test the differences in effectiveness of four different computer-assisted memory training strategies, which were hypothesized to improve different memory skills of persons with brain injury. METHOD AND PROCEDURES: Twenty-six persons with brain injury were randomly assigned to four age- and gender-matched memory training groups (self-paced, feedback, personalized, visual presentation) and they were trained using the related computer software, evaluated by the Rivermead Behavioural Memory Test (RBMT), self-efficacy scale and built-up computer performance records. MAIN OUTCOMES AND RESULTS: All the four memory training methods showed positive among the persons with brain injury as compared with a control group, although there was no statistically significant difference among the four training methods. However, clinical improvement was found in all four methods and the Feedback group showed significant improvement in self efficacy, in comparison with the other groups. CONCLUSION: This attempt to develop and evaluate different computer applications for memory retraining was made and the effectiveness of applying customized computer technology in memory rehabilitation was critically evaluated. Results of the present study showed that the unique customized therapeutic characteristics of computer-assisted memory retraining (e.g. self-paced practice, performance feedback, salient visual presentation and personalized training contents) are positive attributes of memory skill retraining outcomes.

Adolescent↗

PubMedDate not supplied

An emotional mediation theory of differential age effects in episodic and semantic memories.

Although there is a large decrement in central episodic memory processes as adults age, there is no appreciable decrement in central semantic memory processes (Allen et al., Journal of Gerontology: Psychological Sciences, 57B, P173-P186, 2002; Allen et al., Experimental Aging Research, 28, 111-142, 2002; Mitchell, Journal of Experimental Psychology: Learning, Memory, and Cognition, 15, 31-49, 1989). The authors develop a theory of episodic memory's connections to cognitive, emotional, and motivational systems to explain these differential age effects. The theory is discussed within the context of the cognitive neuroscience research regarding limbic system connectivity in conjunction with Damasio's notion of somatic markers (Descartes' error: Emotion, reason, and the human brain, New York: Grosset/Putnam, 1994). The central hypothesis is that elements of limbic system circuitry, including portions of the medial temporal lobes and frontal cortex, are associated with both working and long-term episodic memory performance, and by extension, with the capacity to engage in emotion-guided, self-regulatory processes that depend heavily on episodic memory. In contrast, the semantic memory system may have less shared interface with episodic and affective networks (i.e., the limbic-related system), and therefore remain independent of neurocognitive changes impacting emotional states and episodic-type memory processes. Accordingly, this framework may account for the pattern of age-related declines in episodic relative to semantic memory, particularly if older adults experience less emotional activation, and therefore fewer somatic markers, than younger adults. An initial empirical examination of this emotional mediation theory is presented, using preexisting data that include indicators of age, chronic tendency to focus on negative emotional stimuli (neuroticism), and working memory performance.

Adolescent↗

PubMed2006

Language-dependent access to autobiographical memory in Japanese-English bilinguals and US monolinguals.

Japanese bilinguals retrieved autobiographical memories in response to 20 English and 20 Japanese cue words. US monolinguals were cued with 40 English words. All participants reported one earliest memory. Japanese bilinguals retrieved more memories and earlier memories when cued with Japanese words. They also retrieved more memories when the cue language matched either the language of memory encoding or the language of first thought. Although English cues elicited equivalent numbers of English and Japanese memories in the more fluent speakers of English, Japanese words elicited significantly larger numbers of Japanese memories in all Japanese-English bilinguals. The average age of cued autobiographical memories was significantly earlier for US than for Japanese students but age of the earliest memory did not differ.

Adolescent↗

PubMed2004

In multiple myeloma clonotypic CD38- /CD19+ / CD27+ memory B cells recirculate through bone marrow, peripheral blood and lymph nodes.

It is believed that myeloma cells are derived from a germinal center (GC) or post GC B cell. The GC B cell can differentiate into both a memory B cell and a plasma cell (PC). In this study, we investigated the recirculating potential of memory B cells clonally related to the myeloma PC (termed clonotypic). The V(H)DJ(H) immunoglobulin gene rearrangement of the myeloma clone was identified for 10 myeloma patients and allele-specific oligonucleotides (ASO) IgH RT-PCR assays were designed for each patient. Memory B cells (CD38- /CD19+ /CD27+) and their subsets defined by the monoclonal antibodies CD62L, CCR6, CXCR4, CXCR5, CCR7 were flow-sorted as single cells and analyzed by ASO RT-PCR analysis. In addition, aspirated peripheral lymph nodes (PLN) of 7 myeloma patients in complete or partial remission were analyzed for the presence of clonotypic cells. Circulating clonotypic memory B cells were identified in PBMNC of 7/10 patients and both CD62L positive and negative clonotypic memory B cells were identified. Furthermore, comparable frequencies of clonotypic cells were found in the CCR6 +/- and CXCR4 +/- memory B cell subsets, whereas all clonotypic memory and later stage B cells were CXCR5 positive. In accordance with their immunophenotype, clonotypic memory B-cells were identified in peripheral blood, bone marrow and PLNs. Clonotypic memory B-cells were present in the majority of myeloma patients and seem to have the same diverse recirculating/homing capacity as normal memory B cells.

ADP-ribosyl Cyclase↗

PubMedDate not supplied

Effect of sentence length and complexity on working memory performance in Hungarian children with specific language impairment (SLI): A cross-linguistic comparison.

BACKGROUND: English-speaking children with specific language impairment (SLI) perform more poorly than their typically developing peers in verbal working memory tasks where processing and storage are simultaneously required. Hungarian is a language with a relatively free word order and a rich agglutinative morphology. AIMS: To examine the effect of linguistic structure on working memory performance. It was examined whether syntactic complexity has a larger impact on working memory performance than sentence length in Hungarian-speaking children, similar to the findings in English speaking children. METHODS & PROCEDURES: In Experiment 1, performance accuracy was measured with two linguistic span tasks that included stimuli with varying sentence length and syntactic complexity. Experiment 2 examined the impact of sentence length and morphological complexity on working memory performance. OUTCOMES & RESULTS: Children with SLI performed more poorly than their age-matched peers in all working memory tasks. Their error patterns differed from those of children with typical language development. Children with SLI produced a high number of interference errors that indicate poor executive functions. The findings were compared with previous results of English-speaking children. Complexity affected working memory performance accuracy differently across languages. In English, it was the increase of syntactic complexity that resulted in a decrease in performance accuracy, whereas in Hungarian, it was the morphological complexity that had a large impact on working memory performance. CONCLUSIONS: Working memory performance depends on the linguistic characteristics of the language tested. In both English- and Hungarian-speaking children, complexity has a larger effect on verbal working memory performance than the length of the stimuli. However, complexity affects working memory performance accuracy differently across languages.

Analysis of Variance↗

PubMed2001

Midlife women's attributions about perceived memory changes: observations from the Seattle Midlife Women's Health Study.

Memory changes are of increasing interest as midlife women approach menopause. Recent studies of relationships between estrogen and Alzheimer's disease have prompted interest in memory experiences around the time of menopause. The purpose of this analysis, part of the larger Seattle Midlife Women's Health Study (SMWHS), was to describe the types of memory changes women perceived during midlife, to describe their attributions about the memory changes, and to describe the relationship among these types and attributions of memory changes and age, menopausal transition stage, hormone replacement therapy (HRT) use, stress, and major life roles. Women (n = 230) with a mean age of 46.7 years, enrolled in the SMWHS, described whether they had noticed any changes in their memory, when they noticed them first, the nature of the changes, and what they thought were the reasons for the changes. Types of memory changes were collapsed into five categories, which included difficulty recalling words or numbers, forgetting related to everyday behavior, concentration problems, need for memory aids, and forgetting events. Six categories describing attributions about the memory changes were increased role burden and stress, getting older, physical health, menstrual cycle changes/hormones, inadequate concentration, and emotional factors. Stress, physical health, and aging as attributions, rather than the menstrual cycle or hormone use, were linked to most types of memory change.

Adult↗

PubMed1988

Neuronal activity in human lateral temporal cortex related to short-term verbal memory, naming and reading.

Extracellular microelectrode recordings were obtained from lateral temporal cortex that was subsequently resected in patients undergoing craniotomies under local anaesthesia for treatment of medically intractable epilepsy. During these recordings patients performed visually presented measures of overt and silent naming and word reading, short-term verbal memory and a control task requiring matching of angles. These measures were designed so that the same visual stimuli elicited language, short-term memory or spatial responses. Statistically significant changes within and between these various measures were identified. Technically satisfactory recordings were obtained from 17 populations reflecting activity predominantly from 1 neuron, in 13 patients. Two populations demonstrated no significant changes in any measured functions. Only 1 population showed changes suggesting a relation to visual perception. Four populations in or adjacent to the superior temporal gyrus altered activity with overt speech. Four other populations in the anterior temporal lobe altered activity during silent, but not overt speech. Some relation to language or memory was established for 13 of the 17 populations: 1 altered activity during reading alone, 6 during memory alone, and 6 to both. Most of the recording sites showing these language and memory changes were not essential for those functions based on surface electrical stimulation mapping. Thus the area of temporal lobe that participates in language and memory, as indicated by changes in neuronal activity, is substantially larger than the areas essential for those functions as determined by stimulation mapping. Within that participatory area, changes related to language were most often an increase in activity sustained throughout the task, a pattern suggestive of mechanisms of selective attention. Changes related to memory most often included a sustained increase in activity at the time of entry of information into memory, and again at retrieval, with decreased activity during the time the memory was stored. A few neuronal populations demonstrated relative inhibition of activity during the memory task, compared with control measures.

Electric Stimulation↗

PubMed2001

Semantic dementia: relevance to connectionist models of long-term memory.

Semantic dementia is a recently documented syndrome associated with non-Alzheimer degenerative pathology of the polar and inferolateral temporal neocortex, with relative sparing (at least in the early stages) of the hippocampal complex. Patients typically show a progressive deterioration in their semantic knowledge about people, objects, facts and the meanings of words. Yet, at least clinically, they seem to possess relatively preserved day-to-day (episodic) memory. Neuropsychological investigations of semantic dementia provide, therefore, a unique opportunity to investigate the organization of human long-term memory and, more specifically, to determine the relationship between semantic memory and other cognitive systems, such as episodic memory. In this review, we summarize recent empirical findings from patients with semantic dementia and discuss whether the neuropsychological phenomena of the disease are consistent with current cognitive and computational models of human long-term memory and amnesia. Six specific issues are addressed: (i) the relative preservation of category-level (superordinate) compared with fine-graded (subordinate) semantic knowledge as the disease progresses; (ii) the better recall of recent autobiographical and semantic memories compared with those in the distant past; (iii) the preservation of new learning, as measured by recognition memory, early in the disease; (iv) the interaction between autobiographical experience and semantic knowledge in the current, but not the distant, time-period; (v) increased long-term forgetting of newly learned material; and (vi) impaired implicit memory. It is concluded that recent findings from semantic dementia offer strong support for the view that memory consolidation in humans is dependent upon interactions between the hippocampal complex and neocortex. Furthermore, these investigations have provided computational modellers of human memory with a novel set of neuropsychological data to be simulated and tested.

Amnesia↗

PubMed2003

Source versus content memory in patients with a unilateral frontal cortex or a temporal lobe excision.

It has been suggested previously that patients with a frontal lobe lesion might have a specific impairment in the retrieval of the source of information despite adequate memory for facts. Patients with an anterior temporal excision are known to have impairments in memory for facts and the question arises as to whether they are also impaired in source memory. The present study compared memory for facts and their source in patients with a unilateral frontal cortical or an anterior temporal excision in a situation in which both types of information were encoded explicitly. Patients with a unilateral frontal cortex or a temporal lobe excision watched videos of a game show and were instructed to attend to both the trivia facts and their source (the identity of the speaker or the relative time of presentation). Patients with a frontal cortex excision were not impaired on either fact or source memory. This was true even when a subgroup of patients with an excision involving the dorsolateral frontal cortex was examined. In contrast, patients with a left temporal lobe excision were impaired in both fact and identity source memory and right temporal lobe patients were impaired in identity source memory. All patients performed similarly to normal controls in temporal source memory. The present results are consistent with the view that source information is part of an associative network of information about an episode and that the medial temporal region is critical for both source and content memory. Furthermore, if source information is encoded explicitly, the frontal cortex does not appear to be necessary for its retrieval. Instead, it is proposed that the frontal cortex plays a metacognitive role in memory retrieval.

Adolescent↗

PubMed2005

Contrasting effects of reward expectation on sensory and motor memories in primate prefrontal neurons.

The value of reward obtained with successful behavior is important for guiding purposeful behavior. The lateral prefrontal cortex (LPFC) has been implicated in working memory that guides goal-directed behavior. However, mechanism that integrates the reward value into the working memory for goal-directed behavior is not understood. To help clarify this issue, we examined the effect of reward expectation on the neuronal process in the LPFC associated with memory-based sensorimotor processing. By temporally dissociating visuospatial sensory and saccade-directional motor memories in the LPFC, we here show that reward expectation significantly enhanced the directional selectivity of sensory working memory but did not affect the directional selectivity of motor memory. The enhancement of sensory working memory in the neuronal population was sustained during the delay but extinguished soon after the motor memory appeared. These results suggest that the expectation of high reward value primarily affects the sensory working memory that may be used for behavioral guidance rather than preparation for forthcoming saccades. It thus appears that the LPFC is a neuronal substrate for working memory used to guide a reward-oriented behavior, rather than reflecting an efficient control of motor action in motivated states.

Animals↗

PubMed2006

Age differences in memory-load interference effects in syntactic processing.

The effects of a memory load on syntactic processing by younger and older adults were examined. Participants were asked to remember a noun phrase (NP) memory load while they read sentences varying in syntactic complexity. Two types of NPs were used as memory loads: proper names or definite descriptions referring to occupations or roles. The NPs used in the sentence and memory load either matched (e.g., all proper names or all occupations), or they mismatched. Participants read complex sentences more slowly than they did simpler sentences; for young adults, this complexity effect was exacerbated when memory interference was generated by matching NPs in the sentence and memory load, whereas for older adults, memory-load interference did not vary with sentence complexity or memory-load matching. These results suggest that a general reduction in older adults' processing capacity was produced by the memory load, whereas the matching memory loads and sentence NPs produced a more specific form of interference that affected young adults' online processing.

Adult↗

PubMed1992

Beliefs about memory changes across the adult life span.

Beliefs about age-related differences in memory were examined with an adaptation of the Short Inventory of Memory Experiences. In Experiment 1, 142 adults (mean age = 36 years) reported significantly more positive expectations for memory in everyday life for persons aged 25 years than for those aged 70 years. In Experiment 2, a between-subjects design with 189 adults (mean age = 34 years) was employed to examine the generality of memory beliefs about age-related change and the anticipated slope. Beliefs about the memory of 25-year-olds were significantly more positive than for 45- and 65-year-olds, which were correspondingly higher than for 85-year-olds. Secondary regression analyses revealed that participants with good memory self-perceptions anticipated better memory performance for others overall. In addition, older respondents exhibited more differentiated memory beliefs across age groups than younger respondents, especially at the two younger target ages. Examination of age-based memory beliefs with this type of instrument provides a new opportunity to integrate cognitive and social psychological approaches to the study of memory in aging.

Adolescent↗

PubMed1992

The lineage relationship between virgin and memory B cells.

J11d is expressed on a variety of hemopoietic cells, including B cells. In previous studies, we have shown that B cells are heterogeneous with respect to their levels of J11d expression and that memory B cells are contained within the J11dlo B cell population. In this report, we have further examined the relationship between memory precursors and memory cells. We have found that the ability of J11dlo B cells from unprimed mice to respond to primary antigenic stimulation was generally low; the lowest response occurred following immunization with soluble antigen in vitro. Following adoptive transfer into irradiated mice and repeated stimulation of these mice with antigen, J11dlo cells generated memory responses which were similar to those generated by J11dlo memory cells obtained from primed mice. In contrast, J11dhi B cells from unprimed mice gave rise to both primary and memory responses, but the memory responses were lower than those generated by J11dlo cells. Although the expression of J11d on both J11dhi and J11dlo cells from unprimed mice decreased after adoptive transfer, J11dlo, as compared to J11dhi, virgin cells proliferated more rapidly. These results suggest that memory responses are elaborated predominantly from J11dlo virgin cells. Taken together with previous results, our studies indicate that, J11dlo B cells are different from J11dhi B cells. Hence, they are either memory precursors or are memory cells.

Animals↗

PubMed1997

Neuropsychology and advances in memory function.

Recent developments in the functional and neural bases of several aspects of memory are described including long term cortical memory storage, the transition from immediate to permanent memory mediated by medial temporal structures, working memory, memory retrieval, and implicit memory. These are linked to current data on the nature of anterograde and retrograde amnesia in the degenerative diseases, and also to issues in the clinical diagnosis of memory impairments. Understanding the bases of memory can inform the diagnosis of memory impairments in degenerative diseases, and the patterns of impairment seen in the degenerative diseases can help contribute to knowledge of the mechanisms of normal memory.

Humans↗

PubMed1997

Parietal and hippocampal contribution to topokinetic and topographic memory.

This paper reviews the involvement of the parietal cortex and the hippocampus in three kinds of spatial memory tasks which all require a memory of a previously experienced movement in space. The first task compared, by means of positron emission tomography (PET) scan techniques, the production, in darkness, of self-paced saccades (SAC) with the reproduction, in darkness, of a previously learned sequence of saccades to visual targets (SEQ). The results show that a bilateral increase of activity was seen in the depth of the intraparietal sulcus and the medial superior parietal cortex (superior parietal gyrus and precuneus) together with the frontal sulcus but only in the SEQ task, which involved memory of the previously seen targets and possibly also motor memory. The second task is the vestibular memory contingent task, which requires that the subject makes, in darkness, a saccade to the remembered position of a visual target after a passively imposed whole-body rotation. Deficits in this task, which involves vestibular memory, were found predominantly in patients with focal vascular lesions in the parieto-insular (vestibular) cortex, the supplementary motor area-supplementary eye field area, and the prefrontal cortex. The third task requires mental navigation from the memory of a previously learned route in a real environment (the city of Orsay in France). A PET scan study has revealed that when subjects were asked to remember visual landmarks there was a bilateral activation of the middle hippocampal regions, left inferior temporal gyrus, left hippocampal regions, precentral gyrus and posterior cingulate gyrus. If the subjects were asked to remember the route, and their movements along this route, bilateral activation of the dorsolateral cortex, posterior hippocampal areas, posterior cingulate gyrus, supplementary motor areas, right middle hippocampal areas, left precuneus, middle occipital gyrus, fusiform gyrus and lateral premotor area was found. Subtraction between the two conditions reduced the activated areas to the left hippocampus, precuneus and insula. These data suggest that the hippocampus and parietal cortex are both involved in the dynamic aspects of spatial memory, for which the name 'topokinetic memory' is proposed. These dynamic aspects could both overlap and be different from those involved in the cartographic and static aspects of 'topographic' memory.

Brain Diseases↗