Age-Associated Memory Changes in Adults With Williams Syndrome

Age-associated changes on measures of episodic and working memory were examined in 15 adults with Williams Syndrome (WS; M age = 48.3 years, SD = 14.7; M IQ = 62.9, SD = 8.5) and their performance was compared to that of 33 adults with mental retardation (MR) with unspecified etiologies (M age = 54.2 years, SD = 8.9; M IQ = 61.7, SD = 6.5). Among the group with WS, older adults were significantly poorer than younger adults on the free recall task, a measure of episodic memory. Although this finding is consistent with normal aging, it occurred at a chronologically early age in adults with WS and was not found in their peers with unspecified MR. Although both groups showed small declines with age on a backward digit span task, a measure of working memory, for the group with WS the rate of decline on backward digit span was slower as compared to their performance on the free recall task. The findings from this study indicate a chronologically early and precipitous age-associated decrease in long-term, episodic memory in adults with WS.     

Patterns of Verbal Long-Term and Working Memory Performance Reveal Deficits in Strategic Processing in Children With Frontal Infarcts Related to Sickle Cell Disease

Frontal brain regions are thought to mediate strategic processes that facilitate memory. We hypothesized that children with frontal cerebral infarcts related to sickle cell disease (SCD) would exhibit impairments in long-term and working memory as a result of disruptions in strategic processing. Word-list learning and digit span tasks were used to assess verbal memory and strategic processing in 21 children with SCD without infarcts (controls) and in 10 children with SCD with frontal infarcts. On the word-list learning task, children with frontal infarcts performed more poorly in terms of learning and free recall, although recognition and cued recall were adequate; this pattern suggested intact encoding and storage with impaired retrieval. Children with frontal infarcts performed more poorly on backward digit span, although forward digit span was adequate; this pattern suggested intact maintenance with impaired manipulation of information in working memory. Overall, these findings support the notion that disruptions in strategic processing contribute to memory impairments in children with frontal infarcts.     

Patterns of verbal long-term and working memory performance reveal deficits in strategic processing in children with frontal infarcts related to sickle cell disease

Frontal brain regions are thought to mediate strategic processes that facilitate memory. We hypothesized that children with frontal cerebral infarcts related to sickle cell disease (SCD) would exhibit impairments in long-term and working memory as a result of disruptions in strategic processing. Word-list learning and digit span tasks were used to assess verbal memory and strategic processing in 21 children with SCD without infarcts (controls) and in 10 children with SCD with frontal infarcts. On the word-list learning task, children with frontal infarcts performed more poorly in terms of learning and free recall, although recognition and cued recall were adequate; this pattern suggested intact encoding and storage with impaired retrieval. Children with frontal infarcts performed more poorly on backward digit span, although forward digit span was adequate; this pattern suggested intact maintenance with impaired manipulation of information in working memory. Overall, these findings support the notion that disruptions in strategic processing contribute to memory impairments in children with frontal infarcts.     

Depression does not aggravate the episodic memory deficits associated with Alzheimer's disease.

In a population-based study of persons between 75 and 96 years of age, normal old adults (n = 296), patients with Alzheimer's disease (AD; n = 45), and patients with concomitant AD and depression (AD-D; n = 9) were compared on free recall and recognition of slowly and rapidly presented words and digit span. With the exception of forward digit span, the normal old group outperformed the 2 AD groups across all tasks. In free recall, only the normal old group performed better as task pacing decreased; however, all groups benefited from more study time in recognition. This suggests that both AD and AD-D patients have deficits in the ability to use more study time for remembering. Of most importance, the 2 AD groups were indistinguishable for all task variables. This lack of comorbidity effects is discussed relative to the view that depression, much like many other individual-difference variables that affect memory performance in normal aging, may be overshadowed by the influence of the neurodegenerative process in AD.     

Memory in learning disabled children: Digit span and the Rey auditory verbal learning test

Scores on the Rey Auditory Verbal Learning Test (RAVLT) were compared to WISC-R digit span results in a sample of 153 learning disabled students. With statistical controls for age and IQ, regression analyses indicated no significant relationships between the RAVLT and longest forward span, longest backward span and total digit span raw score. Factor analysis of the RAVLT variables, forward span, backward span and total digit span raw score yielded three factors that were interpreted to represent a long term memory factor, a short-term memory factor with high coding demands and a short-term memory factor with low coding demands. Conclusions were made regarding the inadequacy of using only digit span when making diagnostic statements about the auditory memory functioning of learning disabled students.     

The Roles of Verbal Short-Term Memory and Working Memory in the Acquisition of Grammar by Children With Williams Syndrome

The roles of verbal short-term and working memory were examined in a sample of children with Williams syndrome (mean chronological age 10 years, 2 months) and a sample of grammar-matched children who are developing normally. Forward digit span, nonword repetition, and backward span were all found to be correlated with receptive grammatical ability in the sample of children with Williams syndrome, but not in the sample of children who are developing normally. The relation between working memory, as measured by backward digit span, and grammatical ability was found to be significantly stronger in children with Williams syndrome than in the control group. This finding highlights the possibility that children with Williams syndrome may rely on their working memory to a greater extent than children who are developing normally to learn grammar. Hierarchical regression analyses indicated receptive vocabulary may mediate the relations among forward digit span, backward digit span, and grammatical ability for the children with Williams syndrome. Phonological short-term memory, however, contributed independently to grammatical ability even after receptive vocabulary was taken into account.     

The roles of verbal short-term memory and working memory in the acquisition of grammar by children with Williams syndrome

The roles of verbal short-term and working memory were examined in a sample of children with Williams syndrome (mean chronological age 10 years, 2 months) and a sample of grammar-matched children who are developing normally. Forward digit span, nonword repetition, and backward span were all found to be correlated with receptive grammatical ability in the sample of children with Williams syndrome, but not in the sample of children who are developing normally. The relation between working memory, as measured by backward digit span, and grammatical ability was found to be significantly stronger in children with Williams syndrome than in the control group. This finding highlights the possibility that children with Williams syndrome may rely on their working memory to a greater extent than children who are developing normally to learn grammar. Hierarchical regression analyses indicated receptive vocabulary may mediate the relations among forward digit span, backward digit span, and grammatical ability for the children with Williams syndrome. Phonological short-term memory, however, contributed independently to grammatical ability even after receptive vocabulary was taken into account.     

成人数字、词语和视空间工作记忆广度的发展特征及影响因素

目的:考察成人(18~49岁)数字、词语和视空间工作记忆广度发展变化的趋势及其影响因素。方法:采用多维记忆评估量表中的3个工作记忆广度分测验对280名正常成人进行测查,并收集一般资料。结果:成人的数字、词语和视空间广度成绩随年龄的增长均呈下降趋势(F=2.96~6.87,P<0.01);出现随龄衰减现象的先后顺序依次为视空间广度、词语广度和数字广度;在记忆广度总成绩和大多数分测验成绩上男女无显著差异,仅在30-34岁年龄组,男性视空间广度位置的成绩好于女性(11.02±3.17/8.67±3.18,t=2.15,P<0.05)。逐步回归分析结果显示,教育是成人数字、词语和视空间广度的保护因素(Beta值=0.546,0.445,0.423;P<0.01)。结论:成人阶段数字、词语和视空间工作记忆广度的发展变化基本上趋于一致,并且受教育程度能对不同的工作记忆广度起促进作用。     

The Roles of Verbal Short-Term Memory and Working Memory in the Acquisition of Grammar by Children With Williams Syndrome

The roles of verbal short-term and working memory were examined in a sample of children with Williams syndrome (mean chronological age 10 years, 2 months) and a sample of grammar-matched children who are developing normally. Forward digit span, nonword repetition, and backward span were all found to be correlated with receptive grammatical ability in the sample of children with Williams syndrome, but not in the sample of children who are developing normally. The relation between working memory, as measured by backward digit span, and grammatical ability was found to be significantly stronger in children with Williams syndrome than in the control group. This finding highlights the possibility that children with Williams syndrome may rely on their working memory to a greater extent than children who are developing normally to learn grammar. Hierarchical regression analyses indicated receptive vocabulary may mediate the relations among forward digit span, backward digit span, and grammatical ability for the children with Williams syndrome. Phonological short-term memory, however, contributed independently to grammatical ability even after receptive vocabulary was taken into account.     

Dementia,ageing, and the structure of human memory

The memory performance of patients suffering from senile dementia of the Alzheimer type (SDAT) (N = 29), normal subjects of equivalent age and education (N = 58), and young normal controls (N = 42) was tested using free recall and verbal and nonverbal span. Three measures were derived from the free recall task: primacy based on the first item, secondary memory based on the middle serial positions, and primary memory based on recency and the Waugh-Norman correction factor. The SDAT patients differed from the normal elderly on all free recall and span measures except for primary memory. The elderly were clearly inferior to the young on secondary memory, and were marginally poorer on primary memory and the two span measures. Three possible explanations of this pattern of results are considered, based on the dichotomous modal model of memory, levels of processing, and working memory. It is suggested that the assumption that SDAT patients suffer from a deficit in the central executive component of working memory offers the best of these interpretations.     

Different trait markers for schizophrenia and bipolar disorder: a neurocognitive approach.

BACKGROUND: The aim of this study was to assess visual information processing and cognitive functions in unaffected siblings of patients with schizophrenia, bipolar disorder and control subjects with a negative family history. METHODS: The siblings of patients with schizophrenia (N = 25), bipolar disorder (N = 20) and the controls subjects (N = 20) were matched for age, education, IQ, and psychosocial functioning, as indexed by the Global Assessment of Functioning scale. Visual information processing was measured using two visual backward masking (VBM) tests (target location and target identification). The evaluation of higher cognitive functions included spatial and verbal working memory, Wisconsin Card Sorting Test, letter fluency, short/long delay verbal recall and recognition. RESULTS: The relatives of schizophrenia patients were impaired in the VBM procedure, more pronouncedly at short interstimulus intervals (14, 28, 42 ms) and in the target location task. Marked dysfunctions were also found in the spatial working memory task and in the long delay verbal recall test. In contrast, the siblings of patients with bipolar disorder exhibited spared performances with the exception of a deficit in the long delay recall task. CONCLUSIONS: Dysfunctions of sensory-perceptual analysis (VBM) and working memory for spatial information distinguished the siblings of schizophrenia patients from the siblings of individuals with bipolar disorder. Verbal recall deficit was present in both groups, suggesting a common impairment of the fronto-hippocampal system.     

Alzheimer病与Parkinson病患者记忆损害的比较研究

目的：测查Alzheimer病、Parkinson病患者的记忆功能，了解这两种疾病病人记忆损伤的特征。方法：采用多维记忆评估量表中的12个分测验对30例原发性Parkinson病患者、30例临床诊断可能的Alzhdmer病患者及年龄、性别和教育程度与2个病人组相匹配的2个正常对照组进行外显记忆、内隐记忆及日常生活记忆等记忆功能的评定。结果：AD组在所有的分测验和记忆因子上均差于对照组；PD组在图画再认、数字广度、汉词回忆、图形再生、经历定向等分测验和记忆广度、再认记忆、自由回忆、日常记忆、外显记忆等记忆因子上均显著低于对照组：经以教育年限为协变量校正后发现。除自由组词、残图命名、数字广度、空间广度、汉词回忆、常识记忆、记忆广度、内隐记忆外，AD组在其余各分测验和记忆因子上均存显著差于PD病人组。结论：AD病人存在着广泛的记忆功能障碍：PD病人存在着工作记忆和策略记忆的障碍：两者的记忆功能障碍存在着明显的不同。     

Compromised encoding of proprioceptively determined joint angles in older adults: the role of working memory and attentional load

Perceiving the positions and movements of one’s body segments (i.e., proprioception) is critical for movement control. However, this ability declines with older age as has been demonstrated by joint angle matching paradigms in the absence of vision. The aim of the present study was to explore the extent to which reduced working memory and attentional load influence older adult proprioceptive matching performance. Older adults with relatively HIGH versus LOW working memory ability as determined by backward digit span and healthy younger adults, performed memory-based elbow position matching with and without attentional load (i.e., counting by 3 s) during target position encoding. Even without attentional load, older adults with LOW digit spans (i.e., 4 digits or less) had larger matching errors than younger adults. Further, LOW older adults made significantly greater errors when attentional loads were present during proprioceptive target encoding as compared to both younger and older adults with HIGH digit span scores (i.e., 5 digits or greater). These results extend previous position matching results that suggested greater errors in older adults were due to degraded input signals from peripheral mechanoreceptors. Specifically, the present work highlights the role cognitive factors play in the assessment of older adult proprioceptive acuity using memory-based matching paradigms. Older adults with LOW working memory appear prone to compromised proprioceptive encoding, especially when secondary cognitive tasks must be concurrently executed. This may ultimately result in poorer performance on various activities of daily living.     

Implicit learning in children and adults with Williams syndrome

In comparison to explicit learning, implicit learning is hypothesized to be a phylogenetically older form of learning that is important in early developmental processes (e.g., natural language acquisition, socialization)and relatively impervious to individual differences in age and IQ. We examined implicit learning in a group of children and adults (9.49 years of age)with Williams syndrome (WS)and in a comparison group of typically developing individuals matched for chronological age. Participants were tested in an artificial-grammar learning paradigm and in a rotor-pursuit task. For both groups, implicit learning was largely independent of age. Both groups showed evidence of implicit learning but the comparison group outperformed the WS group on both tasks. Performance advantages for the comparison group were no longer significant when group differences in working memory or nonverbal intelligence were held constant.     

Implicit Learning in Children and Adults With Williams Syndrome

In comparison to explicit learning, implicit learning is hypothesized to be a phylogenetically older form of learning that is important in early developmental processes (e.g., natural language acquisition, socialization) and relatively impervious to individual differences in age and IQ. We examined implicit learning in a group of children and adults (9-49 years of age) with Williams syndrome (WS) and in a comparison group of typically developing individuals matched for chronological age. Participants were tested in an artificial-grammar learning paradigm and in a rotor-pursuit task. For both groups, implicit learning was largely independent of age. Both groups showed evidence of implicit learning but the comparison group outperformed the WS group on both tasks. Performance advantages for the comparison group were no longer significant when group differences in working memory or nonverbal intelligence were held constant.     

Implicit Learning in Children and Adults With Williams Syndrome

In comparison to explicit learning, implicit learning is hypothesized to be a phylogenetically older form of learning that is important in early developmental processes (e.g., natural language acquisition, socialization) and relatively impervious to individual differences in age and IQ. We examined implicit learning in a group of children and adults (9-49 years of age) with Williams syndrome (WS) and in a comparison group of typically developing individuals matched for chronological age. Participants were tested in an artificial-grammar learning paradigm and in a rotor-pursuit task. For both groups, implicit learning was largely independent of age. Both groups showed evidence of implicit learning but the comparison group outperformed the WS group on both tasks. Performance advantages for the comparison group were no longer significant when group differences in working memory or nonverbal intelligence were held constant.     

智力障碍青少年工作记忆和加工速度的认知功能缺陷

目的:探讨智力障碍青少年的工作记忆和加工速度是否存在缺陷。方法:在广州市3所智障学校选取13~16岁智力障碍青少年和正常青少年各42例,分别作为研究组和对照组,采用韦氏记忆量表(WMS)中的数字工作广度(顺背、倒背)、空间工作记忆广度(顺背、倒背)和3项加工速度(感觉运动、知觉速度、扫描速度)进行测试。结果:1智力障碍青少年的工作记忆和加工速度得分显著低于智力正常青少年(t=-23.61,-19.35;P0.01);2智力障碍青少年工作记忆和加工速度的性别差异均不显著;3工作记忆和加工速度各变量间均显著相关(P0.05);4智力障碍青少年的工作记忆对加工速度的回归效应显著,预测率为36.00%。结论:智力障碍青少年的工作记忆与加工速度存在缺陷;其工作记忆对加工速度具有预测性。     

Variability in memory performance in aged healthy individuals: an fMRI study

Episodic memory performance varies in older subjects but underlying biological correlates remain as yet ambiguous. We investigated episodic memory in healthy older individuals (n=24; mean age: 64.4+/-6.7 years) without subjective memory complaints or objective cognitive impairment. Episodic memory was assessed with repetitive learning and recall of abstract geometric patterns during fMRI. Group analysis of brain activity during initial learning and maximum recall revealed hippocampal activation. Correlation analysis of brain activation and task performance demonstrated significant hippocampal activity during initial learning and maximum recall in a success-dependent manner. Neither age nor gray matter densities correlated with hippocampal activation. Functional imaging of episodic memory thus permits to detect objectively variability in hippocampal recruitment in healthy aged individuals without subjective memory complaints. Correlation analysis of brain activation and performance during an episodic memory task may be used to determine and follow-up hippocampal malfunction in a very sensitive manner.     

Recreational use of 3,4-methylenedioxymethamphetamine (MDMA) or 'ecstasy': evidence for cognitive impairment

BACKGROUND: It has recently been shown that 3,4-methylenedioxymethamphetamine (MDMA) or 'ecstasy' causes long-lasting alterations to brain structure and function in animals, and there is mounting evidence that recreational users of the drug show impairments in some aspects of cognitive functioning including memory for verbal information. The present study investigates possible effects on other cognitive functions and explores the temporal course of development and resolution of these impairments by comparing novice, regular and abstaining users with a matched group of non-users. METHODS: Eighty participants categorized as non-users, novice users, regular users or currently abstinent users of MDMA were assessed on tests of verbal IQ, reversed digit span, immediate and delayed recall of a prose passage and of a complex geometric figure and verbal fluency. RESULTS: The four groups were well-matched for verbal IQ and on demographic variables. They differed in frequency of cannabis use over the last month, but this did not correlate with any cognitive test scores. All three groups of MDMA users showed significantly poorer verbal fluency and immediate and delayed prose recall than non-users. Days since last use and total lifetime consumption of MDMA made separate contributions to the variance in recall scores, accounting jointly for almost half of the variance in delayed recall. By contrast, the groups did not differ on either visual recall or reversed digit span. CONCLUSIONS: The observed deficits provide further evidence of impairments of verbal but not visual memory in MDMA users, and indicate that the deficits are not attributable either to differences in general reasoning ability or to impairment of working memory. The data further suggest that the observed impairments may be attributable to a combination of reversible acute effects of MDMA resolving over a period of 2-3 weeks and more long-term changes associated with extent of lifetime consumption.     

Neuroanatomical and cognitive mediators of age-related differences in episodic memory

Aging is associated with declines in episodic memory. In this study, the authors used a path analysis framework to explore the mediating role of differences in brain structure, executive functions, and processing speed in age-related differences in episodic memory. Measures of regional brain volume (prefrontal gray and white matter, caudate, hippocampus, visual cortex), executive functions (working memory, inhibitory control, task switching, temporal processing), processing speed, and episodic memory were obtained in a sample of young and older adults. As expected, age was linked to reduction in regional brain volumes and cognitive performance. Moreover, neural and cognitive factors completely mediated age differences in episodic memory. Whereas hippocampal shrinkage directly affected episodic memory, prefrontal volumetric reductions influenced episodic memory via limitations in working memory and inhibitory control. Age-related slowing predicted reduced efficiency in temporal processing, working memory, and inhibitory control. Lastly, poorer temporal processing directly affected episodic memory. No direct effects of age on episodic memory remained once these factors were taken into account. These analyses highlight the value of a multivariate approach with the understanding of complex relationships in cognitive and brain aging.