Hippocampal metabolites and memory performances in patients with amnestic mild cognitive impairment and Alzheimer's disease

In patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD), previous studies have reported the decrease of N-acetylaspartate (NAA) concentration and the increase of myo-inositol (MI) concentration using proton magnetic resonance spectroscopy (1H-MRS). However, it remains to be investigated what aspects of cognition these metabolite changes reflect. In this study we evaluated the correlations between the subtests of Wechsler Memory Scale-Revised (WMS-R) and the concentrations of NAA and MI. The study group was composed of 42 patients with aMCI and 67 patients with AD. 1H-MR spectra with a single voxel-point resolved spectroscopy (PRESS) at a short echo time were acquired from the bilateral hippocampi and posterior cingulate gyrus. Positive correlations were shown between the NAA concentration in the left hippocampus and verbal memory, visual memory, general memory, attention and delayed recall; and furthermore, between the NAA concentration in the right hippocampus and verbal memory and general memory. Negative correlations were shown between the MI concentration in the left hippocampus and verbal memory, general memory, and delayed recall, and between the MI concentration in the right hippocampus and verbal memory. There was no significant correlation between any subtest of WMS-R and these two metabolite concentrations in the posterior cingulate gyrus. These findings suggest that bilateral, especially left hippocampal NAA and MI concentrations are associated with memory dysfunction observed in patients with aMCI and AD. In contrast, NAA and MI concentrations in the posterior cingulate gyrus may be less related to memory function than those in the hippocampus.     

Aging and memory for dreams.

This study investigated the influence of aging on memory for home drams and the extent to which cognitive variables such as visual memory, visuospatial IQ, and verbal IQ could account for possible differences herein. Subjects were 80 men and women of ages 45 to 75 years. Memory for dreams was measured by narrative length and frequency of recall. With respect to both measures no significant age differences were noted. Over-all differences in dream recall seemed best explained by visual memory scores. Partial correlational analyses, however, indicated that the small age differences memory or on any of the other cognitive variables. Dream contents were scored for aggression, friendliness, emotion, activities, and the number of characters and objects. The incidence of emotions among women appeared to be lower beyond the age of 60. Comparisons with previous data for young adults indicated that large reductions in aggression, friendliness, and emotion occur before the age of 45.     

Psychometric properties and reference data for Danish versions of Free and Cued Selective Reminding Test,Category Cued Memory Test and Logical Memory

Memory assessment is a key element in neuropsychological testing. Gold standard evaluation is based on updated normative data, but in many small countries (e.g. in Scandinavia) such data are sparse. In Denmark, reference data exist for non‐verbal memory tests and list‐learning tests but there is no normative data for memory tests which capture narrative recall and cued recall. In a nation‐wide study, Free and Cued Selective Reminding Test (FCSRT ), WMS ‐III Logical Memory (LM ) and a newly developed test Category Cued Memory Test (CCMT ‐48) were applied in 131 cognitively intact persons (aged 60–96 years). Regression‐based reference data for Danish versions of FCSRT , CCMT ‐48 and LM adjusted for age, education and gender are provided. Gender and age‐group had a significant impact on the expected scores, whereas the effect of education had a limited effect on expected scores. Test performances were significantly correlated in the range 0.21–0.51. Based on these findings and previous results it may be relevant to assess both free recall, cued recall and recognition to tap the earliest changes associated with neurodegeneration, and this study therefore provides an important supplement to existing Danish normative data. Future studies should investigate the discriminative validity of the tests and the clinical utility of the presented reference data.     

The Wechsler Memory Scale—Revised: Psychometric characteristics and clinical application

The psychometric characteristics of the Wechsler Memory Scale—Revised (WMS-R) are evaluated and related to dits clinical utility. The accuracy of the scale scores is shown to be limited by their high standard error, low reliabilities, and consequent large standard errors of measurement. Specific procedures are discussed for establishing confidence intervals and for testing the significance of differences between scores. It is concluded that the WMS-R, like the original Wechsler Memory Scale, provides only a rough estimate of overall memory functioning. The multidimensional index scores have not been shown effective in describing the nature or the pattern of memory deficits. Recommendations for the clinical use of the WMS-R are provided.     

Impairment in material-specific long-term memory following unilateral mediodorsal thalamic damage and presumed partial disconnection of the mammillo-thalamic tract

Neuropsychological findings suggest material-specific lateralization of the medial temporal lobe's role in long-term memory, with greater left-sided involvement in verbal memory, and greater right-sided involvement in visual memory. Whether material-specific lateralization of long-term memory also extends to the anteromedial thalamus remains uncertain. We report two patients with unilateral right (OG) and left (SM) mediodorsal thalamic pathology plus probable correspondingly lateralized damage of the mammillo-thalamic tract. The lesions were mapped using high-resolution structural magnetic resonance imaging and schematically reconstructed. Mean absolute volume estimates for the mammillary bodies, hippocampus, perirhinal cortex, and ventricles are also presented. Estimates of visual and verbal recall and item recognition memory were obtained using the Doors and People, the Rey Complex Figure Test, and the Logical Memory subtests of the Wechsler Memory Scales. Each patient's performance was compared to a group of healthy volunteers matched for demographic characteristics, premorbid IQ, and current levels of functioning. A striking double dissociation was evident in material-specific long-term memory, with OG showing significant impairments in visual memory but not verbal memory, and SM showing the opposite profile of preserved visual memory and significantly impaired verbal memory. These impairments affected both recall and item recognition. The reported double dissociation provides the strongest evidence yet that material-specific lateralization of long-term memory also extends to the anteromedial thalamus. The findings are also discussed in relation to proposals that distinct anatomical regions within the medial temporal lobe, anteromedial thalamus, and associated tracts make qualitatively different contributions to recall and item recognition.     

Validity of the Rey Visual Design Learning Test in primary and secondary school children.

The Rey Visual Design Learning Test (Rey, 1964, cited in Spreen & Strauss, 1991, Wilhelm, 2004) assesses immediate memory span, new learning, delayed recall and recognition for nonverbal material. Two studies are presented that focused on the construct validity of the RVDLT in primary and secondary school children. In the first study, primary school children performed the RVDLT and the Biber Figural Learning Test, as well as the WISC-R Block design Test, Boston Naming Test, and the Trailmaking Test, to assess discriminant validity. In the second study, the age range was expanded and the subtest Visual Reproductions of the Wechsler Memory Scale with a Delayed recall phase was used to assess the construct validity. A test for visual-motor integration and a test for attention, concentration, and speed of information processing were also added to complete the test battery for assessing discriminant validity. Moderate to high correlations were found between scores on the RVDLT and the tests used to assess construct validity. The correlational pattern of RVDLT scores and the scores on the discriminant tests is discussed.     

Use of the everyday memory questionnaire with children.

The Everyday Memory Questionnaire (EMQ; Sunderland, Harris, & Baddeley, 1983) was examined for its suitability to assess children's memory. The parents of 226 school children (6-12 years) completed the EMQ in relation to their own children. A subset of these children (N = 101), in 6, 8 and 10 years age groups, completed subtests of the Wide Range Assessment of Memory and Learning (WRAML; Sheslow & Adams, 1990). Comparison of EMQ and WRAML data found aspects of verbal memory correlated moderately with the EMQ in the 10 years age group. There were no meaningful correlations in the 8 years age group. In the 6 years age group aspects of visual memory correlated moderately with the EMQ. The diagnostic utility of the EMQ for children was assessed by comparing the school group to children diagnosed with ADHD and/or learning disorders. Diagnostic indicators revealed the EMQ to have high sensitivity (89%) but poor positive predictive power, identifying 40% of the school group as having memory deficits. Negative predictive power (confirming a negative diagnosis) was high. Validity data suggested that the EMQ could be useful with children at least as young as 10 years and further research needs to be conducted to establish the utility of the EMQ in clinical groups with primary memory deficits.     

A comparison of Chinese and American memories for public events

Memory for public events was compared across Chinese and U.S. participants to explore competing explanations for cultural differences in flashbulb memories. Participant recall of the canonical features of events was more detailed and more likely to include a specific time in the United States than in the Chinese reports. Vividness was positively correlated with the flashbulb memory scores only in the U.S. sample. In both cultures, emotion, national importance, and thinking about the event predicted vividness and recall of memory details. Chinese participants reported primarily disasters and social events, and their memories were more likely to include international events than U.S. participants. The U.S. participants recalled primarily political events and terrorism. These results suggest that culture has important influences on the quantity, level of detail, completeness, and vividness of autobiographical memories as well as on the types of events triggering flashbulb memories.     

Expanding the ecological validity of WAIS-IV and WMS-IV with the Texas functional living scale

Assessment of functional status is an important aspect of clinical evaluation. As part of the standardization of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Wechsler Memory Scale-Fourth Edition (WMS-IV), participants completed the Texas Functional Living Scale (TFLS), a measure of Instrumental Activities of Daily Living. The relationships between TFLS and WAIS-IV and WMS-IV were examined in both normally developing and clinical samples. In general, the highest correlations were between TFLS and measures of general cognitive ability (WAIS-IV FSIQ [Full Scale IQ] and GAI [General Ability Index]) and working memory (WAIS-IV WMI [Working Memory Index] and WMS-IV VWMI [Visual Working Memory Index]). Across the clinical populations, working memory subtests were generally strongly related to TFLS performance, although this relationship was more consistent with WAIS-IV than WMS-IV. Contrast scaled scores are presented for the TFLS based on WAIS-IV or WMS-IV performance. These scores allow the evaluation of functional abilities within the context of cognitive and memory ability, enhancing and expanding the utility of the WAIS-IV and WMS-IV.     

Use of the Everyday Memory Questionnaire With Children

The Everyday Memory Questionnaire (EMQ; Sunderland, Harris, & Baddeley, 1983) was examined for its suitability to assess children's memory. The parents of 226 school children (6-12 years) completed the EMQ in relation to their own children. A subset of these children (N=101), in 6, 8 and 10 years age groups, completed subtests of the Wide Range Assessment of Memory and Learning (WRAML; Sheslow & Adams, 1990). Comparison of EMQ and WRAML data found aspects of verbal memory correlated moderately with the EMQ in the 10 years age group. There were no meaningful correlations in the 8 years age group. In the 6 years age group aspects of visual memory correlated moderately with the EMQ. The diagnostic utility of the EMQ for children was assessed by comparing the school group to children diagnosed with ADHD and/or learning disorders. Diagnostic indicators revealed the EMQ to have high sensitivity (89%) but poor positive predictive power, identifying 40% of the school group as having memory deficits. Negative predictive power (confirming a negative diagnosis) was high. Validity data suggested that the EMQ could be useful with children at least as young as 10 years and further research needs to be conducted to establish the utility of the EMQ in clinical groups with primary memory deficits.     

Insensitivity of visual short-term memory to irrelevant visual information

Several authors have hypothesized that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996b). Experiment 1 replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of DVN on recall of static matrix patterns, despite a significant effect of a concurrent spatial tapping task. Experiment 4 showed no effect of DVN on encoding or maintenance of arrays of matrix patterns, despite testing memory by a recognition procedure to encourage visual rather than spatial processing. Serial position curves showed a one-item recency effect typical of visual short-term memory. Experiment 5 showed no effect of DVN on short-term recognition of Chinese characters, despite effects of visual similarity and a concurrent colour memory task that confirmed visual processing of the characters. We conclude that irrelevant visual noise does not impair visual short-term memory. Visual working memory may not be functionally analogous to verbal working memory, and different cognitive processes may underlie visual short-term memory and visual imagery.     

Sensitivity to Levels of Importance in the Logical Memory Subtest

The performance of Alzheimer's disease (AD) and neuropsychiatric patients was examined using the Logical Memory (LM) subtest of the WMS-R, utilizing a levels of importance methodology described by Haut et al. (1990). Although patient groups were matched for dementia severity, we found the expected differences between groups in terms of absolute level of performance. There was considerable variability, however, in the AD patients' performance. AD patients' recall and sensitivity to levels of importance depended on the story (Anna or Robert), and when the passages were recalled (immediate or delayed recalls). Results suggested that AD patients were able to utilize semantic information in their immediate recall, though this was dependent on individual story characteristics. AD patient's delayed recall was essentially absent. Thus, no conclusions could be drawn with respect to the level of importance factor. NP patient's recall performance was similar to patterns observed in other clinical samples for both immediate and delayed memory.     

Co-occurring disorders: a possible key to visual perceptual deficits in children with developmental coordination disorder?

A study was conducted to examine how visual perceptual functioning in children with DCD may be influenced by co-occurring learning problems such as reading disabilities (RD) and/or attention deficit hyperactivity disorder (ADHD). Participants included seven groups of children: 27 children with DCD only, 11 with ADHD only, 14 with RD only, 63 with DCD and at least one other disorder (i.e., DCD + ADHD, DCD + RD, DCD + ADHD + RD), and 73 typically developing controls. Visual perceptual skills were assessed using the Test of Visual Perceptual Skills (TVPS) and the Rey Osterreith Complex Figure (ROCF; copy and delayed recall). Children with DCD and at least one other disorder were found to have impairments on the TVPS compared to children with DCD only, ADHD only, and typically developing controls, particularly on subtests assessing visual memory. On the ROCF, children with DCD and at least one other disorder scored significantly lower than children with ADHD only or RD only. Children with DCD plus one other disorder were then subdivided into three groups: DCD + ADHD, DCD + RD, and DCD + ADHD + RD and compared to children with DCD only, ADHD only, and RD only. Results indicated that children with DCD + ADHD + RD had significant impairments on the TVPS compared to children with DCD only and children with ADHD only. On the ROCF, children with DCD + ADHD + RD scored significantly lower than all of the groups, except the DCD+RD group. These findings suggest that DCD on its own is not associated with visual perceptual problems; rather, it is the presence of co-occurring disorders that is a possible key to visual perceptual deficits in children with DCD. The number of co-occurring disorders present with DCD is associated with the severity of the visual perceptual dysfunction. Deficits in visual memory skills appear to be a specific area of difficulty for children with DCD and co-occurring RD and/or ADHD.     

Short-term memory for Chinese characters and radicals

Short-term memory for Chinese radicals and characters, varying in orthographic complexity, frequency, and—for radicals—intercharacter frequency (the number of compound characters that contain the radical), was studied using an immediate free-recall task. When radicals or characters are relatively frequent, so that their pronunciations are well known by literate Chinese, they seem to be maintained in verbal form in short-term memory. For these stimuli, intercharacter frequency and complexity have relatively small influences on memory span. Stimuli low in frequency, with pronunciations that are not apt to be known, seem to be maintained in visual form in short-term memory. Memory span is much smaller for these stimuli and is influenced by both intercharacter frequency and complexity. Furthermore, short-term memory for relatively high-frequency characters is interfered with more by a verbal than by a visual intervening task, whereas the opposite is true for low-frequency characters.     

Word memory test performance in children.

One-hundred and thirty-five children between the ages of 7 and 18 years were evaluated clinically. Their diagnoses included Fetal Alcohol Syndrome (FAS) or Effects, Schizophrenia, Bipolar Mood Disorder, various neurological diseases, Attention Deficit Hyperactivity Disorder (ADHD), Conduct Disorder, Oppositional-Defiant Disorder and learning disabilities. As part of a comprehensive neuropsychological assessment, the children were given the Word Memory Test (WMT; Green, Allen, & Astner, 1996; Green & Astner, 1995), containing various subtests which measure, respectively, effort and verbal memory. Although age and verbal intelligence are known to affect scores on most ability tests, they were not found to be significant determinants of WMT effort scores. Younger children did not score any lower on the effort subtests than older children. The children scored as well as a group of parents seeking custody of their children and they scored higher than adult patients with mild head injuries. The computerized WMT requires some basic reading skills and some children with lower than a grade 3 reading level scored at a relatively low level on the effort subtests. The current data suggest that most children with at least a grade 3 reading level can pass the WMT using the adult criteria. It is concluded that the WMT is potentially useful in the evaluation of effort during pediatric neuropsychological evaluations. Further research is needed to replicate these findings and to develop child norms for the memory subtests.     

不同年龄视觉通道错误记忆的实验研究

两个实验运用DRM研究范式 ,分别以汉字词和彩色图片为材料 ,揭示了青年、中年和老年人都存在基于概念结构的视觉关联性错误记忆以及在自由回忆、再认、抵御犯关联性错误记忆及抵抗外界无关因素干扰等情节长时记忆能力的各个方面随年龄发展变化的不同特点 ,并发现对信息来源的监控评定水平受信息材料性质及年龄因素的影响     

Looking sharp: Becoming a search template boosts precision and stability in visual working memory

Visual working memory (VWM) plays a central role in visual cognition, and current work suggests that there is a special state in VWM for items that are the goal of visual searches. However, whether the quality of memory for target templates differs from memory for other items in VWM is currently unknown. In this study, we measured the precision and stability of memory for search templates and accessory items to determine whether search templates receive representational priority in VWM. Memory for search templates exhibited increased precision and probability of recall, whereas accessory items were remembered less often. Additionally, while memory for Templates showed benefits when instances of the Template appeared in search, this benefit was not consistently observed for Accessory items when they appeared in search. Our results show that becoming a search template can substantially affect the quality of a representation in VWM.     

Assessment of Working Memory Capacity in Preschool Children Using the Missing Scan Task

The purpose of this study was to investigate the feasibility and validity of a modified version of Buschke's missing scan methodology, the Missing Scan Task (MST), to assess working memory capacity (WMC) and cognitive control processes in preschool children 3–6 years in age. Forty typically developing monolingual English‐speaking children between 36 and 84 months in age participated in the study. The children were tested on measures of WMC (MST), verbal and nonverbal memory (NEPSY Narrative Memory and Memory for Designs subtests), and language skills (Peabody Picture Vocabulary Test, fourth edition). Children showed increased working memory capacity scores with age, as measured by the MST, with significant differences between 3‐ and 5‐year‐olds and 3‐ and 6‐year‐olds. Significant correlations were also found between the MST and language and verbal and nonverbal memory scores. MST scores still remained significantly correlated with the other measures of memory even after age and global language were accounted for in a regression analysis, demonstrating that the MST captures unique variance related specifically to WMC and cognitive control processes used to retrieve and scan information in short‐term memory (STM). The results of this study demonstrate that the MST is a feasible and valid methodology for assessing WMC in preschool children as young 3 years of age. Copyright © 2014 John Wiley & Sons, Ltd.