Short-Term Memory Deficits Are Not Uniform in Down and Williams Syndromes

Neuropsychological investigation of the development of the mnesic function in mental retardation has primarily focused on evaluating short-term memory (STM). Studies have often documented a reduced verbal short-term memory span in individuals with mental retardation and with Down syndrome in particular, compared to groups of mental age-matched controls. However, recent evidence suggests that verbal short-term memory is not equally impaired in all individuals with mental retardation. Findings in children with Williams syndrome are particularly relevant in this regard. Also, data concerning STM for visual information suggest that visual-object and visual-spatial working memory may be differently compromised in people with mental retardation. In particular, individuals with Williams syndrome exhibit specific difficulties in visual-spatial but not in visual-object working memory tasks compared to typically-developing children matched for mental age. Instead, people with Down syndrome show reduced performance in both visual-spatial and visual-object tests. Taken together, these results reinforce the view that intellectual disability is not a unitary condition characterized by homogeneous slowness of cognitive development but a variety of conditions in which some cognitive functions may be more disrupted than others. The finding that the working memory deficit in individuals with Williams and Down syndrome may be qualitatively differentiated also supports the hypothesis that it is not simply a manifestation of general cognitive impairment but, rather, the expression of a specific deficit of a discrete cognitive ability.     

The psychological nature of subjective memory complaint in non-demented older adults: The respective predictive values of psycho-affective,lifestyle, and cognitive inhibition variables

Introduction/ObjectiveThe aim of this study was to investigate, using path analysis (Lisrel 8.52), the relationships between subjective memory complaint and cognitive inhibition, lifestyle, and psycho-affective variables on a sample of non-demented older adults.MethodOur sample was composed of 109 older adults, who were required to undertake two cognitive inhibition tasks (stroop and verbal fluency) and to respond to scales designed to measure individuals’ psycho-affective status (depression/subjective health) and subjective memory complaint level (Mac Nair). Lifestyle predictors (education and activity levels) were also assessed.Results/ConclusionThis study highlights the importance of adopting a multifactorial approach to the study of subjective memory complaint. In addition to executive variables (verbal fluency task), predictors such as subjective health and activity levels seem to be crucial in our understanding of the psychological nature of subjective memory complaint.     

Event-based prospective memory in depression: The impact of cue focality

This study is the first to compare event-based prospective memory performance in individuals with depression and healthy controls. The degree to which self-initiated processing is required to perform the prospective memory task was varied. Twenty-eight individuals with depression and 32 healthy controls worked on a computerised prospective memory task. Prospective cues were either presented focally or non-focally to the ongoing activity. Collapsing data across both conditions, controls outperformed individuals with depression in the prospective memory task. Overall, participants showed a poorer prospective memory performance in the non-focal condition that required self-initiated processing to a higher degree than the focal condition. Importantly, as revealed by a group by task condition interaction, groups did not differ in the focal condition, whereas, controls outperformed individuals with depression in the non-focal condition. The results are in line with the multiprocess framework of event-based prospective remembering and the cognitive-initiative account of depression-related cognitive deficits.     

Diurnal cycle of salivary cortisol in older adult men and women with subjective complaints of memory deficits and/or depressive symptoms: relation to cognitive functioning

In populations of young and older adults, it has been shown that individuals may be categorized into one of three diurnal subgroups when salivary cortisol levels are assessed over a 2-day period and compared for their consistency across days: a typical subgroup, a flat subgroup, and an inconsistent subgroup. Interestingly, recent studies have reported that the typical subgroup represents the majority of the young and older adult population, a finding that is difficult to reconcile with previous studies showing increased cortisol levels in older adults with depression or cognitive impairments. In order to assess whether a typical diurnal cortisol profile is representative across different subgroups of older adults, we assessed diurnal cortisol cycle representation in a sample of older adults with subjective complaints of depression and/or memory problems. Furthermore, given the robust relationship between cortisol and cognitive function, the present study examined the association between the three diurnal subgroups and cognitive performance. Forty-two older individuals were recruited on the basis of reporting subjective complaints of either memory problems and/or depressive mood. Participants were asked to sample their saliva over a 2-day period and were then asked to undergo a neuropsychological evaluation that taps into short-term memory, declarative memory and language. The results showed that 69% of the sample presented a Flat cycle of salivary cortisol over a 2-day period while 19% presented an inconsistent pattern and 12% presented a typical pattern. Participants in the flat subgroup were significantly impaired on letter verbal fluency. Furthermore, a relationship was found between diurnal cortisol subgroup representation and subjective complaint profile. These findings show that older adults with complaints of memory problems and/or depressive symptoms do not present the typical profile of the diurnal cortisol cycle, and they provide a preliminary view of how diurnal cortisol profile relates to cognitive function during human aging.     

Working and long-term memory deficits in schizophrenia: is there a common prefrontal mechanism?

This study tested the hypothesis that dorsolateral prefrontal cortex deficits contribute to both working memory and long-term memory disturbances in schizophrenia. It also examined whether such deficits were more severe for verbal than nonverbal stimuli. Functional magnetic resonance imaging was used to assess cortical activation during performance of verbal and nonverbal versions of a working memory task and both encoding and recognition tasks in 38 individuals with schizophrenia and 48 healthy controls. Performance of both working memory and long-term memory tasks revealed disturbed dorsolateral prefrontal cortex activation in schizophrenia, although medial temporal deficits were also present. Some evidence was found for more severe cognitive and functional deficits with verbal than nonverbal stimuli, although these results were mixed.     

Spatial memory following prenatal alcohol exposure: more than a material specific memory deficit.

Spatial memory deficits have been reported following prenatal alcohol exposure and animal studies have demonstrated hippocampal vulnerability to alcohol. This study examined spatial memory in children diagnosed with fetal alcohol syndrome (FAS) or fetal alcohol effects (FAE) and matched controls. Spatial memory was examined with location recall measures. Since visual perceptual skills and nonspecific memory impairment could impact spatial memory, tasks assessing perception and verbal memory were administered. Analyses revealed group differences on perceptual and verbal and spatial memory tasks. There was no significant difference in spatial memory once perceptual and verbal memory task performance was taken into account, suggesting that differences in spatial memory were not solely attributable to a material specific memory deficit.     

Cognitive functioning in healthy older adults aged 64-81: a cohort study into the effects of age, sex, and education

The objective of this study was to determine a possible differential effect of age, education, and sex on cognitive speed, verbal memory, executive functioning, and verbal fluency in healthy older adults. A group of 578 healthy participants in the age range of 64-81 was recruited from a large population study of healthy adults (Maastricht Aging Study). Even in healthy individuals in this restricted age range, there is a clear, age-related decrease in performance on executive functioning, verbal fluency, verbal memory, and cognitive speed tasks. The capacity to inhibit information is affected most. Education had a substantial effect on cognitive functioning: participants with a middle or high level of education performed better on cognitive tests than did participants with a low level of education. Women performed better than men on verbal memory tasks. Therefore, education and sex must be taken into account when examining an older individual's cognitive performance.     

Memory awareness disruptions in amnestic mild cognitive impairment: comparison of multiple awareness types for verbal and visuospatial material

Successful memory is normally accompanied by explicit awareness of retrieval and confidence in the accuracy of the retrieval product. Prior findings suggest that these features of metamemory can be dissociated from retrieval accuracy in Amnestic Mild Cognitive Impairment (aMCI). However, the literature on this question contains variable and conflicting results, likely because of differences in experimental conditions. We sought to systematically evaluate memory awareness disruptions in aMCI using multiple measures and stimulus formats within the same individuals. Memory awareness was tested with global predictions and postdictions, judgments of learning, confidence level ratings, and modified feeling-of-knowing ratings in tasks of visuospatial and verbal memory. These tests were administered to 14 individuals with aMCI and 15 healthy, age-matched controls. Memory awareness accuracy was calculated as the correspondence between subjective judgments and memory performance.Individuals with aMCI demonstrated impaired global and trial-level retrospective task awareness for visuospatial and verbal stimuli. Additionally, modified feeling-of-knowing awareness was impaired selectively for verbal stimuli. Statistical effect sizes for global awareness impairments were comparable to impairments in several objective neuropsychological memory assessments.Memory awareness (metamemory) disruptions in aMCI were most evident for a subset of subjective judgment types and task input modalities. These findings advance understanding of the nature of memory impairments in aMCI and support the utility of incorporating memory awareness testing to better characterize memory integrity in older adults.     

记忆抑制在正常人群与抑郁人群中的研究进展

抑郁症认知障碍的突出表现之一为患者的负性记忆偏向。已有研究常关注患者对负性信息自下而上的选择性注意,往往忽略了自上而下执行控制障碍对记忆的影响。近年研究提示,抑郁症患者和抑郁状态个体的记忆抑制缺陷在其负性记忆偏向的形成和维持中起到了重要作用,无法有效地主动抑制负性记忆可能是患者持续性负性反刍的主要原因。从抑郁症自上而下的执行控制缺陷入手,研究患者的记忆抑制障碍与其主要症状－负性反刍间的相关性,不仅能从理论上丰富Beck的抑郁症认知模型,还能指导临床建立更准确的预后评估指标,同时制定更有效的治疗方案。本文分别介绍了健康成人及抑郁症患者和抑郁状态个体的记忆抑制研究现状,并就当前在抑郁人群研究领域亟待解决的三个问题进行了探讨。     

Encoding and retrieval in aging and memory loss, a fMRI study

Mild cognitive impairment (MCI) is a term for nondemented individuals with memory complaints and deficits greater than age-adjusted normal performance. Functional MRI (fMRI) may be a more sensitive method than other techniques to reveal functional abnormalities in individuals with MCI, only a proportion of whom progress to Alzheimer's disease (AD). fMRI was carried out while subjects (four MCI, five age-matched normal controls, and one AD) performed incidental encoding (deep and shallow) and recognition tasks for colored and black and white photographs contrasted to baseline fixation. fMRI revealed interesting dissociations between activation patterns and behavioral performance when comparing the MCI and AD to the NC.     

Cognitive and communicative function: The effects of chronological age and “handicap age”

Abstract

Three classes of cognitive tests (short-term memory, long-term memory access/recall, and verbal ability) and one class of communicative tests (visual speech-reading) were administered to 49 hearing-impaired and 69 normal hearing subjects, varying in age between 23 and 75 years. It was found that when dB-loss and “handicap age” were partialled out, the negative effects of cognitive ageing remained: Speed in accessing alphanumeric symbols from long-term memory and as rehearsal speed correlated substantially with chronological age. Discriminant analyses revealed a communality between the discrimination of old from young subjects, and skilled from less skilled speech-readers: Visual decoding skill and rehearsal speed constituted the common discriminators. Departing from this result, an age-dependent componential model of visual speech-reading is delineated. with particular reference to the assumption that a temporally early lexical access system is crucial to the decoding of lip movements.     

The Influence of Learning Style and Cognitive Ability on Recall of Names and Faces in an Older Population

The present study examined whether, for older adults, a verbal or imagery cognitive style is associated with recall of names and faces learned in an experimental condition. Cognitive abilities that are represented in current models of face recognition and name recall were also examined. Those abilities included picture naming, verbal fluency (i.e., naming items within a given category), vocabulary comprehension, visual memory, and the learning of unassociated word pairs. Fifty older adults attempted to learn first and last names of 20 student actors and actresses pictured on videotapes (40 names total). On average, participants learned the most first names, followed by last names, and the fewest full names. The greater the number of responses on a questionnaire associated with an imagery cognitive style, the more the names of faces were correctly identified by participants. There was no significant relationship between a verbal cognitive style and the number of names and faces recalled. As for cognitive abilities, all of the abilities measured—with the exception of vocabulary comprehension—were significantly associated with the number of names and faces learned. A regression analysis indicated that the best predictor of successful name-face learning was the participants' ability to learn and recall 5 unrelated word pairs. When that cognitive measure was deleted from the regression analysis, delayed visual memory and verbal fluency were the next best predictors of the older adults' ability to learn names and faces.     

The influence of cognitive styles and strategies in the digit span backwards task: Effects on performance and neuronal activity

The way information is processed in the brain varies strongly between individuals. A prominent distinction is made between visual and verbal processing in everyday-life as well as concrete tasks at hand. To investigate the role of routinely-used cognitive styles and task-specific cognitive strategies, n = 40 participants were presented with the digit span backwards task - which is widely used as a measure of working memory capacity - with acoustically or optically presented stimuli. In a dual task condition, the participants had to remember both an acoustically and an optically presented digit series. The task specific cognitive strategy was predictive for dual task performance, while the habitual cognitive style was not. Also, the preference for a verbal or visual cognitive style was not associated with the task specific strategy, indicating that a visual or verbal strategy can be adapted deliberately in order to perform the task at hand. Functional magnetic resonance imaging showed that a verbal processing style is associated with higher activation in the middle frontal gyrus, which is crucial for working memory performance. The results indicate that a verbal processing style is associated with more effort, possibly due to the adaptation of a task-specific strategy.     

Memory,Print Exposure,and Metacognition: Components of Reading in Chinese Children

This study examined the relative contributions of visual and verbal memory, metacognition about reading, and print exposure to reading comprehension among 100 Chinese fifth graders. The four concurrently measured componential skills were substantially associated with reading comprehension and reliably distinguished between good and poor readers. In a hierarchical regression, after controlling for the effects of verbal intelligence, both verbal and visual memory abilities predicted unique variance in reading comprehension. The distinctness of each memory skill underscores the existence of two unique memory processes in Chinese reading. Future research should examine the longitudinal contributions of these cognitive abilities to reading comprehension.     

Cognitive abilities profiles of Caucasian vs Japanese subjects in the Hawaii Family Study of Cognition

General intelligence (the unrotated first principal component) was partialled out of the cognitive abilities factors—verbal ability, spatial ability, perceptual speed, and visual memory—obtained for the 15 tests of cognitive abilities used in the Hawaii Family Study of Cognition (HFSC). The resulting cognitive abilities profiles indicated that HFSC subjects of Caucasian ancestry scored higher relative to subjects of Japanese ancestry on the verbal and visual memory factors, but lower on the spatial and perceptual speed factors. This ethnic group difference in the shape of the cognitive abilities profiles was found to be highly consistent across sexes and generations, in spite of the large mean differences across these groups in factor scores.     

Increased sensitivity to proactive interference in amnestic mild cognitive impairment is independent of associative and semantic impairment

Episodic memory deficit is the hallmark of amnestic mild cognitive impairment (aMCI). There is, however, an overlap in performance among patients with aMCI and elderly controls (EC). The memory deficit in aMCI therefore needs to be better characterized. Studies have shown that associative memory is selectively impaired in aMCI, and recent work suggested that aMCI may be hypersensitive to semantic proactive interference (PI). It is not known whether this increased PI is related to associative or semantic impairment. EC (n = 44) and patients with aMCI (n = 30) performed two tasks presenting a gradually increasing PI effect across four lists. One task used semantic cueing, the other phonological cueing. We controlled for associative memory by introducing it as a covariate and by matching our subjects for it. Patients with aMCI had a greater PI effect than EC matched for associative memory, regardless of the type of cueing. The increased PI effect in patients with aMCI is independent of their associative and semantic impairment.     

The influence of learning style and cognitive ability on recall of names and faces in an older population

The present study examined whether, for older adults, a verbal or imagery cognitive style is associated with recall of names and faces learned in an experimental condition. Cognitive abilities that are represented in current models of face recognition and name recall were also examined. Those abilities included picture naming, verbal fluency (i.e., naming items within a given category), vocabulary comprehension, visual memory, and the learning of unassociated word pairs. Fifty older adults attempted to learn first and last names of 20 student actors and actresses pictured on videotapes (40 names total). On average, participants learned the most first names, followed by last names, and the fewest full names. The greater the number of responses on a questionnaire associated with an imagery cognitive style, the more the names of faces were correctly identified by participants. There was no significant relationship between a verbal cognitive style and the number of names and faces recalled. As for cognitive abilities, all of the abilities measured--with the exception of vocabulary comprehension--were significantly associated with the number of names and faces learned. A regression analysis indicated that the best predictor of successful name-face learning was the participants' ability to learn and recall 5 unrelated word pairs. When that cognitive measure was deleted from the regression analysis, delayed visual memory and verbal fluency were the next best predictors of the older adults' ability to learn names and faces.     

Sex differences in cognition in healthy elderly individuals

ABSTRACT

Sex differences in patterns of cognitive test performance have been attributed to factors, such as sex hormones or sexual dimorphisms in brain structure, that change with normal aging. The current study examined sex differences in patterns of cognitive test performance in healthy elderly individuals. Cognitive test scores of 957 men and women (age 67–89), matched for overall level of cognitive test performance, age, education, and depression scale score, were compared. Men and women were indistinguishable on tests of auditory divided attention, category fluency, and executive functioning. In contrast, women performed better than men on tests of psychomotor speed and verbal learning and memory, whereas men outperformed women on tests of visuoconstruction and visual perception. Our finding that the pattern of sex differences in cognition observed in young adults is observed in old age has implications for future studies of both healthy elderly individuals and of those with cognitive disorders.     

Neuropsychological and neurophysiological effects of strengthening exercise for early dementia: A pilot study

ABSTRACT

Research demonstrates a positive effect of aerobic exercise on cognitive functioning in older adults. Unfortunately, aerobic exercise is often contraindicated for older adults due to cardiovascular and functional limitations. Low-intensity strengthening exercise may offer a practical alternative, but the neuropsychological benefits and potential neurophysiological mechanisms are less well understood. The current study evaluated the effects of a 10-week strengthening exercise intervention on cognitive functioning and EEG in a sample of 13 older adults with early dementia, and 9 normative controls. Results revealed beneficial effects of strengthening exercise on verbal memory coupled with frontal beta and delta power asymmetries and N200 amplitude asymmetry. Results point to increased cognitive efficiency following 10 weeks of strengthening exercise. The findings suggest it is feasible to conduct a strengthening intervention with early dementia patients, and to gather neuropsychological and neurophysiological data to evaluate outcomes. Strengthening exercise may serve as a useful alternative to aerobic exercise.     

You see, the ends don't justify the means: visual imagery and moral judgment

We conducted three experiments indicating that characteristically deontological judgments-here, disapproving of sacrificing one person for the greater good of others-are preferentially supported by visual imagery. Experiment 1 used two matched working memory tasks-one visual, one verbal-to identify individuals with relatively visual cognitive styles and individuals with relatively verbal cognitive styles. Individuals with more visual cognitive styles made more deontological judgments. Experiment 2 showed that visual interference, relative to verbal interference and no interference, decreases deontological judgment. Experiment 3 indicated that these effects are due to people's tendency to visualize the harmful means (sacrificing one person) more than the beneficial end (saving others). These results suggest a specific role for visual imagery in moral judgment: When people consider sacrificing someone as a means to an end, visual imagery preferentially supports the judgment that the ends do not justify the means. These results suggest an integration of the dual-process theory of moral judgment with construal-level theory.