Patterns of cognitive performance in middle-aged and older adults: A cluster analytic examination

Cognitive decline in speeded abilities, executive function, and memory is believed to typify normal aging. However, there is significant variability in cognitive function with advanced age and some reports of relatively intact cognitive function among a subset of older individuals. The present study consists of a cluster analysis to examine the patterns of cognitive function in middle-aged and older individuals. Analyses revealed 3 clusters of middle-aged adults, including an intact group, persons with poor motor speed, and a group with reduced executive function. Three clusters were also identified for older adults, including a group with poor executive function, persons with reduced speed performance (attention, executive function, motor), and a group with global cognitive decline. No evidence emerged for a cluster of older adults with intact performance in all domains or with isolated memory deficits. Findings generally support the frontal aging hypothesis and may provide important information about healthy cognitive aging.     

Relationship of neuropsychological performance to functional status in nursing home residents and community-dwelling older adults.

OBJECTIVES: The authors examined the association between neuropsychological tests of executive functioning and episodic memory and functional disability in nursing home residents versus community-dwelling older adults. METHODS: The neuropsychological performance of 96 residents from the Jewish Home and Hospital, Bronx, NY and 192 gender- and age-matched older adults from residential communities in the New York metropolitan area was assessed in eight tasks (Word List Recall, Delayed Recall, Recognition, Boston Naming, Verbal Fluency, Trailmaking A and B, and Digit Symbol Substitution). Functional status was derived from the Clinical Dementia Rating scale (CDR) extended activities of daily living scores. Regression analyses were performed to test for differences in cross-sectional age-gradients for cognitive and functional status between nursing home residents and community-dwellers. Furthermore, regression analyses, controlling for age, gender, dementia status, and education, were performed to determine the association between neuropsychological performance and functional status, comparing domains of executive functioning and memory. RESULTS: Community-dwelling older adults showed age-related deficits both in overall cognitive status and functional disability, which were larger in nursing home residents. Executive functioning was associated with functional disability beyond the effects of age, gender, education, dementia status, residential status, overall cognitive status, memory, and cognitive speed. CONCLUSION: Executive functioning is associated with functional deficits in both community-dwelling older adults and nursing home residents. Measures of executive functioning may prove useful in intervention studies aimed at delaying institutionalization.     

Neuropsychological profile in bipolar disorder: a preliminary study of monotherapy lithium-treated euthymic bipolar patients evaluated at a 2-year interval

Objective: To investigate the cognitive impairment of a sample of euthymic bipolar patients treated with lithium monotherapy at baseline in a 2‐year longitudinal study. Method: Fifteen DSM‐IV‐TR bipolar out‐patients and 15 healthy‐matched controls were cognitively assessed twice over a 2‐year follow‐up. All patients underwent lithium monotherapy on the first evaluation, and they were euthymic in both evaluations. Cognitive assessment was performed by means of a neuropsychological test battery tapping into the main cognitive domains (executive function, attention, processing speed, verbal memory and visual memory). Results: Repeated measures multivariate analysis of variance showed that the bipolar disorder group was cognitively impaired in the executive domain, attention and processing speed, and such deficits were maintained over time. Conclusion: Our results showed that executive dysfunction is the main long‐term neuropsychological deficit of bipolar disorder. Also, the persistence of these deficits did not seem to be influenced by any clinical or pharmacological variables.     

Neurofeedback training improves attention and working memory performance

Objectives

The present study aimed to investigate the effectiveness of the frontal-midline theta (fmθ) activity uptraining protocol on attention and working memory performance of older and younger participants.

Methods

Thirty-two participants were recruited. Participants within each age group were randomly assigned to either the neurofeedback training (fmθ uptraining) group or the sham-neurofeedback training group.

Results

There was a significant improvement in orienting scores in the older neurofeedback training group. In addition, there was a significant improvement in conflict scores in both the older and young neurofeedback training groups. However, alerting scores failed to increase. In addition, the fmθ training was found to improve working memory function in the older participants. The results further showed that fmθ training can modulate resting EEG for both neurofeedback groups.

Conclusions

Our study demonstrated that fmθ uptraining improved attention and working memory performance and theta activity in the resting state for normal aging adults. In addition, younger participants also benefited from the present protocol in terms of improving their executive function.

Significance

The current findings contribute to a better understanding of the mechanisms underlying neurofeedback training in cognitive function, and suggest that the fmθ uptraining protocol is an effective intervention program for cognitive aging.     

The association between depressive and cognitive symptoms in amnestic mild cognitive impairment

BACKGROUND: Depressive symptoms are frequently observed in older adults with mild cognitive impairment (MCI). However, little is known regarding the cognitive characteristics of this important subgroup. METHODS: We examined executive functions (controlled inhibition) and verbal episodic memory in 33 healthy older adults (control group), 18 older adults with amnestic MCI plus subclinical depressive symptoms (a-MCI/D+ group), and 26 older adults with amnestic MCI but no depressive symptoms (a-MCI group). RESULTS: Compared to the a-MCI and control groups, patients with a-MCI/D+ showed poor controlled inhibition. Moreover, in verbal episodic memory these patients recalled fewer words than control participants on immediate free, delayed free, and delayed total (free plus cued) recall. Performance on immediate recall suggested a self-retrieval deficit, but delayed performance also revealed the existence of an encoding impairment. In the a-MCI group, participants exhibited normal performance on the executive task, but pervasive memory impairment; the memory deficit concerned free and total recall on both immediate and delayed tasks, suggesting the existence of encoding and self-retrieval disturbances. CONCLUSIONS: This study reveals differences between the pattern of cognitive impairment for a-MCI/D+ and a-MCI subgroups particularly at the level of executive capacities. In terms of memory functioning, the differences between the subgroups were more subtle; more studies are needed in order to better characterize the memory impairment of a-MCI/D+ and a-MCI patients.     

The association between depressive mood and cognitive performance in an elderly general population - the MEMO Study

The aim of this study was to analyse the influence of the severity of depressive symptoms on different domains of cognitive function in the elderly. In a population-based cross-sectional study, 385 participants aged 65-83 years were interviewed with the Center for Epidemiologic Studies Depression Scale (CES-D) and performed a standardized neuropsychological test assessing attention, memory, cognitive speed and motor function. Multivariate linear regression analyses revealed a significant effect of depressive symptoms on a single test (Stroop test 1) and two summary scores (memory and motor function). After full adjustment for education and Mini Mental State Examination, the memory score was partly attenuated. Stratified analysis showed that an increase in CES-D scores led to a larger decline of cognitive test results in participants with mild to moderate depressive symptoms, compared to those with a high degree of depressive symptoms. Our results suggest that depressive mood in older adults is primarily associated with decreased processing speed and motor functioning, but not executive control functions. According to our results depressive mood is not necessarily associated with memory deficits in older adults. Changes in depressive symptoms in milder forms of depressive mood are associated with a larger decline in cognitive function than in severer forms of depressive mood.     

Confirmatory factor analysis of the ADNI neuropsychological battery

The Alzheimer’s Disease Neuroimaging Initiative (ADNI) is a large multi-center study designed to develop optimized methods for acquiring longitudinal neuroimaging, cognitive, and biomarker measures of AD progression in a large cohort of patients with Alzheimer’s disease (AD), patients with Mild Cognitive Impairment, and healthy controls. Detailed neuropsychological testing was conducted on all participants. We examined the factor structure of the ADNI Neuropsychological Battery across older adults with differing levels of clinical AD severity based on the Clinical Dementia Rating Scale (CDR). Confirmatory factor analysis (CFA) of 23 variables from 10 neuropsychological tests resulted in five factors (memory, language, visuospatial functioning, attention, and executive function/processing speed) that were invariant across levels of cognitive impairment. Thus, these five factors can be used as indicators of cognitive function in older adults who are participants in ADNI.     

The influence of aerobic fitness on cerebral white matter integrity and cognitive function in older adults: Results of a one‐year exercise intervention

Cerebral white matter (WM) degeneration occurs with increasing age and is associated with declining cognitive function. Research has shown that cardiorespiratory fitness and exercise are effective as protective, even restorative, agents against cognitive and neurobiological impairments in older adults. In this study, we investigated whether the beneficial impact of aerobic fitness would extend to WM integrity in the context of a one‐year exercise intervention. Further, we examined the pattern of diffusivity changes to better understand the underlying biological mechanisms. Finally, we assessed whether training‐induced changes in WM integrity would be associated with improvements in cognitive performance independent of aerobic fitness gains. Results showed that aerobic fitness training did not affect group‐level change in WM integrity, executive function, or short‐term memory, but that greater aerobic fitness derived from the walking program was associated with greater change in WM integrity in the frontal and temporal lobes, and greater improvement in short‐term memory. Increases in WM integrity, however, were not associated with short‐term memory improvement, independent of fitness improvements. Therefore, while not all findings are consistent with previous research, we provide novel evidence for correlated change in training‐induced aerobic fitness, WM integrity, and cognition among healthy older adults. Hum Brain Mapp 34:2972–2985, 2013. © 2012 Wiley Periodicals, Inc.     

Cognitive functioning in community dwelling older adults with chronic partial epilepsy

PURPOSE: To examine cognitive functioning in community-dwelling older adults with chronic partial epilepsy and demographically matched healthy older adults. METHODS: Standardized measures of neurocognitive function were collected as part of an ongoing study investigating health-related quality-of-life issues in older adults with epilepsy. Cognitive tests consisted of the Mattis Dementia Rating Scale (subscales include attention, initiation/perseveration, construction, conceptualization, memory), Logical Memory subtest from the WMS-III (immediate and delayed recall scores), and word fluency. Mood was measured with the Geriatric Depression Scale. Older adults with epilepsy (n=25) and healthy older adults (n=27) completed testing. All participants were at least 60 years old, living independently in the community, and had no history of drug/alcohol abuse or life-threatening medical conditions. All older adults with epilepsy had been diagnosed as having medically intractable partial complex seizures, including those with histories of secondary generalization. RESULTS: Older adults with epilepsy demonstrated impairments across all cognitive measures compared with the healthy controls. Seizure onset (age) and seizure duration (years) were not statistically associated with neurocognitive function or self-reported mood. Older adults with epilepsy who were receiving antiepileptic drug (AED) polytherapy (n=11) displayed worse performance on the attention, initiation/perseveration, and memory subscales of the DRS and Logical Memory delayed recall score compared with those older adults with epilepsy receiving monotherapy (n=14). The number of AEDs taken was not associated with seizure frequency. CONCLUSIONS: Negative effects on cognitive function are experienced by older adults with chronic partial epilepsy. AED polytherapy may increase the risk for negative cognitive dysfunction.     

Cognitive rehabilitation in multiple sclerosis: a review of the literature

Introduction

Cognitive impairment is now well-known in multiple sclerosis (MS). However, few rehabilitation interventions are proposed or really efficient.

Objectives

To present a review of cognitive rehabilitation intervention research conducted in people with multiple sclerosis (MS), regarding different findings about episodic memory, working memory, attention and executive function disorders in MS.

Data sources

A search of Medline (yield 20 papers) and of PsychInfo (yield 1 article), using combinations of the following terms: cognitive rehabilitation, multiple sclerosis, cognitive therapy, neuropsychological rehabilitation, in the title or in the abstract, from 1960 to March 2010, excluding animal studies.

Results

Episodic memory rehabilitation studies appear to be promising. Programs on working memory, attention and executive functions are in the very early phases.

Conclusions

Results are encouraging and allow specific recommendations for future research about: (1) inclusion criteria, often not defined, (2) a specific baseline adapted to the program of rehabilitation, (3) a control measure regarding program efficiency and (4) a role for the psychologist (presence and advice during the program).     

Understanding heterogeneity in older adults: Latent growth curve modeling of cognitive functioning

Background: Clarifying relationships between specific neurocognitive functions in cognitively intact older adults can improve our understanding of mechanisms involved in cognitive decline, which may allow identification of new opportunities for intervention and earlier detection of those at increased risk of dementia.

Method: The present study employed latent growth curve modeling to longitudinally examine the relationship between executive attention/processing speed, episodic memory, language, and working memory functioning utilizing the neuropsychological test battery from the National Alzheimer’s Disease Coordinating Center. A total of 691 relatively healthy older adults (M_age = 69.07, SD = 6.49) were assessed at baseline, and 553 individuals completed three visits spanning a two-year period.

Results: Better cognitive performance was concomitantly associated with better functioning across domains. Subtle declines in executive attention/processing speed processes were found, while, on average, memory and language performance improved with repeated testing. Lower executive attention/processing speed performance at baseline predicted less incremental growth rate in memory. In turn, higher initial memory functioning was associated with incremental improvements in language performance.

Conclusions: These results are consistent with the notion that intact executive function and attention processes are important to preserving memory functioning with advanced age, but are also the functions most susceptible to decline with age. These findings also provide further insight into the critical role of practice effects in clinical assessment practice and have implications for pharmaceutical trials. Practice effects should be routinely considered as they may give the appearance of retention of function within the cognitive domains considered to be a hallmark of Alzheimer’s disease pathology.     

Elaborated spaced-retrieval and prospective memory in mild Alzheimer's disease

Prospective memory, or the timely remembering of a planned action, is conceptualised as a cognitive process demanding episodic memory and executive attention. Impairments in these skills are characteristic of the cognitive decline in early Alzheimer's disease, providing an expectation of prominent prospective memory difficulties in this population, and yet surprisingly, memory performance in early Alzheimer's disease has rarely been evaluated within a prospective memory framework. In a preliminary study we demonstrated that older adults with early Alzheimer's disease (n=14), as compared to healthy older adults (n=14), were significantly impaired in a simple experimental paradigm of prospective remembering (a text-reading task). In a subsequent intervention study, we investigated the efficacy of spaced-retrieval for improving the prospective remembering performance of older adults with early Alzheimer's disease (n=16) compared to healthy older adults (n=16) under two learning conditions: a spaced-retrieval technique alone or spaced-retrieval combined with elaborated encoding of task. The majority of the Alzheimer's disease group (63%) demonstrated benefit in prospective remembering in the combined condition as compared to spaced-retrieval alone. Participants with Alzheimer's disease who demonstrated better executive attention (Trail Making- set-shifting) and/or better retrospective memory (Hopkins Verbal Learning Test-Revised- recognition) were more successful in the combined learning condition.     

Age differences in stroop interference in working memory

Working memory capacity can be conceptualized as the ability to use controlled attention in short term memory (Engle, Tuholski, Laughlin, & Conway, 1999). We tested this idea in young and older adults by combining the task demands of two neuropsychological tests, word span, and Stroop color-naming. Young and older adults were asked to name the colors of a series of congruent and incongruent color-words (between 2 and 6 words/trial). After all the color-words were presented participants attempted to recall the colors in their serial order. This task required inhibition of the prepotent word reading response (i.e., color naming), with a concurrent memory load (caused by the need to maintain already named colors in short-term memory). Older adults showed greater interference effects, and these interference effects increased as a function of memory load. Regression analyses showed that measures of working memory capacity and executive function accounted for unique variance in incongruent color-word errors for older adults. Defining working memory capacity as the ability to use controlled attention in short-term memory may be a fruitful way to think about this concept in studies of executive function.     

Association between tea consumption and cognitive function in cognitively healthy older adults and older adults with mild cognitive impairment

BackgroundProspective studies suggest that tea consumption may decrease the risk for cognitive impairment in late life. However, little research has examined the association between tea consumption and cognitive performance across multiple domains. In addition, no research has examined the benefit of tea consumption on cognitive performance among older adults with existing impairment.AimsThe current study examined the association between tea consumption and performance on tasks of global cognitive function, episodic memory and executive function in cognitively healthy (CH) older adults and older adults with mild cognitive impairment (MCI).MethodsThe analytical sample included 1849 community-dwelling older adults from the Shanghai Brain Aging Study (65.6% female, mean age of 69.50 (8.02) years). Following ascertainment of cognitive function, 816 were categorised as MCI. In addition to completion of a demographics questionnaire, participants reported their tea consumption and completed a battery of tests to measure global cognitive function, episodic memory and working memory.ResultsIndependent analyses of covariance revealed a significant association between tea consumption and measures of episodic memory; however, these associations were restricted to CH older adults but not older adults with MCI. Tea consumption was not associated with working memory performance.ConclusionsThe current study suggests that the benefit of tea consumption is restricted to cognitively healthy older adults and does not extend to older adults with MCI.     

Cognitive performance in suicidal depressed elderly: preliminary report.

OBJECTIVE: Deficits in executive functions may play an important role in late-life suicide; however the association is understudied. This study examined cognitive function in general and executive functioning specifically in depressed elderly with and without suicidal ideation and attempts. DESIGN: Case-control study. Setting: University-affiliated psychiatric hospital. PARTICIPANTS: We compared 32 suicidal depressed participants aged 60 and older with 32 non-suicidal depressed participants equated for age, education, and gender. MEASUREMENTS: We assessed global cognitive function and executive function with the Dementia Rating Scale (DRS) and the Executive Interview (EXIT25), respectively. RESULTS: Suicidal and non-suicidal depressed groups were comparable in terms of severity of depression and burden of physical illness. Suicidal participants performed worse on the EXIT25, and on the DRS total scale, as well as on Memory and Attention subscales. The differences were not explained by the presence of dementia, substance use, medication exposure, or brain injury from suicide attempts. CONCLUSIONS: Poor performance on tests of executive function, attention, and memory is associated with suicidal behavior in late-life depression.     

Longitudinal change in neuropsychological performance using latent growth models: a study of mild cognitive impairment

The goal of the current study was to examine cognitive change in both healthy controls (n?=?229) and individuals with mild cognitive impairment (MCI) (n?=?397) from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). We applied latent growth modeling to examine baseline and longitudinal change over 36 months in five cognitive factors derived from the ADNI neuropsychological test battery (memory, executive function/processing speed, language, attention and visuospatial). At baseline, MCI patients demonstrated lower performance on all of the five cognitive factors when compared to controls. Both controls and MCI patients declined on memory over 36 months; however, the MCI patients declined at a significantly faster rate than controls. The MCI patients also declined over 36 months on the remaining four cognitive factors. In contrast, the controls did not exhibit significant change over 36 months on the non-memory cognitive factors. Within the MCI group, executive function declined faster than memory, while the other factor scores changed slower than memory over time. These findings suggest different patterns of cognitive change in healthy older adults and MCI patients. The findings also suggest that, when compared with memory, executive function declines faster than other cognitive factors in patients with MCI. Thus, decline in non-memory domains may be an important feature for distinguishing healthy older adults and persons with MCI.     

Associations Between the Prevalence,Treatment, Control of Hypertension and Cognitive Trajectories Among Chinese Middle-Aged and Older Adults

ObjectiveTo investigate the associations between the prevalence, treatment, control of hypertension, and trajectories of cognitive performance among Chinese middle-aged and older adults.DesignAn 8-year longitudinal study.SettingChina.ParticipantsChinese middle-aged and older adults.MeasurementsData from the China Health and Retirement Longitudinal Study were utilized. Group-based trajectory modeling was performed to identify heterogeneous trajectories of episodic memory and executive function. Multinomial logistic regression models were established to examine the relationships between hypertension status and cognitive trajectories, stratified by sex.ResultsThree episodic memory trajectories and four executive function trajectories were identified in males and females. Hypertension prevalence was associated with worse episodic memory and executive function trajectories in females. Compared with treated hypertensives, untreated hypertensives were more likely to have worse executive function trajectories, both in males and females. Among male treated hypertensives, those with uncontrolled blood pressure (BP) had worse episodic memory trajectories compared with their counterparts with controlled at standard targets, while females with uncontrolled BP demonstrated worse executive function trajectories compared with females controlled at standard targets. There was basically no significant difference in cognitive trajectory memberships between individuals with controlled hypertension corresponding to intensive or standard BP targets.ConclusionsThe prevalence of hypertension was associated with worse cognitive trajectories, and the treatment and control of hypertension were related to more favorable cognitive trajectories. Intensive BP control target was not associated with additional benefit beyond the recognized protective effect of standard BP targets on cognitive trajectories.