Variance In Cognitive Performance Research Articles

Cognitive function of Brazilian elderly persons: longitudinal study with non-clinical community sample

Several biopsychosocial changes in individuals' life might happen, resulting in a decline of long-term cognitive abilities. In this way, the aim of this study was to compare cognition in non-clinical older adults in Brazil during a four-year period, as well as to examine which variables may explain cognitive function variations identified during this time. For this purpose, a longitudinal study was developed including 108 older Brazilians in phase I and 64 in phase II, from 2013 to 2017. Socio-demographic variables were assessed and the following instruments were administered: the Mini-Mental State Examination (MMSE), the Wechsler Adult Intelligence Scale (WAIS) - 3rd Edition - Digital Symbol-Coding subtests, the Verbal Fluency Test (animal category), the Rey Auditory-Verbal Learning Test, the Beck Anxiety Inventory (BAI), and the Geriatric Depression Scale 15-item version (GDS-15). In order to compare cognitive variables, the Wilcoxon signed-rank test for repeated measures was used. Temporal comparisons of nominal variables were carried out using McNemar’s chi-square tests for matched pairs. Finally, multiple linear regression and correlation analyses were applied, using the participants’ cognitive performance variation scores (Δ) as dependent variables. Global cognitive function delayed verbal episodic memory, and processing speed experienced a significant decline in four years. Symptoms of anxiety were the main predictor of cognitive performance variations in this sample.

Assessing the Efficacy and Mechanisms of Pycnogenol® on Cognitive Aging From In Vitro Animal and Human Studies.

Brain aging is a complex and multifactorial process broadly involving changes in the brain’s structure, neuronal activity, and biochemical profile. These changes in brain function have also been linked to age-associated variations in cognitive function. Recent research has suggested a role of increased oxidative stress and reduced cognition in older people. Therefore, studies that examine the effects of antioxidants on cognitive performance are important, particularly in the context of an increase in elderly populations in most Western countries. One such antioxidant, Pycnogenol, is a standardized plant-based extract obtained from the bark of the French maritime pine and has a long historical use to treat inflammation and improve health. More recently, Pycnogenol has been subjected to more than 100 research trials. In vitro and animal studies using the standardized extract have indicated a multimodal action of Pycnogenol, and several human studies have shown improvements in cognitive function after chronic administration. In this paper, we review these studies in the context of understanding both biological and cognitive changes due to Pycnogenol and evaluate possibilities of Pycnogenol to improve neurocognitive function.

A Critical Analysis of FDA Guidance for User Percentile Device Design Criteria Versus Currently Available Human Factors Engineering Data Sources and Industry Best Practices

A staggering report was recently released by the International Consortium of Investigative Journalists (ICIJ) indicating that 83,000 deaths and 1.7 million injuries were linked to medical device adverse events reported over the last decade (Diaz-Struck, 2018). Furthermore, a 2013 report by McKinsey & Company suggested that such adverse events and associated quality issues cost the medical device industry between $2.5 billion and $5 billion per year on average (Fuhr, George, & Pai, 2013). There is also indication that some aspects of both medical device human factors engineering (HFE) design and Food and Drug Administration (FDA) HFE validation criteria may not provide proper methodologies for selecting and testing patient populations. This may lead medical devices that pass FDA HFE validation to still exhibit significant use errors when utilized by actual patients in the real world. This paper explores the possible sources of HFE performance problems with medical devices and links potential problems to HFE validation methodologies within the FDA HFE guidance framework. The paper also examines device design teams’ failure to utilize HFE best practices in the design and testing of medical devices. Critical conclusions drawn from this analysis suggest that, currently, medical devices may not be designed and validated according to the full percentile range recommended by FDA guidance and HFE best practice. The analysis also indicates that both the FDA and medical device design teams have failed to understand that designing devices to meet a specific range of user needs includes not only physical attributes, but also a wide range of percentile-based cognitive and physiological HFE performance variables. This problem is potentially causing patients who reside at the extremes of percentile distributions (i.e., those with extreme, but acceptable degrees of functional and/or cognitive limitations) to not be able to use devices successfully, which may significantly impact clinical outcomes. The analysis additionally indicates that such failure to design for proper percentile extremes is related to respondent recruiting methods and, more generally, a lack of awareness regarding HFE theory and best practice. Furthermore, for certain categories of modern medical devices, including drug delivery devices, little to no validated HFE percentile-based device design data exists to facilitate medical device development. These issues are not limited to the design of medical devices, but also apply to the design of secondary components of the device system, including device packaging, labeling and instructions for use. To resolve such issues, the authors propose generation of an HFE medical device design criteria dataset for use by development teams during design and testing. The FDA may also reference the proposed dataset during HFE review and validation.

Attention, memory, and executive functions profile in a prospective cohort of patients with malignant glioma

A prospective cohort study was structured to examine patient’s tumor mass factors that could determine a specific cognitive function profile in patients with Malignant Glioma who survived after the Stupp protocol, while adjusting for previously explored confounding factors. Neuropsi - Attention and Memory (Second edition) was applied after tumor resection, but before any other oncological treatment. Follow-up neuropsychological evaluation was conducted when patients completed the Stupp protocol treatment scheme. To estimate the mean difference between follow-up and baseline Neuropsi subtest scores, a Bayesian Mixed Effects Model was fitted with three random-effect regressors representing tumor locations, co-administered medications and by-patient cognitive performance variability. Sixteen patients were included. Temporal lobe tumors were the most frequent (31.2%) and more than three-fourths of those were located in the left lobe; such results agree with the clinical and statistical significance that supports an impairment in the Semantic Verbal Fluency subtest (Mean score change = −5.97, 95% Credible Interval = [−8.01, −3.80]). The findings suggest that any potential variants in a determined cognitive dysfunction profile could be more influenced by tumor location than any other variable related to the patient’s tumor mass or administered oncological medications; however, because the limited sample representativeness, additional studies are required.

The feasibility of working memory tablet tasks in predicting scholastic skills in classroom settings

SummaryCognitive assessment in natural group settings facilitates data collection but poses threats to the validity. In this study, tablet‐based working memory (WM) tasks, the counting span, and reading span were used in predicting 12‐year‐old children's (N = 837) scholastic skills and fluid intelligence in a classroom with environmental noise. WM tasks had excellent internal consistency, correlated with scholastic skills, and accounted for more of the variance in cognitive performance (grade point average, fluid intelligence, scholastic skills) compared with individually administered (n = 190) digit span task. Furthermore, the multilevel analysis revealed that compared with the classrooms with no noise, when naturally occurring speech or nonspeech types of environmental noises were present during assessment, WM scores or the reliability estimates were not lower. In contrast, when both types of noises were present, the relationships between some of the WM and achievement scores were even stronger. Thus, assessments in natural classroom contexts may promote revealing the individual differences in WM.

Brain Activity For Food Inhibition In Children With Higher Cardiorespiratory Fitness: An Fmri Study

Inhibitory cognitive control in children has been associated with future educational attainment, healthy body composition and eating behavior. Regular practice of aerobic exercise has shown to improve inhibitory cognitive control in children, however the brain areas involved in this cognitive domain, in particular those related to the inhibition of high caloric food, are unclear. PURPOSE: To identify the effects of enhanced cardiorespiratory fitness on brain activity involved in food-specific inhibitory control in children. METHODS: 22 children (10±1.4 years old) participated in this study by completing general anthropometric assessments, a graded shuttle run test to estimate cardiorespiratory fitness (VO2max) and a food-specific cognitive task while acquiring functional magnetic resonance imaging (fMRI) data by a 1.5 T MRI scanner. During the scanner children performed a Go/No-go task. Pictures of objects (neutral) were used as Go stimulus and caloric food and toys pictures as No-go stimulus. The entire protocol consisted in three blocks No-go food, and three No-go toy. Each block contained 50 trials (80% Go stimulus). Children were divided in two groups (Lower fitness x Higher Fitness) separated by the median value of VO2max. Unpaired Student's t-tests were used to compare cognitive performance between groups. Food specific-inhibitory control was assessed comparing which brain areas were more activated during No-Go conditions (Food) between groups by a two sample t-test. RESULTS: No differences were found between groups for the cognitive performance (number of errors) and general anthropometric variables (p>0.05). However, children with higher cardiorespiratory fitness during the food-specific cognitive task had greater activation of areas related to cognition (prefrontal cortex and inferior parietal lobule), motor control (primary motor cortex and primary somatosensory cortex) and homeostatic regulation (insular cortex) (T=2.89; p<0.005). CONCLUSION: Cardiorespiratory fitness might influence the brain activity during inhibition control of high caloric food in children. This finding suggests that regularly performed aerobic exercise by children may promote functional adaptations on the brain that could affect future eating behaviors.

Covariation of intraindividual variability in cognitive speed and cognitive performance across young, middle, and older adulthood.

Intraindividual variability (IIV) in cognitive speed, or moment-to-moment changes in ability, is a developmental phenomenon indicative of neurological integrity that increases gradually across adulthood. Past research has shown that IIV negatively covaries with cognitive performance, in which higher IIV at one occasion is associated with poorer cognitive ability at the same occasion. However, this association has been demonstrated only in older adulthood. Further, all past examinations of IIV change with cognitive change did not remove the average or between-person effect from within-person change in IIV. Using the PATH Through Life Study, we evaluated whether there were differences across 3 age cohorts (20-24, 40-44, and 60-64 years at baseline) in the relationship between 8-year change in IIV and change in cognitive ability (N = 7,485). Change in IIV was partitioned into between-person and within-person components, and multilevel models covarying for education, sex, diabetes, hypertension, and anxiety and depressive symptoms were conducted. IIV was negatively related to baseline cognitive performance at the between-person level. Notably, this relation was apparent and, in fact, strongest for those in young adulthood. Level of IIV was also negatively associated with cognitive change, but primarily for the youngest cohort. In contrast to previous research, there was minimal evidence of significant covariation in which within-person changes in IIV were associated with changes in cognitive performance, regardless of age group. Overall, IIV is a stable characteristic negatively associated with cognition in adulthood, but this link may primarily exist at the between-person level. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Cognitive Profiling Related to Cerebral Amyloid Beta Burden Using Machine Learning Approaches.

Background: Cerebral amyloid beta (Aβ) is a hallmark of Alzheimer’s disease (AD). Aβ can be detected in vivo with amyloid imaging or cerebrospinal fluid assessments. However, these technologies can be both expensive and invasive, and their accessibility is limited in many clinical settings. Hence the current study aims to identify multivariate cost-efficient markers for Aβ positivity among non-demented individuals using machine learning (ML) approaches.Methods: The relationship between cost-efficient candidate markers and Aβ status was examined by analyzing 762 participants from the Alzheimer’s Disease Neuroimaging Initiative-2 cohort at baseline visit (286 cognitively normal, 332 with mild cognitive impairment, and 144 with AD; mean age 73.2 years, range 55–90). Demographic variables (age, gender, education, and APOE status) and neuropsychological test scores were used as predictors in an ML algorithm. Cerebral Aβ burden and Aβ positivity were measured using 18F-florbetapir positron emission tomography images. The adaptive least absolute shrinkage and selection operator (LASSO) ML algorithm was implemented to identify cognitive performance and demographic variables and distinguish individuals from the population at high risk for cerebral Aβ burden. For generalizability, results were further checked by randomly dividing the data into training sets and test sets and checking predictive performances by 10-fold cross-validation.Results: Out of neuropsychological predictors, visuospatial ability and episodic memory test results were consistently significant predictors for Aβ positivity across subgroups with demographic variables and other cognitive measures considered. The adaptive LASSO model using out-of-sample classification could distinguish abnormal levels of Aβ. The area under the curve of the receiver operating characteristic curve was 0.754 in the mild change group, 0.803 in the moderate change group, and 0.864 in the severe change group, respectively.Conclusion: Our results showed that the cost-efficient neuropsychological model with demographics could predict Aβ positivity, suggesting a potential surrogate method for detecting Aβ deposition non-invasively with clinical utility. More specifically, it could be a very brief screening tool in various settings to recruit participants with potential biomarker evidence of AD brain pathology. These identified individuals would be valuable participants in secondary prevention trials aimed at detecting an anti-amyloid drug effect in the non-demented population.

Alzheimer's Environmental and Genetic Risk Scores are Differentially Associated With General Cognitive Ability and Dementia Severity.

We investigated the association of the Australian National University Alzheimer's Disease Risk Index (ANU-ADRI) and an Alzheimer disease (AD) genetic risk score (GRS) with cognitive performance. The ANU-ADRI (composed of 12 risk factors for AD) and GRS (composed of 25 AD risk loci) were computed in 1061 community-dwelling older adults. Participants were assessed on 11 cognitive tests and activities of daily living. Structural equation modeling was used to evaluate the association of the ANU-ADRI and GRS with: (1) general cognitive ability (g), (2) dementia-related variance in cognitive performance (δ), and (3) verbal ability (VA), episodic memory (EM), executive function (EF), and processing speed (PS). A worse ANU-ADRI score was associated with poorer performance in "g" [β (SE)=-0.40 (0.02), P<0.001], δ [-0.40 (0.04), P<0.001], and each cognitive domain [VA=-0.29 (0.04), P<0.001; EM=-0.34 (0.03), P<0.001; EF=-0.38 (0.03), P<0.001; and PS=-0.40 (0.03), P<0.001]. A worse GRS was associated with poorer performance in δ [-0.08 (0.03), P=0.041] and EM [-0.10 (0.03), P=0.035]. The ANU-ADRI was broadly associated with worse cognitive performance, including general ability and dementia severity, validating its further use in early dementia risk assessment.

Cortical Thickness and Cognitive Performance After Out-of-Hospital Cardiac Arrest

Background. Cognitive impairment is common in long-term survivors of out-of-hospital cardiac arrest (OHCA) but corresponding neuroimaging data are lacking. Objectives. This study explored the relationship among the cortical brain structure, cognitive performance, and clinical variables after OHCA. Methods. Three months after resuscitation, 13 OHCA survivors who had recovered from a coma to living independently and 19 healthy controls were assessed by cerebral magnetic resonance imaging and neuropsychological tests quantifying memory, fine-motor coordination, and attention/executive functions. Cortical thickness (Cth) and surface area (SA) were compared between groups and analyzed for relationships with cognitive performance as well as the clinical variables of coma duration and the time to return of spontaneous circulation (ROSC). All analyses were controlled for age and sex. Results. Analyses of SA revealed no significant differences. Compared with controls, survivors had significantly reduced memory and fine-motor coordination and significantly thinner cortex in large clusters in the frontal, parietal, and inferior temporal cortices, with additional regions in the left occipital lobe and the left temporal lobe. Widespread thinner cortical regions were significantly associated with decreased memory performance in survivors when compared with those in controls and were significantly associated with an increased time to ROSC and increased coma duration in the OHCA group. Increased coma duration, but not increased time to ROSC, was significantly correlated with cognitive test performance. Conclusions. The results suggest that widespread Cth reductions correspond to the cognitive impairments observed after OHCA. Neuroimaging studies of long-term OHCA survivors are warranted to guide the development of diagnostics and treatment options.

Differences in cognitive performance and cognitive decline across European regions: a population-based prospective cohort study

BackgroundA large variation in cognitive performance exists between European regions. However, it is unclear how older Europeans differ in the rate of cognitive decline. MethodsWe analysed data from 22 181 individuals (54% women; median age 71) who participated in the Survey on Health, Ageing and Retirement in Europe. Cognition was measured using tests on verbal fluency, immediate and delayed recall. We used linear regression and linear mixed effects regression to examine regional differences in the level of cognitive performance and the rate of cognitive decline. ResultsScandinavians had the highest baseline cognitive scores (mean standardized overall cognitive score 0.3), followed by Western Europeans (mean 0.2), Central and Eastern Europeans (mean 0.1) and individuals from Mediterranean countries (mean -0.4). These differences persisted even after adjustment for sociodemographic and clinical characteristics. The annual cognitive decline in Scandinavia (0.59%) was approximately two times greater than in Western Europe (0.28%), Central and Eastern Europe (0.25%) and Mediterranean countries (0.23%). DiscussionThere are substantial differences in cognitive performance as well as rates of cognitive decline among the elderly throughout European regions. This might be explained by differing levels of cognitive reserve.

Spatial cognitive performance is linked to thigmotaxis in field crickets

Information is acquired through cognitive processes and is essential for enhanced fitness in many animal species. However, little is known about intraspecific variation in cognitive performance, or about phenotypic correlates of this variation, especially in invertebrates. Here we quantified individual variation in spatial learning, exploration, boldness and thigmotaxis (wall hugging) in female Texas field crickets, Gryllus texensis. We trained females to locate a food reward (dish baited with food) located in one arm of a radial arm maze, followed by a cognitive test (probe) trial where no food reward was present. Our results suggest that female crickets could learn and remember the food location, as latency to find the reward dish, distance travelled, number of complete arm entries and number of errors made prior to finding the reward dish all declined with training trials and during the cognitive test trial. Furthermore, females performed equally well on all cognitive measures during the cognitive test trial and the last training trial, suggesting they did not rely on olfactory cues to locate the correct dish during the cognitive test trial. Individual variation in cognitive measures during the test trial were significantly negatively correlated with thigmotaxis during the trial, but were not correlated with body size, latency to leave the novel maze's acclimation zone or the percentage of the novel maze explored during initial exploration of the maze. Our findings suggest individuals with reduced thigmotaxis either (1) are better at learning a spatial task and/or (2) rely more heavily on vision than olfaction. These results contribute to the growing literature examining links between personality and cognition, and highlight the importance of quantifying correlated aspects of the phenotype when assessing individual variation in cognitive performance in a cognitive test.

COGNITIVE VARIABILITY AND BRAIN AGING IN LATE-LIFE DEPRESSION

Introduction Dispersion across cognitive test scores, a measure of variability in cognitive performance, may be an indication of pathological aging. The aim of the current study was to investigate the association of test dispersion with structural brain variables and cognitive decline in non-demented older adults with major depression (MD) and healthy controls (HC). We hypothesized that those with greater dispersion would have lower hippocampal volumes (HPC) and higher white matter hypointensities (WMH) and that dispersion would predict cognitive decline at one-year follow-up. Methods Subjects included 121 MD and 39 HC subjects who participated in the NBOLD study at UConn Health. Inclusion criteria were age 60+ and a psychiatrist's diagnosis of MD for the patient group. Dementia and other major neuropsychiatric illnesses were exclusion criteria. Dispersion was calculated as the standard deviation of z-scores divided by group mean z-scores of a demographically adjusted neuropsychological test performance across a comprehensive battery. Results Dispersion positively correlated with WMH in both HC (r=0.386; p =.001) and MD (r=0.318; p=0.001), and negatively correlated with left HPC volume in MD (r=-0.191; p=0.034). Linear regression analyses accounting for baseline cognitive performance, demographics, and depression found that dispersion predicted cognitive tasks performed at a year follow up. For older adults with MD word list (WL) 1-3 (p=.038), WL delayed recall (DR) (p=.020) and symbol digit modality test (SDMT) (p=.035) were predictors. For HC dispersion was predicted for logical memory (LM) DR (p=.004) and Benton test (p=.003). Conclusions Dispersion is correlated with evidence of brain aging in older adults with MD. Future studies may look at ways to reduce dispersion in older adults and help prevent cognitive decline. This research was funded by Research reported in this poster was supported by the National Institute of General Medical Sciences of the National Institutes of Health under linked Award Numbers RL5GM118969, TL4GM118971, and UL1GM118970. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Educational and research grant from the Leo and Anne Albert Charitable Trust.

Understanding cognitive functioning in glioma patients: The relevance of IDH-mutation status and functional connectivity.

IntroductionCognitive deficits occur frequently in diffuse glioma patients, but are limitedly understood. An important marker for survival in these patients is isocitrate dehydrogenase (IDH) mutation (IDH‐mut). Patients with IDH‐mut glioma have a better prognosis but more often suffer from epilepsy than patients with IDH‐wildtype (IDH‐wt) glioma, who are generally older and more often have cognitive deficits. We investigated whether global brain functional connectivity differs between patients with IDH‐mut and IDH‐wt glioma, and whether this measure reflects variations in cognitive functioning in these subpopulations beyond the associated differences in age and presence of epilepsy.MethodsWe recorded magnetoencephalography and tested cognitive functioning in 54 diffuse glioma patients (31 IDH‐mut, 23 IDH‐wt). Global functional connectivity between 78 atlas regions spanning the entire cortex was calculated in two frequency bands (theta and alpha). Group differences in global functional connectivity were tested, as was their association with cognitive functioning, controlling for age, education, and presence of epilepsy.ResultsPatients with IDH‐wt glioma had lower functional connectivity in the alpha band than patients with IDH‐mut glioma (p = 0.040, corrected for age and presence of epilepsy). Lower alpha band functional connectivity was associated with poorer cognitive performance (p < 0.034), corrected for age, education, and presence of epilepsy.ConclusionGlobal functional connectivity is lower in patients with IDH‐wt diffuse glioma compared to patients with IDH‐mut diffuse glioma. Moreover, having lower functional alpha connectivity relates to poorer cognitive performance in patients with diffuse glioma, regardless of age, education, and presence of epilepsy.

GRIN2B promoter methylation deficits in early-onset schizophrenia and its association with cognitive function.

We investigated GRIN1 and GRIN2B promoter methylation in first-episode schizophrenia patients compared with siblings and controls, testing for correlations between DNA methylation, cognitive performance and clinical variables. Blood-derived DNA from all groups underwent bisulfite conversion and pyrosequencing to determine methylation at CpG sites within the GRIN1 and GRIN2B promoters and results were compared with the measure of global methylation LINE-1. We found hypomethylation among all CpGs analyzed within GRIN2B promoter in patients and greater LINE-1 methylation in patients and siblings. CpG4 was correlated to a measure of intellectual function. Changes in GRIN2B promoter methylation may represent an environmental influence contributing to glutamatergic dysfunction in psychosis and relate to lower cognitive performance in subjects with first-episode schizophrenia.

Cognitive Fitness to Drive in Huntington's Disease: Assessing the Clinical Utility of DriveSafe DriveAware.

DriveSafe DriveAware (DSDA) has been validated as an off-road screening tool for predicting on-road driving performance in clinical populations, but its utility in people with Huntington's disease (HD) is unknown. Our aim was to evaluate the utility of DSDA in people with HD by demonstrating sensitivity of DSDA scores to HD progression and exploring associations between DSDA performance and cognitive functions that are essential to driving and impaired in people with HD. We administered the iPad application version of DSDA to 26 pre-symptomatic and symptomatic participants with HD. Disease progression was assessed via measures of motor impairment, disease burden and functional capacity. Standardised neuropsychological tests were used to assess cognitive function across several domains including attention, processing speed, planning, and visuoperception. Results underscore the sensitivity of DSDA to HD progression and cognitive impairment; that is, poorer DSDA performance was associated with greater HD severity and poorer cognitive ability across the domains of attention, processing speed, and planning. Nevertheless, we identified a proportion of participants with HD who were predicted to pass on-road testing based on DSDA, but scored in the impaired range on multiple cognitive tests. These participants tended to score closer to the cut-off score used by DSDA to categorise pass/fail outcomes. Our findings demonstrate potential for use of DSDA in the HD population, however, significant variability in cognitive performance among those predicted to 'pass' on-road driving assessment suggests the screening tool requires further development for use with HD drivers.

Precise relative-quantity judgement in the striped field mouse Apodemus agrarius Pallas.

Applying the classical experimental scheme of training animals with food rewards to discriminate between quantities of visual stimuli, we demonstrated that not only can striped field mice Apodemus agrarius discriminate between clearly distinctive quantities such as 5 and 10, but some of these mice also exhibit high accuracy in discriminating between quantities that differ only by one. The latter include both small (such as 2 versus 3) and relatively large (such as 5 versus 6, and 8 versus 9) quantities of elements. This is the first evidence of precise relative-quantity judgement in wild rodents. We found striking individual variation in cognitive performance among striped field mice, which possibly reflects individual cognitive variation in natural populations. We speculate that high accuracy in differentiating large quantities is based on the adaptive ability of wild rodents to capture subtle changes in their environment. We suggest that the striped field mouse may be a powerful model species to develop advanced cognitive tests for comparative studies of numerical competence in animals and for understanding evolutionary roots of quantity processing.

The right kind of smart: emotional intelligence's relationship to cognitive status in community-dwelling older adults.

To examine whether emotional intelligence (EI) is associated with cognitive function (CF) in a sample of community-dwelling, non-demented elderly out-patients. Correlational cross-sectional study. Two memory clinics in an urban community in central Israel. Individuals age 60 and older without dementia, recruited from two memory clinics (N = 151). Health history was obtained from medical charts. All participants underwent tests measuring CF, basic and instrumental function, general mental ability (GMA), EI, and depression. Mean age of the participants was 79 years (SD = 7.00) with 96 females (63.6%). Mean score for Montreal Cognitive Assessment (MoCA) was 21.62 (SD = 3.09) and for EI was 14.08 (SD = 3.30). Linear multiple regression analysis was conducted to examine associations of CF with EI while controlling for gender, age, education, GMA, and Charlson Comorbidity Index (CCI). Age, education, GMA, and CCI were significant correlates of CF and accounted for 31.1% of the variance [F(7,143) = 10.8, p<0.01] in CF. EI was added in the second block and was the factor most strongly associated with CF, explaining an additional 9.1% (a total of 40.2%) of the variance in CF [F(8,142) = 13.2, p<0.01]. This study is the first to show the association between EI and CF in older adults. Future prospective studies are needed to explicate the possibility of EI as a protective factor against cognitive decline.

Cognitive function among older adults: ELSI-Brazil results.

ABSTRACTOBJECTIVE To investigate macroregional variations in cognitive function in a national sample representative of the Brazilian population aged 50 years and older.METHODS Data from the baseline of the Longitudinal Study of Brazilian Elderly (ELSI-Brazil), collected between 2015 and 2016, were used. Memory was measured by means of a 10-word list and executive function, by semantic verbal fluency, based on the naming of animals. Gender, age, education, and rural or urban residence were potentially confoundingRESULTS Among the 9,412 ELSI-Brazil participants, 9,085 were included in the analysis; 53.9% were women and the average age was 63.0 (0.42) years. After adjusting for potential confounding variables, average scores for memory and verbal fluency were lower in the Northeast region and higher in the Midwest and Southeast, respectively. In the South region, higher scores were found for immediate and combined memory. In all regions, older participants and those with lower schooling had worse scores for memory and verbal fluency.CONCLUSIONS There are differences in cognitive function among older adults in the different macroregions, independent of age, gender, schooling, and rural or urban residence.

Going beyond the mean: Intraindividual variability of cognitive performance in prodromal and early neurodegenerative disorders

Objective: Intraindividual variability (IIV), generally defined as short-term variations in behavior, has been proposed as a sign of subtle early impairment in neurodegenerative disorders, presumably associated with the disintegration of neuronal network connectivity. We aim to provide a review of IIV as a sensitive cognitive marker in prodromal neurodegenerative disorders.Method: A narrative review focusing not only on theoretical and methodological definitions, including an overview on the neural correlates of IIV, but mainly on results from population-based and clinical-based studies on the role of IIV as a reliable predictor of mild cognitive impairment (MCI) and conversion to dementia in neurodegenerative disorders, mostly Alzheimer’s and Parkinson’s disease.Results: Most studies focus on MCI and Alzheimer’s disease and demonstrate that IIV is a reliable cognitive marker. IIV is partly more sensitive than mean performance in the prediction of cognitive impairment or progressive deterioration and is independent of socio-demographic variables and disease mediators (e.g., genetic susceptibility). Neuroimaging data, mostly from healthy subjects, suggest a relationship between IIV and dysfunction of the default mode network, presumably mediated by white matter disintegration in frontal and parietal areas.Conclusions: IIV measures may provide valuable information about diagnosis and progression in prodromal stages of neurodegenerative disorders. Thus, further conceptual and methodological clarifications are needed to justify the inclusion of IIV as a sensible cognitive marker in routine clinical neuropsychological assessment.