Occupational activity and cognitive reserve: implications in terms of prevention of cognitive aging and Alzheimer's disease

Mindset matters: contributions from grit and growth mindsets to successful aging

OBJECTIVE

Though we all age, some age more successfully than others. Health and social connections have been identified as cornerstones to successful aging, yet the contributions from psychological factors are less clear. Our goal was to examine the influence of grit and growth mindset in successful aging in middle and older age. We also assessed whether grit or growth mindset mediated the lifestyle-successful aging relationship.

METHOD

We used a telephone questionnaire to measure grit and growth mindset, successful aging, and lifestyle for 263 adults, ages 40-80 years.

RESULTS

Higher grit-effort and growth mindset predicted more successful aging in younger (40-64 years) and older groups (65-80 years). Additionally, exercise frequency predicted successful aging for the combined sample and partially mediated the relationship between growth mindset and successful aging.

CONCLUSIONS

Our findings reveal grit-effort and a growth mindset as important contributors to successful aging in middle and older adulthood. Because psychological constructs are malleable, continued study of grit and growth mindsets is essential to enable their eventual application in changing the aging process.

Associations of multilingualism and language proficiency with cognitive functioning: epidemiological evidence from the SwissDEM study in community dwelling older adults and long-term care residents

BACKGROUND

We explored whether number of languages spoken and language proficiency are associated with cognitive performance among older adults living in the community and in long-term care (LTC) in Switzerland.

METHODS

Among study participants, 664 lived in the community in the Canton of Zurich (Mean age = 72.97 years; SD = 6.08), 386 lived in the community in Ticino (Mean age = 76.24 years; SD = 6.66), and 176 resided in LTC in Ticino (Mean age = 87.61 years; SD = 6.45). We recorded sociodemographic variables, number of languages spoken, language proficiency, and assessed overall cognitive performance, immediate and delayed memory, and verbal fluency with standardized tests. We used adjusted regression models.

RESULTS

A higher number of spoken languages was positively associated with overall cognitive performance, verbal fluency and immediate and delayed memory performance in community-dwelling older adults in the Cantons of Ticino and Zurich, (all p values ≤ 0.012;), but not in in older adults living in LTC homes (all p values ≥ 0.35). Higher language proficiency was associated with better memory performance among individuals living in the community in Ticino (p value = 0.003), and to better performance in verbal fluency and memory tasks in Zurich (p values ≤ 0.002). Among LTC residents, proficiency levels were not associated with cognitive performance.

CONCLUSIONS

Multilingualism and greater language proficiency were associated with better cognitive functioning in community-dwelling but not in institutionalized older adults. Multilingualism may contribute to cognitive reserve, as well as protect and delay cognitive decline in late life.

Cognitive decline monitoring through a web-based application

Cognitive decline usually begins after individuals reach maturity, which is more evident in late adulthood. Rapid and constant cognitive screenings allow early detection of cognitive decline and motivate individuals to participate in prevention interventions. Due to accelerated technological advances, cognitive screening and training are now available to the layperson using electronic devices connected to the internet. Large datasets generated by these platforms provide a unique opportunity to explore cognitive development throughout life and across multiple naturalistic environments. However, such data collection mechanisms must be validated. This study aimed to determine whether the data gathered by commercial visuospatial and phonological working memory tests (CogniFit Inc., San Francisco, USA) confirm the well-established argument that age predicts cognitive decline. Data from 3,212 participants (2,238 females) who were 45 years old or older were analyzed. A linear regression analysis explored the relationship between age and working memory while controlling for gender, sleep quality, and physical activity (variables that are known to affect working memory). We found that age negatively predicts working memory. Furthermore, there was an interaction between age and gender for visuospatial working memory, indicating that although male participants significantly outperformed females, the relationship between age and working memory differs for females and males. Our results suggest that the computerized assessment of visuospatial and phonological working memory is sensible enough to predict cognitive functions in aging. Suggestions for improving the sensitivity of self-reports are discussed. Further studies must explore the nature of gender effects on cognitive aging.

Design and Harmonization Approach for the Multi-Institutional Neurocognitive Discovery Study (MINDS) of Adult Congenital Heart Disease (ACHD) Neuroimaging Ancillary Study: A Technical Note

Dramatic advances in the management of congenital heart disease (CHD) have improved survival to adulthood from less than 10% in the 1960s to over 90% in the current era, such that adult CHD (ACHD) patients now outnumber their pediatric counterparts. ACHD patients demonstrate domain-specific neurocognitive deficits associated with reduced quality of life that include deficits in educational attainment and social interaction. Our hypothesis is that ACHD patients exhibit vascular brain injury and structural/physiological brain alterations that are predictive of specific neurocognitive deficits modified by behavioral and environmental enrichment proxies of cognitive reserve (e.g., level of education and lifestyle/social habits). This technical note describes an ancillary study to the National Heart, Lung, and Blood Institute (NHLBI)-funded Pediatric Heart Network (PHN) "Multi-Institutional Neurocognitive Discovery Study (MINDS) in Adult Congenital Heart Disease (ACHD)". Leveraging clinical, neuropsychological, and biospecimen data from the parent study, our study will provide structural-physiological correlates of neurocognitive outcomes, representing the first multi-center neuroimaging initiative to be performed in ACHD patients. Limitations of the study include recruitment challenges inherent to an ancillary study, implantable cardiac devices, and harmonization of neuroimaging biomarkers. Results from this research will help shape the care of ACHD patients and further our understanding of the interplay between brain injury and cognitive reserve.

Predicting phenotypes of elderly from resting state fMRI

Machine learning techniques are increasingly embraced in neuroimaging studies of healthy and diseased human brains. They have been used successfully in predicting phenotypes, or even clinical outcomes, and in turning functional connectome metrics into phenotype biomarkers of both healthy individuals and patients. In this study, we used functional connectivity characteristics based on resting state functional magnetic resonance imaging data to accurately classify healthy elderly in terms of their phenotype status. Additionally, as the functional connections that contribute to the classification can be identified, we can draw inferences about the network that is predictive of the investigated phenotypes. Our proposed pipeline for phenotype classification can be expanded to other phenotypes (cognitive, psychological, clinical) and possibly be used to shed light on the modifiable risk and protective factors in normative and pathological brain aging.

Determining impairment in the Swedish, Polish and German ECAS: the importance of adjusting for age and education

Objective: Age and years of education are strong predictors of cognitive performance in several versions of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) and cutoffs for the Swedish and Polish versions are not established yet. Here we evaluated the performance of healthy subjects on the national versions of the Swedish and Polish ECAS and compared cognitive performance on three European translations of the ECAS. Methods: The ECAS performances of healthy subjects from Sweden (n = 111), Poland (n = 124) and Germany (n = 86) were compared. Based on the test results on the national versions of ECAS, age- and education-adjusted cutoffs were compared for the German, Swedish and Polish versions, respectively. Results: Age and years of education correlated with performance in the ECAS. Swedish subjects under the age of 60 years and Swedish subjects with low education level scored significantly higher in memory than the respective German and Polish subgroups. German and Polish subjects over 60 years of age performed significantly better in language than the respective Swedish subgroup. The Polish cohort in total had lower executive scores compared to the Swedish cohort, and lower than the German subjects in the higher education subgroup. Conclusions: The results highlight the importance of establishing age- and education-adjusted ECAS cutoffs not only in general, but also for seemingly similar populations of different origins. The results should be taken into account when comparing cognition data across patient populations including in drug trials where an ECAS test result is being used as an inclusion criterium or outcome measure.

Cognitive reserve and individual differences in brain tumour patients

The aim of the paper is to determine the effects of the cognitive reserve on brain tumour patients' cognitive functions and, specifically, if cognitive reserve helps patients cope with the negative effects of brain tumours on their cognitive functions. We retrospectively studied a large sample of around 700 patients, diagnosed with a brain tumour. Each received an MRI brain examination and performed a battery of tests measuring their cognitive abilities before they underwent neurosurgery. To account for the complexity of cognitive reserve, we construct our cognitive reserve proxy by combining three predictors of patients' cognitive performance, namely, patients' education, occupation, and the environment where they live. Our statistical analysis controls for the type, side, site, and size of the lesion, for fluid intelligence quotient, and for age and gender, in order to tease out the effect of cognitive reserve on each of these tests. Clinical neurological variables have the expected effects on cognitive functions. We find a robust positive effect of cognitive reserve on patients' cognitive performance. Moreover, we find that cognitive reserve modulates the effects of the volume of the lesion: the additional negative impact of an increase in the tumour size on patients' performance is less severe for patients with higher cognitive reserve. We also find substantial differences in these effects depending on the cerebral hemisphere where the lesion occurred and on the cognitive function considered. For several of these functions, the positive effect of cognitive reserve is stronger for patients with lesions in the left hemisphere than for patients whose lesions are in the right hemisphere. The development of prevention strategies and personalized rehabilitation interventions will benefit from our contribution to understanding the role of cognitive reserve, in addition to that of neurological variables, as one of the factors determining the patients' individual differences in cognitive performance caused by brain tumours.

Racial Differences in Employment and Poverty Histories and Health in Older Age

INTRODUCTION

Black Americans encounter more barriers in the job market and earn less than White Americans. However, the extent to which racial disparities in employment and poverty histories impact health is not fully understood. This study characterized employment‒poverty histories for Black and White middle-aged adults and examined their association with health.

METHODS

Respondents born in 1948-1953 and enrolled in the 2004 Health and Retirement Study (N_Black=555, N_White=2,209) were included. Sequence analysis grouped respondents with similar employment‒poverty trajectories from 2004 to 2016, and confounder-adjusted regression analyses estimated the associations between these trajectories and health in 2018. Analyses were conducted in 2021-2022.

RESULTS

More than 23% of Black respondents experienced both employment and poverty fluctuations, including bouts of extreme poverty (<50% of the federal poverty threshold), whereas no trajectory for White respondents included extreme poverty. Adversities in employment‒poverty were associated with worse health. For example, among Black respondents, those who experienced both employment and poverty fluctuations had worse cognition than those employed and not poor (β= -0.55 standardized units, 95% CI= -0.81, -0.30). Similarly, among White respondents, those who experienced employment fluctuations had worse cognition than those employed (β= -0.35, 95% CI= -0.46, -0.24). Notably, the employed and not poor trajectory was associated with worse survival among Black respondents than among White respondents.

CONCLUSIONS

Employment fluctuations were associated with worse health, especially cognitive function, where the association was stronger among Black Americans who experienced both employment fluctuations and poverty. Findings highlight the importance of enhancing employment stability and of antipoverty programs, especially for Black Americans.

Socioeconomic and Contextual Differentials in Memory Decline: A Cross-Country Investigation Between England and China

OBJECTIVES

Although cognitive functioning is strongly associated with biological changes in the brain during the aging process, very little is known about the role of sociocultural differentials between the western and eastern parts of the world. We examined the associations between individual socioeconomic markers (e.g., education, household wealth) and contextual levels characteristics (e.g., urbanicity) with memory performance and memory decline over up to 8 years of follow-up in England and China.

METHODS

The analytical samples included participants aged 50+ from the English Longitudinal Study of Aging (n = 6,687) and the China Health and Retirement Longitudinal Study (n = 10,252). Mixed linear models were employed to examine the association between baseline individual socioeconomic markers (education, wealth) and contextual-level characteristics (urbanicity) on the change in memory over time.

RESULTS

Our analyses showed that higher education and wealth were associated with better baseline memory in both England and China. Still, the impact of contextual-level characteristics such as urbanicity differed between the 2 countries. For English individuals, living in a rural area showed an advantage in memory, while the opposite pattern was observed in China. Memory decline appeared to be socioeconomically patterned by higher education, wealth, and urbanicity in China but not in England.

DISCUSSION

Our findings highlight substantial socioeconomic and contextual inequity in memory performance in both England and China, as well as in the rate of memory decline primarily in China. Public health strategies for preventing memory decline should target the socioeconomic gaps at the individual and contextual levels to protect those particularly disadvantaged.

Education reduces cognitive dysfunction in Alzheimer's disease by changing regional cerebral perfusion: An in-vivo arterial spin labeling study

OBJECTIVE

Formal education and other cognitive challenges influence brain structure and improve function. It is believed that cognitive activities create a cognitive reserve (CR) that can slow the decline due to aging and neurodegenerative diseases. This study investigated alterations of regional cerebral blood flow (rCBF) associated with high and low CR in different stages of Alzheimer's disease (AD) and examined whether rCBF alteration mediates the relationship between education and cognitive performance.

METHODS

Patients with AD or amnestic mild cognitive impairment (aMCI) and healthy controls were divided into low cognitive reserve (LCR) and high cognitive reserve (HCR) subgroups according to median of education years (≤ 9 vs. > 9 years). The final study population included 89 AD patients (67 LCR, 22 HCR), 74 aMCI patients (44 LCR, 30 HCR), and 66 healthy controls (29 LCR, 37 HCR). All subjects were examined by arterial spin labeling magnetic resonance imaging and a neurocognitive test battery. rCBF was compared among groups by two-way analysis of variance. Mediation analyses were used to explore the relationships among education, rCBF, and cognitive test scores.

RESULTS

There were significant interaction effects of disease state (AD, aMCI, HC) and education level (LCR, HCR) on CBF in right hippocampus, posterior cingulate cortex, and right inferior parietal cortex (R_IPC). Education regulated episodic memory score by influencing right hippocampal CBF in HC_HCR and aMCI_HCR subgroups.

CONCLUSION

Our results indicate that the protective effect of education against cognitive dysfunction in early-stage AD is mediated at least partially by altered CBF in right hippocampus.

Mediation effects of cognitive, physical, and motivational reserves on cognitive performance in older people

Introduction

We study from a multidimensional perspective the different factors that help prevent the development of cognitive impairment in old aging.

Methods

This study analyzed in 300 elderly subjects the relationship between cognitive reserve (CR), physical reserve (PR) and motivational reserve (MR) with cognitive impairment. This study also takes into consideration different variables (sex, age, educational level, and institutionalization) that might affect the results in the different types of reserves (CR, physical and MR) and cognitive impairment.

Results

The results show that people with a higher cognitive reserve, physical reserve and motivational reserve have less cognitive impairment.

Discussion

Therefore, it is important to consider measuring the CR as a variable to diagnose neurodegenerative illnesses but it is also essential to consider the physical state and physical activity, as well as the motivational dimension. With the cognitive reserve and sex variables no significant differences were observed. Age had a negative effect on strategic flexibility, but those with higher CR had better cognitive flexibility and the educational.

Network analysis of the associations between personality traits, cognitive functioning, and inflammatory markers in elderly individuals without dementia

Introduction

Lower cognitive functioning in old age has been associated with personality traits or systemic inflammatory markers. Associations have also been found between personality traits and inflammatory markers. However, no study has explored the inter-relationships between these three components simultaneously. The present study aims to better understand the inter-relationships among personality traits, inflammatory markers, and cognitive performance in elderly individuals without dementia.

Methods

This study utilizes a network analysis approach, a statistical method that allows visualization of the data's unique pairwise associations. We performed a cross-sectional analysis on 720 elderly individuals without dementia, using data from Colaus|PsyColaus, a population-based study conducted in Lausanne, Switzerland. The Revised NEO Five-Factor Inventory (NEO-FFI-R) was used to assess personality traits, and interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) were used as peripheral inflammatory markers. Cognitive domains were investigated using the Mini-Mental State Examination (MMSE), the Verbal Fluency Test, the Stroop Test, the DO40, and the Free and Cued Selective Reminding (FCSR) test.

Results

Openness was associated with verbal fluency and Agreeableness with immediate free recall. In contrast, no association between inflammatory markers and personality traits or cognition was identified.

Discussion

In elderly individuals without dementia, a high level of Openness or Agreeableness was associated with executive functioning/semantic memory and episodic memory, respectively.

Twenty-four-hour time-use composition and cognitive function in older adults: Cross-sectional findings of the ACTIVate study

Introduction

Physical activity, sedentary behaviour and sleep are associated with cognitive function in older adults. However, these behaviours are not independent, but instead make up exclusive and exhaustive components of the 24-h day. Few studies have investigated associations between 24-h time-use composition and cognitive function in older adults. Of these, none have considered how the quality of sleep, or the context of physical activity and sedentary behaviour may impact these relationships. This study aims to understand how 24-h time-use composition is associated with cognitive function across a range of domains in healthy older adults, and whether the level of recreational physical activity, amount of television (TV) watching, or the quality of sleep impact these potential associations.

Methods

384 healthy older adults (age 65.5 ± 3.0 years, 68% female, 63% non-smokers, mean education = 16.5 ± 3.2 years) participated in this study across two Australian sites (Adelaide, n = 207; Newcastle, n = 177). Twenty-four-hour time-use composition was captured using triaxial accelerometry, measured continuously across 7 days. Total time spent watching TV per day was used to capture the context of sedentary behaviours, whilst total time spent in recreational physical activity was used to capture the context of physical activity (i.e., recreational accumulation of physical activity vs. other contexts). Sleep quality was measured using a single item extracted from the Pittsburgh Sleep Quality Index. Cognitive function was measured using a global cognition index (Addenbrooke's Cognitive Examination III) and four cognitive domain composite scores (derived from five tests of the Cambridge Neuropsychological Test Automated Battery: Paired Associates Learning; One Touch Stockings of Cambridge; Multitasking; Reaction Time; Verbal Recognition Memory). Pairwise correlations were used to describe independent relationships between time use variables and cognitive outcomes. Then, compositional data analysis regression methods were used to quantify associations between cognition and 24-h time-use composition.

Results

After adjusting for covariates and false discovery rate there were no significant associations between time-use composition and global cognition, long-term memory, short-term memory, executive function, or processing speed outcomes, and no significant interactions between TV watching time, recreational physical activity engagement or sleep quality and time-use composition for any cognitive outcomes.

Discussion

The findings highlight the importance of considering all activities across the 24-h day against cognitive function in older adults. Future studies should consider investigating these relationships longitudinally to uncover temporal effects.

The effect of different types of physical activity on cognitive reaction time in older adults in China

Introduction

Aging is not only reflected in the degeneration of physiological functions but is also embodied in the decline of psychological and cognitive functions. The decline of cognitive function can reduce the quality of life in older adults, and even potentially cause Alzheimer's disease, which may lead to a heavy burden on patients, families, and society. The purpose of this study was to investigate the effects of physical activity (PA) on cognitive reaction time in older adults.

Methods

A cross-sectional survey design was used in this study. A total of 839 elderly subjects were recruited from Beijing and Shanghai. In total, 792 subjects met the inclusion criteria (age > 60 years, without disability, speech, and hearing impairment), including 384 men (age:67.7 ± 5.7 years) and 408 women (age: 68.2 ± 5.8 years). The PA was assessed by the Physical Activity Scale for the Elderly (PASE). All kinds of PA were divided into three levels: "Low" (< 50% average score), "Moderate" (50-150% average score), and "High" (>150% average score). The reaction time of subjects was measured by the selective reaction tester (Model: CSTF-XF, TFHT, Beijing, China).

Results

For leisure-time PA, the results showed that the cognitive reaction time of older adults in the "Low" group (1.11 ± 0.32 s) was significantly longer than that in the "Moderate" group (1.05 ± 0.30 s, p < 0.01) and the "High" group (0.99 ± 0.28 s, p < 0.01). For housework PA, there was no significant difference in the cognitive reaction time among the three groups ("Low": 1.09 ± 0.31 s; "Moderate": 1.07 ± 0.31 s; "High": 1.05 ± 0.28 s, p > 0.05). For work-related PA, the results showed that the cognitive reaction time of older adults in the "Low" group (1.09 ± 0.30 s) was significantly longer than that in the "High" group (0.99 ± 0.28 s) and the "Moderate" group (1.03 ± 0.32 s, p < 0.01).

Conclusion

The PA has a positive effect on reducing cognitive reaction time in older adults. It is recommended that older adults maintain a moderate level of leisure PA and work-related PA to delay the decline in cognitive reaction time.

Accelerometer-Assessed Physical Activity and Cognitive Performance among European Adults Aged 50+: The Mediating Effects of Social Contacts and Depressive Symptoms

BACKGROUND

Cognitive decline is a major public health concern worldwide and it is vital to identify and better understand effective population-based means to improve cognitive performance in old age. The current study set out to examine the links between accelerometer-based physical activity with cognitive performance in later life, as well the indirect pathways through one's social network contacts and depression.

METHOD

We used data from 855 participants aged 50 and above who took part in a cross-sectional accelerometer study as part of the Survey of Ageing, Retirement and Health (SHARE). Cognitive function was measured as an average score of fluency, immediate and delayed recall tests, social contacts were the average contact frequency with members of the social support network, and depression was the Euro-D summary score of depressive symptoms. A multiple mediation analysis was conducted to test the direct and indirect associations between total physical activity (intensity gradient) and cognitive function, as well as the mediation of this association by social contacts and depressive symptoms.

RESULTS

Intensity of physical activity was directly related to better cognitive performance (B = 0.170, p = 0.007). The association was partially mediated by social contacts (B = 0.022, 95% CI 0.005, 0.046) and depressive symptoms (B = 0.009, 95% CI 0.009, 0.025), such that total physical activity was linked to cognitive health via more frequent contacts with network members and low depressive symptoms.

CONCLUSIONS

Practitioners might consider encouraging a physically active lifestyle that involves social interactions to support better cognitive aging and mental health.

Education level may modify the association between cardiac index and cognitive function among elders with normal ejection function

Background

Lower cardiac index (CI) in elders has been associated with incident dementia, and higher CI has protectively effect with brain aging. In the present study, we investigated the modulating effects of education level and arterial stiffness on the association between CI and cognitive function among older adults.

Methods

A total of 723 elders (≥60 years, 50.1% women) with normal left ventricular ejection fraction (≥50%) were identified from the Cardiovascular Diseases Risk Factor Two-Township Study. CI was calculated from the Doppler-derived stroke volume. We evaluated arterial stiffness by measuring carotid-femoral pulse wave velocity (CFPWV) and global cognitive function by using the Mini-Mental Short Examination (MMSE). Education level was determined by years of formal education.

Results

In linear regression analysis adjusting for age, sex, formal years of education, and CFPWV, CI was significantly positively associated with MMSE (BETA=0.344±0.130, P = 0.0082). In logistic regression analysis adjusting for age, sex, formal years of education, and CFPWV, subjects with a CI≥75 percentile had a significantly lower risk of low MMSE (<26) (OR = 0.495, 95% CI = 0.274–0.896, P = 0.02). In subgroup analysis, higher CI was significantly associated with higher MMSE and lower risk of low MMSE only in elders with ≤ 9 years of formal education. Causal mediation analysis suggests that higher CI maintains higher MMSE in elders with lower education levels whereas higher CFPWV causes lower MMSE in all the elders.

Conclusion

In elders with normal ejection fraction, a higher CI was associated with a lower risk of cognitive function impairment, independent of arterial stiffness, mainly in subjects with a lower education level and possibly a smaller cognitive reserve.

Cognitive reserve proxies, Alzheimer pathologies, and cognition

This study aimed to explore the moderating effects of the frequently used cognitive reserve (CR) proxies [i.e., education, premorbid intelligence quotient (pIQ), occupational complexity (OC), and lifetime cognitive activity (LCA)] on the relationships between various in vivo Alzheimer's disease (AD) pathologies and cognition. In total, 351 [268 cognitively unimpaired (CU), 83 cognitive impaired (CI)] older adults underwent multi-modal brain imaging to measure AD pathologies and cognitive assessments, and information on CR proxies was obtained. For overall participants, only education moderated the relationship between Aβ deposition and cognition. Education, pIQ, and LCA, but not OC, showed moderating effect on the relationship between AD-signature cerebral hypometabolism and cognition. In contrast, only OC had a moderating effect on the relationship between cortical atrophy of the AD-signature regions and cognition. Such moderation effects of the CR proxies were similarly observed in CI individuals, but most of them were not in CU individuals. The findings suggest that the proposed CR proxies have different moderating effects on the relationships between specific AD pathologies and cognition.

Cognitive Functioning Mediates the Association of Cognitive Reserve with Health-Related Quality of Life

We investigated whether the relations of the cognitive reserve markers education and cognitive level of work to the physical and the mental component of health-related quality of life (HRQoL) were mediated via cognitive functioning in a large sample of 701 older adults (mean age = 70.36 years, SD = 6.87). HRQoL was measured with the 12-item Short-Form Health Survey. To measure cognitive functioning, we used the COGTEL, which is a cognitive test battery assessing prospective memory, verbal short-term memory, verbal long-term memory, working memory, verbal fluency, and inductive reasoning, combined into a composite score. Individuals reported information on their education and their main profession during their working life. Mediation analyses showed that better cognitive functioning mediated the association of higher values in the cognitive reserve markers (longer education and a high cognitive level of work) with higher HRQoL. In conclusion, the present study suggests that the sustainability of cognitive functioning in old age with the help of cognitive reserve is fundamental for the sustainability of quality of life, presumably particularly for the mental HRQoL component.

An Overview of Cognitive Reserve in Aging Based on Keyword Network Analysis

Many studies have reported that Cognitive reserve is a critical mechanism affecting cognitive statuses, such as dementia. The purposes of this study were to identify the knowledge structure and the research trend on cognitive reserve by conducting keyword analysis on research papers ranging from the earliest to the most recent studies done on the topic and to suggest directions for future research. The Web of Science (WOS) database was used to search for articles on cognitive reserve in aging from 2001 to 2020. NetMiner version 4 (cyram, KOREA), a social network analysis program, was used for keyword network analysis. Data analysis showed keywords that could be categorized as cognitive reserve related keywords (cognitive reserve related concepts, cognitive reserve related factor, cognitive reserve diagnosis and measurement, cognitive reserve outcomes) and cognitive reserve research keywords (research subject/disease, research method, intervention, research field). Through trend analysis, we found that various keywords appeared, indicating that the research has gradually developed conceptually and methodically. Based on these findings, future CR studies require the development of multimodal interface-based tools by applying modern digital technology that can be used to more accurately diagnose and monitor CR; remotely, in real time. In addition, to improve CR, it is suggested that the development of cognitive stimulation interventions utilizing VR which fuses AI based interaction technology with the subjects. Finally, CR could develop further through a cooperation of multidisciplinary professionals such as psychology, medicine and nursing.

The protective impact of education on brain structure and function in Alzheimer's disease

BACKGROUND

The Cognitive Reserve (CR) theory posits that brains with higher reserve can cope with more cerebral damage to minimize clinical manifestations. The aim of this study was to examine the effect of education (CR proxy) on brain structure and function in Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) patients and in cognitively healthy elderly (HC) individuals.

METHODS

Fifty-seven AD patients, 57 aMCI patients and 48 HCs were included to investigate the relationships between education years and gray matter volume (GMV), regional homogeneity (ReHo) and functional connectivity (FC) in brain regions to show associations with both structure and function. Taking the severity of the disease into account, we further assessed the relationships in AD stratified analyses.

RESULTS

In AD group, the GMV of the dorsal anterior cingulate cortex (dACC) and ReHo in the left inferior temporal cortex (ITC) were inversely associated with education years, after adjustment for age, sex, Mini-Mental State Examination (MMSE), and total intracranial volume or head motion parameters. Seed-based FC analyses revealed that education years were negatively correlated with the FC between the left anterior ITC and left mid frontal cortex as well as right superior frontal cortex and right angular gyrus. Stratified analyses results indicated that this negative relation between education and GMV, ReHo, FC was mainly present in mild AD, which was attenuated in moderate AD and aMCI groups.

CONCLUSIONS

Our results support the CR theory, and suggest that CR may be protective against AD related brain pathology at the early stage of clinical dementia. These findings could provide the locus of CR-related functional brain mechanisms and a specific time-window for therapeutic interventions to help AD patients to cope better with the brain pathological damage by increasing CR.

Electroencephalography, Magnetoencephalography, and Cognitive Reserve: A Systematic Review

OBJECTIVE

Cognitive reserve (CR) is the capacity to adapt to (future) brain damage without any or only minimal clinical symptoms. The underlying neuroplastic mechanisms remain unclear. Electrocorticography (ECOG), electroencephalography (EEG), and magnetoencephalography (MEG) may help elucidate the brain mechanisms underlying CR, as CR is thought to be related to efficient utilization of remaining brain resources. The purpose of this systematic review is to collect, evaluate, and synthesize the findings on neural correlates of CR estimates using ECOG, EEG, and MEG.

METHOD

We examined articles that were published from the first standardized definition of CR. Eleven EEG and five MEG cross-sectional studies met the inclusion criteria: They concerned original research, analyzed (M)EEG in humans, used a validated CR estimate, and related (M)EEG to CR. Quality assessment was conducted using an adapted form of the Newcastle-Ottawa scale. No ECOG study met the inclusion criteria.

RESULTS

A total of 1383 participants from heterogeneous patient, young and older healthy groups were divided into three categories by (M)EEG methodology: Eight (M)EEG studies employed event-related fields or potentials, six studies analyzed brain oscillations at rest (of which one also analyzed a cognitive task), and three studies analyzed brain connectivity. Various CR estimates were employed and all studies compared different (M)EEG measures and CR estimates. Several associations between (M)EEG measures and CR estimates were observed.

CONCLUSION

Our findings support that (M)EEG measures are related to CR estimates, particularly in healthy individuals. However, the character of this relationship is dependent on the population and task studied, warranting further studies.

Does postponing retirement affect cognitive function? A counterfactual experiment to disentangle life course risk factors

Evidence suggests that contemporaneous labor force participation affects cognitive function; however, it is unclear whether it is employment itself or endogenous factors related to individuals’ likelihood of employment that protects against cognitive decline. We exploit innovations in counterfactual causal inference to disentangle the effect of postponing retirement on later-life cognitive function from the effects of other life-course factors. With the U.S. Health and Retirement Study (1996–2014, n = 20,469), we use the parametric g-formula to estimate the effect of postponing retirement to age 67. We also study whether the benefit of postponing retirement is affected by gender, education, and/or occupation, and whether retirement affects cognitive function through depressive symptoms or comorbidities. We find that postponing retirement is protective against cognitive decline, accounting for other life-course factors (population: 0.34, 95% confidence interval (CI): 0.20,0.47; individual: 0.43, 95% CI: 0.26,0.60). The extent of the protective effect depends on subgroup, with the highest educated experiencing the greatest mitigation of cognitive decline (individual: 50%, 95% CI: 32%,71%). By using innovative models that better reflect the empirical reality of interconnected life-course processes, this work makes progress in understanding how retirement affects cognitive function.

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Research is inconclusive as to employments' protection against cognitive decline.

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Causal inference models can better reflect interconnected life-course processes.

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The parametric g-formula shows a substantial protective effect of ongoing employment.

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Protective effect holds for all subgroups, but is greatest for the highest educated.

The influence of late retirement on health outcomes among older adults in the policy context of delayed retirement initiative: an empirical attempt of clarifying identification bias

Background

The deepening population aging is urging policy makers to launch delayed retirement initiative, when the society is faced with unprecedented challenges of shrinking labor supply, heavier pension burdens and slowing economic growth. However, the health outcomes of late retirees receive scarce attention due to the intrinsic identification difficulties (i.e., (1) self-selection bias – older adults with predetermined ill-health are less likely to delay retirement. (2) there can be situations where the status of late retirement has terminated at the time of interview, although he/she has ever delayed retirement). To fill in this research gap, this study examines the effect of late retirement on the difficulty in physical functioning and problems of cognitive status among older adults.

Method

Using the data from China Health and Retirement Longitudinal Study (CHARLS-2015 harmonized, and CHARLS-2018), this study investigates the influence of late retirement (year 2015) on the difficulty in physical functioning and problems of cognitive status (year 2018) among older adults. A series of robustness checks are also conducted.

Results

Empirical results show that late retirement is associated with better physical functioning and cognitive status. The influence remains robust after considering potential self-selection bias and the sensitivity of including/excluding older adults who have past late retirement experience but have no longer been late retirees at the time of survey.

Conclusion

This study suggests that older adults might benefit from the engagement in late careers in their physical and cognitive functioning.

Older Workers with Physically Demanding Jobs and their Cognitive Functioning

Although employment can provide older people with both financial and nonfinancial rewards, it is questionable whether those benefits extend to all older workers, particularly those with physically demanding jobs. This study aimed to examine whether the perceived level of physical demands placed on older workers 55 or older is significantly associated with their cognitive function. Using the Health and Retirement Study (HRS) 2010 wave, we analyzed two domains of cognition: verbal episodic memory and reasoning. After controlling for demographics and risk factors for age-related cognitive deterioration, the perceived level of physical demands placed on older workers was still significantly and negatively linked with both memory and reasoning domains of cognition. Older workers with more physically demanding jobs tended to have poorer cognitive function. Further longitudinal studies are needed to confirm this relationship.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12126-020-09404-8.

Alzheimer's Disease as a Result of Stimulus Reduction in a GABA-A-Deficient Brain: A Neurocomputational Model

Several research studies point to the fact that sensory and cognitive reductions like cataracts, deafness, macular degeneration, or even lack of activity after job retirement, precede the onset of Alzheimer's disease. To simulate Alzheimer's disease earlier stages, which manifest in sensory cortices, we used a computational model of the koniocortex that is the first cortical stage processing sensory information. The architecture and physiology of the modeled koniocortex resemble those of its cerebral counterpart being capable of continuous learning. This model allows one to analyze the initial phases of Alzheimer's disease by “aging” the artificial koniocortex through synaptic pruning, by the modification of acetylcholine and GABA-A signaling, and by reducing sensory stimuli, among other processes. The computational model shows that during aging, a GABA-A deficit followed by a reduction in sensory stimuli leads to a dysregulation of neural excitability, which in the biological brain is associated with hypermetabolism, one of the earliest symptoms of Alzheimer's disease.

Association between cognitive reserve dimensions and frailty among older adults: A structured narrative review

Frailty is a broadly investigated geriatric condition, which is characterized by an increased vulnerability to stressors. It represents an extremely relevant public health issue, increasingly conceptualized in a multidimensional perspective. The concept of cognitive reserve (CR), as originally conceptualized by Stern, has been developed in the past decades as a potential factor able to determine individual differences in cognitive vulnerability and trajectories occurring with aging. Our purpose was to provide a comprehensive review of the literature exploring the relationship between CR dimensions, selected according to the Stern model, and frailty status. A review of the literature on the association between potential CR dimensions and frailty was carried out through PubMed, Web of Knowledge and Scopus. CR expressed in terms of education, occupation, premorbid intelligence quotient and leisure time activities was associated with frailty in both cross-sectional and longitudinal observations. The majority of reviewed evidence suggests a potential protective role of CR factors against the onset and the worsening of frailty among older adults. To the best of our knowledge, this is the first attempt to provide a comprehensive overview regarding the association between CR dimensions and frailty. Education, occupation, premorbid intelligence quotient and leisure time activities are able to interact with the general concept of frailty, rather than simply affecting the cognitive trajectory towards dementia. The lack of a unique and operationalized approach to the assessment of CR, as well as the wide heterogeneity of frailty evaluation tools and criteria, denote some methodological critical issues that need to be overcome. Geriatr Gerontol Int 2020; 20: 1005-1023..

Impact of music-based intervention on verbal memory: an experimental behavioral study with older adults

Normal age-related declines have been reported in different cognitive functions, such as episodic memory. Some environmental factors have the potential to reduce cognitive decline and promote healthy aging. In this research, we employed musical improvisation as a focal music-based intervention to explore its effects as a modulator of verbal memory. We evaluated two types of verbal memory: a neutral one, employing the Rey Auditory Verbal Learning Test (Study 1), and an emotional one, implementing the Spanish version of Affective Norms for English Words (Study 2) in a volunteer group of older adults. After the acquisition of neutral (Study 1) or emotional (Study 2) verbal information, the participants were exposed to musical improvisation (experimental condition) or two control conditions (rhythmic reproduction as a musically active control condition or a rest condition as a passive control condition) for 3 min. Then, memory was evaluated through two memory tasks (immediate and deferred free-recall and recognition tests). In both studies, we compared memory performance among musicians (with five or more years of music training) and non-musicians. We found a significant improvement in neutral verbal memory among participants involved in musical improvisation, who remembered more words than those in the control conditions. Differences were also found according to the musical experience of the sample, with musicians outperforming non-musicians. The current research supports the late-life cognitive benefits of music-based intervention and music training.

Living arrangements and cognitive abilities of community-dwelling older adults in Singapore

AIM

Dementia is a growing public health concern. It is necessary to focus on factors that may help preserve cognitive function in late life. Limited research has examined how living arrangements are associated with cognitive function in older adults. This study aims to further our understanding of this association in community-dwelling older adults in a multi-ethnic Asian population.

METHODS

Data were obtained from a cross-sectional population survey of 2548 adults aged 60 and older with standardized instruments. Living arrangements were classified as living with adult children and grandchildren, living with adult children only, living with a spouse/partner only, living alone, living with other relatives, and living with non-relatives.

RESULTS

Cognitive function was significantly predicted by living arrangements among community-dwelling older adults. Multivariate linear regression analyses revealed that older adults in multigenerational family households had significantly poorer cognitive function than those living with a spouse/partner (β = 0.54, P < 0.02) and those living with non-relatives (β = 1.08, P < 0.02). This association was independent of the influence of age, gender, ethnicity, education, employment status, marital status, depression, disability, chronic health conditions, and self-reported health.

CONCLUSION

Older adults living in multigenerational households seem to be disadvantaged in their cognitive function. However, we cannot conclude this based on the evidence because of the cross-sectional nature of the data. Further research is needed to reasonably determine the relationship between living arrangements and cognitive function. Regardless, these findings add to the growing understanding of the complex relationship between living arrangements and cognition in older adults and could provide a basis to design effective strategies to delay cognitive decline in community-dwelling older adults.

Role of EEG in Measuring Cognitive Reserve: A Rapid Review

This review aimed to systematically summarize the possible neural correlates of cognitive reserve thus giving an insight into prospective biomarkers for the concept. A total of 44 studies were analyzed following PRISMA guidelines and four studies were included in the further analysis. The results indicated a relationship between P3b waveform and cognitive reserve, while more ambiguous outcomes were found when conducting resting-state EEG. This review indicates the first steps into assessing CR using physiological measures; however, more research is needed for deeper understanding of its underlying mechanisms.

Working status is related to post stroke/TIA cognitive decline: data from the TABASCO study

BACKGROUND AND AIMS

Occupational status may influence physical and mental post-stroke outcomes. We aimed to evaluate the association between occupational status and type, or engagement in social and family activities, neuroimaging measures and cognitive decline (CD) in a prospective cohort of stroke patients.

METHODS

We included 273 first-ever stroke survivors at working age. All patients underwent 3T MRI at admission, as well as clinical and cognitive assessments at admission, 6, 12 and 24 months thereafter.

RESULTS

Ninty nine (36.3%) of the participants were unemployed prior to the stroke. Age, sex, work type, other comorbidities, stroke severity or location were not associated with return to work. Patients who returned to work (87.4%) had better cognitive results and less depressive symptoms than those who retired after the event. Pre-stroke unemployment was associated with diabetes mellitus, hypertension, dyslipidemia, depression, poorer cognitive scores and brain atrophy. During the follow-up, 11% developed CD. CD was more common among previously unemployed than employed participants (19.2% vs. 6.3%, p = 0.001). Multiple regression adjusted for risk factors, revealed that pre-stroke unemployment was an independent predictor of CD (HR, 3.0; 95% CI: 1.06-8.44). Furthermore, engagement in mentally stimulating jobs decreased the risk for CD.

CONCLUSIONS

Pre-stroke unemployment and post-stroke work disruption were each associated with depression and poorer cognitive performance up to two years post-stroke, as well as with brain atrophy at admission. Retirement after the stroke may increase the risk of developing CD. These results highlight the importance of continued employment in preserving cognitive abilities among stroke survivors.

Assessment of Lifestyle Experiences across Lifespan and Cognitive Ageing in the Indian Context

With rising numbers of elderly and dementia in developing societies, there is a need to understand factors protective against dementia. Evidence suggests that lifetime cognitive activities including education, occupation, and complex leisure activities contribute to cognitive reserve. However, these factors are understudied in India. This paper describes the validation of the Lifetime of Experiences Questionnaire (LEQ), a comprehensive measure of complex lifetime activities, to the Indian cultural context. It also examines the relationship between lifetime experiences and cognition among 52 healthy elderly and 30 dementia patients. High inter-rater (κ=0.923, p < 0.001), test-retest (ρ: 0.905 to 0.986) reliability, and internal consistency were found for LEQ-total (0.992) and sub-scores. Literate dementia patients (25) scored significantly lower mid-life (27.5 vs. 23.3), late-life (28.5 vs. 22.5) and total LEQ (83.5 vs. 20.9) scores than literate healthy group (37). LEQ scores positively correlated with global cognition, and domains of attention and memory on the Addenbrooke’s Cognitive Examination, in healthy and dementia groups. Moreover, LEQ scores correlated positively with age at onset of dementia and negatively with clinical dementia rating (CDR) scores. Our study demonstrates that lifetime activities, especially mid-life experiences, play a protective role in development of late-life dementia, and need to be advocated to preserve late-life cognition.

Internet use in old age predicts smaller cognitive decline only in men

Internet use provides cognitive stimulation and thereby may contribute to the accumulation of cognitive reserve that is proposed to be instrumental for maintaining cognitive health in ageing. As the first study so far, we examined possible gender differences in the relationship between Internet use and subsequent cognitive decline over six years assessed through changes in Trail Making Test (TMT) accomplishment time in 897 older adults. Latent change score modelling (taking into account baseline cognitive level, chronic diseases, age, and central contributions to cognitive reserve through education, profession, and leisure engagement) revealed a significant interaction of frequency of Internet use and gender. More frequent Internet use in the first wave of data collection significantly predicted a smaller subsequent augmentation in TMT accomplishment time (i.e., a smaller subsequent cognitive decline) only in men, but not in women. In conclusion, frequent Internet use may contribute to the accumulation of cognitive reserve. The gender difference noted highlights an advantage for males. While this finding could be interpreted as gender-specific, it may be that the Internet activities males engage in differ from those of females, calling for a fine-grained investigation of Internet-based activities in future studies.

An update of the profile of older adults with dementia in Europe: findings from SHARE

Background: The increase in longevity due to the reduction of premature deaths has led to an increase of the number of people with dementia. The objective of the present work was to analyze the profile of the European population with dementia aged more than 50.Methods: The sample of individuals aged 51 or more years was taken from a European database within the last wave of the SHARE Project (Wave 6, March 2017). Participants with and without a diagnosis of dementia were compared in terms of socio-demographic, general health, mental health, behavioural risks, education and employment, by age group. Categorical variables were compared using chi-square test, quantitative variables were compared with the independent sample t-test.Results: From 45,340 subjects (40% males) 897 (2%) had dementia. The findings corroborate recent evidence stating that individuals with dementia have a lower physical and mental health as well as a lower quality of life than people without dementia. It was also verified that people with dementia: (i) had a lower employment rate; (ii) showed lower levels of formal education; (iii) less were living a married life; (iv) exhibited a moderate pattern of behavioural risks, but had higher levels of physical inactivity; (v) had more chronic diseases and (iv) higher intake of more than 5 drugs per day. The unfavourable health and well-being status of dementia subjects was found in all age groups.Conclusions: An update of the profile of older Europeans with dementia was performed with data from 18 countries. The findings of co-morbidity, high rates of intake of more than 5 drugs daily and low levels of well-being irrespective of age should be considered in the assessment and management of dementia in the European population.

A Positive Relationship between Cognitive Reserve and Cognitive Function after Stroke: Dynamic Proxies Correlate Better than Static Proxies

OBJECTIVES

How brain damage after stroke is related to specific clinical manifestation and recovery is incompletely understood. We studied cognitive reserve (CR) in stroke patients by two types of measurements: (i) objectively verifiable static proxies (i.e., education, occupational attainment), and (ii) subjective, dynamic proxies based on patient testimony in response to a questionnaire. We hypothesized that one or both of these types of CR measurements might correlate positively with patient cognitive performance during the post-acute and chronic phases of recovery.

METHOD

Thirty-four stroke patients underwent neuropsychological assessment at 2, 6 and 24 months after stroke onset. In chronic stage at 24+ months, self-rating assessments of cognitive performance in daily life and social integration were obtained. CR before and after stroke was estimated using static proxies and dynamic proxies were obtained using the Cognitive Reserve Scale (CRS-Pre-stroke, CRS-Post-stroke).

RESULTS

CRS-Pre-stroke and CRS-Post-stroke showed significant mean differences. Dynamic proxies showed positive correlation with self-assessment of attention, metacognition, and functional ability in chronic stage. In contrast, significant correlations between static proxies and cognitive recovery were not found.

CONCLUSIONS

Dynamic proxies of CR were positively correlated with patients' perception of their functional abilities in daily life. To best guide cognitive prognosis and treatment, we propose that dynamic proxies of CR should be included in neuropsychological assessments of patients with brain damage.

Complexity of Primary Lifetime Occupation and Cognitive Processing

Today, there are a lack of studies focusing on the relationship between occupational complexity and executive functioning. This is noteworthy since executive functions are core aspects of cognitive processing. The present study was aimed to investigate if three occupational complexity factors (with data, people, and things) of main lifetime occupation were related to performance in executive tasks (inhibition, switching, updating). We analyzed cross-sectional data that were available for 225 participants aged 50-75 years. Results from structural equation models showed that higher complexity levels of working with data were related to lower error rates in the updating component of cognitive control. In addition, higher rates of complexity working with people was associated with lower error rates in task-switching, which also persisted after adjustment of fluid intelligence. Complexity with things, however, was not related to performance in the executive tasks. Future studies would benefit from a longitudinal design to investigate if the results from this study also hold in the long term and to further investigate the directionality between factors.

Measuring Cognitive Reserve (CR) - A systematic review of measurement properties of CR questionnaires for the adult population

Aim

The aim of this systematic review was to summarize and critically appraise the quality of published literature on measurement properties of questionnaires assessing Cognitive Reserve (CR) in adults (>18 years).

Methods

We systematically searched for published studies on MEDLINE, PsycINFO, and Web of Science through August 2018. We evaluated the methodological quality of the included studies and the results on measurement properties based on a consensus-based standard checklist.

Results

The search strategy identified 991 publications, of which 37 were selected evaluating the measurement properties of six different questionnaires. Construct validity of the Cognitive Reserve Index questionnaire was most extensively evaluated, while evaluation of the remaining measurement properties of this questionnaire was scarce. Measurement properties of the Cognitive Reserve Questionnaire and the Cognitive Reserve Scale were assessed more completely. While the Lifetime of Experience Questionnaire seems to be the most thorough instrument, a finale recommendation for one specific questionnaire cannot be drawn, since about half of the measurement properties for each questionnaire were poorly or not assessed at all.

Conclusions

There is a need of high quality methodological studies assessing measurement properties of CR questionnaires, especially regarding content validity, structural validity, and responsiveness.

Trial registration

PROSPERO Registration number CRD42018107766.

Contact frequency and cognitive health among older adults in Israel

Objectives: The current study set out to examine the links between contact frequency with one's social network and cognitive health in later life. It assessed both direct and indirect pathways and the possible role of ethnicity in the effect of the social network on cognitive function. Method: We used data from adults aged 50 and above, which was collected in Israel as part of the Survey of Ageing, Retirement and Health (SHARE). A moderated mediation analysis was conducted to test the direct and indirect associations between contact frequency and cognitive function, as well as the moderation of these associations by population group. Three population groups were examined - veteran-Jews, Arabs and immigrants from the former Soviet Union. Results: Contact frequency with the close social milieu was found to be directly positively related to cognitive function. The association was also mediated by depressive symptoms, such that frequent contacts were linked to cognitive health via reduced depressive symptoms. This indirect link differed, however, among the three population groups. Conclusion: Contact frequency is important for cognitive health in the second half of life, and it operates both directly and by decreasing depressive symptoms. However, these links are not found among all ethnic groups and may, therefore, depend on the culture and social norms of each group and the meaning attributed to social ties.

A Systematic Review on the Possible Relationship Between Bilingualism, Cognitive Decline, and the Onset of Dementia

A systematic review was conducted to investigate whether bilingualism has a protective effect against cognitive decline in aging and can protect against dementia. We searched the Medline, ScienceDirect, Scopus, and ERIC databases with a cut-off date of 31 March, 2019, thereby following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol. Our search resulted in 34 eligible studies. Mixed results were found with respect to the protective effect of bilingualism against cognitive decline. Several studies showed a protective effect whereas other studies failed to find it. Moreover, evidence for a delay of the onset of dementia of between 4 and 5.5 years in bilingual individuals compared to monolinguals was found in several studies, but not in all. Methodological differences in the set-up of the studies seem to explain these mixed results. Lifelong bilingualism is a complex individual process, and many factors seem to influence this and need to be further investigated. This can be best achieved through large longitudinal studies with objective behavioral and neuroimaging measurements. In conclusion, although some evidence was found for a cognitive reserve-enhancing effect of lifelong bilingualism and protection against dementia, to date, no firm conclusions can be drawn.

Social networks and social activities promote cognitive functioning in both concurrent and prospective time: evidence from the SHARE survey

The study aimed to investigate the role of social activities, social networks as well as socioeconomic status (SES) in influencing some aspects of cognitive functioning (immediate and delayed verbal recall tests and semantic verbal fluency) in elderly people over time. This analysis was conducted on a sample of 31,954 healthy elderly people (58% female, mean age 65.54 ± 9.74) interviewed in both the fourth and sixth waves of the Survey on Health, Aging and Retirement in Europe (SHARE), in 2011 and 2015. A structural equation model with measurement component was used to assess the relationship between cognitive function, social life and SES over time. Multilevel ordinal logistic regression was applied to explain satisfaction with social network in relation to different types of social network across countries. Being equipped with good cognitive skills did not seem to be predictive of their maintenance over time (latent coefficient = 0.24, p value = 0.34). On the contrary, the subject's social and participatory life, understood as satisfying one's social network and engaging in diversified non-professional social activities, seemed to play a crucial role in the maintenance of cognitive functions in the elderly (latent coefficient = 3.5, p value = 0.03). This research suggests that a socially active and participatory lifestyle mitigates the effects of the physiological process of brain aging.

Does Gender Differentiate the Effects of Retirement on Cognitive Health?

Prior research on change in cognitive performance before and after retirement suffers from inattention to gender context. This study theoretically motivates the testing of gender differences in cognitive decline after retirement. I drew 67,905 observations of cognitive function based on the Telephone Interview for Cognitive Status from 18,453 participants (7,830 men and 10,623 women) in the Health and Retirement Study (1992-2014). I used fixed-effects two-stage least square models to account for unobserved heterogeneity between men and women in the sample and the endogeneity of retirement decision. I also controlled for change in depressive symptoms, mobility limitations, individual wealth, medical expenses, and spousal income. Retirement predicts a decrease in the cognitive score by 2.168 on a scale of 0-35 for women, but no change for men. Continued employment may buffer against risk factors that aggravate women's cognitive health.

Effect of sociodemographic and physical activity on cognitive function in older adults: A nationwide cross-sectional survey

OBJECTIVE

We aimed to assess the effect of socioeconomic status and physical activity on cognitive function using a large population-based survey data in China.

METHODS

We took advantage of the Chinese Longitudinal Healthy Longevity Survey conducted in 2014 to examine the relationship between sociodemographic, physical activity, and cognitive function in older adults (OAs) for persons aged above 65 (N = 2848). Socioeconomic status was assessed by sex, age, co-residence situation, category of residence, years of schooling, and marital status. Multiple linear regression for predictors was utilized. Physical activity was assessed using activities of daily living (ADL) and instrumental activities of daily living (IADL) measures. Cognitive function was assessed by the Modified Mini-Mental State Examination.

RESULTS

The mean age of the OAs was 80.65 years (SD = 8.55). Their mean Mini-Mental State Examination score was 21.55 (SD = 2.38), mean ADL Total score was 6.24 (SD = 0.95), and mean IADL Total score was 10.21 (SD = 3.84). OAs' age at testing, co-residence and category of residence significantly predicted both ADL Total score and IADL Total score (P < 0.05), sex significantly predicted IADL Total score (R²  = 0.02, β = 0.13, P = 0.000) but not ADL Total score (R²  = 0.00, β = 0.02, P = 0.211). OAs' sex, age, co-residence, and years of schooling significantly predicted cognitive function (P < 0.05), IADL total score significantly predicted cognitive function (P < 0.01), while the relationship between ADL total score and cognitive function was not significant (P = 0.94).

CONCLUSION

OAs' sex, age, co-residence, years of schooling, and IADL were significantly associated with cognitive function. Improving OAs' IADL, especially in lower social classes, may help to improve the overall cognitive function of the OAs.

Highlighting the Role of Cognitive and Brain Reserve in the Substance use Disorder Field

BACKGROUND

Cognitive reserve (CR) refers to the ability of an individual to cope with brain pathology remaining free of cognitive symptoms. This protective factor has been related to compensatory and more efficient brain mechanisms involved in resisting brain damage. For its part, Brain reserve (BR) refers to individual differences in the structural properties of the brain which could also make us more resilient to suffer from neurodegenerative and mental diseases.

OBJECTIVE

This review summarizes how this construct, mainly mediated by educational level, occupational attainment, physical and mental activity, as well as successful social relationships, has gained scientific attention in the last years with regard to diseases, such as neurodegenerative diseases, stroke or traumatic brain injury. Nevertheless, although CR has been studied in a large number of disorders, few researches have addressed the role of this concept in drug addiction.

METHODS

We provide a selective overview of recent literature about the role of CR and BR in preventing substance use onset. Likewise, we will also discuss how variables involved in CR (healthy leisure, social support or job-related activities, among others) could be trained and included as complementary activities of substance use disorder treatments.

RESULTS

Evidence about this topic suggests a preventive role of CR and BR on drug use onset and when drug addiction is established, these factors led to less severe addiction-related problems, as well as better treatment outcomes.

CONCLUSION

CR and BR are variables not taken yet into account in drug addiction. However, they could give us a valuable information about people at risk, as well as patient's prognosis.

Issues in Building a Nursing Home Syndromic Surveillance System with Textmining: Longitudinal Observational Study

Background

New nursing homes (NH) data warehouses fed from residents’ medical records allow monitoring the health of elderly population on a daily basis. Elsewhere, syndromic surveillance has already shown that professional data can be used for public health (PH) surveillance but not during a long-term follow-up of the same cohort.

Objective

This study aimed to build and assess a national ecological NH PH surveillance system (SS).

Methods

Using a national network of 126 NH, we built a residents’ cohort, extracted medical and personal data from their electronic health records, and transmitted them through the internet to a national server almost in real time. After recording sociodemographic, autonomic and syndromic information, a set of 26 syndromes was defined using pattern matching with the standard query language-LIKE operator and a Delphi-like technique, between November 2010 and June 2016. We used early aberration reporting system (EARS) and Bayes surveillance algorithms of the R surveillance package (Höhle) to assess our influenza and acute gastroenteritis (AGE) syndromic data against the Sentinelles network data, French epidemics gold standard, following Centers for Disease Control and Prevention surveillance system assessment guidelines.

Results

By extracting all sociodemographic residents’ data, a cohort of 41,061 senior citizens was built. EARS_C3 algorithm on NH influenza and AGE syndromic data gave sensitivities of 0.482 and 0.539 and specificities of 0.844 and 0.952, respectively, over a 6-year period, forecasting the last influenza outbreak by catching early flu signals. In addition, assessment of influenza and AGE syndromic data quality showed precisions of 0.98 and 0.96 during last season epidemic weeks’ peaks (weeks 03-2017 and 01-2017) and precisions of 0.95 and 0.92 during last summer epidemic weeks’ low (week 33-2016).

Conclusions

This study confirmed that using syndromic information gives a good opportunity to develop a genuine French national PH SS dedicated to senior citizens. Access to senior citizens’ free-text validated health data on influenza and AGE responds to a PH issue for the surveillance of this fragile population. This database will also make possible new ecological research on other subjects that will improve prevention, care, and rapid response when facing health threats.

Insulin Peptides as Mediators of the Impact of Life Style in Alzheimer's disease

The search for the cause of Alzheimer's disease (AD), that affects millions of people worldwide, is currently one of the most important scientific endeavors from a clinical perspective. There are so many mechanisms proposed, and so disparate changes observed, that it is becoming a challenging task to provide a comprehensive view of possible pathogenic processes in AD. Tauopathy (intracellular neurofibrillary tangles) and amyloidosis (extracellular amyloid plaques) are the anatomical hallmarks of the disease, and the formation of these proteinaceous aggregates in specific brain areas is widely held as the ultimate pathogenic mechanism. However, the triggers of this dysproteostasis process remain unknown. Further, neurofibrillary tangles and plaques may only constitute the last stages of a process of still uncertain origin. Thus, without an established knowledge of its etiology, and no cure in the horizon, prevention - or merely delaying its development, has become a last-resort goal in AD research. As with other success stories in preventive medicine, epidemiological studies have provided basic knowledge of risk factors in AD that may contribute to understand its etiology. Disregarding old age, gender, and ApoE4 genotype as non preventable risk factors, there are diverse life-style traits - many of them closely related to cardiovascular health, that have been associated to AD risk. Most prominent among them are diet, physical and mental activity, exposure to stress, and sleep/wake patterns. We argue that all these life-style factors engage insulinergic pathways that affect brain function, providing a potentially unifying thread for life-style and AD risk. Although further studies are needed to firmly establish a link between faulty insulinergic function and AD, we herein summarize the evidence that this link should be thoroughly considered.

Cognitive frailty: A conceptual systematic review and an operational proposal for future research

OBJECTIVE

To analyze the definition of "cognitive frailty" and to study the conceptual and operational definitions used and their implications for empirical research. The relationships between this concept and cognitive reserve, the role of neuropathology and brain reserve, motor signs of aging and the reversibility of cognitive frailty are also discussed.

STUDY DESIGN

Systematic review of empirical studies identified from Medline Advanced 1966, CINAHL, Web of Science, PsycINFO, and Scopus until August 2017.

MAIN - OUTCOME MEASURES

Effect sizes. The quality of the articles was assessed by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement. Three independent reviewers participated in the study selection and data extraction.

RESULTS

Nineteen studies involving 31,707 participants met the inclusion criteria. Significant associations were reported between cognitive frailty and physical frailty or gait speed. Screening instruments were usually used to determine objective cognitive decline rather than extensive neuropsychological assessments. Educational level was the only indicator of cognitive reserve that was systematically included in the evaluation of cognitive frailty. Motor decline and gait variables were not systematically included in protocols for the assessment of cognitive frailty.

CONCLUSIONS

A strong operational definition would benefit both the development of treatments to counter cognitive frailty and the assessment of treatment effectiveness. Nevertheless, since there is clear agreement regarding the importance of interventions for and the prevention of cognitive frailty, randomized controlled trials investigating the efficacy of preventive interventions are necessary.

Social network changes among older Europeans: the role of gender

This study examined changes in the social networks of older Europeans. It utilizes the framework of the socioemotional selectivity theory and the convoy model to explore the social networks' changes over time, as well as the turnover of specific social network members. Furthermore, the study analyzed gender as a predictor of these transformations. The inquiry focused on older adults aged 65+ who participated in the fourth and sixth waves of the Survey of Health, Ageing, and Retirement in Europe (n = 13,938). The findings reveal a general trend of network expansion over time, with addition of new members and a higher proportion of family ties. These trends mask considerable individual variability in change trajectories, however. A series of OLS and Poisson regressions revealed that women were more likely to report network growth via addition of new social network members, and lower family involvement. These findings underscore the dynamic nature of older Europeans' interpersonal milieu. They also underscore the role of gender in social network transformations and show that the dynamics of older Europeans' personal networks differ for men and women.

[Memory stimulation training and the functionality of the elderly without cognitive impairment: an integrative review]

The scope of this article is to identify the repercussions of the effect of memory stimulation in healthy elderly individuals. It is an integrative review of the literature, namely of articles published in the last seven years in English, Portuguese and Spanish. The selection was performed through cross-checking of key words: health of the elderly, memory and cognition in the Lilacs, Medline and IBECS databases. The inclusion criteria were: original article; addressing key issue; full text electronically available; population 60 years and above without diagnosis of cognitive impairment. Twelve articles were selected and it was identified that the effect of memory stimulation in the elderly without cognitive impairment can improve performance in advanced, instrumental and basic activities of daily living and in psychological, social and quality of life components in the elderly. Based on analysis of the articles it is important to emphasize the need for further longitudinal and intervention studies focused on cognitive stimulation in the elderly without cognitive impairment and that future research can overcome such limitations by working towards efficient monitoring and evaluation, which is more rigorous and committed to facilitate the cognitive performance of the elderly in daily activities.