Reserve Theory Research Articles

Cognitive Reserve and Cognitive Functioning among Oldest Old Adults: Findings from the Georgia Centenarian Study

ABSTRACT Objectives Living a long life does not guarantee the maintenance of optimal cognitive functioning; however, similar to older adults in general, cognitive reserve may also protect oldest-old adults from cognitive decline. The purpose of this study was to assess cognitive reserve among centenarians and octogenarians and to evaluate a process model of cognitive reserve. Methods A total of 321 centenarians and octogenarians from the Georgia Centenarian Study were included in this study. Cognitive reserve components included level of education, occupational responsibility, current social engagement, past engaged lifestyle, and activity. Cognitive functioning was measured with the Mini-Mental Status Examination. Results Structural equation modeling was computed, and the overall model fit well, χ2 (df = 3) = 5.02, p = .17; CFI = .99, RMSEA = .05. Education is directly and indirectly related to cognitive functioning through occupational responsibility and past engaged lifestyle. Current social engagement is related to cognitive functioning directly and indirectly through current activities. The four direct predictors (i.e., education, current social engagement, current activity, and past engaged lifestyle) explained 35% of the variance in cognitive functioning. Conclusion The results provide important information for cognitive reserve theories with implications for interventions that build cognitive reserve.

Sex differences in risk factors that predict progression from mild cognitive impairment to Alzheimer's dementia.

To evaluate whether cerebrospinal fluid biomarkers, apolipoprotein e4, neuroimaging abnormalities, and neuropsychological data differentially predict progression from mild cognitive impairment (MCI) to dementia for men and women. Participants who were diagnosed with MCI at baseline (n = 449) were classified as either progressing to Alzheimer's dementia at follow-up or as not progressing. Men and women were first compared using bivariate analyses. Sex-stratified Cox proportional hazard regressions were performed examining the relationship between baseline data and the likelihood of progressing to dementia. Sex interactions were subsequently examined. Cox proportional hazard regression controlling for age and education indicated that all variables significantly predicted subsequent progression to dementia for men and women. Sex interactions indicated that only Rey Auditory Verbal Learning Test (RAVLT) delayed recall and Functional Activities Questionnaire (FAQ) were significantly stronger risk factors for women. When all variables were entered into a fully adjusted model, significant risk factors for women were Aβ42, hippocampal volume, RAVLT delayed recall, Boston Naming Test, and FAQ. In contrast, for men, Aβ42, p-tau181, p-tau181/Aβ42, hippocampal volume, category fluency and FAQ were significant risk factors. Interactions with sex were only significant for p-tau181/Aβ42 and RAVLT delayed recall for the fully adjusted model. Men and women with MCI may to differ for which factors predict subsequent dementia although future analyses with greater power are needed to evaluate sex differences. We hypothesize that brain and cognitive reserve theories may partially explain these findings.

Sudden Stops, Productivity and the Optimal Level of International Reserves for Small Open Economies

This paper contributes to the theory of optimal international reserves by extending the Jeanne-Rancière (Econ J 121:905-930, 2011) endowment small open economy (SOE) model to a SOE with production that accounts for the main sources of economic growth. We, first, derive a richer analytical version of the optimal reserves formula in our set-up, essentially driven by labour-augmenting productivity and the saving rate. Then, under a plausible calibration based on 1975-2020 data averages for typical emerging market countries facing the risk of sudden stops in capital inflows, we find that the optimal reserves-to-output ratio is 7.5%, i.e., the mid-point in the range between that in Jeanne and Rancière (Econ J 121:905-930, 2011), of 9.1%, calibrated to the same sample of 34 middle-income countries, and that in Bianchi et al. (Am Econ Rev 108(9):2629-2670, 2018), of 6.0%, obtained in a different, sovereign debt model without capital and production. We explain the lower optimal reserves-to-output ratio relative to the endowment SOE by the role of capital accumulation as precautionary saving: the accumulated capital stock can potentially be used as a pledge to external creditors in obtaining borrowing, thereby insuring better a SOE against sudden stops. As the countries in our sample appear quite heterogeneous, we also compute the optimal reserves-to-output ratio by region. It turns out that our extended to production insurance SOE model matches well the average reserves-to-output ratio in the data for Latin America, represented by nearly half of our sample, 16 countries, at just above 10%. Yet, for Asia, Africa and Europe our regional model-based ratios understate considerably the respective data averages, suggesting the need to explore alternative modelling approaches.

Research note: Bridging the gaps between the theory and practice of nonprofit operating reserves

AbstractOver the last decade, scholars and practitioners have advocated for nonprofits to develop operating reserves to help them survive economic shocks, but questions about what can be considered financial reserves remain. To understand what it takes to build reserves, most previous studies used Liquid Unrestricted Net Assets (LUNA) calculated from organizations' Form 990 tax returns as the measure of reserves. Practitioners, however, seem to conceptualize reserves differently. Drawing from an original survey of arts and culture nonprofits as well as human services nonprofits administered during the early days of the COVID‐19 pandemic, we compared self‐reported measures of reserves to those based on academic definitions. We then explored if the factors found to estimate the size of nonprofit financial reserves in previous studies would predict the level of reserves that practitioners consider. Whether using the book value of reserves (i.e., LUNA) or the way practitioners think about reserves, we generally reached the same conclusions regarding the factors associated with reserve levels. These findings increase the reliability of studies that use LUNA despite the differences between “book” measures of reserves and how leaders consider their rainy‐day funds.

Higher global efficiency in functional brain network could delay cognitive decline in amyloid‐positive individuals: The cognitive reserve theory

AbstractBackgroundIt is known that cognitive reserve (CR) support resilience against the effects of brain pathology. However, it still remains to be elucidated what can be served as a proxy for the CR. In the current study we investigated whether particular functional brain features have protective effect for future cognitive decline. We also examined if the relationship is different according to amyloid‐beta (aß) positivity.MethodFunctional MRI data, clinical and neuropsychological data, and follow‐up information were downloaded from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. In the final analysis, 48 cognitively normal (CN) elderly and 46 elderly with mild cognitive impairment (MCI) were included. Cognitive decline was measured by mini mental status examination (MMSE) change score from baseline and the last follow‐up. Resting state function image data processing was carried out using FMRIB’s Software Library and Brain Connectivity Toolbox. Cox proportional hazards models were conducted to investigate the associations between several cognitive reserve proxies and future cognitive decline. In addition, the relationship was explored separately for aß positivityResultMean follow‐up month were 45.84 (50.33 for CN, 41.15 for MCI). Based on MMSE change score, 41 were identified as cognitively decliners. Among baseline functional brain network parameters (density, clustering coefficients, path length, and global efficiency) education, and American National Adult Reading Test (AMNART) error score, and 4 ADNI neuropsychological summary scores, global efficiency (HR=2.04, 95% CI 1.07‐3.91) and ADNI‐EF score (HR=0.41, 95% CI 0.26‐0.64) were significant in the Cox proportional hazard model (Figure1A). This association was observed only in aß positive group, whereas no significant association was found in aß negative group (Figure 1BC).ConclusionOur findings indicate that higher global efficiency in functional brain network and better executive function could delay cognitive decline, especially in aß positive group. Cognitive reserve is to preserve cognitive function better in the presence of brain pathology. Our study preliminary suggest that higher brain efficiency could play a key role in cognitive reserve in elders.

Association between brain reserve proxies and clinical progression in Alzheimer’s disease dementia

AbstractBackgroundGiven that dementia prevalence is getting higher around the world, it is important to make a prognosis about clinical progression after dementia diagnosis. Brain reserve theory suggests that greater reserve supports for functional adaptation to clinical progression in neurodegeneration. Therefore, we examined if reserve proxies at baseline were associated with clinical progression among Alzheimer’s disease dementia (ADD).MethodWe selected ADD data from Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. Composite FDG‐PET ROIs (angular gyri, posterior cingulate, and inferior temporal gyri; FDG ROIs), structural MRI volumes for hippocampus, entohinal, and intracranial volume (ICV), American National Adult Reading Test (AMNART) error score, functional activities questionnaire (FAQ), mini mental status examination (MMSE), and other clinical and neuropsychological data, and follow‐up data were downloaded. Clinical progression was measured by change score of clinical dementia rating sum of box (CDR SB change) between baseline and the last follow‐up. Cox proportional hazards models were conducted to investigate the associations between reserve proxies and further progression with covariates of age, gender, and MMSE.ResultWe included 120 patients with ADD at baseline. Mean follow‐up month were 11.42 (5.82, range 6∼24month). Based on CDR SB change, 87 were identified as progression group, while 33 were stable group. At baseline, there were no significant group difference in demographic variables, follow‐up month, CDR SB, FDG ROIs, MRI volumes, distribution of APOE ε4 and Aß positive. However, progression group showed lower performance in AMNART and some neuropsychological tests. Among reserve proxies (education, AMNART, FDG ROIs, ICV, FAQ), FDG ROIs (HR=2.209, p=0.002, 95% CI 1.339‐3.643) was significant in the Cox proportional hazard model. This association was observed only in lager ICV group (HR=4.628, p=0.001, 95% CI 1.810‐11.837), whereas no significant association was found in smaller ICV group.ConclusionOur findings indicate that relatively preserved brain metabolism may slow a rate of clinical progression in ADD, particularly in greater ICV group. In addition to ICV, which is widely used proxy for brain reserve, glucose brain metabolism could play a key role in functional compensation in the process of neurodegeneration.

The protective impact of education on brain structure and function in Alzheimer\u2019s disease

BackgroundThe 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.MethodsFifty-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.ResultsIn 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.ConclusionsOur 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.

The Dow Doesn’t Serve Society

It has recently been shown that American GDP causes several human imperatives and is itself caused by globalization (Bechtel, 2021). This note reports a surprising exception to this finding; namely, in contrast to other human imperatives, the Dow doesn’t cause any good, nor is it caused by any good. The findings here will inform the conceptual collision between Federal Reserve theory and modern monetary theory (Kelton, 2021) vis-à-vis the global isolation of the Dow. Hopefully, this information will also prevent young holders, who can’t afford the long-term Dow strategy advocated by media pundits, from getting hurt.

Examining the Role of the Noradrenergic Locus Coeruleus for Predicting Attention and Brain Maintenance in Healthy Old Age and Disease: An MRI Structural Study for the Alzheimer's Disease Neuroimaging Initiative.

The noradrenergic theory of Cognitive Reserve (Robertson, 2013–2014) postulates that the upregulation of the locus coeruleus—noradrenergic system (LC–NA) originating in the brainstem might facilitate cortical networks involved in attention, and protracted activation of this system throughout the lifespan may enhance cognitive stimulation contributing to reserve. To test the above-mentioned theory, a study was conducted on a sample of 686 participants (395 controls, 156 mild cognitive impairment, 135 Alzheimer’s disease) investigating the relationship between LC volume, attentional performance and a biological index of brain maintenance (BrainPAD—an objective measure, which compares an individual’s structural brain health, reflected by their voxel-wise grey matter density, to the state typically expected at that individual’s age). Further analyses were carried out on reserve indices including education and occupational attainment. Volumetric variation across groups was also explored along with gender differences. Control analyses on the serotoninergic (5-HT), dopaminergic (DA) and cholinergic (Ach) systems were contrasted with the noradrenergic (NA) hypothesis. The antithetic relationships were also tested across the neuromodulatory subcortical systems. Results supported by Bayesian modelling showed that LC volume disproportionately predicted higher attentional performance as well as biological brain maintenance across the three groups. These findings lend support to the role of the noradrenergic system as a key mediator underpinning the neuropsychology of reserve, and they suggest that early prevention strategies focused on the noradrenergic system (e.g., cognitive-attentive training, physical exercise, pharmacological and dietary interventions) may yield important clinical benefits to mitigate cognitive impairment with age and disease.

Cumulative exposure to psychosocial stressors at work and global cognitive function: the PROspective Quebec Study on Work and Health

ObjectivesPsychosocial stressors at work have been proposed as modifiable risk factors for mild cognitive impairment (MCI). This study aimed to evaluate the effect of cumulative exposure to psychosocial stressors at...

159 The Role of Education on the Association between OSA and Cognitive Functions in Middle-age and Older Adults

Abstract Introduction A weak relation between an increase in education and improved health knowledge was observed among those who attended college, but not among those whose highest educational level attainment was high school (Altindag, Cannonier, & Mocan, 2014). Alachantis and colleagues (2005) had applied cognitive reserve theory (Stern, 2002) to help explain why OSA patients with higher intelligence scores perform well on cognitive tasks. The resource substitution theory (RST; Ross & Mirowsky, 2006) posits that higher education compensates for background disadvantages rather than magnifying background advantages. The goals of the current study were to examine the interaction between educational level and obstructive sleep apnea (OSA) on cognitive functions such as verbal fluency, psychomotor vigilance, executive functions, visuospatial ability, and attention span and to determine whether the results would support the RST. Methods One hundred and nine participants (47 ApneaLinkTM -screened controls and 62 untreated OSA patients) participated in the study and completed the Wisconsin Card Sorting Test, WAIS-III digit span and block design, semantic and phonemic fluency tests, and a psychomotor vigilance task. Subjective sleep (PSQI and ESS) and health measures (depression, anxiety, mood disturbance, diabetes, hypertension) were assessed. A hierarchical regression was conducted to test for the additional variance explained by the interaction term even after accounting for the covariates. Results In semantic fluency and visuospatial ability tasks, patients with higher education performed better than patients with high school or less education. This moderation effect of education was not observed for the control group. A significant interaction effect was not observed for vigilance, phonemic fluency, attention span, or executive functions although education was a significant predictor for all cognitive tasks. Conclusion The resource substitution theory was supported as the benefit of education seemed more crucial for OSA patients than for controls, specifically in semantic fluency and visuospatial ability. This benefit of higher education contributing to larger cognitive reserves in patients with OSA helped buffer some cognitive deficits but not for others, but this buffer no longer works when the cognitive demand gets larger. Support (if any) A grant from the Center for Integrative Research on Cognitive Neural Science, Southern Illinois University Carbondale was received.

Activity Engagement and Cognitive Performance Amongst Older Adults.

Research supporting cognitive reserve theory suggests that engaging in a variety of cognitive, social, and physical activities may serve as protective factors against age-related changes in mental functioning, especially if the activities are cognitively engaging. Individuals who participate in a variety of cognitive activities have been found to be more likely to maintain a higher level of cognitive functioning and be less likely to develop dementia. In this study, we explore the relationship between engaging in a variety of activities and cognitive performance amongst 206 healthy older adults between the ages of 65–85. Age and years of education were found to be the most significant predictors of a global composite representing cognitive performance, consistent with previous work linking these variables to age-related changes in cognition and the cognitive reserve. We interpret these results to suggest that age and education are better predictors of global cognitive performance in older adults than self-reported activity engagement.

Multilingualism and the Reserve Theory

It has been well recognized that patients with comparable dementia severity may show different levels of brain pathology. This is commonly explained by cognitive or brain reserve theory: patients with more reserve can tolerate more severe brain pathologies because the reserve can compensate for the neuropathological processes. Various life experiences contribute to the reserve, one of which may be multilingualism. Multilinguals need to select the appropriate language for a conversational partner and to keep other languages inactivated. Such experiences reinforce the multilingual executive functions, and change neuroanatomical and neurophysiological features of the brain, which some researchers propose can serve as a reserve and prevent dementia. The earliest such report was Bialystok et al.'s (2007) paper, which demonstrated multilinguals showing signs of dementia approximately four years later than monolinguals. This finding seemed to support the hypothesis of multilingualism as a reserve, and was followed by many other reports testing the same. Notwithstanding the initial excitement, the data obtained so far have been mixed at best in terms of the possibility of multilingualism influencing the neuropathological processes of dementia. This paper summarizes recent findings on multilingualism and the reserve theory, and discusses identified research issues that need to be resolved.

Burnout and job performance: a two-wave study on the mediating role of employee cognitive functioning

ABSTRACT This two-wave study examined whether job burnout relates negatively to employees’ performance in executive functions (i.e., working memory, inhibition capacity, cognitive flexibility, reasoning, problem solving, and planning – assessed through psychometric tests) and positively to everyday cognitive failures (rated by colleagues) over time. Furthermore, based on cognitive reserve and self-regulation theories, we hypothesized that poor cognitive functioning mediates the negative relationship between burnout and job performance (i.e., task and contextual performance), as rated by employees and their close colleagues. The study was conducted among 102 employees and their colleagues, who were followed up over a period of about a year. Structural equation modelling analyses revealed that burnout related to lower performance on working memory and inhibition capacity and to more cognitive failures over time, while reduced cognitive flexibility was associated to higher burnout over time. Moreover, results showed that poor working memory and cognitive failures mediated the negative relationship between burnout and task performance. These findings suggest that burnout prevents optimal utilization of cognitive resources limiting cognitive functioning and consequently, job performance.

Early Child-Parent Relationship Quality and Cognitive Function in Older Rural Chinese Adults: The Mediating Role of Educational Attainment.

Objectives: Framed within a life course perspective and cognitive reserve theory, this study examined the mediating role of educational attainment for the association between child-parent relationships during childhood and cognitive function among older adults in rural China. Methods: Data were obtained from three waves of the China Health and Retirement Longitudinal Study (N = 9809). We employed latent growth curve modeling to test the association among early child-parent relationship quality, educational attainment, and cognitive function in later life. Results: Early child-mother relationship quality was associated with the level and change in cognitive function. Early child-father relationship quality was only related to baseline cognitive function. Educational attainment mediated the relationship between early child-parent relationship quality with mothers and fathers and cognitive function. Discussion: Parental relationship experience in childhood was one distal factor related to cognitive function among older adults. The findings supported the long-term impacts of childhood conditions for later life health consequences.

Modern aspects of the theory and practice of international reserves

Modern aspects of the theory and practice of international reserves

Cognitive reserve protects language functions in patients with brain tumours

Cognitive reserve (CR) theory suggests that individual differences in general intelligence (IQ), occupational attainment or participation in leisure/recreational activities protect against cognitive decline. However the relationship between CR and cognitive functioning in patients with brain tumours has been very rarely investigated in past research. The present study systematically assesses whether CR concept can also be applied to cognitive functions of neurosurgical patients affected by brain tumours. We investigated the role of different CR proxies (education level, premorbid IQ, current IQ, working and leisure activity) in protecting language against brain tumours and surgery effects, considering interactions with demographic (sex/age), anatomical (hemisphere/lobe location of lesion) and clinical/biological variables (tumour type: High/Low Grade Glioma or Meningioma; lesion volume; lesion aggressiveness). One-hundred patients undergoing neuropsychological assessment before and immediately after surgery participated. A “Language Score” summarizing performance on all language tests was derived with Principal Component Analysis. Data were then analyzed with Multiple Regression and Classification and Regression Tree analyses to investigate possible relationships between predictors (CR proxies and clinical variables) and Language Score. We found that premorbid IQ was the best predictor of pre-operatory language integrity, above and beyond all clinical variables considered, also moderating lesion volume effects. Moreover, patients with lower pre-operatory language integrity and low-to-moderately aggressive tumours showed a mitigating effect of current IQ over surgery consequences. Results thus suggest that different CR proxies play a role in moderating cognitive decline following brain tumours and surgery.

A profile of brain reserve in adults at genetic risk of Alzheimer's disease.

IntroductionThe apolipoprotein E (APOE) ε4 allele is the greatest genetic risk factor for Alzheimer's disease (AD). Our aim was to identify the structural brain measures that mitigate the negative effect of APOE ε4 on cognition, which would have implications for AD diagnosis and treatment trial selection.MethodsA total of 742 older adults (mean age: 70.1 ± 8.7 years) were stratified by APOE status and classified as cognitively normal (CDR 0) or with very mild dementia (CDR 0.5). Regional brain volume and cognitive performance were measured.ResultsThere were significant interactions between APOE and CDR on the left precuneus and on bilateral superior frontal volumes. These regions were preserved in CDR‐0 ε3/ε4 and ε4/ε4 carriers but were reduced in CDR‐0.5 ε3/ε4 and ε4/ε4 carriers, compared to their respective ε3/ε3 counterparts. Educational attainment predicted greater brain reserve.DiscussionThis pattern of preserved brain structure in cognitively normal ε4 carriers with comprised medial temporal volume is consistent with the theory of brain reserve.

Reserva cognitiva e os diferentes perfis de ganho cognitivo em idosos

O objetivo desse estudo foi verificar diferentes perfis de ganho cognitivo em idosos para a reserva cognitiva. Trata-se de uma scoping review, utilizando-se PubMed, Medline, Web of Science, Science Direct, Lilacs, SciELO, PsycInfo, PsycNet e AgeLine como base de dados; restringiu-se a busca entre o ano de 2008 e 2018. Identificou-se 2295 estudos e 51 foram elegíveis para a revisão. Dentre os 51 estudos selecionados, encontrou-se 9 perfis diferentes para manutenção cognitiva, sendo que 5 estudos não especificaram o perfil. Conclusão: Os perfis encontrados representaram relevância para a teoria de reserva cognitiva e forneceram esclarecimentos de como fatores individuais e de vida diária podem fazer o cérebro mais resiliente no envelhecimento e na velhice; no entanto, esses fatores individuais e o modo como eles contribuem para o desenvolvimento da reserva cognitiva e da manutenção da cognição ainda permanecem obscuras na literatura

Protective effects of cognitive and brain reserve in multiple sclerosis: Differential roles on social cognition and ‘classic cognition’

BackgroundAccording to cognitive reserve (CR) and brain reserve (BR) theories, lifetime intellectual enrichment and maximal brain volume protect against cognitive decline. ObjectiveTo examine the effects of CR and BR on social cognition in multiple sclerosis (MS), and compare it with ‘classic cognition’. MethodsWe included 60 MS patients and 60 healthy controls matched on age, sex, and education. Education was used has a proxy of CR and intracranial volume (ICV) as a proxy of BR. Participants underwent Theory of Mind (ToM) testing (Eyes Test, Videos Test), comprehensive neuropsychological assessment and 3Tesla brain MRI. Cortical and subcortical grey matter (GM) volumes were calculated. ResultsWe found positive effects of education and ICV on general cognitive status and ToM performance, respectively. Higher education moderated the impact of subcortical GM atrophy on ‘classic’ cognitive status (R2=0.219, p=<0.001). Conversely, greater ICV attenuated the impact of cortical GM atrophy on Eyes Test (R2=0.158, p=0.002) and Videos Test (R2=0.198, p=0.001). Stratification for disease duration showed that the protective effect of education/ICV occurred in early stages of disease (<10 years). ConclusionCR and BR have differential protective roles in MS, with BR having a positive effect on social cognition and CR on ‘classic’ cognitive domains.