Contribution of education, occupation and cognitively stimulating activities to the formation of cognitive reserve

The Role of RIN3 Gene in Alzheimer's Disease Pathogenesis: a Comprehensive Review

Alzheimer's disease (AD) is a globally prevalent form of dementia that impacts diverse populations and is characterized by progressive neurodegeneration and impairments in executive memory. Although the exact mechanisms underlying AD pathogenesis remain unclear, it is commonly accepted that the aggregation of misfolded proteins, such as amyloid plaques and neurofibrillary tau tangles, plays a critical role. Additionally, AD is a multifactorial condition influenced by various genetic factors and can manifest as either early-onset AD (EOAD) or late-onset AD (LOAD), each associated with specific gene variants. One gene of particular interest in both EOAD and LOAD is RIN3, a guanine nucleotide exchange factor. This gene plays a multifaceted role in AD pathogenesis. Firstly, upregulation of RIN3 can result in endosomal enlargement and dysfunction, thereby facilitating the accumulation of beta-amyloid (Aβ) peptides in the brain. Secondly, RIN3 has been shown to impact the PICLAM pathway, affecting transcytosis across the blood-brain barrier. Lastly, RIN3 has implications for immune-mediated responses, notably through its influence on the PTK2B gene. This review aims to provide a concise overview of AD and delve into the role of the RIN3 gene in its pathogenesis.

Childhood engagement in cognitively stimulating activities moderates relationships between brain structure and cognitive function in adulthood

Greater engagement in cognitively stimulating activities (CSA) during adulthood has been shown to protect against neurocognitive decline, but no studies have investigated whether CSA during childhood protects against effects of brain changes on cognition later in life. The current study tested the moderating role of childhood CSA in the relationships between brain structure and cognitive performance during adulthood. At baseline (N=250) and 5-year follow-up (N=204) healthy adults aged 20-80 underwent MRI to assess four structural brain measures and completed neuropsychological tests to measure three cognitive domains. Participants were categorized into low and high childhood CSA based on self-report questionnaires. Results of multivariable linear regressions analyzing interactions between CSA, brain structure, and cognition showed that higher childhood CSA was associated with a weaker relationship between cortical thickness and memory at baseline, and attenuated the effects of change in cortical thickness and brain volume on decline in processing speed over time. These findings suggest higher CSA during childhood may mitigate the effects of brain structure changes on cognitive function later in life.

Educational Attainment and Later-Life Cognitive Function in High- and Middle-Income Countries: Evidence From the Harmonized Cognitive Assessment Protocol

OBJECTIVES

Identifying social policies that can promote cognitive health is crucial for reducing the global burden of dementia. We evaluated the importance of educational attainment for later-life cognitive function in various social and geographic settings.

METHODS

Using harmonized data for individuals aged ≥65 years from the United States Health and Retirement Study (HRS) and its international partner studies in England, Mexico, China, and India, and each study's respective Harmonized Cognitive Assessment Protocol (HCAP), we conducted a cross-national comparative study to examine the role of educational attainment in later-life cognitive function across countries (n = 14,980, 2016-2019). We used multivariable-adjusted regression to estimate associations between educational attainment and harmonized global cognitive function scores.

RESULTS

In Mexico, China, and India, the general cognitive function scores on average are approximately one standard deviation of the HRS-HCAP cognitive function score distribution lower compared to the United States and England, paralleling patterns of educational attainment across countries. In all countries, higher educational attainment was associated with progressively higher later-life cognitive function scores. Population-level differences in educational attainment explained about 50%-90% of the observed differences in cognitive function scores across countries.

DISCUSSION

The relationship between education and later-life cognitive function across social and geographic contexts underscores the crucial role of education to promote cognitive health and reduce dementia risk. Continual improvement of educational attainment in low- and middle-income settings may yield a significant pay-off in later-life cognitive health.

Unexpected cognitive similarities between older adults and young people: Scores variability and cognitive performances

BACKGROUND

Increased interindividual variability in cognitive performance during aging has been proposed as an indicator of cognitive reserve.

OBJECTIVE

To determine if interindividual variability performance in episodic memory (PAL), working memory (SWM), reaction time (RTI), and sustained attention (RVP) could differentiate clusters of differential cognitive performance in healthy young and older adults and search for cognitive tests that most contribute to these differential performances.

METHODS

We employed hierarchical cluster and canonical discriminant function analyses of cognitive scores using the Cambridge Neuropsychological Test Automated Battery (CANTAB) to identify cognitive variability in older and young adults using the coefficient of variability of cognitive performances between and within groups. We also analyzed potential influences of age, education, and physical activity.

RESULTS

Cluster analysis distinguished groups with differential cognitive performance and correlation analysis revealed coefficient of variability and cognitive performance associations. The greater the coefficient of variability the poorer was cognitive performance in RTI but not in PAL and SWM. Older adults showed diverse trajectories of cognitive decline, and better education or higher percentage of physically active individuals exhibited better cognitive performance in both older and young adults.

CONCLUSION

PAL and SWM are the most sensitive tests to investigate the wide age range encompassing older and young adults. In older adults' intragroup analysis PAL showed greater discriminatory capacity, indicating its potential for clinical applications late in life. Our data underscore the importance of studying variability as a tool for early detection of subtle cognitive declines and for interpreting results that deviate from normality.

Cognitive reserve and other determinants of cognitive function in older adults: Insights from a community-based cross-sectional study

Background

India will be the home of 323 million elderly persons by 2050. This means a surge in the dependent population primarily due to age-related cognitive decline. Evidence suggests that life course factors may have a modulatory role on cognitive function. The present study explores such potential influence by investigating the effect of cognitive reserve (a latent construct using education and occupation) and physical, psychological, and social determinants on cognitive function in community dwelling elderly.

Methods

A community-based cross-sectional study was conducted in urban areas of West Bengal (India) among elderly aged ≥60 years. Data was collected by personal interviews for socio-demographic and medical profile. Cognitive function was assessed using Bangla Adaptation of Mini-Mental State Examination (BAMSE). Educational level and occupational complexity were used as proxy indicators for calculating cognitive reserve.

Results

Of the 370 elderlies interviewed (mean age = 68.9 years), cognitive function was abnormal in 13.5%. The cognitive function had a significant inverse relationship with depression symptoms, loneliness, hypertension, anemia, and basic activities of daily living. There was a significant difference in the cognitive reserve of the elderly with normal and abnormal cognitive function (mean 33.7 and 26.8, respectively). In the presence of covariates like sleep quality, depression, hypertension, and hemoglobin levels, the effect of age on cognitive function had a significant mediation influence of cognitive reserve - total effect = -0.2349; 95% CI = (-0.2972 to -0.1725) and direct effect = -0.2583; 95% CI = (-0.3172 to -0.1994).

Conclusion

The quantum of effect of the age on cognitive function decreases with good cognitive reserve as a cognitive reserve has a significant mediation effect on the relationship between age and cognitive function.

Sex differences in cognitive aging and the role of socioeconomic status: Evidence from multi-cohort studies

BACKGROUND

Sex differences exist in cognitive function, and socioeconomic status (SES) may play a role in changing these discrepancies. This study investigated the role of SES in contributing to sex differences in cognitive function.

METHODS

We conducted a pooled multi-cohort study on the basis of four comparative cohort studies from the UK, the US, Europe and China to assess sex differences and the role of SES in cognitive decline by birth cohort (1930-1938, 1939-1945, 1946-1968). Cognitive function was measured in three domains based on the mean and SD of the corresponding tests: episodic memory, working memory, and time orientation. SES was the summed scores of education and household wealth.

FINDINGS

61,019 individuals were involved. Cognitive function of women declined faster than those of men as growing old (particularly after 80 years old). As SES increased, cognitive function increased more for women than for men in most cases among later-born cohorts (1930-1938, 1939-1945, 1946-1968) (e.g., episodic memory scores at 60 years old: women exhibited an increase from -0.09 [95%CI -0.12, -0.07] in low SES to 0.89 [0.86, 0.92] in high SES; men from -0.16 [-0.19, -0.14] to 0.59 [0.56, 0.62]). However, sex-specific cognitive benefits were absent in the oldest birth cohort (1895-1929).

INTERPRETATION

These findings highlight the importance of considering the role of SES in the discrepancy of sex difference in cognitive aging.

The perceived mental effort of everyday activities in older adults

People's perceptions of the mental effort required for everyday activities may drive variation in the relationships between lifestyles and cognitive ability. We asked n = 259 healthy older adults aged 60 to 70 years (90 males, 169 females) to provide a rating of the Perceived Mental Effort (PME) for each activity instance they recalled over a 48-h period as part of a time-use recall. PME was rated on a 9-point scale from "very, very low" (score of 1) to "very, very high" (score of 9). Across the entire sample, participants rated a total of 196 different activities and 17,433 activity instances. The mean PME for individual activities was 3.50 ± 1.58. PMEs varied significantly by activity domain, with highest ratings being for Work (5.48 ± 1.72) and the lowest for Self-Care (2.89 ± 0.98). In multivariate analyses, PME ratings were higher in males than females (+0.30), PMEs were higher later in the day, increased with task duration, and decreased with age (all p < 0.0001). Time-weighted average individual PMEs across the two days of recall ranged from 1.86 to 6.50, and were 0.3 units higher for males, but unrelated to age. Repeated intra-individual PME ratings for the same activity were very reliable (ICC = 0.995, mean absolute difference = 0.03 ± 0.17). PMEs show promise as a reliable measure of mental effort.

Metamemory mediates the protective effect of cognitive reserve on episodic memory during aging

The present study investigated the impact of cognitive reserve on episodic memory and metamemory control during aging using a multidimensional index of cognitive reserve and a measure of metamemory control abilities. We tested the hypotheses that cognitive reserve may play a protective role against age-related differences in episodic memory and metamemory control and that metamemory control may mediate the effect of cognitive reserve on episodic memory during aging. Young and older adults carried out a readiness-recall task in which task difficulty was manipulated through a variation of the nature of the cue-target pair link (weak vs. strong semantic associates). Episodic memory was assessed through recall performance, and metamemory by a task difficulty index reflecting the ability to adjust study time to task difficulty. Results confirmed that older adults recall fewer words, indicating an age-related deficit in episodic memory, and that older adults adjust less to task difficulty, suggesting impaired metamemory control. Findings also showed that metamemory control moderates the age-related decline in episodic memory and that cognitive reserve plays a protective role against age-related deficits in episodic memory and metamemory control. In addition, metamemory abilities mediated the beneficial effect of cognitive reserve on episodic memory performance during aging. Hence, this study sheds new light on the mechanisms underlying the impact of cognitive reserve on cognitive aging, highlighting the role of metacognitive processes.

The age differences and effect of mild cognitive impairment on perceptual-motor and executive functions

It is unclear whether the decline in executive function (EF) and perceptual-motor function (PMF) found in older adults with mild cognitive impairment (MCI) is the result of a normal aging process or due to MCI. This study aimed to determine age-related and MCI-related cognitive impairments of the EF and PMF. The EF and PMF were investigated across four groups of 240 participants, 60 in each group, including early adult, middle adult, older adult, and older adult with probable MCI. The EF, working memory, inhibition, and cognitive flexibility were evaluated using digit span backward tasks, the Stroop color-word test, and the modified switching verbal fluency test, respectively. The PMF, visual perception, visuoconstructional reasoning, and perceptual-motor coordination were evaluated using the clock reading test, stick design test, and stick catching test, respectively. Group differences were found for all subdomains of EF and PMF (p < 0.05), except for perceptual-motor coordination, indicating that this subdomain could be maintained in older adults and was not affected by MCI. For the age difference, working memory, cognitive flexibility, visual perception, and visuoconstructional reasoning remained stable across middle adults and started to decline in older adults, while cognitive inhibition began to decrease in middle adults and it further declined in older adults. To control the confounding effect of education level, the results showed that only cognitive flexibility was further decreased in older adults with probable MCI compared to those without MCI (p < 0.05). In conclusion, cognitive inhibition decreased earlier in middle adults, whereas EF and PMF started to decline in older adults. Cognitive flexibility was the only MCI-sensitive cognitive function.

An individualized functional magnetic resonance imaging protocol to assess semantic congruency effects on episodic memory in an aging multilingual population

The cognitive stimulation induced by multilingualism may slow down age-related memory impairment. However, a suitable neuroscientific framework to assess the influence of multilingualism on age-related memory processes is missing. We propose an experimental paradigm that assesses the effects of semantic congruency on episodic memory using functional magnetic resonance imaging (fMRI). To this end, we modified the picture-word interference (PWI) task to be suitable for the assessment of older multilingual subjects undergoing fMRI. In particular, stimulus materials were prepared in multiple languages (French, German, Luxembourgish, English) and closely matched in semantic properties, thus enabling participants to perform the experiment in a language of their choice. This paradigm was validated in a group (n = 62) of healthy, older participants (over 64 years) who were multilingual, all practicing three or more languages. Consistent with the engagement of semantic congruency processes, we found that the encoding and recognition of semantically related vs. unrelated picture-word pairs evoked robust differences in behavior and the neural activity of parietal-temporal networks. These effects were negligibly modulated by the language used to perform the task. Based on this validation in a multilingual population, we conclude that the proposed paradigm will allow future studies to evaluate whether multilingualism aptitude engages neural systems in a manner that protects long-term memory from aging-related decline.

Cognitive reserve and its correlates in child and adolescent offspring of patients diagnosed with schizophrenia or bipolar disorder

AIM

To analyze cognitive reserve (CR) in child and adolescent offspring of patients diagnosed with schizophrenia (SZ-off) or bipolar disorder (BD-off) and compare them with a group of community controls (CC-off). We also aimed to investigate whether there was an association between CR and clinical and neuropsychological variables according to group.

METHODS

The study included 46 SZ-off, 105 BD-off and 102 CC-off. All participants completed assessments regarding CR and clinical, neuropsychological and psychosocial functioning. CR was measured with a proxy based on premorbid intelligence, parental occupational level, educational attainment, developmental milestones and sociability. The clinical assessment included the Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime, the Semi-structured Interview for Prodromal Syndromes, and the Global Assessment Functioning scale. The neuropsychological assessment included measures of executive functioning, attention, verbal memory, working memory and processing speed.

RESULTS

SZ-off showed a lower level of CR compared to BD-off and CC-off, while BD-off showed an intermediate level of CR between SZ-off and CC-off. Moreover, an association between higher CR and less lifetime psychopathology, fewer prodromal psychotic symptoms, higher psychosocial functioning, and a higher working memory score was observed in all groups, but it was stronger in SZ-off.

CONCLUSIONS

CR seemed to be associated with psychopathology, clinical symptoms, psychosocial functioning, and some cognitive functions. SZ-off appeared to benefit more from a higher CR, therefore it could be considered a protective factor against the development of clinical symptomatology and cognitive impairment.

Relationships between enriching early life experiences and cognitive function later in life are mediated by educational attainment

The study of how engagement in enriching cognitive, physical and social activities in childhood impacts cognitive function decades later will advance our understanding of how modifiable lifestyle activities promote cognition across the lifespan. 88 healthy older adults (aged 60-80 years) returned a retrospective questionnaire regarding their participation in seven lifestyle activities (musical instrument playing, language learning, sport participation, art/dance lessons, scouting, volunteering, family vacations) before age 13 years. After controlling for current age, educational attainment, socioeconomic status of the mother and current engagement in lifestyle activities, a greater number of activities were significantly associated with better vocabulary abilities, episodic memory and fluid intelligence. The relationships with vocabulary and fluid intelligence were mediated by educational attainment. We postulate that engagement in a higher number of enriching early life activities is a reflection of both one's sociocontextual environment and engagement with that environment. This engagement leads to attributes relevant for educational aspirations/attainment, ultimately contributing to factors that have a lifespan impact on cognitive function.

The Importance of Improving Educational Attainment for Dementia Prevalence Trends From 2000 to 2014, Among Older Non-Hispanic Black and White Americans

OBJECTIVES

While a number of studies have documented a notable decline in age-standardized prevalence in dementia in the U.S. population, relatively little is known about how dementia has declined for specific age and race groups, and the importance of changing educational attainment on the downward trend. We assess (a) how the trends in dementia prevalence may have differed across age and race groups and (b) the role of changing educational attainment in understanding these trends.

METHODS

This article estimates a series of logistic regression models using data from the Health and Retirement Study (2000-2014) to assess the relative annual decline in dementia prevalence and the importance of improving educational attainment for non-Hispanic Whites and non-Hispanic Blacks.

RESULTS

Consistent with other studies, we found significant declines in dementia for non-Hispanic Blacks and non-Hispanic Whites across this period. Nonetheless, these declines were not uniform across age and race groups. Non-Hispanic Blacks aged 65-74 years had the steepest decline in this period. We also found that improved educational attainment in the population was fundamentally important in understanding declining dementia prevalence in the United States.

DISCUSSION

This study shows the importance of improvement in educational attainment in the early part of the twentieth century to understand the downward trend in dementia prevalence in the United States from 2000 to 2014.

Assessment of the Financial Capacity in the Context of Normal and Pathological Cognitive Aging. Preliminary Analysis of the Portuguese Version of the Numerical Activities of Daily- Living- Financial (NADL-F)

Financial capacity (FC) is conceptualized as a dimension that encompasses a wide range of basic aptitudes and the capacity to judge and assess situations and make decisions according to one best interests. The Numerical Activities of Daily-Living-Financial (NADL-F) is an instrument of FC for clinical use developed in Italy. This study aims to perform a preliminary analysis on the psychometric characteristics of the Portuguese version of NADL-F. NADL-F as well as other neuropsychological instruments were administered to three groups: Healthy Control (n = 11); Mild Neurocognitive Disorder group (n = 19); Major Neurocognitive Disorder group (n = 19). NADL-F and its tasks were considered acceptable, showed good reliability for the entire sample (α = .808) and the majority of the domains correlated significantly with each other and with the total scale. Between group comparisons showed significant differences regarding all domains. Arithmetic, schooling and executive functioning accounted for 54.1% of the variance on the test. The Portuguese version of NADL-F proved to be an acceptable and valid instrument of assessing FC in the context of cognitive aging. NADL-F is an instrument that emulates real life financial situations, and it can be used in a second level of evidence in the clinical model of FC assessment.

Early Warning Value of ASL-MRI to Estimate Premorbid Variations in Patients With Early Postoperative Cognitive Dysfunctions

Background: Postoperative cognitive dysfunction (POCD) is a general complication following cardiac and major non-cardiac surgery amongst the elderly, yet its causes and mechanisms are still unknown. The present study aimed to detect whether regional cerebral blood flow (CBF) is altered in the brain before surgery in POCD patients compared with non-POCD (NPOCD) patients, thus, CBF variation may potentially predict the occurrence of early POCD.

Methods: Fifty patients scheduled for spinal stenosis surgery were enrolled in the study. All study participants completed a battery of neuropsychological tests (NPTs) by a well-trained neuropsychologist before the surgery and 1 week after the surgery. POCD was defined when the preoperative to postoperative difference of at least two of the NPTs’ |Z|-scores with reference to a control group exceeded 1.96. Pulsed arterial spin-labeling (ASL) MRI was scanned at least 1 day before surgery. The ASLtbx toolkit and SPM12 were applied to preprocess and correct the images, which were then normalized to the MNI brain template space to obtain standardized cerebral perfusion images.

Results: POCD was identified in 11 out of 50 patients (22%). The CBF of the right superior temporal lobe, right and left middle cingulate gyrus, and the right hippocampus, and parahippocampal gyrus in POCD group was lower than that in NPOCD group (P < 0.001). The CBF of the pars triangularis of inferior frontal gyrus in POCD group was higher than that in NPOCD group (P < 0.001).

Conclusions: These preliminary findings suggest that CBF premorbid alterations may happen in cognitively intact elderly patients that develop early POCD. Alterations of preoperative CBF might be a bio-marker for early POCD that can be detected by noninvasive MRI scans.

The Frontal Assessment Battery 20 years later: normative data for a shortened version (FAB15)

OBJECTIVE

The Frontal Assessment Battery (FAB) is a neuropsychological tool largely used to assess executive functions. Prior studies found a marked ceiling effect for the prehension behavior subtest (PBT) in healthy and clinical populations. Aims of the present study were (i) to examine the psychometric properties of the FAB without the contribution of PBT and (ii) to provide normative data for a revised version of the FAB after exclusion of PBT (FAB15).

METHODS

The normative sample included 1,187 healthy participants. PBT had near-zero variance, poor content validity, and no discrimination power. Internal consistency increased when PBT was excluded. We assessed the FAB15 factorial structure, interrater, and test-retest reliabilities. Normative data  for the FAB15 were extracted through a regression-based procedure according to sex, age, and education.

RESULTS

The principal component analysis revealed a single "executive factor" or alternatively a bifactorial solution reflecting the different degree of discriminative capability vs. difficulty of the subtests. The FAB15 demonstrated excellent interrater and test-retest reliabilities. Regression analysis showed that sex (lowly educated women < lowly educated men), higher age, and lower education affected FAB15 score. Accordingly, three grids for adjustment of raw scores (men, women, and both) were constructed. The cut-off was fixed at the non-parametric outer tolerance limit on the fifth centile (9.36, 95% CI).

CONCLUSION

The observation of a ceiling effect in healthy subjects makes PBT not suitable for inclusion in a neuropsychological battery. The FAB15 may successfully replace the conventional FAB as a more severe and valid short screening tool to assess executive functioning.

Associations between life course marital biography and late-life memory decline

Late-life marital status is associated with cognitive aging; however, the influence of life course marital biography (i.e., changes in marital status) on late-life cognitive trajectories, as well as gender differences in the effects of marital biography, remain to be explored. Associations between (a) marital status at study baseline (currently married, previously married, never married) and (b) retrospectively reported life course marital biography (i.e., age at first marriage, time spent unmarried following initial marriage, history of divorce, history of widowhood) and up to 20 years of subsequent episodic memory trajectories were examined using latent growth curve models in 3,061 participants aged 51 + in the Health and Retirement Study 2017 Life History Mail Survey. Gender differences were examined with multiplicative interaction terms and stratified models. Participants who were married at study baseline demonstrated higher initial memory than previously and never married individuals. Older age at first marriage and shorter duration spent unmarried were each associated with better initial episodic memory among previously married individuals only; longer duration spent unmarried was associated with slower memory decline. Stratified models suggested that these associations may be driven by women. These results highlight the importance of considering multiple aspects of marital biography, not just current marital status, in cognitive aging research. Marital biography may have an enduring influence on cognitive aging, particularly among previously married older women. Future work is needed to identify mechanisms (e.g., socioeconomic resources, cognitive stimulation, self and spousal health, emotional support) through which marital histories influence cognitive aging. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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

INTRODUCTION

The 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.

METHODS

A 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.

RESULTS

There 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.

DISCUSSION

This pattern of preserved brain structure in cognitively normal ε4 carriers with comprised medial temporal volume is consistent with the theory of brain reserve.

Positive Effect of Cognitive Reserve on Episodic Memory, Executive and Attentional Functions Taking Into Account Amyloid-Beta, Tau, and Apolipoprotein E Status

Studies exploring the simultaneous influence of several physiological and environmental factors on domain-specific cognition in late middle-age remain scarce. Therefore, our objective was to determine the respective contribution of modifiable risk/protective factors (cognitive reserve and allostatic load) on specific cognitive domains (episodic memory, executive functions, and attention), taking into account non-modifiable factors [sex, age, and genetic risk for Alzheimer's disease (AD)] and AD-related biomarker amount (amyloid-beta and tau/neuroinflammation) in a healthy late-middle-aged population. One hundred and one healthy participants (59.4 ± 5 years; 68 women) were evaluated for episodic memory, executive and attentional functioning via neuropsychological test battery. Cognitive reserve was determined by the National Adult Reading Test. The allostatic load consisted of measures of lipid metabolism and sympathetic nervous system functioning. The amyloid-beta level was assessed using positron emission tomography in all participants, whereas tau/neuroinflammation positron emission tomography scans and apolipoprotein E genotype were available for 58 participants. Higher cognitive reserve was the main correlate of better cognitive performance across all domains. Moreover, age was negatively associated with attentional functioning, whereas sex was a significant predictor for episodic memory, with women having better performance than men. Finally, our results did not show clear significant associations between performance over any cognitive domain and apolipoprotein E genotype and AD biomarkers. This suggests that domain-specific cognition in late healthy midlife is mainly determined by a combination of modifiable (cognitive reserve) and non-modifiable factors (sex and age) rather than by AD biomarkers and genetic risk for AD.

Cognitive Differences in the Older Adults Living in the General Community: Gender and Mental Occupational State Study

Older adults are particularly vulnerable to cognitive impairment with age, and gender differences are remarkable. However, there is very little evidence to identify both baseline cognitive and occupational gender differences prior to older adults' retirement to design more efficient personalized cognitive interventions. This descriptive observational study examined gender differences in initial cognitive performance in 367 older adults with subjective memory complaints from a primary healthcare center in Zaragoza (Spain). To evaluate initial cognitive performance, the Spanish version of the Mini-Mental State Examination (MEC-35) and the set test were used to measure verbal fluency. Sociodemographic and clinical characteristics were evaluated, and cognitive and occupational differences were analyzed per gender. Men had higher educational and occupational levels, were older and more of them were married (p < 0.001) than women. Regarding cardiovascular risk factors, diabetes and cerebrovascular accidents were more frequent in women, while hypercholesterolemia and obesity were more frequent in men (p < 0.001). High blood pressure was more frequent in women, but not significantly so (p = 0.639). Global cognition was higher in men (p < 0.001) for attention, calculation, and language (p < 0.001). Verbal fluency was higher in women, but the difference was not statistically significant (p = 0.105). These results could be generalized to other health centers in the province and other Spanish autonomous communities as their sociodemographic variables are similar. Individualized interventions that adapt to gender, cognitive and initial occupational performance should be developed and adapted to elderly populations living in the general community to maintain their cognitive capacity and prevent their cognitive impairment and the social health costs this would imply.

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.

Cognitive Reserve and Driving-Related Cognitive Abilities in a Sample of Oldest Old Drivers Undergoing Assessment of Fitness to Drive

This study examines the relationship between age, cognitive reserve (CR), and driving-related cognitive abilities in a sample of oldest old drivers undergoing evaluation of fitness to drive. Structural equation modeling was used to investigate the associations between age, CR, and performances to a standardized set of cognitive tests assessing fitness to drive. Education and work complexity were used as proxy measures of CR. The results showed both measures of CR, but not age, were significantly associated with higher general intelligence. Education also predicted higher decision speed, and decision speed partly mediated the effect of education on general intelligence. These findings suggest that over age of 80 years old, CR was a better predictor of driving-related cognitive abilities than age. Education was associated with better performance across different cognitive domains including processing speed.

Sex differences and the role of education in cognitive ageing: analysis of two UK-based prospective cohort studies

BACKGROUND

Previous studies have shown an excess risk of Alzheimer's disease and related dementias among women. Education is thought to have a causal association with dementia onset. We aimed to investigate the role of education in influencing sex differences in cognitive ageing.

METHODS

We analysed data from two prospective cohort studies in the UK; the English Longitudinal Study of Ageing (ELSA) and the Whitehall II study, to assess sex differences in cognitive performance and cognitive decline by birth cohort (birth year 1930-38, 1939-45, or 1946-55), before and after adjustment for education, and by high and low education level. Memory was assessed using immediate recall, for which data were available from all waves of the ELSA (2002-14) and Whitehall II (1997-2015) studies. Fluency was assessed using a semantic fluency test based on an animal naming task, with data available from all waves of the Whitehall II study and waves one to five (2002-10) and wave seven (2014) of the ELSA study. Cognitive scores were standardised separately in each study based on the mean and SD of the corresponding test among participants aged 50-59 years with secondary education.

FINDINGS

15 924 participants were included from the two studies. In pooled analyses, women had better memory scores than men in all birth cohorts, irrespective of adjustment for education (eg, at age 60 years, birth cohort 1930-38, mean difference between sexes [male scores minus female scores] -0·25 SDs [95% CI -0·32 to -0·19] after adjustment for education), and in both education level groups. Memory decline was faster in men than in women (at age 60 years, birth cohort 1946-55, mean difference in 13-year change -0·15 SDs [-0·20 to -0·09]; after adjustment for education -0·14 SDs [-0·20 to -0·08]). Men had better fluency scores than women in earlier birth cohorts and in the low education group (at age 60 years, birth cohort 1930-38, mean difference 0·20 SDs [95% CI 0·05 to 0·36]); but women had better fluency scores than men in later birth cohorts and in the high education group (at age 60 years, birth cohort 1946-55, mean difference -0·17 SDs [-0·24 to -0·10]). No sex differences were observed for fluency decline.

INTERPRETATION

Our findings suggest that decreasing disparities between sexes in education, due to secular increases in educational opportunities, could attenuate sex differences in dementia risk and cognitive decline in the future.

FUNDING

National Institute on Aging, National Institutes of Health; UK Medical Research Council; British Heart Foundation; and National Institute for Health Research.

Cognitive reserve and brain maintenance in aging and dementia: An integrative review

This research is an integrative review of scientific evidence differentiating between cognitive reserve (CR) and brain maintenance concepts. Thus, we have examined how CR socio-behavioral proxies (i.e. education, occupational attainment, and leisure activities) may help to cope with age-related cognitive decline and negative consequences of brain pathology. We also analyze lifestyle factors associated with brain maintenance or the relative absence of change in neural resources over time. Medline and Web of Science databases were used for the bibliographic search in the last 20 years. Observational cohort studies were selected to analyze the effect of different CR proxies on cognitive decline, including dementia incidence, whereas studies employing functional neuroimaging (fMRI) were used to display the existence of compensation mechanisms. Besides, structural MRI studies were used to test the association between lifestyle factors and neural changes. Our findings suggest that education, leisure activities, and occupational activity are protective factors against cognitive decline and dementia. Moreover, functional neuroimaging studies have verified the existence of brain networks that may underlie CR. Therefore, CR may be expressed either through a more efficient utilization (neural reserve) of brain networks or the recruitment of additional brain regions (compensation). Finally, lifestyle factors such as abstaining from smoking, lower alcohol consumption, and physical activity contributed to brain maintenance and were associated with the preservation of cognitive function. Advances in multimodal neuroimaging studies, preferably longitudinal design, will allow a better understanding of the neural mechanisms associated with the prevention of cognitive decline and preservation of neural resources in aging.

Sex and gender differences in cognitive and brain reserve: Implications for Alzheimer's disease in women

Women represent ⅔ of the cases of Alzheimer's disease (AD). Current research has focused on differential risks to explain higher rates of AD in women. However, factors that reduce risk for AD, like cognitive/brain reserve, are less well explored. We asked: what is known about sex and gender differences in how reserve mitigates risk for AD? We conducted a narrative review of the literature, with keywords: "sex/gender differences", "cognitive/brain reserve", "Alzheimer's Disease", and the following cognitive reserve contributors: "education", "IQ", "occupation", "cognitive stimulation", "bilingualism", "socioeconomic status", "physical activity", "social support". Sixteen papers disaggregated their data by sex. Those papers observed sex and gender differences in reserve contributors. There is also evidence that greater reserve may be more beneficial in lowering AD risk in women, although more research is needed. We discuss how traditional reserve contributors are gendered and may not capture factors that support cognition in aging women.

The Association between Longest-Held Lifetime Occupation and Late-Life Cognitive Impairment: Korean Longitudinal Study of Aging (2006-2016)

The association between longest-held lifetime occupation and late-life cognitive impairment: Korean Longitudinal Study of Aging (2006–2016). Backgrounds: Our study hypothesized that occupation in adulthood may be one of the modifiable factors in cognitive performance. This follow-up study aimed to examine whether there was an association between the longest-held occupation in a lifetime and cognitive impairment. Methods: This study used data from the 2006, 2012, and 2016 waves of the Korean Longitudinal Study of Aging, and a total of 1733 subjects aged over 65 were included. Longest-held occupation in a lifetime was classified into blue-collar, pink-collar, and white-collar. Cognitive function was evaluated using the Korean version of the Mini-Mental State Examination. Results: In males, no significant associations were observed. In females, on the contrary, risk of cognitive impairment in the blue-collar occupation was consistently higher than in the white-collar occupation over the 10-year follow-up (2006, OR = 2.49, 95% CI 1.05–5.88; 2016, OR = 2.17, 95% CI 1.02−4.65). Conclusions: Lifetime occupation should be taken into consideration in the process of screening for cognitive decline in the elderly, especially females. This study needs to be interpreted cautiously in view of inherent data and methodological limitations.

Longitudinal association between lifetime workforce participation and risk of self-reported cognitive decline in community-dwelling older adults

BACKGROUND

Although many governments are promoting workforce participation (WP) by older people, evidence of WP's effects on active aging is inadequate. We examined whether there is a gender-specific beneficial effect of lifetime WP from adulthood though old age against self-reported cognitive decline (CD) among community-dwelling older adults.

METHODS

We used data from a community-based prospective study of 2,422 men and 2,852 women aged ≥65 with neither poor cognition nor disability in basic activities of daily living at baseline. Self-reported CD was measured using the Cognitive Performance Scale. Lifetime WP evaluated the presence or absence of WP at baseline, the longest-held occupation, and lifetime working years (total working years throughout lifetime). Generalized estimating equations of the multivariable Poisson regression model were applied to evaluate a cumulative incidence ratio (CIR) for self-reported CD and a 95% confidence interval (CI), controlled for age, education, self-perceived economic status, chronic medical conditions, smoking history, physical activity, depression, and instrumental activities of daily living. To examine any gender-specific association, stratified analyses by gender were performed.

RESULTS

The 33-month cumulative incidence of self-reported CD was 15.7% in men and 14.4% in women. After covariate adjustments and mutual adjustment for three items of lifetime WP, men who had their longest held job in a white-collar occupation reported significantly decreased self-reported CD compared to men engaged in blue-collar jobs (CIR 0.72; 95% CI, 0.57-0.91), and women had a significant dose-response relationship between longer lifetime working years and less decline in subjective cognitive functioning (P for trend <0.029). Among both genders, WP at baseline was not associated with self-reported CD.

CONCLUSIONS

Our results suggest that lifetime WP, especially lifetime principal occupation in men and lifetime working years in women, may play a more prominent role in preventing self-reported CD than later-life WP.

Early-life education may help bolster declarative memory in old age, especially for women

Although declarative memory declines with age, sex and education might moderate these weaknesses. We investigated effects of sex and education on nonverbal declarative (recognition) memory in 704 older adults (aged 58-98, 0-17 years of education). Items were drawings of real and made-up objects. Age negatively impacted declarative memory, though this age effect was moderated by sex and object-type: it was steeper for males than females, but only for real objects. Education was positively associated with memory, but also interacted with sex and object-type: education benefited women more than men (countering the age effects, especially for women), and remembering real more than made-up objects. The findings suggest that nonverbal memory in older adults is associated negatively with age but positively with education; both effects are modulated by sex, and by whether learning relates to preexisting or new information. The study suggests downstream benefits from education, especially for girls.

Understanding Older Workers’ Decisions to Participate in Voluntary Training Opportunities

Abstract. Age-related changes in training decisions were examined using a within-subject experimental design presenting training framing cues of topic (generativity vs. non-generativity), goal (direction: approach vs. avoidance; referent: mastery vs. performance), and structure (self-paced vs. instructor-paced). As age increased, age-related cues were hypothesized to be more strongly and positively related to the training decision. One hundred and twenty-nine participants completed a policy-capturing study and self-report survey. Age moderated the relationship between the training topic and the training decision. Contrary to the hypothesis, as age increased, the non-generativity topic (rather than the generativity topic) was more strongly and positively related to the training decision. Age did not moderate the relationship between the other training features and the training decision.

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.

Cognitive efficiency in late midlife is linked to lifestyle characteristics and allostatic load

We investigated whether cognitive fitness in late midlife is associated with physiological and psychological factors linked to increased risk of age-related cognitive decline. Eighty-one healthy late middle-aged participants (mean age: 59.4 y; range: 50-69 y) were included. Cognitive fitness consisted of a composite score known to be sensitive to early subtle cognitive change. Lifestyle factors (referenced below as cognitive reserve factors; CRF) and affective state were determined through questionnaires, and sleep-wake quality was also assessed through actimetry. Allostatic load (AL) was determined through a large range of objective health measures. Generalized linear mixed models, controlling for sex and age, revealed that higher cognitive reserve and lower allostatic load are related to better cognitive efficiency. Crystallized intelligence, sympathetic nervous system functioning and lipid metabolism were the only sub-fields of CRF and AL to be significantly associated with cognition. These results show that previous lifestyle characteristics and current physiological status are simultaneously explaining variability in cognitive abilities in late midlife. Results further encourage early multimodal prevention programs acting on both of these modifiable factors to preserve cognition during the aging process.

No Evidence of Association Between Soccer Heading and Cognitive Performance in Professional Soccer Players: Cross-Sectional Results

Although the scientific community has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during soccer heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The aim of this study is to investigate the effects of soccer heading on cognitive functioning in active professional soccer players. Male soccer players (n = 44), from two soccer teams that play in the Brazilian A Series Championship, and non-athletes (n = 47), comparable in age and education, were submitted to cognitive assessment, consisting of computerized and conventional neuropsychological testing (Neupsilin battery). In the computerized cognitive assessment, soccer players performed better than controls on reaction time measures in general motor coordination, executive functioning and memory tests, and on accuracy measures in executive functioning tests. There were no significant differences between groups on the Neupsilin battery. A comparison between two sub-groups of soccer players, based on the self-reported number of headings, did not show significant differences on tests performance. No significant correlations were found between an estimate of exposure to heading during professional soccer career and cognitive performance. Our data demonstrate no evidence of cognitive impairment in soccer players, compared to non-athletes, and no association between heading exposure and performance on neuropsychological tests. Longitudinal investigations, including neuroimaging assessment, will help to clarify whether soccer heading may be associated with brain injury and cognitive dysfunction.

Clinical dementia severity associated with ventricular size is differentially moderated by cognitive reserve in men and women

Background

Interindividual differences in cognitive reserve (CR) are associated with complex and dynamic clinical phenotypes observed in cognitive impairment and dementia. We tested whether (1) CR early in life (E-CR; measured by education and IQ), (2) CR later in life (L-CR; measured by occupation), and (3) CR panel (CR-P) with the additive effects of E-CR and L-CR, act as moderating factors between baseline ventricular size and clinical dementia severity at baseline and across 2 years. We further examined whether this moderation is differentially represented by sex.

Methods

We examined a longitudinal model using patients (N = 723; mean age = 70.8 ± 9.4 years; age range = 38–90 years; females = 374) from the Sunnybrook Dementia Study. The patients represented Alzheimer’s disease (n = 439), mild cognitive impairment (n = 77), vascular cognitive impairment (n = 52), Lewy body disease (n = 30), and frontotemporal dementia (n = 125). Statistical analyses included (1) latent growth modeling to determine how clinical dementia severity changes over 2 years (measured by performance on the Dementia Rating Scale), (2) confirmatory factor analysis to establish a baseline E-CR factor, and (3) path analysis to predict dementia severity. Baseline age (continuous) and Apolipoprotein E status (ɛ4−/ɛ4+) were included as covariates.

Results

The association between higher baseline ventricular size and dementia severity was moderated by (1) E-CR and L-CR and (2) CR-P. This association was differentially represented in men and women. Specifically, men in only the low CR-P had higher baseline clinical dementia severity with larger baseline ventricular size. However, women in the low CR-P showed the (1) highest baseline dementia severity and (2) fastest 2-year decline with larger baseline ventricular size.

Conclusions

Clinical dementia severity associated with ventricular size may be (1) selectively moderated by complex and additive CR networks and (2) differentially represented by sex.

Trials registration

ClinicalTrials.gov, NCT01800214. Registered on 27 February 2013.

Electronic supplementary material

The online version of this article (10.1186/s13195-018-0419-2) contains supplementary material, which is available to authorized users.

Effects of Degree of Urbanization and Lifetime Longest-Held Occupation on Cognitive Impairment Prevalence in an Older Spanish Population

Our aim was to estimate the prevalence of cognitive impairment in rural and urban elderly populations and to examine the relationship between lifetime occupation and general cognitive performance. A cross-sectional study was carried out covering a representative sample (n = 749) of adults aged ≥65 years. Two categories were created to define the degree of urbanization using a criterion of geographical contiguity in combination with a minimum population threshold: densely populated (urban) areas and intermediate-thinly populated (rural) areas. Occupational histories were ranked by skill level requirements according to the Spanish National Classification of Occupations. Prevalence estimates of cognitive impairment were measured with the Mini-Mental State Examination. Results show that rural residence was not significantly associated with higher risk of cognitive impairment. A protective effect of cognitive demands at work against age-related cognitive decline was observed. However, this effect was not independent of confounder factors, such as age and education. A low overall prevalence of cognitive impairment was observed (6.5%), compared with previous estimates, possibly due to the sample selection in senior centers. Occupation during active life is not an isolated protective factor against cognitive impairment, and it is closely related to educational level. In future geriatric programs, description of both factors should be taken into consideration in screening older adults at increased risk of cognitive impairment and dementia.

The role of cognitive reserve and memory self-efficacy in compensatory strategy use: A structural equation approach

INTRODUCTION

The use of compensatory strategies plays an important role in the ability of older adults to adapt to late-life memory changes. Even with the benefits associated with compensatory strategy use, little research has explored specific mechanisms associated with memory performance and compensatory strategies. Rather than an individual's objective memory performance directly predicting their use of compensatory strategies, it is possible that some other variables are indirectly influencing that relationship. The purpose of this study was to: (a) examine the moderating effects of cognitive reserve (CR) and (b) evaluate the potential mediating effects of memory self-efficacy on the relationship between objective memory performance and compensatory strategy use.

METHOD

Two structural equation models (SEM) were used to evaluate CR (latent moderator model) and memory self-efficacy (mediator model) in a sample of 155 community-dwelling older adults over the age of 55.

RESULTS

The latent variable moderator model indicated that CR was not substantiated as a moderator variable in this sample (p = .861). However, memory self-efficacy significantly mediated the association between objective memory performance and compensatory strategy use (β = .22, 95% confidence interval, CI [.002, .437]). More specifically, better objective memory was associated with lower compensatory strategy use because of its relation to higher memory self-efficacy.

CONCLUSIONS

These findings provide initial support for an explanatory framework of the relation between objective memory and compensatory strategy use in a healthy older adult population by identifying the importance of an individual's memory perceptions.

Episodic memory in normal aging and Alzheimer disease: Insights from imaging and behavioral studies

Age-related cognitive changes often include difficulties in retrieving memories, particularly those that rely on personal experiences within their temporal and spatial contexts (i.e., episodic memories). This decline may vary depending on the studied phase (i.e., encoding, storage or retrieval), according to inter-individual differences, and whether we are talking about normal or pathological (e.g., Alzheimer disease; AD) aging. Such cognitive changes are associated with different structural and functional alterations in the human neural network that underpins episodic memory. The prefrontal cortex is the first structure to be affected by age, followed by the medial temporal lobe (MTL), the parietal cortex and the cerebellum. In AD, however, the modifications occur mainly in the MTL (hippocampus and adjacent structures) before spreading to the neocortex. In this review, we will present results that attempt to characterize normal and pathological cognitive aging at multiple levels by integrating structural, behavioral, inter-individual and neuroimaging measures of episodic memory.

Association between long-term cognitive decline in Vietnam veterans with TBI and caregiver attachment style

OBJECTIVE

To examine whether a caregiver's attachment style is associated with patient cognitive trajectory after traumatic brain injury (TBI).

SETTING

National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.

PARTICIPANTS

Forty Vietnam War veterans with TBI and their caregivers.

MAIN OUTCOME MEASURE

Cognitive performance, measured by the Armed Forces Qualification Test percentile score, completed at 2 time points: preinjury and 40 years postinjury.

DESIGN

On the basis of caregivers' attachment style (secure, fearful, preoccupied, dismissing), participants with TBI were grouped into a high or low group. To examine the association between cognitive trajectory of participants with TBI and caregivers' attachment style, we ran four 2 × 2 analysis of covariance on cognitive performances.

RESULTS

After controlling for other factors, cognitive decline was more pronounced in participants with TBI with a high fearful caregiver than among those with a low fearful caregiver. Other attachment styles were not associated with decline.

CONCLUSION AND IMPLICATION

Caregiver fearful attachment style is associated with a significant decline in cognitive status after TBI. We interpret this result in the context of the neural plasticity and cognitive reserve literatures. Finally, we discuss its impact on patient demand for healthcare services and potential interventions.

The Predictive Impact of Biological and Sociocultural Factors on Executive Processing: The Role of Age, Education, and Frequency of Reading and Writing Habits

Although the impact of education and age on executive functions (EF) has been widely studied, the influence of daily cognitive stimulation on EF has not been sufficiently investigated. Therefore, the aim of the present study was to evaluate whether the age, education, and frequency of reading and writing habits (FRWH) of healthy adults could predict their performance on measures of inhibition and cognitive flexibility. Inhibition speed, inhibitory control, and set shifting were assessed using speed, accuracy, and discrepancy scores on the Trail-Making Test (TMT) and Hayling Test. Demographic characteristics and the FRWH were assessed using specialized questionnaires. Regression analyses showed that age and the FRWH predicted speed and accuracy on the TMT. The FRWH predicted both speed and accuracy on the Hayling Test, for which speed and accuracy scores were also partly explained by age and education, respectively. Surprisingly, only the FRWH was associated with Hayling Test discrepancy scores, considered one of the purest EF measures. This highlights the importance of regular cognitive stimulation over the number of years of formal education on EF tasks. Further studies are required to investigate the role of the FRWH so as to better comprehend its relationship with EF and general cognition.

Diferenças quanto à escolaridade em adultos no desempenho no teste de cancelamento dos sinos

O papel de variáveis sociodemográficas na cognição humana, em especial da escolaridade, vem sendo estudado em indivíduos saudáveis. Esta pesquisa objetivou verificar se há diferenças entre grupos de diferentes níveis educacionais no processamento atencional visual avaliado pelo Teste de Cancelamento dos Sinos. Participaram 124 adultos jovens, distribuídos em três grupos, 5-8, 9-11 e 12 ou mais anos de educação formal, emparelhados por idade. As variáveis de acurácia e tempo, assim como os resultados qualitativos de estratégias utilizadas, foram comparados entre grupos (ANCOVA One-Way e Qui-quadrado). Observou-se uma discrepância entre dados quantitativos e qualitativos. Os grupos de diferentes escolaridades não se diferenciaram entre si quanto a acurácia e tempo; houve, porém, diferenças significativas quanto à distribuição de participantes por coluna em que o primeiro sino foi cancelado e pelas estratégias de cancelamento utilizadas. Novos estudos são relevantes com grupos de diferentes idades e com populações clínicas neurológicas e/ou psiquiátricas.

Measuring the impact of exercise on cognitive aging: methodological issues

Physical exercise and fitness have been proposed as potential factors that promote healthy cognitive aging. Support for this hypothesis has come from cross sectional, longitudinal, and intervention studies. In the present review, we discuss several methodological problems that limit the conclusions of many studies. The lack of consensus on how to retrospectively measure exercise intensity is a major difficulty for all studies that attempt to estimate lifelong impact of exercise on cognitive performance in older adults. Intervention studies have a much better capacity to establish causality, but still suffer from difficulties arising from inadequate control groups and the choice and modality of administration of cognitive measures. We argue that, while the association between exercise and preserved cognition during aging is clearly demonstrated, the specific hypothesis that physical exercise is a cause of healthy cognitive aging has yet to be validated. A number of factors could mediate the exercise-cognition association, including depression, and social or cognitive stimulation. The complex interactions among these 3 factors and the potential impact of exercise on cognition remain to be systematically studied. At this time, the best prescription for lifestyle interventions for healthy cognitive aging would be sustained physical, social, and mental activities. What remains unknown is which type of activity might be most useful, and whether everyone benefits similarly from the same interventions.

Path dependence in social and psychological risk factors for dementia

This article focuses on social and psychological risk factors for Alzheimer’s disease, dementia, and cognitive impairment and presents some key points for prevention in developing countries based on previous studies, a social science theory, and our preliminary survey. Previous population-based studies found that educational and occupational attainment, income, participation in social and mental activities, and psychological distress were associated with dementia risk. According to the theory of path dependence, earlier factors largely determine successive ones, where education is one of these early experiences in life. Our preliminary survey suggested that education sets a path that several psychosocial risk factors are dependent on. The expansion of basic education is indispensable. Resources for prevention should be concentrated on individuals with a low level of education. In order to break from a path creating self-reinforcement of risk factors, it is necessary to implement early and active interventions.

Longitudinal cognitive screening study in community-dwelling individuals

Cognitive changes in normal aging can be similar to the alterations that take place in the initial stages of a dementia process. Longitudinal studies can provide a better understanding of this progression.

Role of cognitive reserve in progression from mild cognitive impairment to dementia

Cognitive reserve is the ability to optimize performance through differential recruitment of brain networks, which may reflect the use of alternative cognitive strategies.