Cognitive Reserve Factors Research Articles

Exercise, memory, and the hippocampus: Uncovering modifiable lifestyle reserve factors in refractory epilepsy

Physical exercise is an emerging target for improving cognition in aging and neurological disease. Due to the beneficial impact of exercise on hippocampal health and the vulnerability of the hippocampus in medication-resistant temporal lobe epilepsy (TLE), exercise could present a promising intervention in TLE. We investigated whether exercise engagement is associated with verbal memory function and hippocampal integrity in 29 young to middle-aged adults with refractory TLE and 21 demographically matched controls. Participants completed a self-reported questionnaire of weekly exercise, three tests of verbal memory, and a subset (n = 44) underwent structural MRI. Individuals with TLE self-reported lower exercise scores than controls across all levels of exercise intensity (p < 0.001). In TLE, greater exercise engagement was associated with better verbal memory (word-list recall and associative learning; rho = 0.46–0.47; ps FDR < 0.05), and with larger contralateral hippocampal volumes (rho = 0.61; p < 0.01). These effects remained significant when controlling for several clinical and demographic factors. These findings suggest that exercise may be a cognitive reserve factor in TLE, potentially mitigating memory decline by enhancing contralateral hippocampal integrity. With future replication and longitudinal investigation, exercise holds promise as a low-cost and accessible modifiable lifestyle target for improving cognitive health in individuals with refractory TLE

Neuroimaging analysis reveals distinct cerebral perfusion responses to fasting-postprandial metabolic switching in Alzheimer's disease patients.

Extended fasting-postprandial switch intermitting time has been shown to affect Alzheimer's disease (AD). Few studies have investigated the cerebral perfusion response to fasting-postprandial metabolic switching (FMS) in AD patients. We aimed to evaluate the cerebral perfusion response to FMS in AD patients. In total, 30 AD patients, 32 mild cognitive impairment (MCI) patients, and 30 healthy control individuals (HCs) were included in the quantification of cerebral perfusion via cerebral blood flow (CBF). The cerebral perfusion response to FMS was defined as the difference (ΔCBF) between fasting and postprandial CBF. Patients with AD had a regional negative ΔCBF in the anterior temporal lobe, part of the occipital lobe and the parietal lobe under FMS stimulation, whereas HCs had no significant ΔCBF. The AD patients had lower ΔCBF values in the right anterior temporal lobe than the MCI patients and HCs. ΔCBF in the anterior temporal lobe was negatively correlated with cognitive severity and cognitive reserve factors in AD patients. AD patients exhibited a poor ability to maintain cerebral perfusion homeostasis under FMS stimulation. The anterior temporal lobe is a distinct area that responds to FMS in AD patients and negatively correlates with cognitive function.

Steroid hormones: risk and resilience in women's Alzheimer disease.

More women have Alzheimer disease (AD) than men, but the reasons for this phenomenon are still unknown. Including women in clinical research and studying their biology is key to understand not just their increased risk but also their resilience against the disease. In this sense, women are more affected by AD than men, but their reserve or resilience mechanisms might delay symptom onset. The aim of this review was to explore what is known about mechanisms underlying women's risk and resilience in AD and identify emerging themes in this area that merit further research. We conducted a review of studies analyzing molecular mechanisms that may induce neuroplasticity in women, as well as cognitive and brain reserve. We also analyzed how the loss of steroid hormones in aging may be linked to AD. We included empirical studies with human and animal models, literature reviews as well as meta-analyses. Our search identified the importance of 17-b-estradiol (E2) as a mechanism driving cognitive and brain reserve in women. More broadly, our analysis revealed the following emerging perspectives: (1) the importance of steroid hormones and their effects on both neurons and glia for the study of risk and resilience in AD, (2) E2's crucial role in women's brain reserve, (3) women's verbal memory advantage as a cognitive reserve factor, and (4) E2's potential role in linguistic experiences such as multilingualism and hearing loss. Future directions for research include analyzing the reserve mechanisms of steroid hormones on neuronal and glial plasticity, as well as identifying the links between steroid hormone loss in aging and risk for AD.

Exposure factors associated with dementia among older adults in Iceland: the AGES-Reykjavik study.

The study aimed to assess whether factors related to cognitive performance were associated with the development of dementia. Additionally, the study aimed to establish whether cognitive performance at baseline or change in cognition between baseline and follow-up (five-year period) had a stronger association with whether an individual would fulfill a dementia criterion at follow-up. The data was collected from 2002 to 2011. Logistic regression was applied to the AGES-Reykjavik Study epidemiological data. The analysis, which builds upon previous data analyses of the same dataset, included 1,491 participants between the ages of 66 and 90. All those included were considered to have normal cognition at baseline; 8.2% (n = 123) of them fulfilled a dementia criterion at follow-up five years later. The study's results indicated that being high on cognitive reserve factors reduced the risk of developing dementia. Compared to other known dementia risk factors, cognitive reserve factors (education level, participation in leisure activities, and self-reported health) were more likely than others to have an association with dementia. Additionally, the study's findings showed that cognitive performance at baseline, rather than change in cognition between baseline and follow-up five years later, had a stronger association with dementia at the follow-up assessment. Together, these findings support the notion that promoting high cognitive reserve throughout the lifespan and reaching high cognitive performance is important in reducing dementia risk.

NREM sleep as a novel protective cognitive reserve factor in the face of Alzheimer's disease pathology

BackgroundAlzheimer’s disease (AD) pathology impairs cognitive function. Yet some individuals with high amounts of AD pathology suffer marked memory impairment, while others with the same degree of pathology burden show little impairment. Why is this? One proposed explanation is cognitive reserve i.e., factors that confer resilience against, or compensation for the effects of AD pathology. Deep NREM slow wave sleep (SWS) is recognized to enhance functions of learning and memory in healthy older adults. However, that the quality of NREM SWS (NREM slow wave activity, SWA) represents a novel cognitive reserve factor in older adults with AD pathology, thereby providing compensation against memory dysfunction otherwise caused by high AD pathology burden, remains unknown.MethodsHere, we tested this hypothesis in cognitively normal older adults (N = 62) by combining 11C-PiB (Pittsburgh compound B) positron emission tomography (PET) scanning for the quantification of β-amyloid (Aβ) with sleep electroencephalography (EEG) recordings to quantify NREM SWA and a hippocampal-dependent face-name learning task.ResultsWe demonstrated that NREM SWA significantly moderates the effect of Aβ status on memory function. Specifically, NREM SWA selectively supported superior memory function in individuals suffering high Aβ burden, i.e., those most in need of cognitive reserve (B = 2.694, p = 0.019). In contrast, those without significant Aβ pathological burden, and thus without the same need for cognitive reserve, did not similarly benefit from the presence of NREM SWA (B = -0.115, p = 0.876). This interaction between NREM SWA and Aβ status predicting memory function was significant after correcting for age, sex, Body Mass Index, gray matter atrophy, and previously identified cognitive reserve factors, such as education and physical activity (p = 0.042).ConclusionsThese findings indicate that NREM SWA is a novel cognitive reserve factor providing resilience against the memory impairment otherwise caused by high AD pathology burden. Furthermore, this cognitive reserve function of NREM SWA remained significant when accounting both for covariates, and factors previously linked to resilience, suggesting that sleep might be an independent cognitive reserve resource. Beyond such mechanistic insights are potential therapeutic implications. Unlike many other cognitive reserve factors (e.g., years of education, prior job complexity), sleep is a modifiable factor. As such, it represents an intervention possibility that may aid the preservation of cognitive function in the face of AD pathology, both present moment and longitudinally.

Protecting cognitive function and delaying dementia: preliminary evidence from Lebanon

AbstractBackgroundIn Lebanon, it is projected that dementia will become a health crisis within the next 20 years. Therefore, the protection and management of cognitive impairment in older adults are of great significance for the aging population. We will present findings from research examining the role cognitive reserve factors and vitamin D play in cognitive impairment among older adults.MethodsIn the first study, we investigated the cognitive function and cognitive reserve factors of 508 community‐based Lebanese older adults aged 65 years using secondary data analysis. In a second cross‐sectional study, we explored the cognitive performance and serum vitamin D levels in 254 older (&gt;60 years) as well as younger (30‐60 years) adults.ResultsStudy 1. Older adults with dementia had lower education levels and attained lower occupational complexity. High education, complex occupation attainment, and leisure activity significantly predicted better global cognitive function. An older adult who gained high education levels or high complexity level occupation was 7.1 or 4.6 times more likely to have better global cognitive function than another who attained lower education or complexity level occupation, respectively. Study 2. Pearson’s correlation and stepwise linear regression analyses showed that a low serum 25 dihydroxy vitamin D (&lt;30ng/ml) level was associated with a higher risk of cognitive impairment in older as well as younger adults (30 years).ConclusionThese results suggest that cognitive reserve factors should be taken into consideration clinically during dementia diagnosis and when initiating community‐based preventive strategies in Arab populations. These findings also suggest that vitamin D correction needs to be explored as an intervention to prevent cognitive impairment. Other evidence supporting lifestyle changes and cognitive rehabilitation for the prevention and treatment of cognitive impairment should also be considered. Such interventions may reduce the risk of cognitive impairment and Alzheimer’s disease in older adults.

Influence of current physical exercise on the relationship between aging and episodic memory and fluid intelligence

The present study examined the effects of current physical exercise and age on episodic memory and fluid intelligence, assessed with a free-recall task and the Culture Fair Intelligence Test (Cattell, 1963) respectively, while statistically controlling for other cognitive reserve factors (educational level, leisure activities, and vocabulary level). Two hundred and eight participants aged 20 to 85 participated in the study. Physical exercise level was indexed by weekly frequency over the last 12 months using self-reported measurement (from none to 4 times a week). Overall, results show a beneficial effect of physical exercise especially from a weekly practice of 2 times, and significant interaction between physical exercise and age on episodic memory and fluid intelligence capacities indicating a reduced effect of age in more physically active participants. These results reinforce the view that physical exercise is a strong and specific reserve factor that reduces decline in some cognitive functions during aging.

Episodic memory and ageing: the role of cognitive reserve factors and cognitive resources according to task difficulty.

Episodic memory is the memory system which is most affected by ageing. However, similar memory decline is not seen in all older adults. Various cognitive reserve factors, such as the Openness Personality Trait and level of educational attainment, and cognitive resources linked to these factors, such as executive control and crystallised knowledge, can predict older adults' memory performance. This study examined the link between and the role of these variables in older adults' memory performances according to the difficulty of the task. Forty participants (aged between 60 and 82) learned 24 paired words with two encoding conditions (reading and generation), and then performed a cued recall. They were asked for their level of educational attainment, and their openness, executive control and crystallised knowledge levels were respectively measured using a personality questionnaire (Big Five), an inhibition test (Stroop) and a vocabulary test (Mill Hill). Only crystallised knowledge predicts older adults' recall of generated words while openness and executive control predict and mediate the effect of level of education on older adults' recall of read words. Openness is a reserve factor and is an essential component, along with executive control, in difficult memory tasks.

Estimation of cognitive reserve and its impact on cognitive performance in older adults

Objectives Cognitive reserve provides evidence in the search for answers regarding the role that lifestyle has in the protection of cognition in old age. Through a structural equations model, different things were analyzed: the relative weight of education, occupational complexity, free time activities and the intelligence quotient in cognitive reserve; and its impact on three cognitive domains: memory, language and executive functions. Design A trail analysis was executed, using structural equations procedure. Participants 167 older participants (mean = 76.74 years, standard deviation = 6.8 years). Measurements Participants were assessed with: Sociodemographic Questionnaire, Occupational Activity Agency Questionnaire, Social Participation Questionnaire and Neuropsychological Evaluation Battery for: memory, language and executive functions. Results The cognitive reserve factor is well represented by the measures included, with values ​​between .43 and .86, and shows a direct effect on language (β = .52, p < .001), executive functions (β = .77, p <.001), and memory (β = .36, p = .003). Conclusions In conclusion, lifestyle factors, such as education, occupational complexity, leisure time activities and intelligence quotient have an impact on the conformation of cognitive reserve and performance in some psychological processes.

Gender differences in the moderating capacity of reserve and resilience factors on the association of Alzheimer’s disease brain pathology and cognitive function

AbstractBackgroundIn the context of ageing and Alzheimer’s disease (AD), factors linked to reserve and resilience may confer protection against impact of underlying neuropathology on cognitive function. Such factors are differentially manifested in men and women, yet limited studies have explored potential divergence in their capacity to moderate cognitive outcomes, particularly within at‐risk preclinical populations. Here we evaluate gender dichotomies in the effect modification of independent brain and cognitive reserve factors on associations of AD‐related neuropathology and cognition.MethodGender‐stratified analysis of CHARIOT:PRO SubStudy data (2,451 preclinical older adults: 60‐85 years, screened at Imperial College London and University of Edinburgh) was performed using a‐priori confounder‐adjusted linear regression models. The effect modifying role of brain (intracranial volume) and cognitive (educational attainment, estimated premorbid‐intelligence: epIQ, physical activity) reserve proxies on the associations of AD neuropathology (brain amyloid load: via PET/CSF Aβ42; and hippocampal volumes: structural MRI) with multidomain cognitive performance (assessed via learning effect [i.e. difference in initial administration and baseline scores – median 3.5 months] on the Repeatable Battery Assessment of Neuropsychological Status‐RBANS) were independently examined in men and women.ResultLearning effects were negatively modulated by amyloid positivity and male gender. Larger hippocampal volumes predicted better global cognition in men, and better immediate memory for both men and women (All P‐values&lt;0.05). In mutually adjusted models (additionally accounting for age and ApoE), education and physical activity modified the effects of amyloid positivity on cognition, while epIQ moderated associations with hippocampal volume. The moderation was more pronounced for highly physically active men (β=7.7; p=0.04) and marginally for women educated to Bachelors’ level (β=5.9; p=0.06). Above‐median epIQ moderated associations of hippocampal volume with global cognition only in women (β=0.0003; p=0.03). Adjustment for BMI, smoking, blood pressure and diabetes had no remarkable effect on the results.ConclusionWe noted differential effects of cognitive reserve in men and women supporting the importance of accounting for sex/gender divergence when exploring moderators of AD‐related neuropathology on function. Further research into mechanisms underlying sex/gender differences in preservation and maintenance of cognitive function are warranted for personalised strategies towards increasing neurocognitive resilience and delaying transitions to more severe clinical states.

The relevance of early cognitive diagnosis in middle age or the threshold of old age—for a better quality of life for the long‐lived

AbstractBackgroundSome clinical observations regarding patients referred by relatives in middle age or on the old age threshold (55‐65 years) for a diagnosis of their clinical condition may already bring to light factors revealing an early cognitive decline.MethodFamily history interview; Interview with patient; Application of neuropsychological tests. Report elaboration and return of results to family members and patients.ResultSome changes in the patient referred by family members are described and then attested, such as: recurrence or intensification of forgetfulness; individual and social withdrawal; some loss of daily life activity functionality. The patient, in turn, in this phase, usually underestimates, or denies, any degree of difficulty in his daily life.ConclusionThe delay in diagnosis and appropriate intervention based on Cognitive Reserve factors in each clinical case favors possible dementia. Early intervention, before entering old age, is recommended, for a better quality of life in longevity.

Social support, neurocognition, and posttraumatic stress disorder: Findings from the Canadian Longitudinal Study on Aging

ABSTRACT Objective Most research investigating neurocognitive changes in participants with PTSD has focused on young adults. Numerous studies have recognized the crucial role of social support in diminishing the likelihood of developing PTSD. The current study evaluates the cognitive performance of middle-aged and older adults with symptoms of PTSD, and examines if perceived social support can act as a cognitive reserve factor. Method The study was conducted using data from the Canadian Longitudinal Study on Aging, a nationwide study on health and aging. The current study included 1,096 participants in the PTSD group and 22,158 participants in the comparison group, all between the ages of 45 and 85. Participants completed the MOS (Medical Outcomes Study) Social Support Survey as well as neuropsychological tests in the domains of executive functioning, declarative memory, and prospective memory. Results The PTSD group had worse performance in the domains of executive functioning and prospective memory than the comparison group. Furthermore, when examining global cognitive impairments (impairment was defined as scoring 1.5 or more standard deviations below age and education adjusted comparison group), the PTSD group demonstrated greater impairment rates than the comparison group on two or more tests. Moderation analyses revealed that greater social support was associated with better executive functioning for the comparison group, although this was not found to be true for the PTSD group. Conclusion The PTSD group experienced greater cognitive deficits compared to the comparison group. Higher levels of perceived social support were associated with better performance on neurocognitive measures for the comparison group. However, social support did not appear to moderate this relationship for the PTSD group.

Association between cardiometabolic risk and cognitive impairment

Several risk factors are associated with cognitive impairment in older people, but little attention has been paid to cardiometabolic variables, as well as how cognitive reserve can mediate this association. To determine the association of cardiometabolic risk factors with cognitive functioning and whether the cognitive reserve mediates this association. A cross-sectional study with 300 participants with a median age of 56 years (53% male) was conducted. Participants had a cognitive functioning assessment. Fasting glucose, HDL-cholesterol, and blood pressure were measured. A Structural Equation Modeling, revealed a direct effect of cardiometabolic latent risk factors on both a cognitive functioning (β = -.204; p = .056), and cognitive reserve factors (β = -.236, p = .04). Cognitive reserve was directly associated with cognitive functioning (β = .327, p = .01), but did not mediate the association between the cardiometabolic risk factors and cognitive functioning (β = .077, p = .07). The overall goodness of fitness was excellent χ2 (50) = 58.357, p = .195, comparative fit index = .980, Tucker-Lewis Index = .974, root mean square error of approximation = .023 and Standardized Root Mean Square Residual = .041. A direct effect of cardiometabolic risk factors on cognitive functioning was observed.

Episodic memory and aging: The role of cognitive reserve and cognitive resources according to task difficulty

Episodic memory is the most affected memory system in aging. However, memory decline is not similar in every older adult. Various cognitive reserve factors, as Openness personality trait or educational level, and cognitive resources linked to these factors, as executive control and crystallized knowledge, can predict older adults' memory performance. This study examined the link between and the role of these variables in older adults' memory performances according to the task difficulty. Forty participants (60-82years old) learned 24paired words with two encoding conditions (reading and generation) and then performed a cued recall. Their educational level was asked, and their Openness, executive control and crystallized knowledge levels were respectively measured using a personality questionnaire (Big Five), an inhibition test (Stroop) and a vocabulary test (Mill Hill). Only crystallized knowledge predicts older adults' generated words recall while Openness and executive control predict and mediate educational level effect on older adults' read words recall. Openness is a reserve factor and is an essential component, along with executive control, in difficult memory tasks.

Bilingualism: A Global Public Health Strategy for Healthy Cognitive Aging.

Dementia is a global public health priority which cost global societies $818 billion in 2015 and is disproportionately impacting low and middle-income countries (LMICs). With limited availability of disease modifying drugs to treat Alzheimer's disease (AD), researchers have increasingly focused on preventative strategies which may promote healthy cognitive aging and mitigate the risk of cognitive impairment in aging. Lifelong bilingualism has been presented as both a highly debated and promising cognitive reserve factor which has been associated with better cognitive outcomes in aging. A recent metanalysis has suggested that bilingual individuals present on average 4.05 years later with the clinical features of AD than monolinguals. Bilinguals are also diagnosed with AD ~2.0 years later than monolingual counterparts. In this perspective piece we critically evaluate the findings of this metanalysis and consider the specific implications of these findings to LMICs. Furthermore, we appraise the major epidemiological studies conducted globally on bilingualism and the onset of dementia. We consider how both impactful and robust studies of bilingualism and cognition in older age may be conducted in LMICs. Given the limited expenditure and resources available in LMICs and minimal successes of clinical trials of disease modifying drugs we propose that bilingualism should be positioned as an important and specific public health strategy for maintaining healthy cognitive aging in LMICs. Finally, we reflect upon the scope of implementing bilingualism within the education systems of LMICs and the promotion of bilingualism as a healthy cognitive aging initiative within government policy.

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.

Cognitive Reserve Factors in a Developing Country: Education and Occupational Attainment Lower the Risk of Dementia in a Sample of Lebanese Older Adults.

Background: Dementia secondary to neurodegenerative diseases is prevalent among older adults and leads to social, psychological and economic burden on patients, caregivers and the community as a whole. Cognitive reserve factors such as education, and mental stimulation among others were hypothesized to contribute to the resilience against age-related cognitive impairment. Educational attainment, occupation complexity, physical activity, and leisure activity are explored in the context of protecting the older adults' cognitive function. We investigated the cognitive reserve effect on dementia, cognitive decline and impairment, and global cognitive function.Methods: This study is a secondary analysis of data from a cross-sectional, community-based cohort study that aimed at investigating factors associated with dementia and their prevalence. The sample was of 508 community based older adults in Lebanon, aged 65 years and above in addition to 502 informants designated by these older adults. Older adults and informants answered structured questionnaires administered by interviewers, as well as a physical assessment and a neurological examination. Older adults were diagnosed for dementia. Global cognitive function, depression, and cognitive decline were assessed.Results: Older adults with dementia had lower levels of education, and attained lower occupational complexity. Factors such as high education, complex occupation attainment, and leisure activity, significantly predicted better global cognitive function. An older adult who attained high education levels or high complexity level occupation was 7.1 or 4.6 times more likely to have better global cognitive function than another who attained lower education or complexity level occupation respectively.Conclusion: These results suggest that cognitive reserve factors ought to be taken into consideration clinically during the course of dementia diagnosis and when initiating community-based preventive strategies.

Resting state versus Task Based Exploration of Age-Related Changes of the Neurofunctional Connectome.

Event Abstract Back to Event Resting state versus Task Based Exploration of Age-Related Changes of the Neurofunctional Connectome. Perrine Ferre1* 1 Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Canada According to the World Health Organization, the proportion of individuals over age 60 is expected to double by 2050. Cognitive impairments can be extremely frequent in particular in older age, and has been recurrently shown to be the most feared health conditions associated with aging. In this context, a better understanding of the mechanisms that can support cognitive health during aging is crucial. Most of the current knowledge about the aged-related changes in brain neurofunctional organization stems from studies using cognitive tasks for which performance has a tendency to decrease with aging (e.g.: working memory). Few of those studies have looked at language processing related to vocabulary and semantic knowledge, abilities that have been shown to be relatively preserved in aging. The way by which the aging brain can continue to be efficient such as it is the case for vocabulary and semantic knowledge is still poorly looked at. Over the last decade, an increasing interest has been devoted to describing age-related changes in the functional connectivity of the brain. However, in most cases, these studies have been conducted while participants were in a “resting state”, namely without engaging in any particular cognitive task. Important changes in the pattern of functional connectivity has been described in such resting state conditions. It remains to be determined if age-related differences in functional connectivity are also present within the neurofunctional organization in specific cognitive contexts, and in particular when participants are engaged in tasks requiring verbal and semantic processing of words. In the present study, a brain connectome analysis was performed on 300 adults ranging from 18 to 80 years old. They were tested systematically for whole brain connectivity to search for consistent differences as a function of age, performance, education or cognitive reserve factors during an fMRI session of resting-state and while performing three lexical-semantic tasks (antonyms, synonyms, picture naming). Then, similarities in age effect on brain connectivity across all tasks was examined for language-related seed regions. Results confirm that performances for the lexical-semantic tasks are preserved. Brain imaging also shows the existence of qualitative discrepancies between task-evoked and resting state connectivity patterns. Mean functional connectivity shows a general tendency to decrease with age, whatever the cognitive context. However, during lexical-semantic tasks, enhanced connectivity in semantic and visual-attentional regions is revealed. No interactions were to be found between connectivity patterns and performance, education or cognitive reserve as a function of age, thus not bringing imaging support to some of the determinants of presumed compensation of cognitive aging. The results of the present study suggest that investigation of functional connectivity in aging cannot solely rely on resting-state imaging data, especially when interpretation of cognitive processes is at stake. Our results also challenge the current models of aging in their ability to account for age differences in the semantic-language domain. Keywords: lexical-semantics, Aging, functional connectivity (FC), Resting-state fMRI, Task-based functional connectivity Conference: Academy of Aphasia 56th Annual Meeting, Montreal, Canada, 21 Oct - 23 Oct, 2018. Presentation Type: poster presentation Topic: not eligible for a student prize Citation: Ferre P (2019). Resting state versus Task Based Exploration of Age-Related Changes of the Neurofunctional Connectome. . Conference Abstract: Academy of Aphasia 56th Annual Meeting. doi: 10.3389/conf.fnhum.2018.228.00011 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Apr 2018; Published Online: 22 Jan 2019. * Correspondence: Miss. Perrine Ferre, Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, Canada, perrine_ferre@hotmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Perrine Ferre Google Perrine Ferre Google Scholar Perrine Ferre PubMed Perrine Ferre Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. 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Association of lifelong exposure to cognitive reserve-enhancing factors with dementia risk: A community-based cohort study.

BackgroundVariation in the clinical manifestation of dementia has been associated with differences in cognitive reserve, although less is known about the cumulative effects of exposure to cognitive reserve factors over the life course. We examined the association of cognitive reserve-related factors over the lifespan with the risk of dementia in a community-based cohort of older adults.Methods and findingsInformation on early-life education, socioeconomic status, work complexity at age 20, midlife occupation attainment, and late-life leisure activities was collected in a cohort of dementia-free community dwellers aged 75+ y residing in the Kungsholmen district of Stockholm, Sweden, in 1987–1989. The cohort was followed up to 9 y (until 1996) to detect incident dementia cases. To exclude preclinical phases of disease, participants who developed dementia at the first follow-up examination 3 y after the baseline were excluded (n = 602 after exclusions). Structural equation modelling was used to generate latent factors of cognitive reserve from three periods over the life course: early (before 20 y), adulthood (around 30–55 y), and late life (75 y and older). The correlation between early- and adult-life latent factors was strong (γ = 0.9), whereas early–late (γ = 0.27) and adult–late (γ = 0.16) latent factor correlations were weak. One hundred forty-eight participants developed dementia during follow-up, and 454 remained dementia-free. The relative risk (RR) of dementia was estimated using Cox models with life-course cognitive reserve-enhancing factors modelled separately and simultaneously to assess direct and indirect effects. The analysis was repeated among carriers and noncarriers of the apolipoprotein E (APOE) ε4 allele. A reduced risk of dementia was associated with early- (RR 0.57; 95% CI 0.36–0.90), adult- (RR 0.60; 95% CI 0.42–0.87), and late-life (RR 0.52; 95% CI 0.37–0.73) reserve-enhancing latent factors in separate multivariable Cox models. In a mutually adjusted model, which may have been imprecisely estimated because of strong correlation between early- and adult-life factors, the late-life factor preserved its association (RR 0.65; 95% CI 0.45–0.94), whereas the effect of midlife (RR 0.73; 95% CI 0.50–1.06) and early-life factors (RR 0.76; 95% CI 0.47–1.23) on the risk of dementia was attenuated. The risk declined progressively with cumulative exposure to reserve-enhancing latent factors, and having high scores on cognitive reserve-enhancing composite factors in all three periods over the life course was associated with the lowest risk of dementia (RR 0.40; 95% CI 0.20–0.81). Similar associations were detected among APOE ε4 allele carriers and noncarriers. Limitations include measurement error and nonresponse, with both biases likely favouring the null. Strong correlation between early- and adult-life latent factors may have led to a loss in precision when estimating mutually adjusted effects of all periods.ConclusionsIn this study, cumulative exposure to reserve-enhancing factors over the lifespan was associated with reduced risk of dementia in late life, even among individuals with genetic predisposition.

Influence of cognitive reserve on neuropsychological functioning in bipolar disorder: Findings from a 5-year longitudinal study.

The present study examined the 5-year longitudinal course of cognitive functioning in a large sample of well-characterized patients with bipolar disorder (BP), compared to healthy controls (HCs), and the influence of cognitive reserve factors (e.g., education and IQ) on cognitive change over time. Participants included 159 individuals diagnosed with BP and 54 HCs recruited as part of a longitudinal naturalistic study of BP who had completed neuropsychological testing at the time of their enrollment and again 5years later. The overall relative rate of change did not differ between the BP and HC groups. In total, 46.5% of the BP group and 37% of the HC group showed evidence of decline on at least one measure over time. T-test analyses did not find differences between BP 'decliners' and 'non-decliners' in cognitive reserve variables. However, we found that higher baseline intellectual ability was associated with more stability in cognitive test scores over time for the BP group. Results of linear regression modeling revealed that lower verbal IQ and education were related to increased cognitive decline in specific domains in the BP group. This study has explored the influence of cognitive reserve on preservation of specific cognitive abilities over time in BP. The BP group did not demonstrate accelerated cognitive decline over 5years compared to the HC group. Although the trajectory of cognitive change over time was similar between BP patients and HCs, higher overall intellectual ability may be a protective factor against cognitive decline, particularly for BP patients.