The cognitive reserve hypothesis: a longitudinal examination of age-associated declines in reasoning and processing speed

Factors associated with mild cognitive impairment and dementia amongst the oldest old: findings based on the nationally representative "old age in Germany (D80+)" study

BACKGROUND/AIMS

Particularly among the oldest old, there is restricted knowledge regarding the factors associated with mild cognitive impairment and dementia using data from large, nationally representative samples. Thus, our aim was to address this knowledge gap.

METHODS/DESIGN

We used data from the nationally representative "Old Age in Germany (D80+)" study covering community-dwelling and institutionalized individuals in the entire country (n = 2,555). Mean age was 85.5 years (SD: 4.2), ranging from 80 to 100 years (61.7% of the participants were female). The DemTect was used to measure cognitive impairment in terms of probable mild cognitive impairment and probable dementia. Sociodemographic, lifestyle-related, psychosocial and health-related independent variables were included in the multinomial regression analysis.

RESULTS

In the analytic sample, 57.8% of the individuals did not have cognitive impairment, 24.2% of the individuals had mild cognitive impairment and 18.0% had probable dementia. Regression analysis identified some sociodemographic (e.g., advanced age, being male, lower education), lifestyle-related (lower cognitive activities), psychosocial (higher loneliness and absence of meaning in life), as well as health-related (e.g., functional impairment) factors associated with probable MCI and probable dementia. Loneliness was only associated with these outcomes among women, but not men.

DISCUSSIONS

Based on large, nationally representative data, this study revealed several factors associated with probable MCI and dementia - which enhances our current understanding mainly based on small or selective samples.

CONCLUSION

Such knowledge may help to address those at risk for cognitive impairment. Longitudinal studies are required to gain further insights.

Reevaluating the Role of Education in Cognitive Decline and Brain Aging: Insights from Large-Scale Longitudinal Cohorts across 33 Countries

Why education is linked to higher cognitive function in aging is fiercely debated. Leading theories propose that education reduces brain decline in aging, enhances tolerance to brain pathology, or that it does not affect cognitive decline but rather reflects higher early-life cognitive function. To test these theories, we analyzed 407.356 episodic memory scores from 170.795 participants > 50 years, alongside 15.157 brain MRIs from 6.472 participants across 33 Western countries. More education was associated with better memory, larger intracranial volume and slightly larger volume of memory-sensitive brain regions. However, education did not protect against age-related decline or weakened effects of brain decline on cognition. The most parsimonious explanation for the results is that the associations reflect factors present early in life, including propensity of individuals with certain traits to pursue more education. While education has numerous benefits, the notion that it provides protection against cognitive or brain decline is not supported.

Global incidence and prevalence of delirium and its risk factors in medically hospitalized older patients: A systematic review and meta-analysis

BACKGROUND

Delirium is a common complication among older medical patients that can lead to undesirable outcomes.

OBJECTIVES

This study systematically investigated the incidence, prevalence, and risk factors of delirium to improve its recognition, prevention, and management in medically hospitalized older patients.

METHODS

The study protocol was registered at PROSPERO on April 29, 2024 (registration number: CRD42024536624). We searched the PubMed, Embase, and ProQuest databases for relevant articles published between database inception and September 25, 2024. We included observational studies reporting the prevalence, incidence, and risk factors of delirium among medically hospitalized older patients. Two independent reviewers extracted the data. A random-effects model was used for data analysis.

RESULTS

A total of 35 studies encompassing 12,097 participants met the inclusion criteria, yielding a 23.6 % pooled prevalence of delirium (95 % confidence interval = 19 % to 29 %) and a 13.5 % pooled incidence of delirium (n = 32, 95 % confidence interval = 11 % to 17 %) among medically hospitalized older patients. Study quality and country were significant moderators for explaining the heterogeneity observed in the prevalence and incidence of delirium, respectively (both P < 0.001). The risk factors of delirium included frailty (odds ratio = 2.05), physical restraints (5.01), prior falls (1.99), severe illness (1.32) (evaluated using the Acute Physiology and Chronic Health Evaluation II), and cognitive impairment (2.61). Older age increased delirium risk, whereas years of education mitigated it (B = 1.69 and 0.92, respectively).

CONCLUSION

Our findings considerably enhance the understanding of the prevalence of delirium and its influencing factors in medically hospitalized older patients. The insights this study provides can enable health-care providers to apply quick and effective assessment tools and can thereby support the implementation of interventions to prevent delirium.

REGISTRATION

The study protocol has been prospectively registered on PROSPERO (registration no. CRD42024536624).

Relationship Between Accelerated Biological Aging, Race, Perceived Discrimination, and Limitations in Activities of Daily Living

This cross-sectional study aimed to evaluate the relationship between accelerated aging (PhenoAge) and limitations in Activities of Daily Living (ADLs) in White, Black, and Hispanic older adults (≥ 50 years). We further aimed to explore how perceived discrimination may differentially impact this association. We ran multivariable logistic regression models to evaluate the strength of the association between accelerated aging, ADLs, and perceived discrimination using 2014/2016 Health and Retirement Study (HRS) data for White (n=2107), Black (n=435), and Hispanic (n=351) adults aged 50 and older who contributed epigenetic clock data during the 2016 HRS Venous Blood Study. We hypothesized that accelerated aging would be associated with greater levels of functional limitations, and that perceived discrimination would impact this relationship with evident disadvantage among Blacks and Hispanics relative to Whites. We found that more Blacks and Hispanics reported ADLs (23.68% and 23.08% respectively) than Whites (12.48%, p<0.01). Blacks reported more discrimination (M 3.71, SD 4.26, p<0.01) than Hispanics (M 2.69, SD 3.84) or Whites (M 2.86, SD 3.52). ADLs were associated with accelerated aging (OR=1.42, 95% confidence interval = 1.13,1.78) and discrimination (OR=1.07, 95% confidence interval = 1.04,1.10). Our research examining how exposure to discrimination differentially affects the biological aging-ADL association across racial and ethnic groups contributes to efforts addressing health disparities associated with functional decline. This work is part of a broader body of research aiming to understand the impact of discrimination on biological outcomes and their consequences for health and loss of independence.

Reevaluating the Role of Education in Cognitive Decline and Brain Aging: Insights from Large-Scale Longitudinal Cohorts across 33 Countries

Why education is linked to higher cognitive function in aging is fiercely debated. Leading theories propose that education reduces brain decline in aging, enhances tolerance to brain pathology, or that it does not affect cognitive decline but rather reflects higher early-life cognitive function. To test these theories, we analyzed 407.356 episodic memory scores from 170.795 participants >50 years, alongside 15.157 brain MRIs from 6.472 participants across 33 Western countries. More education was associated with better memory, larger intracranial volume and slightly larger volume of memory-sensitive brain regions. However, education did not protect against age-related decline or weakened effects of brain decline on cognition. The most parsimonious explanation for the results is that the associations reflect factors present early in life, including propensity of individuals with certain traits to pursue more education. While education has numerous benefits, the notion that it provides protection against cognitive or brain decline is not supported.

The Independent and Interactive Effects of Economic Stability and Healthcare Access on 10-Year Cognitive Trajectories of Black/African American and White Older Adults from the ACTIVE Study

OBJECTIVES

Social and structural determinants of health (SSDoH) have been linked to racial disparities in Alzheimer's disease and related dementias (ADRD). Research has established that living in an environment with greater economic stability (ES) or healthcare access (HCA) is associated with better baseline cognition, but the interactive effects between these distinct SSDoH on cognition over time have not been studied. Therefore, the present study examined the independent and interactive effects of ES and HCA on 10-year change in cognitive functioning within a large sample of racially diverse community-dwelling older adults.

METHODS

Participants included 701 Black/African American and 1804 White older adults from the Advanced Cognitive Training for Independent and Vital Elderly study. Multilevel mixed effects models were used to assess associations between ES and HCA factors on individual-level memory and reasoning trajectories.

RESULTS

Results revealed there was no significant ES × HCA interaction on longitudinal cognitive trajectories across the whole sample or within race-stratified groups, but there was a significant interaction on memory level. Higher ES levels were independently associated with slower age-related memory declines among Black/African American older adults. In contrast, higher ES and HCA levels were both independently associated with faster age-related reasoning declines among White participants.

DISCUSSION

Results demonstrated that ES and HCA exerted synergistic effects on memory level across ages in the whole sample. Differential associations between SSDoH and cognitive outcomes across racial groups suggest that improving access to economic resources within Black/African American communities may reduce racial disparities in ADRD.

Validation of the abbreviated version of the Token Test in Latin American Spanish stroke patients

BACKGROUND

The abbreviated version of the Token Test (aTT) is widely used to assess language comprehension deficits in stroke patients (SPs). However, aTT has not been validated for Latin American Spanish speakers, so clinicians tend to use cut-off scores for aTT validated in developed countries.

AIMS

To provide normative data for the Spanish aTT (Sp-aTT) in healthy Chilean Spanish-speaking and SP, determining the influence of sociodemographic variables such as gender, age and education on Sp-aTT performance.

METHODS & PROCEDURES

A total of 210 healthy volunteers (age range = 18-88 years) and 197 SPs (age range = 23-94 years), all native speakers of Chilean Spanish, were recruited. The association of age, gender and years of education on the Sp-aTT performance was analysed. Specificity and sensibility analyses of the Sp-aTT to diagnose language comprehension deficits were completed.

OUTCOMES & RESULTS

Only age (p < 0.001) and years of education (p < 0.001) impacted the total score of Sp-aTT. Gender did not show an association with Sp-aTT performance (p = 0.181). For SPs, the Sp-aTT score showed a significant positive correlation (rho = 0.4, p < 0.001) with the aphasia severity rating scale (ASRS) score. For Sp-aTT, the area under the curve was 0.97, and the optimal cut-off score for the Sp-aTT was 30 (0.73 of sensitivity, 0.92 of specificity and a Youden index of 0.644).

CONCLUSIONS & IMPLICATIONS

Age and years of education are two key factors to be controlled for when determining the optimal cut-off points for the Sp-aTT. Our results also highlight the need for language-specific norms in stroke and aphasia research.

WHAT THIS PAPER ADDS

What is already known on the subject The aTT has been validated and adapted in several countries. Its properties in screening and detecting comprehensive deficits in SPs highlight its potential as a screening tool in clinical practice. Moreover, considering that stroke is the third largest cause of death worldwide, research and clinical practice have focused on how to improve early detection of deficits in these people, especially those related to cognition, language and functionality in SPs. Therefore, counting with validated and adapted tools is essential for clinicians because it could contribute to accurate intervention and classification of language disorders. What this paper adds to the existing knowledge The main contribution of this study is to provide normative data for the aTT in Latin American Spanish speakers. No previous studies have focused on validating this test and analysing the influence of three critical variables (age, gender and years of education) on its performance in SPs from Latin America. In addition, we propose a classification of the severity of comprehension deficits in SPs. Finally, we found comprehension deficits in patients with right and left hemisphere stroke, which would imply that these deficits would not be exclusive to left hemisphere stroke. What are the potential or actual clinical implications of this work? Contribute with validation of language comprehension tools, such as the aTT, could improve early diagnosis of patients with language disorders. This validation provides a test based on the sociodemographic characteristics of Latin American Speakers, which has yet to be established. Due to this, normative data considering the sociodemographic characteristics of the target population is crucial for accurately classifying comprehension deficits after brain damage.

Which intellectual activities are related to cognitive reserve? Introduction and testing a three-dimensional model

BACKGROUND

A common belief among people and some researchers is that keeping yourself mentally active may decrease the risk of dementia. Over the past years, despite widespread efforts to identify proxies for protecting cognitive reserve against age-related changes, it is still not clear what type of intellectual activity would be beneficial for cognitive reserve. To fill this gap, we propose a three-dimensional model of intellectual activity. According to this conceptual model, intellectual activities could be distinguished based on their locations in a three-dimensions space, including; (1) Activation: active vs. passive, (2) Novelty: novel vs. familiar, and (3) Productivity: productive vs. receptive. We assumed that the activities that are categorized as more active, novel, and productive could be considered as a cognitive reserve proxy.

METHODS

To test this hypothesis, a sample of 237 participants older than 50 years (Mage = 58.76 ± 6.66; 63.7% women) was recruited to take part in the study. Episodic, semantic and working memory were assessed with computerized battery tests (Sepidar) and a self-report questionnaire was used to assess intellectual activities. Activities were categorized in terms of; (1) passive, familiar, and receptive activities (radio/watching TV), (2) active, familiar, and receptive activities (solving crosswords), (3) active, novel, and receptive activities (reading), and (4) active, novel, and productive activities (writing).

RESULTS

The results indicated that writing moderates the effect of age on episodic and semantic memory. Reading only moderates the effect of age on semantic memory, and radio/watching TV and solving crosswords do not play a role in moderation analysis.

CONCLUSIONS

Our finding suggests that intellectual activities have different moderating effects on the relationships between age and memory performance. Individuals with high levels of participation in novel and productive activities over the life course are less likely to clinically demonstrate cognitive impairments. Our results support the potential benefit of the three-dimensional model to provide a better insight into the complex role of intellectual activities in cognitive reserve, particularly for older adults. Further research is needed to evaluate the efficacy and the benefits of the model.

The Real-World Usability, Feasibility, and Performance Distributions of Deploying a Digital Toolbox of Computerized Assessments to Remotely Evaluate Brain Health: Development and Usability Study

BACKGROUND

An ongoing global challenge is managing brain health and understanding how performance changes across the lifespan.

OBJECTIVE

We developed and deployed a set of self-administrable, computerized assessments designed to measure key indexes of brain health across the visual and auditory sensory modalities. In this pilot study, we evaluated the usability, feasibility, and performance distributions of the assessments in a home-based, real-world setting without supervision.

METHODS

Potential participants were untrained users who self-registered on an existing brain training app called BrainHQ. Participants were contacted via a recruitment email and registered remotely to complete a demographics questionnaire and 29 unique assessments on their personal devices. We examined participant engagement, descriptive and psychometric properties of the assessments, associations between performance and self-reported demographic variables, cognitive profiles, and factor loadings.

RESULTS

Of the 365,782 potential participants contacted via a recruitment email, 414 (0.11%) registered, of whom 367 (88.6%) completed at least one assessment and 104 (25.1%) completed all 29 assessments. Registered participants were, on average, aged 63.6 (SD 14.8; range 13-107) years, mostly female (265/414, 64%), educated (329/414, 79.5% with a degree), and White (349/414, 84.3% White and 48/414, 11.6% people of color). A total of 72% (21/29) of the assessments showed no ceiling or floor effects or had easily modifiable score bounds to eliminate these effects. When correlating performance with self-reported demographic variables, 72% (21/29) of the assessments were sensitive to age, 72% (21/29) of the assessments were insensitive to gender, 93% (27/29) of the assessments were insensitive to race and ethnicity, and 93% (27/29) of the assessments were insensitive to education-based differences. Assessments were brief, with a mean duration of 3 (SD 1.0) minutes per task. The pattern of performance across the assessments revealed distinctive cognitive profiles and loaded onto 4 independent factors.

CONCLUSIONS

The assessments were both usable and feasible and warrant a full normative study. A digital toolbox of scalable and self-administrable assessments that can evaluate brain health at a glance (and longitudinally) may lead to novel future applications across clinical trials, diagnostics, and performance optimization.

The Association between Education and Cognitive Performance Varies at Different Levels of Cognitive Performance: A Quantile Regression Approach

INTRODUCTION

Educational differences in cognitive performance among older adults are well documented. Studies that explore this association typically estimate a single average effect of education on cognitive performance. We argue that the processes that contribute to the association between education and cognitive performance are unlikely to have equal effects at all levels of cognitive performance. In this study, we employ an analytical approach that enables us to go beyond averages to examine the association between education and five measures of global and domain-specific cognitive performance across the outcome distributions.

METHODS

This cross-sectional study included 1,780 older adults aged 58-68 years from the Longitudinal Aging Study Amsterdam. Conditional quantile regression was used to examine variation across the outcome distribution. Cognitive outcomes included Mini-Mental State Examination (MMSE) score, crystallized intelligence, information processing speed, episodic memory, and a composite score of global cognitive performance.

RESULTS

The results showed that the associations between education and different cognitive measures varied across the outcome distributions. Specifically, we found that education had a stronger association with crystallized intelligence, MMSE, and a composite cognitive performance measure in the lower tail of performance distributions. The associations between education and information processing speed and episodic memory were uniform across the outcome distributions.

CONCLUSION

Larger associations between education and some domains of cognitive performance in the lower tail of the performance distributions imply that inequalities are primarily generated among individuals with lower performance rather than among average and high performers. Additionally, the varying associations across some of the outcome distributions indicate that estimating a single average effect through standard regression methods may overlook variations in cognitive performance between educational groups. Future studies should consider heterogeneity across the outcome distribution.

Association of Physical Frailty and Cognitive Function in a Population-Based Cross-Sectional Study of American Older Adults

INTRODUCTION

Cognitive impairment and frailty are prevalent in older persons. Physical frailty is associated with cognitive decline; however, the role of effect modifiers such as age, sex, race/ethnicity, and cognitive reserve is not well understood.

METHODS

Cross-sectional data from the National Health and Nutrition Examination Survey (2011-2014) were obtained for participants aged ≥60 years. Complete availability of cognitive scores was an inclusion criterion. Physical frailty was defined by the presence of exhaustion, weakness, low body mass, and/or low physical activity, and categorized into three groups: robust (0 present), pre-frail (1-2 present), or frail (3-4 present). Four cognitive test scores were converted to z-scores, and global cognition (composite z-score) was calculated by averaging the four-individual z-scores. Multivariable linear regression models were fit to estimate the associations between frailty and cognitive function. Frailty was also evaluated as a risk factor for self-reported subjective memory complaint (SMC) using logistic regression. All models were adjusted for age, sex, race/ethnicity, education, alcohol use, income, marital status, diabetes, hypertension, and history of stroke. Effect measure modification analyses were conducted by age, sex, race/ethnicity, education, and occupational cognitive demand.

RESULTS

The study population comprised 2,863 participants aged ≥60 years. 50.6% of the participants were categorized into robust, 43.2% pre-frail, and 6.2% frail. After adjusting for covariates, compared to robust participants, frail and prefrail participants had lower adjusted mean global cognitive z-scores, β^ = -0.61, 95% CI: -0.83, -0.38 and β^ = -0.21, 95% CI: -0.30, -0.12, respectively. Both prefrail and frail participants had higher odds of SMC compared to the robust participants. We did not see strong evidence that the association between frailty and cognition was modified by the factors we studied.

DISCUSSION/CONCLUSION

Both pre-frailty and frailty were associated with lower cognitive performance and were more likely to report subjective memory complaints relative to persons without frailty. These findings provide additional evidence that physical frailty may serve as a prognostic factor for cognitive deterioration or dementia, and prevention of frailty may be an important public health strategy.

Directed functional connectivity of the sensorimotor system in young and older individuals

Introduction

Studies in the sensorimotor system of older versus young individuals have shown alterations in functional connectivity and organization. Our objective was to explore the implications of these differences in terms of local organizations, and to identify processes that correlate with neuropsychological parameters.

Methods

Using a novel multivariate analysis method on resting-state functional MRI data obtained from 50 young and 31 older healthy individuals, we identified directed 4-node functional pathways within the sensorimotor system and examined their correlations with neuropsychological assessments.

Results

In young individuals, the functional pathways were unidirectional, flowing from the primary motor and sensory cortices to higher motor and visual regions. In older individuals, the functional pathways were more complex. They originated either from the calcarine sulcus or the insula and passed through mutually coupled high-order motor areas before reaching the primary sensory and motor cortices. Additionally, the pathways in older individuals that resembled those found in young individuals exhibited a positive correlation with years of education.

Discussion

The flow pattern of young individuals suggests efficient and fast information transfer. In contrast, the mutual coupling of high-order motor regions in older individuals suggests an inefficient and slow transfer, a less segregated and a more integrated organization. The differences in the number of sensorimotor pathways and of their directionality suggests reduced efferent degenerated pathways and increased afferent compensated pathways. Furthermore, the positive effect of years of education may be associated with the Cognitive Reserve Hypothesis, implying that cognitive reserve could be maintained through specific information transfer pathways.

Cohort Changes and Sex Differences After Age 50 in Cognitive Variables in the English Longitudinal Study of Ageing

OBJECTIVES

This paper models cognitive aging, across mid and late life, and estimates birth cohort and sex differences in both initial levels and aging trajectories over time in a sample with multiple cohorts and a wide span of ages.

METHODS

The data used in this study came from the first 9 waves of the English Longitudinal Study of Ageing, spanning 2002-2019. There were n = 76,014 observations (proportion male 45%). Dependent measures were verbal fluency, immediate recall, delayed recall, and orientation. Data were modeled using a Bayesian logistic growth curve model.

RESULTS

Cognitive aging was substantial in 3 of the 4 variables examined. For verbal fluency and immediate recall, males and females could expect to lose about 30% of their initial ability between the ages of 52 and 89. Delayed recall showed a steeper decline, with males losing 40% and females losing 50% of their delayed recall ability between ages 52 and 89 (although females had a higher initial level of delayed recall). Orientation alone was not particularly affected by aging, with less than a 10% change for either males or females. Furthermore, we found cohort effects for initial ability level, with particularly steep increases for cohorts born between approximately 1930 and 1950.

DISCUSSION

These cohort effects generally favored later-born cohorts. Implications and future directions are discussed.

Dimensions of cognitive reserve and their predictive power of cognitive performance and decline in the elderly

Background

The relative importance of different components of cognitive reserve (CR), as well as their differences by gender, are poorly established.

Objective

To explore several dimensions of CR, their differences by gender, and their effects on cognitive performance and trajectory in a cohort of older people without relevant psychiatric, neurologic, or systemic conditions.

Methods

Twenty-one variables related to the education, occupation, social activities, and life habits of 1,093 home-dwelling and cognitively healthy individuals, between 68 and 86 years old, were explored using factorial analyses to delineate several dimensions of CR. These dimensions were contrasted with baseline cognitive performance, follow-up over 5 years of participants' cognitive trajectory, conversion to mild cognitive impairment (MCI), and brain volumes using regression and growth curve models, controlling for gender, age, marital status, number of medications, trait anxiety, depression, and ApoE genotype.

Results

Five highly intercorrelated dimensions of CR were identified, with some differences in their structure and effects based on gender. Three of them, education/occupation, midlife cognitive activities, and leisure activities, were significantly associated with late-life cognitive performance, accounting for more than 20% of its variance. The education/occupation had positive effect on the rate of cognitive decline during the 5-year follow up in individuals with final diagnosis of MCI but showed a reduced risk for MCI in men. None of these dimensions showed significant relationships with gray or white matter volumes.

Conclusion

Proxy markers of CR can be represented by five interrelated dimensions. Education/occupation, midlife cognitive activities, and leisure activities are associated with better cognitive performance in old age and provide a buffer against cognitive impairment. Education/occupation may delay the clinical onset of MCI and is also associated with the rate of change in cognitive performance.

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

OBJECTIVES

Living a long life does not guarantee the maintenance of optimal cognitive functioning; however, similar to older adults in general, cognitive reserve may also protect oldest-old adults from cognitive decline. The purpose of this study was to assess cognitive reserve among centenarians and octogenarians and to evaluate a process model of cognitive reserve.

METHODS

A total of 321 centenarians and octogenarians from the Georgia Centenarian Study were included in this study. Cognitive reserve components included level of education, occupational responsibility, current social engagement, past engaged lifestyle, and activity. Cognitive functioning was measured with the Mini-Mental Status Examination.

RESULTS

Structural equation modeling was computed, and the overall model fit well, χ2 (df = 3) = 5.02, p = .17; CFI = .99, RMSEA = .05. Education is directly and indirectly related to cognitive functioning through occupational responsibility and past engaged lifestyle. Current social engagement is related to cognitive functioning directly and indirectly through current activities. The four direct predictors (i.e., education, current social engagement, current activity, and past engaged lifestyle) explained 35% of the variance in cognitive functioning.

CONCLUSION

The results provide important information for cognitive reserve theories with implications for interventions that build cognitive reserve.

Life course engagement in enriching activities: When and how does it matter for cognitive aging?

Growing evidence suggests that participation in enriching activities (physical, social, and mental) across the life course is beneficial for cognitive functioning in older age. However, few studies have examined the effects of enrichment across the entire life course within the same participants. Using 2,931 participants in the Health and Retirement Study, we linked self-report data from later life and retrospective self-report data from early life and midlife to cognitive performance after Age 65. We categorized participants as having either high (top ∼25%) or average to low (bottom ∼75%) level of enrichment during each life period. Thus, eight groups were identified that reflected unique patterns of enrichment during early, mid, and later life (e.g., high-high-high). Using growth curve modeling, we found that life course enrichment patterns predicted both cognitive functioning and the rate of cognitive decline across five time points spanning 8 years (Aim 1). Groups with high enrichment during at least one life period had higher performance and slower decline in older age, compared to those who had average to low levels of enrichment throughout all three life periods. We also found that high enrichment during each life period independently predicted better cognitive performance and that high enrichment during early and later life also predicted slower cognitive decline (Aim 2). These findings support the idea that high enrichment is beneficial for cognition in later life and that the effects are long-lasting, even when individuals are inconsistent in enrichment engagement throughout the entire life course. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Influence of cognitive reserve on cognitive and motor function in α-synucleinopathies: A systematic review protocol

Cognitive reserve has been used to justify neuropathologically unexplainable mismatches in Alzheimer's disease outcomes. Recent evidence has suggested this effect may be replicable across other conditions. However, it is still unclear whether cognitive reserve applies to α-synucleinopathies or to motor outcomes, or if medication confounds effects. This review protocol follows PRISMA-P guidelines and aims to investigate whether cognitive reserve can predict both cognitive and motor outcomes for α-synucleinopathy patients. MEDLINE (via PubMed), Scopus, psycINFO (via Ovid), CINAHL (via EBSCO), and Web of Science have been searched. Cross-sectional, cohort, case-control, and longitudinal studies investigating the association between cognitive reserve and cognitive and/or motor outcomes for Parkinson's disease, dementia with Lewy bodies, or multiple system atrophy will be included. Reviewers will independently perform screening, while also extracting data, assessing the risk of bias (using a version of the Quality in Prognostic Studies tool), and rating evidence quality (using GRADE). If possible, random-effects meta-analyses will be conducted for each unique outcome variable and α-synucleinopathy; otherwise, a narrative synthesis will be performed. Depending on the number of studies, exploratory analyses may involve meta-regression to assess potential confounding effects. Understanding the broader protective effect of cognitive reserve has significant implications for preventive interventions in the wider population.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

DISCUSSION

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

Fall history in older adults impacts acceleration profiles after a near collision with a moving pedestrian hazard

BACKGROUND

Environmental hazards (e.g., pedestrian traffic) cause falls and testing environment impacts gait in older adults. However, most fall risk evaluations do not assess real-world moving hazard avoidance.

AIMS

This study examined the effect of fall history in older adults on acceleration profiles before, during, and after a near collision with a moving hazard, in laboratory and real-world settings.

METHODS

Older adults with (n = 14) and without a fall history (n = 15) performed a collision avoidance walking task with a sudden moving hazard in real-world and laboratory settings. Gait acceleration and video data of participants' first-person views were recorded. Four mixed effects multilevel models analyzed the magnitude and variability of mean and peak anteroposterior and mediolateral acceleration while walking before, during, and after the moving hazard in both environments.

RESULTS

In the real-world environment, older adults without a fall history increased their mean anteroposterior acceleration after the moving hazard (p = 0.046), but those with a fall history did not (p > 0.05). Older adults without a fall history exhibited more intersubject variability than those with a fall history in mean (p < 0.001) and peak anteroposterior (p = 0.015) acceleration across environments and epochs. Older adults without a fall history exhibited a slower peak mediolateral reaction during the moving hazard (p = 0.014) than those with a fall history.

CONCLUSIONS

These results suggest that compared to older adults with a fall history, older adults without a fall history are more adaptable and able to respond last-minute to unexpected hazards. Older adults with a fall history exhibited more homogenous responses.

Predictors of cognitive functioning trajectories among older Americans: A new investigation covering 20 years of age- and non-age-related cognitive change

Despite the extensive study of predictors of cognitive decline in older age, a key uncertainty is how much these predictors explain both the intercept and age- and non-age-related change in cognitive functioning (CF). We examined the contribution of a broad range of life course determinants to CF trajectories. Data came from 7,068 participants in the 1996-2016 Health and Retirement Study. CF was measured as a summary score on a 27-point cognitive battery of items. We estimated multilevel growth curve models to examine the CF trajectories in individuals ages 54-85. We found that the variation in CF level at age 54 was three times as much as the variation in age slope. All the observed individual predictors explained 38% of the variation in CF at age 54. Personal education was the most important predictor (25%), followed by race, household wealth and income, parental education, occupation, and depression. The contributions of activity limitations, chronic diseases, health behaviors (obesity, smoking, vigorous activity), childhood conditions (childhood health, nutrition, financial situation), gender, marital status, and religion were rather small (<5%). Even though the age slope varied with many adulthood factors, they only explained 5.6% of the between-person variation in age slope. Moreover, age explained 23% of within-person variation in CF from age 54 to 85. The rest non-age-related within-person variation could not be explained by the observed time-varying factors. These findings suggest that future research is urgently needed to discover the main determinants of the slope of cognitive decline to slow down the progression of cognitive impairment and dementia.

Processing speed predicts SuperAging years later

BACKGROUND

SuperAging is one of the current concepts related to elite, resilient or high-functioning cognitive aging. The main aim of our study was to find possible predictors of SuperAgers (SA).

METHODS

Community-dwelling older persons (N = 96) aged 80-101 years in 2018 were repeatedly tested (year 2012 and 2018). SA were defined based on their performance in 2018 as persons of 80+ years of age who recalled ≥ 9 words in the delayed recall of the Philadelphia Verbal Learning Test, and had a normal performance in non-memory tasks [the Boston Naming Test, the Trail Making Test Part B, and Category Fluency ("Animals")], which was defined as a score within or above one standard deviation from the age and education appropriate average. Three composite scores (CS; immediate memory, processing speed, and executive functions) were created from the performance in 2012, and analysed as possible predictors of SA status in 2018.

RESULTS

We identified 19 SA (15 females) and 77 nonSA (42 females), groups did not significantly differ in age, years of education, and sex. The logistic regression model (p = 0.028) revealed three predictors of SA from the baseline (year 2012), including processing speed (p = 0.006; CS-speed: the Prague Stroop Test-Dots and the Digit Symbol Substitution Test), sex (p = 0.015), and age (p = 0.045).

CONCLUSIONS

Thus, SA may be predicted based on the level of processing speed, which supports the hypothesis of the processing speed theory of healthy aging.

Including cognitive assessments with functional testing predicts capabilities relevant to everyday walking in older adults

BACKGROUND

Dual-task (DT) testing reflects real-world walking demands in older adults but is not always feasible to perform in clinic. Whether clinical measures that predict single-task (ST) performance also predict DT performance or dual-task effects (DTEs) has not been fully explored.

RESEARCH QUESTION

What are the relationships between cognitive performance, functional mobility, and self-reported physical activity and balance confidence and ST and DT Gait Speed and Cognitive Reaction Time, as well as DTEs on Gait Speed (DTE_GS) and Cognitive Reaction Time (DTE_RT), in older adults?

METHODS

Sixty-two older adults (71.5 ± 7.1 years, 17 males) completed cognitive performance, functional mobility, and self-report physical activity and balance confidence assessments. Three 1-min trials were performed: 1) ST Cognition (clock task), 2) ST Gait and 3) DT Cognition + Gait, with Cognitive Reaction Time (recorded during clock task performance via DirectRT) and Gait Speed (measured during walking trial via APDM system) recorded, and DTE_GS and DTE_RT calculated, as the cognitive and gait outcomes. Six multivariate regressions were conducted to test whether cognitive performance, functional mobility, and self-report assessments predicted Gait Speed and Cognitive Reaction Time in ST and DT conditions and DTEs.

RESULTS

The Comprehensive Trail Making Test (CTMT) predicted Reaction Time in ST cognitive (β = - 0.525, p = .003) and DT (β = - 0.510, p = .006) trials. The Physical Activity Scale for the Elderly (PASE) predicted DTE_RT (β = - 0.397, p = .008). The 10-Meter Walk Test (10MWT) predicted Gait Speed in ST gait (β = 0.692, p < .001) and DT (β = 0.715, p < .001) trials. The Four Square Step Test (FSST) predicted ST Gait Speed (β = - 0.233, p = .034). The Montreal Cognitive Assessment (MoCA) (β = 0.293, p = .027), 10MWT (β = 0.322, p = .046), and the FSST (β = 0.378, p = .019) predicted DTE_GS.

SIGNIFICANCE

The 10MWT, CTMT, and MoCA can be easily implemented in the clinic and may be good choices to assess cognitive and functional abilities necessary for ambulation in older adults.

Longitudinal episodic memory trajectories in older adults with normal cognition

OBJECTIVE

To determine the longitudinal trajectories and normative standards of episodic memory in older adults.

METHODS

Participants were drawn from the cognitively normal(CN) subgroup of the population-based HELIAD cohort, a fairly representative cohort of the older Greek population. Verbal and non-verbal memory were assessed using the Greek Verbal Learning Test and Medical College of Georgia-Complex Figure Test. Baseline and longitudinal associations of memory performance with age, sex and formal education were explored with linear regression analysis and generalized estimated equations.

RESULTS

A total of 1607 predominantly female (60%) individuals (73.82 ± 5.43 years), with a mean educational attainment of 8.17(±4.86) years were CN at baseline. Baseline analysis revealed a continuum of memory decline with aging and lower educational attainment. Women performed better in composite and verbal memory measures, while men performed better in non-verbal memory tasks. A subgroup of 761 participants with available assessments after 3.07(±0.82) years remained CN at follow-up. Composite memory scores yearly diminished by an additional 0.007 of a SD for each additional year of age at baseline. Regarding verbal learning, immediate free verbal recall, delayed free verbal recall and delayed cued verbal recall, an additional yearly decrease of 0.107, 0.043, 0.036 and 0.026 words were respectively recorded at follow-up, for each additional year of age at baseline. Women underwent steeper yearly decreases of 0.227 words in delayed cued verbal recall. No significant longitudinal associations emerged for immediate non-verbal memory, delayed non-verbal memory and immediate cued verbal recall.

CONCLUSIONS

In the present study, aging (but not educational attainment) was consistently associated with steeper verbal memory decline.

Supplemental data for this article is available online at https://doi.org/10.1080/13854046.2022.2059011 .

Education and long-term outcomes in first episode psychosis: 10-year follow-up study of the PAFIP cohort

BACKGROUND

Lower levels of education have been associated with the development of psychosis. Investigating educational achievement in the first episode of psychosis (FEP) patients may shed light on the origins of the alterations and on the variability of outcomes in psychotic disorders.

METHODS

Education achievement was explored in a large sample (n = 659) of FEP patients enrolled in programa de atención a fases iniciales de psicosis (PAFIP), a research and assistance program conducted in Spain. Patients were stratified according to the Spanish educational system according to their attendance in primary (low), secondary (medium) or university studies (high). The three groups were compared on available premorbid, clinical and neuropsychological variables. A subgroup of patients (n = 209), comprising the 10-year follow-up PAFIP cohort, were again compared.

RESULTS

Overall, 49% and 37% of FEP patients had low and medium levels of education, respectively. In total, 13% of the patients with a higher level of education were more frequently women (64%) and older at illness onset (36 years old), reported better premorbid adjustment, presented less severe positive symptoms and better functioning; and showed higher premorbid intelligence quotient and better performance on all the explored cognitive domains. Ten years later the FEP patients in the medium- and high-education groups had good global functioning and a neurocognitive performance within the normal limits.

CONCLUSIONS

Higher education is associated with better initial conditions and more favourable outcomes after an FEP. Sharing this information with the world's educational systems is essential to targeting resources and designing innovative programs or strategies to compensate for student difficulties.

Predictors of the rate of cognitive decline in older adults using machine learning

BACKGROUND

The longitudinal rates of cognitive decline among aging populations are heterogeneous. Few studies have investigated the possibility of implementing prognostic models to predict cognitive changes with the combination of categorical and continuous data from multiple domains.

OBJECTIVE

Implement a multivariate robust model to predict longitudinal cognitive changes over 12 years among older adults and to identify the most significant predictors of cognitive changes using machine learning techniques.

METHOD

In total, data of 2733 participants aged 50-85 years from the English Longitudinal Study of Ageing are included. Two categories of cognitive changes were determined including minor cognitive decliners (2361 participants, 86.4%) and major cognitive decliners (372 participants, 13.6%) over 12 years from wave 2 (2004-2005) to wave 8 (2016-2017). Machine learning methods were used to implement the predictive models and to identify the predictors of cognitive decline using 43 baseline features from seven domains including sociodemographic, social engagement, health, physical functioning, psychological, health-related behaviors, and baseline cognitive tests.

RESULTS

The model predicted future major cognitive decliners from those with the minor cognitive decline with a relatively high performance. The overall AUC, sensitivity, and specificity of prediction were 72.84%, 78.23%, and 67.41%, respectively. Furthermore, the top 7 ranked features with an important role in predicting major vs minor cognitive decliners included age, employment status, socioeconomic status, self-rated memory changes, immediate word recall, the feeling of loneliness, and vigorous physical activity. In contrast, the five least important baseline features consisted of smoking, instrumental activities of daily living, eye disease, life satisfaction, and cardiovascular disease.

CONCLUSION

The present study indicated the possibility of identifying individuals at high risk of future major cognitive decline as well as potential risk/protective factors of cognitive decline among older adults. The findings could assist in improving the effective interventions to delay cognitive decline among aging populations.

Factors associated with verbal fluency in older adults living with HIV in West Africa: A longitudinal study

OBJECTIVE

Verbal fluency decline, observed both in aging and HIV infection, has been related to lower quality of life. This study aimed to evaluate the factors associated with categorical fluency in people living with HIV (PLHIV) aged ≥60 years living in West Africa.

METHODS

In this longitudinal study, PLHIV aged ≥60 years, on antiretroviral therapy (ART) for ≥6 months were included in three clinics (two in Côte d'Ivoire, one in Senegal) participating in the West Africa International epidemiological Databases to Evaluate AIDS (IeDEA) collaboration. Categorical fluency was evaluated with the Isaacs Set Test at 60 s at baseline and 2 years later. Factors associated with verbal fluency baseline performance and annual rates of changes were evaluated using multivariate linear regression models.

RESULTS

Ninety-seven PLHIV were included with 41 of them (42%) having a 2-year follow-up visit. The median age was 64 (62-67), 45.4% were female, and 89.7% had an undetectable viral load. The median annual change in categorical fluency scores was -0.9 (IQR: -2.7 to 1.8). Low baseline categorical fluency performance and its decline were associated with older age and being a female. Low educational level was associated with low baseline categorical fluency performance but not with its decline. Categorical fluency decline was also associated with marital status and hypertension.

CONCLUSIONS

Among older West African PLHIV, usual socio-demographic variables and hypertension were the main factors associated with low categorical fluency performance and/or its decline. Interventions that focus on supporting cardiometabolic health are highly recommended to prevent cognitive disorders in PLHIV.

Acute effects of virtual reality treadmill training on gait and cognition in older adults: A randomized controlled trial

INTRODUCTION

Everyday walking often involves walking with divided attention (i.e., dual-tasking). Exercise interventions for older adults should mimic these simultaneous physical and cognitive demands. This proof-of-concept study had a two-fold purpose: 1) identify acute cognitive and gait benefits of a single session of virtual reality treadmill training (VRTT), relative to conventional treadmill training (CTT), and 2) identify differences between those who reduced dual-task costs (i.e., responders) on gait or cognition and those who did not, after the session.

METHODS

Sixty older adults were randomized to complete a single 30-minute session of VRTT (n = 30, 71.2±6.5 years, 22 females) or CTT (n = 30, 72.0±7.7 years, 21 females). Pre- and post-exercise session, participants performed single-task walking, single-task cognitive, and dual-task walking trials while gait and cognition were recorded. Gait variables were gait speed and gait speed variability. Cognition variables were response reaction time, response accuracy, and cognitive throughput. Dual-task effects (DTE) on gait and cognition variables were also calculated.

RESULTS

Post-exercise, there were no group differences (all p>0.05). During single- and dual-task trials, both groups walked faster (single-task: F(1, 58) = 9.560, p = 0.003; dual-task: F(1, 58) = 19.228, p<0.001), responded more quickly (single-task: F(1, 58) = 5.054, p = 0.028; dual-task: F(1, 58) = 8.543, p = 0.005), and reduced cognitive throughput (single-task: F(1, 58) = 6.425, p = 0.014; dual-task: F(1, 58) = 28.152, p<0.001). Both groups also exhibited reduced DTE on gait speed (F(1, 58) = 8.066, p = 0.006), response accuracy (F(1, 58) = 4.123, p = 0.047), and cognitive throughput (F(1, 58) = 6.807, p = 0.012). Gait responders and non-responders did not differ (all p>0.05), but cognitive responders completed fewer years of education (t(58) = 2.114, p = 0.039) and better information processing speed (t(58) = -2.265, p = 0.027) than cognitive non-responders.

CONCLUSIONS

The results indicate that both VRTT and CTT may acutely improve gait and cognition. Therefore, older adults will likely benefit from participating in either type of exercise. The study also provides evidence that baseline cognition can impact training effects on DTE on cognition.

Associations Between Country where Education is Obtained and Cognitive Functioning Among South American and Caribbean Older Adults Living in the U.S

The increasing prevalence of AD among Hispanics calls for a need for examining factors that affect cognitive functioning and risk of AD among Hispanic older adults. The current study examined cognitive functioning among older Hispanic adults living in the U.S. from two Hispanic regions, South America and the Caribbean, in relation to the country where education was obtained. Participants (n = 139) were stratified into groups based on Hispanic education region and diagnostic categories: cognitively normal and amnestic MCI (aMCI). Results of Pearson correlations showed that among Hispanic Americans in general, there were significant positive correlations between the country of education to performance on measures of episodic, verbal, and word list tests. When examined separately by region and diagnosis, only cognitively normal (CN) South Americans showed significant relationships between country of education and cognitive functioning in these areas. Results of general linear models controlling for education identified differences in neuropsychological performance between groups with the CN groups demonstrating better performance than the aMCI groups within each region. Overall, it was evident that relationships between years of education obtained outside of the U.S. and cognitive functioning were not similar among individuals from these two disparate Spanish speaking regions. This is the first study to examine the country where education was obtained among individuals from countries located in different regions with different cultures that may influence their education and cognitive development throughout life. Findings contribute to the cross-cultural neuropsychological literature in understanding factors that are unique to Hispanic older adults at risk for developing AD.

Childhood deprivations predict late-life cognitive impairment among older adults in India

Large population-based studies on the associations of childhood factors with late-life cognition are lacking in many low and middle income countries including India. In this study, we assessed the prevalence of late-life cognitive impairment and examined the associations of childhood socioeconomic status (SES) and health conditions with cognitive impairment among older adults in India. Data for this study were derived from the Longitudinal Ageing Study in India conducted in 2017-18. The effective sample size was 31,464 older adults aged 60 years and above. Cognitive functioning was measured through five global domains (memory, orientation, arithmetic function, executive function, and object naming). The overall score ranged between 0 and 43, and the score was reversed indicating cognitive impairment. Descriptive statistics along with mean scores of cognitive impairment were presented. Additionally, moderated multivariable linear regression models were employed to examine the association between explanatory variables, including childhood SES and health conditions and late-life cognitive impairment. The mean score of cognitive functioning among the study participants was 21.72 (CI 2.64-21.80). About 15% of older adults had poor health conditions, and 44% had lower financial status during their childhood. Older adults who had a fair health during their childhood were more likely to suffer from cognitive impairment in comparison to older adults who had good health during their childhood (Coef: 0.60; CI 0.39, 0.81). In comparison to older adults who had good childhood financial status, those who had poor childhood financial status were more likely to suffer from cognitive impairment (Coef: 0.81; CI 0.56, 1.07). Older adults who had fair childhood health status and poor childhood financial status were more likely to suffer from cognitive impairment in comparison to older adults who had good childhood health and good financial status (Coef: 1.26; CI 0.86, 1.66). Social policies such as improving educational and financial resources in disadvantaged communities and socioeconomically poor children and their families, would help to enhance a better cognitive ageing and a healthy and dignified life in old age.

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.

Cognitive Impairment and Associated Factors among Older Adults with Diabetes in a Suburban Primary Health Center in Thailand

INTRODUCTION

Thailand is a rapidly aging society. The percentage of older adults with diabetes has also been increasing. Since diabetes mellitus is documented as a risk factor for dementia, it is important to address cognitive impairment in older adults with diabetes. Thus, this study aimed to evaluate the prevalence and associated factors of cognitive impairment among older adults with diabetes in a suburban primary health center in Thailand.

METHODS

A cross-sectional study in 244 diabetic patients aged 60 years or older was conducted in a primary health care unit in Pathum Thani, Thailand. Cognitive function was assessed with the validated Thai version of the Mini-Addenbrooke's Cognitive Examination Test. Sociodemographic and health characteristic data were obtained.

RESULTS

The prevalence of cognitive impairment was 54.5% (133 out of 244). Multivariate logistic regression disclosed that factors significantly associated with cognitive impairment were ages 70-79 years compared to ages 60-69 years (odds ratio [OR] 1.90, 95% confidence interval [CI]: 1.01-3.62, p value 0.048), ages ≥80 years compared to ages 60-69 years (OR 3.65, 95% CI: 1.19-11.24, p value 0.024), education ≤ primary school (OR 7.28, 95% CI: 3.56-14.89, p value <0.001), and medication managed by caregiver compared to self-management of medication (OR 13.40, 95% CI: 1.55-116.10, p value 0.019).

CONCLUSION

We revealed that approximately half of older adults with diabetes had cognitive impairment. This finding strongly suggests the need to include cognitive assessment in a standard clinical practice guideline for diabetic patients and to focus more on individuals who are very old, have low education, or are unable to manage their drugs by themselves.

Predicting response time variability from task and resting-state functional connectivity in the aging brain

Aging is associated with declines in a host of cognitive functions, including attentional control, inhibitory control, episodic memory, processing speed, and executive functioning. Theoretical models attribute the age-related decline in cognitive functioning to deficits in goal maintenance and attentional inhibition. Despite these well-documented declines in executive control resources, older adults endorse fewer episodes of mind-wandering when assessed using task-embedded thought probes. Furthermore, previous work on the neural basis of mind-wandering has mostly focused on young adults with studies predominantly focusing on the activity and connectivity of a select few canonical networks. However, whole-brain functional networks associated with mind-wandering in aging have not yet been characterized. In this study, using response time variability-the trial-to-trial fluctuations in behavioral responses-as an indirect marker of mind-wandering or an "out-of-the-zone" attentional state representing suboptimal behavioral performance, we show that brain-based predictive models of response time variability can be derived from whole-brain task functional connectivity. In contrast, models derived from resting-state functional connectivity alone did not predict individual response time variability. Finally, we show that despite successful within-sample prediction of response time variability, our models did not generalize to predict response time variability in independent cohorts of older adults with resting-state connectivity. Overall, our findings provide evidence for the utility of task-based functional connectivity in predicting individual response time variability in aging. Future research is needed to derive more robust and generalizable models.

Association of Education and Intracranial Volume With Cognitive Trajectories and Mortality Rates Across the Alzheimer Disease Continuum

Objective

To investigate relationships of education and intracranial volume (ICV) (factors related to cognitive and brain reserve, respectively) with cognitive trajectories and mortality in individuals with biomarker-defined Alzheimer disease (AD).

Methods

We selected 1,298 β-amyloid–positive memory clinic patients with subjective cognitive decline (SCD, n = 142), mild cognitive impairment (MCI, n = 274), or AD dementia (n = 882) from the Amsterdam Dementia Cohort. All participants underwent baseline MRI and neuropsychological assessment, and 68% received cognitive follow-up (median 2.3 years, interquartile range 2.4). Mortality data were collected from the Central Public Administration. In the total sample and stratified by disease stage (i.e., SCD/MCI vs dementia), we examined education and ICV as predictors of baseline and longitudinal cognitive performance on 5 cognitive domains (memory, attention, executive, language, and visuospatial functions; linear mixed models) and time to death (Cox proportional hazard models). Analyses were adjusted for age, sex, whole brain gray matter atrophy, and MRI field strength.

Results

Education and ICV showed consistent positive associations with baseline cognition across disease stages. Longitudinally, we observed a relationship between higher education and faster cognitive decline among patients with dementia on global cognition, memory, executive function, and language (range β = −0.06 to −0.13; all p < 0.05). Furthermore, in the total sample, both higher education and larger ICV were related to lower mortality risk (hazard ratio 0.84 and 0.82, respectively; p < 0.05).

Discussion

In this β-amyloid–positive memory clinic sample, both cognitive and brain reserve were positively associated with baseline cognition, whereas only education was related to longitudinal cognition (i.e., accelerated decline among more highly educated patients with dementia). Higher education and ICV both moderately attenuated overall mortality risk in AD.

Associations Between Retinal Nerve Fiber Layer and Ganglion Cell Layer in Middle Age and Cognition From Childhood to Adulthood

IMPORTANCE

The retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) have been proposed as potential biomarkers for Alzheimer disease (AD). Although a number of studies have shown that knowing the thickness of RNFL and GCL can help differentiate between patients with AD and healthy controls, it is unclear whether these associations are observable earlier in life.

OBJECTIVE

To examine whether RNFL and GCL thickness was associated with global cognitive performance in middle age and in childhood and with a decline in cognitive performance from childhood to adulthood and whether RNFL and GCL thickness was associated with decline in specific cognitive domains over the same period.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal cohort study involved members of the Dunedin Multidisciplinary Health and Development Study, a longitudinal representative birth cohort from New Zealand (n = 1037). Participants were born in 1972 to 1973 and followed up until age 45 years, with 94% of the living cohort still participating.

MAIN OUTCOMES AND MEASURES

Cognitive performance (Full Scale IQ, processing speed, perceptual reasoning, and verbal comprehension) measured at ages 7, 9, and 11 years (mean value) and age 45 years, and RNFL and GCL thickness measured via optical coherence tomography (OCT) at age 45 years.

RESULTS

Data were analyzed between August 2020 and April 2021. Data from 865 participants were included in the present study (50.2% male, 49.8% female; 92.2% of the 938 study members seen at age 45 years). Of the 73 participants who were excluded, 63 were excluded because of issues with OCT scans and 10 were excluded because of diseases affecting the retina. Thinner RNFL and GCL were associated with lower Full Scale IQ in childhood and at age 45 years. Thinner RNFL was also associated with a greater decline in processing speed from childhood to adulthood.

CONCLUSIONS AND RELEVANCE

RNFL and GCL thickness in middle age was associated with cognitive performance in childhood and adulthood, and thinner RNFL with a decline in processing speed between childhood and adulthood. These data emphasize the potential utility of OCT measures as biomarkers of cognitive function; however, further longitudinal studies are needed to determine whether retinal thinning precedes cognitive decline and whether other confounding factors may account for this association.

Cognitive reserve over life course and 7-year trajectories of cognitive decline: results from China health and retirement longitudinal study

Background

Cognitive reserve (CR) could partly explain the individual heterogeneity in cognitive decline. No study measured CR from a life course perspective and investigated the association between CR and trajectories of cognitive decline in older Chinese adults.

Methods

Data of 6795 Chinese adults aged 60+ from China Health and Retirement Longitudinal Study were used. Global cognition score (0–32) was assessed in all four waves. A life-course CR score was constructed using markers of childhood circumstance, education, highest occupational class, and leisure activities in later life. Latent growth curve modelling (LGCM) was applied to assess the association between CR and trajectories of cognitive decline.

Results

For the life-course CR, factor loadings of markers in adulthood and later life were larger than that of markers in childhood. The life-course CR score (ranged between − 2.727 and 6.537, SD: 1.74) was higher in urban Chinese adults (0.75, SD: 1.90) than in rural Chinese adults (− 0.50, SD: 1.43). The unconditional LGCM results showed that urban older Chinese adults had better global cognition at baseline (intercept: 15.010, 95% CI: 14.783, 15.237) and a slower rate of cognitive decline per year (linear slope: -0.394, 95% CI: − 0.508, − 0.281) than their rural counterparts (intercept: 12.144, 95% CI: 11.960, 12.329; linear slope: -0.498, 95% CI: − 0.588, − 0.408). After controlling for all covariates, one-unit higher CR score was associated with 1.615 (95% CI: 1.521, 1.709) and 1.768 (95% CI: 1.659, 1.876) unit higher global cognition at baseline for urban and rural older Chinese adults, respectively. The slower rate of cognitive decline associated with higher CR was more evident in rural residents (slope: 0.083, 95% CI: 0.057, 0.108) than in their urban counterparts (0.054, 95% CI: 0.031, 0.077).

Conclusions

CR was associated with better baseline cognition and slower cognitive decline in Chinese older adults. Although rural residents were disadvantaged in both CR and cognition, the protective effect of CR against cognitive decline was stronger for them than in those who live in urban area.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12671-6.

A Longitudinal Examination of Alcohol-Related Blackouts as a Predictor of Changes in Learning, Memory, and Executive Function in Adolescents

INTRODUCTION

In adolescents, the relationship between alcohol-related blackouts (ARBs) and distinct cognitive changes lasting beyond intoxication is unclear. We examined ARBs as a predictor of persistent changes in the development of learning, memory, and executive function in participants from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study.

METHODS

Descriptive analyses of the NCANDA sample (N = 831, 50.9% female, 12-21 years at baseline) identified ARB patterns within participants with an ARB history (n = 106). Latent growth curve modeling evaluated ARB-related performance changes on four neuropsychological measures across five years, excluding baseline data to reduce the magnitude of practice effects over time (n = 790). Measures included the Penn Conditional Exclusion Test (PCET), Penn Letter N-back Test (PLBT), Penn Facial Memory Test immediate (PFMT_i), and delayed (PFMT_d) recognition trials, and the Rey Complex Figure Test copy (RCFT_c), immediate recall (RCFT_i), and delayed recall (RCFT_d) trials. Multivariate models were fit for raw accuracy scores from each measure, with ARB history (i.e., presence of past-year ARBs) as the main independent variable. Age, sex, race, socioeconomic status, assessment site, and alcohol use (i.e., past-year frequency) were included as covariates. Interaction effects between ARB history and alcohol use frequency were tested.

RESULTS

By year five, 16% of participants had experienced at least one ARB (59% of whom reported > 1 ARB and 57% of whom had an ARB lasting > 1 h). After controlling for demographics and alcohol use, ARB history predicted attenuated PFMT_d performance growth at year one. Interaction effects between ARB history and alcohol use frequency predicted attenuated PFMT_d performance growth at years one and two. ARB history predicted attenuated RCFT_i and RCFT_d performance growth by year four, but not PCET or PLBT performance over time. By contrast, greater past-year alcohol use predicted attenuated PFMT_i and PFMT_d performance growth between years two and four in adolescents without an ARB history.

CONCLUSION

We found that ARBs predict distinct, lasting changes in learning and memory for visual information, with results suggesting that the developing brain is vulnerable to ARBs during adolescence and emerging adulthood.

Performance-Based Everyday Problem-Solving in Patients With TBI

OBJECTIVE

The present study examined whether the everyday problems test (EPT), a performance-based measure of everyday problem-solving, can be considered a useful test in assessing functional independence in patients with traumatic brain injury (TBI). The relationship between EPT, cognitive abilities (i.e., selective attention, set switching, and working memory) and self-rated measures of everyday functioning and disability in these patients was also assessed.

METHOD

In this case-control study 25 postcomatose outpatients with TBI (age M = 35.9, SD = 14.21) from a neurorehabilitation unit and 25 matched controls were enrolled. Participants were administered the EPT along with neuropsychological tests of selective attention, set switching and working memory, and self-rated measures of everyday functioning and disability.

RESULTS

Patients with TBI were less accurate and slower than controls in the EPT; the two groups were accurately classified based on EPT completion time (likelihood ratio test χ2 = 28.67, R2 = 0.72, p < .001). In the patient group education and selective attention explained a large portion of variance in EPT accuracy (R2 = 0.53, p = .001), while only selective attention explained a significant portion of variance in EPT time (R2 = 0.24, p < .01). Self-rated measures of everyday functioning and disability did not significantly contribute to EPT performance variance.

CONCLUSION

Including performance-based measures as the EPT in a multifactorial approach to assessment can be useful for unraveling cognitive factors contributing to TBI's impact on everyday functioning. Since attentional processes seem to play a significant role in determining EPT performance, rehabilitation of functional independence should target this ability first.

Data-driven approaches to executive function performance and structure in aging: Integrating person-centered analyses and machine learning risk prediction

Objective: Executive function (EF) performance and structure in nondemented aging are frequently examined with variable-centered approaches. Person-centered analytics can contribute unique information about classes of persons by simultaneously considering EF performance and structure. The risk predictors of these classes can then be determined by machine learning technology. Using data from the Victoria Longitudinal Study we examined two goals: (a) detect different underlying subgroups (or classes) of EF performance and structure and (b) test multiple risk predictors for best discrimination of these detected subgroups. Method: We used a classification sample (n = 778; M_age = 71.42) for the first goal and a prediction subsample (n = 570; M_age = 70.10) for the second goal. Eight neuropsychological measures represented three EF dimensions (inhibition, updating, shifting). Fifteen predictors represented five domains (genetic, functional, lifestyle, mobility, demographic). Results: First, we observed two distinct classes: (a) lower EF performance and unidimensional structure (Class 1) and (b) higher EF performance and multidimensional structure (Class 2). Second, Class 2 was predicted by younger age, more novel cognitive activity, more education, lower body mass index, lower pulse pressure, female sex, faster balance, and more physical activity. Conclusions: Data-driven modeling approaches tested the possibility of an EF aging class that displayed both preserved EF performance levels and sustained multidimensional structure. The two observed classes differed in both performance level (lower, higher) and structure (unidimensional, multidimensional). Machine learning prediction analyses showed that the higher performing and multidimensional class was associated with multiple brain health-related protective factors. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Relationship between Arterial Hypertension with Cognitive Performance in Elderly. Systematic Review and Meta-Analysis

Background: Previous systematic reviews report that arterial hypertension (AHT) is associated with lower performance in cognition in the elderly. However, some studies show that with higher blood pressure, a better cognitive performance is obtained. Objective: The aim of this study was to determine the relationship between AHT with cognitive performance in the elderly. Methods: the review involved a search on PubMed, Scopus and PsycINFO databases from January 1990 to March, 2020 to identify the relationship among AHT and cognitive performance in older people. Results: 1170 articles were identified, 136 complete papers were reviewed, a qualitative analysis of 26 studies and a quantitative analysis of eight studies were carried out. It was found that people with AHT have a lower performance in processing speed SMD = 0.40 (95% CI: 0.25, 0.54), working memory SMD = 0.28 (95% CI: 0.15, 0.41) in short-term memory and learning SMD = −0.27 (95% CI: −0.37, −0.17) and delayed recall SMD = −0.20 (95% CI: −0.35, −0.05). Only one study found that higher blood pressure was associated with better memory performance. Conclusion: Our results suggest that high blood pressure primarily affects processing speed, working memory, short-term memory and learning and delayed recall.

Cognitive functioning and its associated factors among breast cancer patients on chemotherapy at Tikur Anbessa specialized hospital, Addis Ababa Ethiopia: an institution-based comparative cross-sectional study

BACKGROUND

Breast cancer is the second leading cause of cancer in the world. It is the commonest type of cancer in Ethiopia. Cognitive problems are common among breast cancer patients. The study aimed to assess cognitive functioning and its associated factors among breast cancer patients at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia 2020.

METHODS

Institution-based comparative cross-sectional study was conducted. Study subjects were 117 breast cancer patients on chemotherapy and 117 women without breast cancer who volunteered for the study. Data was collected from May-June 2020. The Mini-mental status exam (MMSE) was used to assess cognitive functioning. Data were entered into Epi Data version 4.6.0.2 and analyzed using STATA version 14 software. Univariable and multivariable linear regression model was fitted to identify factors associated with cognitive functioning. A two-tailed p-value less than 0.05 was used to declare statistical significance.

RESULTS

Among the total breast cancer patients 41.9% were diagnosed with earlier sage of the diseases (stage I and II), while the rest 58.1% were diagnosed with stage III and stage IV breast cancer. A significant difference in the MMSE score was observed among breast cancer patients and controls (19.76 ± 5.29, 25.18 ± 4.68 p <  0.0001) respectively. In multivariable linear regression analysis being non-breast cancer (Adjusted beta coefficient (Adj.β.coff). = 3.34, 95% CI (1.92-4.76) p <  0.001), hemoglobin gm/dl (Adj.β.coff =0.34, 95% CI (0.04-0.63) p = 0.02), and primary education (Adj.β.coff =2.98 95%CI (1.16-4.96) p = 0.001) secondary level and more education (Adj.β.coff = 5.47, 95%CI (3.51-7.28) p < 0.001) were significantly associated with MMSE cognitive score.

CONCLUSION

Breast cancer patients had lower mean MMSE scores when compared to non-breast cancer women. Higher hemoglobin level and higher level of education increase the MMSE cognitive score. Clinicians should incorporate routine screening of cognitive functioning for breast cancer patients and further study is required to evaluate cognitive impairment among breast cancer patients in Ethiopia.

Quantifying Age-Related Changes in Brain and Behavior: A Longitudinal versus Cross-Sectional Approach

Cross-sectional versus longitudinal comparisons of age-related change have often revealed differing results. In the current study, we used within-subject task-based fMRI to investigate changes in voxel-based activations and behavioral performance across the life span in the Reference Ability Neural Network cohort, at both baseline and 5 year follow-up. We analyzed fMRI data from between 127 and 159 participants (20–80 years) on a battery of tests relating to each of four cognitive reference abilities. We applied a Gaussian age kernel to capture continuous change across the life span using a 5 year sliding window centered on each age in our participant sample, with a subsequent division into young, middle, and old age brackets. This method was applied separately to both cross-sectional approximations of change and real longitudinal changes adopting a comparative approach. We then focused on longitudinal measurements of neural change to identify regions expressing peak changes and fluctuations of sign change across our sample. Our results revealed several regions expressing divergence between cross-sectional and longitudinal measurements in each domain and age bracket; behavioral comparisons between measurements showed differences in change curves for all four domains, with processing speed displaying the steepest declines. In the longitudinal change measurement, we found lack of support for age-related frontal increases across analysis types, instead finding more posterior regions displaying peak increases in activation, particularly in the old age bracket. Our findings encourage greater focus on longitudinal measurements of age-related changes, which display appreciable differences from cross-sectional approximations.

Loss of Motor Stability After Sports-Related Concussion: Opportunities for Motor Learning Strategies to Reduce Musculoskeletal Injury Risk

Current best practices to direct recovery after sports-related concussion (SRC) typically require asymptomatic presentation at both rest and during a graduated exercise progression, and cognitive performance resolution. However, this standard of care results in a significantly elevated risk for musculoskeletal (MSK) injury after return-to-sport (RTS). The elevated risk is likely secondary to, in part, residual neurophysiological and dual-task motor stability deficits that remain despite RTS. These deficits present as a loss of autonomous control of gait and posture and an increased need for cognition for motor stability. Thus, the incorporation of strategies that can enhance motor stability and restore autonomous control of gait and posture during SRC recovery and RTS progression may facilitate a reduction of the elevated risk of secondary MSK injury. We provide a theoretical framework for the application of motor learning principles to restore autonomous gait and postural stability after SRC via incorporation, or targeted manipulation, of external focus, enhanced expectations, autonomy support, practice schedule variability, and dual-task strategies during rehabilitation and RTS training.

Cognitive Reserve in Individuals Aging With Traumatic Brain Injury: Independent and Interactive Effects on Cognitive Functioning

OBJECTIVE

To examine the influence of 2 temporal factors-age and injury chronicity-on the relationship between cognitive reserve (CR) and cognitive functioning in older adults with chronic traumatic brain injury (TBI).

SETTING

Outpatient research laboratory.

PARTICIPANTS

Adults, 50 years or older, with a 1- to 45-year history of moderate or severe TBI (N = 108).

DESIGN

Cross-sectional observational study.

MAIN MEASURES

CR was estimated using demographically corrected performance on a word-reading test (an approximation of premorbid IQ). Injury chronicity was operationalized as number of years since the date of injury. Composite cognitive scores were computed from performances on neuropsychological tests of processing speed, executive functioning, and memory.

RESULTS

CR was positively and significantly related to all cognitive performances independent of age, injury chronicity, and injury severity. Greater injury chronicity significantly attenuated the effect of CR on processing speed such that individuals more distal from their injury date evidenced a weaker positive relationship between CR and performance.

CONCLUSION

Temporal factors may modify associations between CR and cognition. Findings suggest that the protective effects of CR are temporally delimited, potentially contending with declines in brain reserve. The prognostic value of traditional outcome determinants should be considered in the context of injury chronicity.

A quick test of cognitive speed (AQT): regression-based norms for cognitively healthy 80 to 94-year olds

Slowed processing speed is part of normal aging but also a symptom of many diseases, including dementia. A Quick Test of Cognitive Speed (AQT) consists of three conditions: color naming (AQT1), form naming (AQT2) and dual color-form naming (AQT3) and offers a user-friendly assessment of processing speed that is used internationally to identify cognitive impairment in elderly patients. Appropriate age-norms have however been lacking. This study provides regression-based norms derived from a Swedish sample of 158 cognitively healthy 80 to 94-year olds. The results show age effects in all three conditions, a non-linear education effect in AQT1, and age by gender interactions in AQT2 and AQT3: men performed worse with increasing age, but women remained on a par. However, irrespective of age and gender, AQT2 and AQT3 mean raw and predicted scores were slower than the hitherto recommended cutoff criteria for suspected cognitive impairment.

Solving the Puzzle of Cognitive Reserve Effects on Cognitive Decline: The Importance of Considering Functional Impairment

AIMS

We investigated whether the longitudinal relation between cognitive reserve accumulated across the lifespan and rate of cognitive decline over 6 years differed by the individual's degree of functional impairment.

METHODS

We analyzed longitudinal data from 897 older adults (M = 74.33 years) tested on the Trail Making Test (TMT) in 2 waves 6 years apart.

RESULTS

There was a significant interaction of functional impairment with cognitive reserve on latent change in cognitive functioning. Specifically, with no functional impairment in the first wave of assessment, greater cognitive reserve accumulated across the lifespan significantly predicted a reduced cognitive decline over 6 years (i.e., smaller increase in TMT completion time). In contrast, with certain functional impairment (in at least some activities) in the first wave, greater cognitive reserve build-up predicted a steeper cognitive decline (i.e., larger increase in TMT completion time).

CONCLUSION

Individuals with greater cognitive reserve accumulated across the lifespan show a reduced cognitive decline if they still have relatively little functional impairment, while they will show a steeper decline (compared to individuals with less cognitive reserve) as soon as functional impairment becomes substantial.

Engagement in Cognitively Stimulating Activities Mediates the Relationship between Openness and Attention/Executive Functions, but Not Memory in Older Adults

OBJECTIVE

Openness has a positive association with cognitive functioning and engagement in cognitively stimulating activities (CSA). Older adults who engage in more CSA tend to show greater preservation of their cognitive skills; thus, we examined whether: higher Openness would be associated with higher attention/executive functions (AEF) and verbal memory; and CSA would mediate the relationship between Openness and AEF, as well as verbal memory.

METHOD

477 community-dwelling older adults (65+ years) were included in the current cross-sectional study. Composite variables of AEF (TMT-A&B, COWAT, and DSST) and verbal memory (RBANS immediate and delayed verbal memory subtasks) were included. Openness was assessed via the Big-5 Inventory and CSA with the Leisure Activity Questionnaire.

METHOD

477 community-dwelling older adults (65+ years) were included in the current cross-sectional study. Composite variables of AEF (TMT-A&B, COWAT, and DSST) and verbal memory (RBANS verbal memory subtasks) were included. Openness was assessed via the Big-5 Inventory and CSA with the Leisure Activity Questionnaire.

RESULTS

Linear regressions indicated a significant positive association between Openness and AEF (β = .09, p < .01), but not verbal memory (β = .06, p = .06). A significant partial mediation was demonstrated between Openness, CSA, and AEF (c: β = .08, p < .05, 95%CI = .02-.14; c': β = .02, 95%CI = .01-.03). The mediation of Openness, CSA, and verbal memory was not significant (c: β = .06, p > .05, 95%CI = .01-.11; c': β = .00, 95%CI = -.01-.01).

CONCLUSIONS

The association between Openness and AEF, but not verbal memory, was partially mediated by CSA in healthy older adults. The findings suggest that those who are more open to and highly engaged in CSA may have a later in life advantage in preserving their AEF abilities.

Rhythm and groove as cognitive mechanisms of dance intervention in Parkinson's disease

Parkinson's disease (PD) is associated with a loss of internal cueing systems, affecting rhythmic motor tasks such as walking and speech production. Music and dance encourage spontaneous rhythmic coupling between sensory and motor systems; this has inspired the development of dance programs for PD. Here we assessed the therapeutic outcome and some underlying cognitive mechanisms of dance classes for PD, as measured by neuropsychological assessments of disease severity as well as quantitative assessments of rhythmic ability and sensorimotor experience. We assessed prior music and dance experience, beat perception (Beat Alignment Test), sensorimotor coupling (tapping to high- and low-groove songs), and disease severity (Unified Parkinson's Disease Rating Scale in PD individuals) before and after four months of weekly dance classes. PD individuals performed better on UPDRS after four months of weekly dance classes, suggesting efficacy of dance intervention. Greater post-intervention improvements in UPDRS were associated with the presence of prior dance experience and with more accurate sensorimotor coupling. Prior dance experience was additionally associated with enhanced sensorimotor coupling during tapping to both high-groove and low-groove songs. These results show that dance classes for PD improve both qualitative and quantitative assessments of disease symptoms. The association between these improvements and dance experience suggests that rhythmic motor training, a mechanism underlying dance training, impacts improvements in parkinsonian symptoms following a dance intervention.

Dual-tasking impacts gait, cognitive performance, and gaze behavior during walking in a real-world environment in older adult fallers and non-fallers

INTRODUCTION

Everyday walking often involves simultaneous performance of a cognitive task in environments with competing auditory and visual stimuli. Previous research has not evaluated task performance in these situations, where older adults are known to fall, limiting our understanding of how older adults adjust their gait, visual scanning (gaze), and cognitive processing to avoid falls (or not). The purpose of this study was to examine the effect of dual-task walking in a high-distraction real-world environment on cognitive performance, gait performance, and gaze behavior in older adult fallers relative to non-fallers.

METHODS

Fourteen community-dwelling, older adult fallers (76.6 ± 9.1 years, 11 females) and 15 community-dwelling, older adult non-fallers (77.4 ± 7.6 years, 11 females) participated. Participants performed single-task walking, single-task cognitive (seated category naming), and dual-task walking (category naming + walking) trials for 1 min each in a real-world environment (busy hospital lobby). Gait speed, stride length variability, stride duration variability, gaze fixation duration on 6 areas of interest (AOIs), and percentage of time fixating on 6 AOIs were recorded during single- and dual-task walking trials. Number of correct responses, time to first response, and mean subsequent response time (measure of rate of decline of response retrieval throughout trial) were determined for single-task cognitive and dual-task walking trials. Two-way MANCOVAs and MANOVAs were used to compare the effects of fall status and task condition on gait and cognitive variables. Hierarchical linear regression models were used to assess predictors of gaze behavior variables.

RESULTS

Compared to single-task, during dual-task trials, participants walked 0.21 m/s slower, had 1.5 fewer verbal responses, and a 2823 ms shorter mean subsequent response time, indicating a faster declining rate of retrieval during the cognitive task. Additionally, during dual-task walking, participants fixated their gaze on Far People (AOI) for a significantly smaller percentage of time and on the Near Walking Path (AOI) for a significantly greater percentage of time than during single-task walking. During all trials, being a non-faller predicted a longer average fixation duration on the Far Environment (AOI) than for fallers. Environmental busyness, baseline gait speed, and baseline executive function impacted gaze behavior.

CONCLUSION

All participants exhibited dual-task decrements in gait and cognitive performance and changes in gaze behavior from single- to dual-task walking. Perhaps of more importance, non-fallers appear to have had more freedom to divert their gaze to less relevant environmental stimuli while walking, and two measures of fall risk impacted patterns of gaze behavior differently. Thus, overt visual attention during walking in real-world environments should be further explored in relation to fall risk.

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.