Longitudinal measurement invariance of memory performance and executive functioning in healthy aging

The validity of studying healthy aging with cognitive tests measuring different constructs

A clinically useful characterization of the cognitive aging process requires the development of valid and robust behavioral tests, with an emphasis on explaining and understanding typical inter-individual variability in cognition. Here, using a dataset that includes behavioral scores collected with the National Institute of Health Toolbox Cognition Battery (NIHTB-CB) and other auxiliary tests, we examined (1) the differences between young and old adults across different cognitive domains, (2) the strength of across-subject correlations in behavioral test scores, (3) the consistency of low-dimensional behavioral representations across age using factor analysis, and (4) the accuracy of behavioral scores in predicting participants' age. Our results revealed that (1) elderly females had better verbal episodic memory scores than elderly males, (2) across-subject correlations between behavioral tests varied with age group, (3) although a three-factor model explained the behavioral data in both age groups, some tasks loaded to different factors between the two groups, and (4) age-performance relationship (i.e. a regression model linking age to cognitive scores) in one group cannot be extrapolated to predict age in the other group, indicating an inconsistency in age-performance relationships across groups. These findings suggest that executive function tests might tap into different cognitive processes in different age groups, which might ultimately suggest that a statistically significant between-group difference in test performance might not always reflect differences in the same underlying cognitive processes. Overall, this study calls for more caution when interpreting age-related differences and similarities between age groups with different cognitive abilities even when the same tests are used.

Longitudinal Invariance and Construct Validity of the Chinese Version of the Mini-Mental State Examination Across 10 Years in the Elderly Population

Background and Purpose: In this study, we investigate the longitudinal measurement invariance of the Chinese version of the mini-mental state examination (CMMSE). Methods: The factor structure and longitudinal equivalence of the CMMSE were examined by confirmatory factor analysis. Four CMMSE measurements of 13,132 participants from the China Longitudinal Health and Longevity Study between 2008 and 2018 were included. The nested model of longitudinal invariance proves the existence of strict longitudinal invariance. Results: It showed that the factor structure, factor loadings, intercept error variance, and latent factor means of the CMMSE were invariant across four measurements. Conclusion: These findings indicate that the changes in CMMSE scores can be attributed to real structural change, indicating that the CMMSE is a reliable measurement tool for the study of cognitive aging.

Attention Performance Decline After Age 40 in Clinically Normal Community Dwellers: Evidence from a 10-Year Follow-Up of the Yakumo Study

Age-related changes in attention ability and differences by gender in the rates of change from middle age were investigated. Digit Cancellation Test (D-CAT1 and D-CAT3 conditions, which involve low and high cognitive load, respectively) scores and individually calculated decline rates (DRs) in 10-year follow-up among four age groups (40s, 50s, 60s, and 70s) were examined. Performance in both D-CAT conditions declined with increasing age from the 50s to the 70s, whereas there was no difference between the 40s and 50s, and a gender difference (with the women showing an advantage) was demonstrated in the 40s and 50s groups on the D-CAT3. In the D-CAT1 condition, the DR remained stable from the 40s to the 50s but increased from the 50s and to the 60s and then remained the same. In the D-CAT3 condition, the DR became larger even after the 70s. The DRs did not differ between men and women from middle age onward. Although DRs showed no gender difference, D-CAT performance showed a gender difference, with men being about 20% less capable by the age of 40. We suggest that data showing concrete declines in attentional performance after middle age may be used to reduce accidents encountered in the daily life of older adults.

Sleep Quality Partially Mediate the Relationship Between Depressive Symptoms and Cognitive Function in Older Chinese: A Longitudinal Study Across 10 Years

Objective

This study aimed to examine the relationship between cognitive function and depressive symptoms and to explore the mediating role of sleep quality in the cognition-depression relationship in Chinese older adults (OAs).

Methods

Data came from a nationally representative sample of 16,209 Chinese OAs (aged 65+) from 2008, 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A random intercept cross-lagged panel model (RI-CLPM) combined with mediation analysis was adopted to determine the relationship between cognitive function and depressive symptoms and the mediating effect of sleep quality on the ascertained cognition-depression relationship.

Results

Poorer cognitive function at prior assessment points were significantly associated with severe depressive symptoms at subsequent assessments, and vice versa. Sleep quality partially mediated the prospective relationship of cognition on depressive symptoms, which accounted for 3.92% of the total effect of cognition on depression.

Discussion

Cognitive decline may predict subsequent depressive symptoms, and vice versa. The impact of cognition on depression is partially explained by its influence on sleep quality. Multidisciplinary interventions aimed at reducing depression and cognitive decline per se as well as improving sleep quality would be beneficial for emotional well-being and cognitive health in OAs.

Measurement invariance testing of longitudinal neuropsychiatric test scores distinguishes pathological from normative cognitive decline and highlights its potential in early detection research

OBJECTIVE

Alzheimer's disease (AD) is a growing challenge worldwide, which is why the search for early-onset predictors must be focused as soon as possible. Longitudinal studies that investigate courses of neuropsychological and other variables screen for such predictors correlated to mild cognitive impairment (MCI). However, one often neglected issue in analyses of such studies is measurement invariance (MI), which is often assumed but not tested for. This study uses the absence of MI (non-MI) and latent factor scores instead of composite variables to assess properties of cognitive domains, compensation mechanisms, and their predictability to establish a method for a more comprehensive understanding of pathological cognitive decline.

METHODS

An exploratory factor analysis (EFA) and a set of increasingly restricted confirmatory factor analyses (CFAs) were conducted to find latent factors, compared them with the composite approach, and to test for longitudinal (partial-)MI in a neuropsychiatric test battery, consisting of 14 test variables. A total of 330 elderly (mean age: 73.78 ± 1.52 years at baseline) were analyzed two times (3 years apart).

RESULTS

EFA revealed a four-factor model representing declarative memory, attention, working memory, and visual-spatial processing. Based on CFA, an accurate model was estimated across both measurement timepoints. Partial non-MI was found for parameters such as loadings, test- and latent factor intercepts as well as latent factor variances. The latent factor approach was preferable to the composite approach.

CONCLUSION

The overall assessment of non-MI latent factors may pose a possible target for this field of research. Hence, the non-MI of variances indicated variables that are especially suited for the prediction of pathological cognitive decline, while non-MI of intercepts indicated general aging-related decline. As a result, the sole assessment of MI may help distinguish pathological from normative aging processes and additionally may reveal compensatory neuropsychological mechanisms.

Proportional Changes in Cognitive Subdomains During Normal Brain Aging

Background: Neuroscience lacks a reliable method of screening the early stages of dementia. Objective: To improve the diagnostics of age-related cognitive functions by developing insight into the proportionality of age-related changes in cognitive subdomains. Materials and Methods: We composed a battery of psychophysiological tests and collected an open-access psychophysiological outcomes of brain atrophy (POBA) dataset by testing individuals without dementia. To extend the utility of machine learning (ML) classification in cognitive studies, we proposed estimates of the disproportional changes in cognitive functions: an index of simple reaction time to decision-making time (ISD), ISD with the accuracy performance (ISDA), and an index of performance in simple and complex visual-motor reaction with account for accuracy (ISCA). Studying the distribution of the values of the indices over age allowed us to verify whether diverse cognitive functions decline equally throughout life or there is a divergence in age-related cognitive changes. Results: Unsupervised ML clustering shows that the optimal number of homogeneous age groups is four. The sample is segregated into the following age-groups: Adolescents ∈ [0, 20), Young adults ∈ [20, 40), Midlife adults ∈ [40, 60) and Older adults ≥60 year of age. For ISD, ISDA, and ISCA values, only the median of the Adolescents group is different from that of the other three age-groups sharing a similar distribution pattern (p > 0.01). After neurodevelopment and maturation, the indices preserve almost constant values with a slight trend toward functional decline. The reaction to a moving object (RMO) test results (RMO_mean) follow another tendency. The Midlife adults group's median significantly differs from the remaining three age subsamples (p < 0.01). No general trend in age-related changes of this dependent variable is observed. For all the data (ISD, ISDA, ISCA, and RMO_mean), Levene's test reveals no significant changes of the variances in age-groups (p > 0.05). Homoscedasticity also supports our assumption about a linear dependency between the observed features and age. Conclusion: In healthy brain aging, there are proportional age-related changes in the time estimates of information processing speed and inhibitory control in task switching. Future studies should test patients with dementia to determine whether the changes of the aforementioned indicators follow different patterns.

Longitudinal measurement invariance of neuropsychological tests in a diverse sample from the ELSA-Brasil study

OBJECTIVE

Longitudinal measurement invariance analyses are an important way to assess a test's ability to estimate the underlying construct over time, ensuring that cognitive scores across visits represent a similar underlying construct, and that changes in test performance are attributable to individual change in cognitive abilities. We aimed to evaluate longitudinal measurement invariance in a large, social and culturally diverse sample over time.

METHODS

A total of 5,949 participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) were included, whose cognition was reassessed after four years. Longitudinal measurement invariance analysis was performed by comparing a nested series of multiple-group confirmatory factor analysis models (for memory and executive function factors).

RESULTS

Configural, metric, scalar and strict invariance were tested and supported over time.

CONCLUSION

Cognitive temporal changes in this sample are more likely to be due to normal and/or pathological aging. Testing longitudinal measurement invariance is essential for diverse samples at high risk of dementia, such as in low- and middle-income countries.

Reorganization of brain structural networks in aging: A longitudinal study

Normal aging is characterized by structural and functional changes in the brain contributing to cognitive decline. Structural connectivity (SC) describes the anatomical backbone linking distinct functional subunits of the brain and disruption of this communication is thought to be one of the potential contributors for the age-related deterioration observed in cognition. Several studies already explored brain network's reorganization during aging, but most focused on average connectivity of the whole-brain or in specific networks, such as the resting-state networks. Here, we aimed to characterize longitudinal changes of white matter (WM) structural brain networks, through the identification of sub-networks with significantly altered connectivity along time. Then, we tested associations between longitudinal changes in network connectivity and cognition. We also assessed longitudinal changes in topological properties of the networks. For this, older adults were evaluated at two timepoints, with a mean interval time of 52.8 months (SD = 7.24). WM structural networks were derived from diffusion magnetic resonance imaging, and cognitive status from neurocognitive testing. Our results show age-related changes in brain SC, characterized by both decreases and increases in connectivity weight. Interestingly, decreases occur in intra-hemispheric connections formed mainly by association fibers, while increases occur mostly in inter-hemispheric connections and involve association, commissural, and projection fibers, supporting the last-in-first-out hypothesis. Regarding topology, two hubs were lost, alongside with a decrease in connector-hub inter-modular connectivity, reflecting reduced integration. Simultaneously, there was an increase in the number of provincial hubs, suggesting increased segregation. Overall, these results confirm that aging triggers a reorganization of the brain structural network.

Police Interactions, Perceived Respect, and Longitudinal Changes in Depression in African Americans

Introduction: We examined police exchanges' and feelings of discrimination's impact on changes in adolescent depression symptoms. Relative to other races, police speak more disrespectfully to African Americans and often exert unnecessary force. We investigated the impact of these exchanges on depression.

Methods: Adolescent Health Study data were analyzed. Latent growth curve modeling with mediation illustrated relationships between police exchanges, perceived discrimination, and depression changes.

Results: African American adolescents had significantly higher levels of initial depression than other racial/ethnic identity groups. For African Americans, police exchanges predicted depression changes. Perceived respect predicted levels and changes of depression for both groups, but mediated the relationship between police exchanges and depression changes only in the “other” racial/ethnic identity group.

Discussion: Police stoppings impacted depression changes for African Americans independent of perceived respect. Findings highlight a potentially unique relationship between depression and police exchanges among African Americans. Future studies may investigate roles of individual differences.

Higher Adherence to the Mediterranean Diet Is Associated With Preserved White Matter Integrity and Altered Structural Connectivity

The Mediterranean diet (MedDiet) has been associated with cognitive performance. Yet, controlled trials have yielded contradictory results. To tackle this controversy, a comprehensive multimodal analysis of the association of the MedDiet with cognitive performance and brain structure in normative aging is still necessary. Here, community dwellers ≥50 years from a cohort study on normative aging (n = 76) underwent a (i) magnetic resonance imaging session with two acquisitions: structural and diffusion-weighted imaging (DWI); (ii) neuropsychological battery of tests focusing on memory and executive functioning; and (iii) dietary assessment through the Mediterranean Diet Assessment Screener (MEDAS, score range: 0-14, scores ≥10 indicate high adherence to the Mediterranean diet) 18 months prior to the brain imaging and neuropsychological assessment. We found that high adherence to the MedDiet (MEDAS ≥10) was associated with higher values of fractional anisotropy and lower diffusivity values in the brain white matter. Similarly, high adherence to the MedDiet was associated with higher structural connectivity between left hemisphere brain regions. Specifically, the amygdala, lingual, olfactory, middle occipital gyrus, and calcarine areas. No association was found between high adherence to the MedDiet and total brain volumes or hypointensities. Higher adherence to the MedDiet was positively associated with executive functioning scores. These results suggest that high adherence to the MedDiet positively associates with brain health, specifically with executive function scores and white matter integrity of bundles related to the processing and integration of taste, reward, and decision making. These findings seem to support the view that the MedDiet should be part of recommendations to promote a healthy brain.

25-OH Vitamin D Levels and Cognitive Performance: Longitudinal Assessment in a Healthy Aging Cohort

Background: Declining serum levels of 25-hydroxyvitamin D [25(OH)D, a biomarker of vitamin D status] with aging is a well-recognized phenomenon. However, scarce information is available on the relation between 25(OH)D levels and cognitive performance over time in older individuals. Our purpose was to evaluate, longitudinally, the association of 25(OH)D with cognitive function in a healthy older adults’ cohort.

Methods: Sixty-four individuals over 55 years-old with no cognitive impairment, clustered as healthy “Poor” and “Good” cognitive performers, were followed for an average of 18 months. Seasonal-adjusted 25(OH)D serum levels (measured by high-performance liquid chromatography-tandem mass spectrometry) were related, longitudinally, with cognitive (memory and general/executive) composite scores.

Results: Overall seasonal-adjusted median serum 25(OH)D level was of 47 nmol/l [interquartile range (IQR), 38–60 nmol/l]. A negative correlation between baseline 25(OH)D and the general/executive composite score was found in the “Poor” cognitive performers (r^s = −0.52, p = 0.006), an association lost after adjusting 25(OH)D levels for the season. No effect was found in both groups between seasonal-adjusted 25(OH)D levels and the variation of both memory and general/executive composites during follow-up when adjusted for age, gender and education level.

Conclusion: In this healthy older population with no cognitive impairment, lower serum levels of 25(OH)D were not longitudinally associated with poorer cognitive scores.

Longitudinal measurement invariance of the Satisfaction With Life Scale in adolescence

PURPOSE

The main purpose of this research was to examine the longitudinal measurement invariance of the Satisfaction With Life Scale (SWLS) in adolescence.

METHOD

The sample was composed by 484 adolescents from Spain, 46.7% were males. All participants belonged to six academic levels from Grade 7 to Grade 12, and answered the questionnaires at two different times: at the beginning (M_age1 = 14.95, SD₁ = 1.81) and at the end of the school year (M_age2 = 15.61, SD₂ = 1.81). The reliability of the scale was obtained through Cronbach's alpha, Guttman lambda, and MacDonald's Omega total. The multiple group confirmatory factor analysis (MGCFA) was used to examine the fit of the unifactorial model to data and to test the measurement of longitudinal invariance of the scale across two time points (at the beginning T1, and the end T2, of the academic year), and the time points and groups (gender and age).

RESULTS

The values of the single-factor SWLS structure were T1 (CFI₁ = 1.000, TLI₁ = .997, RMSEA₁ = .080, and SRMR₁ = .028), and T2 (CFI₂ = .997, TLI₂ = .995, RMSEA₂ = .032, and SRMR₂ = .034). On the other hand, values of the reliability and composite reliability when analyzing both time points together as well as separately were as follows: Cronbach's alpha = .86, Guttman's lambda = .84, McDonald's Omega total = .89. Results confirmed the longitudinal invariance of SWLS. The differences in gender and age were not significant and the small differences across time points showed that the means of the latent factor remained the same over time in both variables.

CONCLUSION

The present study confirmed the single-factor structure of the SWLS in Spanish adolescents, as well as a good reliability and composite reliability. The full longitudinal measurement invariance was also found and there were negligible differences across time points considering gender and age. If these findings are further replicated, the scale could be used to compare the life satisfaction across two time points considering different age and gender groups.