Modeling the development of cognitive reserve in children: A residual index approach.

OBJECTIVE: To model cognitive reserve (CR) longitudinally in a neurodiverse pediatric sample using a residual index approach, and to test the criterion and construct validity of this index. METHOD: Participants were N = 115 children aged 9.5-13 years at baseline (MAge = 10.48 years, SDAge = 0.61), and n = 43 (37.4%) met criteria for ADHD. The CR index represented variance in Matrix Reasoning scores from the WASI that was unexplained by MRI-based brain variables (bilateral hippocampal volumes, total gray matter volumes, and total white matter hypointensity volumes) or demographics (age and sex). RESULTS: At baseline, the CR index predicted math computation ability (estimate = 0.50, SE = 0.07, p < .001), and word reading ability (estimate = 0.26, SE = 0.10, p = .012). Longitudinally, change in CR over time was not associated with change in math computation ability (estimate = -0.02, SE = 0.03, p < .513), but did predict change in word reading ability (estimate = 0.10, SE = 0.03, p < .001). Change in CR was also found to moderate the relationship between change in word reading ability and white matter hypointensity volume (estimate = 0.10, SE = 0.05, p = .045). CONCLUSIONS: Evidence for the criterion validity of this CR index is encouraging, but somewhat mixed, while construct validity was evidenced through interaction between CR, brain, and word reading ability. Future research would benefit from optimization of the CR index through careful selection of brain variables for a pediatric sample.

Self-reported mid- to late-life physical and recreational activities: Associations with late-life cognition.

OBJECTIVE: Physical and recreational activities are behaviors that may modify risk of late-life cognitive decline. We sought to examine the role of retrospectively self-reported midlife (age 40) physical and recreational activity engagement - and self-reported change in these activities from age 40 to initial study visit - in predicting late-life cognition. METHOD: Data were obtained from 898 participants in a longitudinal study of cognitive aging in demographically and cognitively diverse older adults (Age: range = 49-93 years, M = 75, SD = 7.19). Self-reported physical and recreational activity participation at age 40 and at the initial study visit were quantified using the Life Experiences Assessment Form. Change in activities was modeled using latent change scores. Cognitive outcomes were obtained annually (range = 2-17 years) using the Spanish and English Neuropsychological Assessment Scales, which measure verbal episodic memory, semantic memory, visuospatial processing, and executive functioning. RESULTS: Physical activity engagement at age 40 was strongly associated with cognitive performance in all four domains at the initial visit and with global cognitive slope. However, change in physical activities after age 40 was not associated with cognitive outcomes. In contrast, recreational activity engagement - both at age 40 and change after 40 - was predictive of cognitive intercepts and slope. CONCLUSIONS: Retrospectively self-reported midlife physical and recreational activity engagement were strongly associated with late-life cognition - both level of performance and rate of future decline. However, the data suggest that maintenance of recreational activity engagement (e.g., writing, taking classes, reading) after age 40 is more strongly associated with late-life cognition than continued maintenance of physical activity levels.

The McCusker Subjective Cognitive Impairment Inventory (McSCI): a novel measure of perceived cognitive decline.

BACKGROUND: Subjective cognitive decline (SCD), i.e. self/other-reported concerns on one's cognitive functioning without objective evidence of significant decline, is an indicator of dementia risk. There is little consensus on reliability and validity of the available SCD measures. Therefore, introducing a novel and psychometrically sound measure of SCD is timely. OBJECTIVE: The psychometric properties of a new SCD measure, the McCusker Subjective Cognitive Impairment Inventory-Self-Report (McSCI-S), are reported. METHODS: Through review of previously published measures as well as our clinical and research data on people with SCD, we developed a 46-item self-report questionnaire to assess concerns on six cognitive domains, namely, memory, language, orientation, attention and concentration, visuoconstruction abilities and executive function. The McSCI-S was examined in a cohort of 526 participants using factor analysis, item response theory analysis and receiver operating characteristic (ROC) curve. RESULTS: A unidimensional model provided acceptable fit (CFI = 0.94, TLI = 0.94, RMSEA [90% CI] = 0.052 [.049, 0.055], WRMR = 1.45). The McSCI-S internal consistency was excellent (.96). A cut-off score of ≥24 is proposed to identify participants with SCDs. Higher McSCI-S scores were associated with poorer general cognition, episodic verbal memory, executive function and greater memory complaints and depressive scores (P < .001), controlling for age, sex and education. CONCLUSIONS: Excellent reliability and construct validity suggest the McSCI-S estimates SCDs with acceptable accuracy while capturing self-reported concerns for various cognitive domains. The psychometric analysis indicated that this measure can be used in cohort studies as well as on individual, clinical settings to assess SCDs.

Toward a statistical validation of brain signatures as robust measures of behavioral substrates.

The "brain signature of cognition" concept has garnered interest as a data-driven, exploratory approach to better understand key brain regions involved in specific cognitive functions, with the potential to maximally characterize brain substrates of behavioral outcomes. Previously we presented a method for computing signatures of episodic memory. However, to be a robust brain measure, the signature approach requires a rigorous validation of model performance across a variety of cohorts. Here we report validation results and provide an example of extending it to a second behavioral domain. In each of two discovery data cohorts, we derived regional brain gray matter thickness associations for two domains: neuropsychological and everyday cognition memory. We computed regional association to outcome in 40 randomly selected discovery subsets of size 400 in each cohort. We generated spatial overlap frequency maps and defined high-frequency regions as "consensus" signature masks. Using separate validation datasets, we evaluated replicability of cohort-based consensus model fits and explanatory power by comparing signature model fits with each other and with competing theory-based models. Spatial replications produced convergent consensus signature regions. Consensus signature model fits were highly correlated in 50 random subsets of each validation cohort, indicating high replicability. In comparisons over each full cohort, signature models outperformed other models. In this validation study, we produced signature models that replicated model fits to outcome and outperformed other commonly used measures. Signatures in two memory domains suggested strongly shared brain substrates. Robust brain signatures may therefore be achievable, yielding reliable and useful measures for modeling substrates of behavioral domains.

Tau and amyloid biomarkers modify the degree to which cognitive reserve and brain reserve predict cognitive decline.

OBJECTIVE: Brain reserve, cognitive reserve, and education are thought to protect against late-life cognitive decline, but these variables have not been directly compared to one another in the same model, using future cognitive and functional decline as outcomes. We sought to determine whether the influence of these protective factors on executive function (EF) and daily function decline was dependent upon Alzheimer's disease (AD) pathology severity, as measured by the total tau to beta-amyloid (T-τ/Aß1-42) ratio in cerebrospinal fluid (CSF). METHOD: Participants were 1201 older adult volunteers in the Alzheimer's Disease Neuroimaging Initiative (ADNI) study. Brain reserve was defined using a composite index of structural brain volumes (total brain matter, hippocampus, and white matter hyperintensity). Cognitive reserve was defined as the variance in episodic memory performance not explained by brain integrity and demographics. RESULTS: At higher levels of T-τ/Aß1-42, brain and cognitive reserve predicted slower decline in EF. Only brain reserve attenuated decline at lower levels of T-τ/Aß1-42. Education had no independent association with cognitive decline. CONCLUSIONS: These results point to a hierarchy of protection against aging- and disease-associated cognitive decline. When pathology is low, only structural brain integrity predicts rate of future EF decline. The ability of cognitive reserve to predict future EF decline becomes stronger as CSF biomarker evidence of AD increases. Although education is typically thought of as a proxy for cognitive reserve, it did not show any protective effects on cognition after accounting for brain integrity and the residual cognitive reserve index.

Effects of early-life environment and adulthood SES on cognitive change in a multiethnic cohort.

OBJECTIVES: Early-life socioeconomic status (SES) and adversity are associated with late-life cognition and risk of dementia. We examined the association between early-life SES and adversity and late-life cross-sectional cognitive outcomes as well as global cognitive decline, hypothesizing that adulthood SES would mediate these associations. METHODS: Our sample (N = 837) was a racially and ethnically diverse cohort of non-Hispanic/Latino White (48%), Black (27%), and Hispanic/Latino (19%) participants from Northern California. Participant addresses were geocoded to the level of the census tract, and US Census Tract 2010 variables (e.g., percent with high school diploma) were extracted and combined to create a neighborhood SES composite. We used multilevel latent variable models to estimate early-life (e.g., parental education, whether participant ever went hungry) and adult (participant's education, main occupation) SES factors and their associations with cross-sectional and longitudinal cognitive outcomes of episodic memory, semantic memory, executive function, and spatial ability. RESULTS: Child and adult factors were strongly related to domain-specific cognitive intercepts (0.20-0.48 SD per SD of SES factor); in contrast, SES factors were not related to global cognitive change (0.001-0.01 SD per year per SD of SES factor). Adulthood SES mediated a large percentage (68-75%) of the total early-life effect on cognition. CONCLUSIONS: Early-life sociocontextual factors are more strongly associated with cross-sectional late-life cognitive performance compared to cognitive change; this effect is largely mediated through associations with adulthood SES.

The Episodic Memory Profile in Autism Spectrum Disorder: A Bayesian Meta-Analysis.

Although autism spectrum disorders (ASD) are commonly characterized by diminished episodic memory, the literature in this area is mixed. We address these inconsistent findings by employing multilevel Bayesian meta-analysis to quantify episodic memory differences between individuals with ASD and typically developing (TD) controls. We used meta-regression to evaluate the effects of test modality (e.g., word list, story recall), delay interval (immediate vs. delayed), retrieval demands (recognition vs. recall), and sensory modality (auditory vs. visual) on episodic memory in ASD. A total of 338 effect sizes from 113 empirical articles, including 5,632 unique participants (ASD = 2,777, TD = 2,855), were included. Results show that the memory deficits associated with ASD were larger for recall (g = -0.52, se = 0.04, 95% CrI [-0.60, -0.43]) compared to recognition (g = -0.25, se = 0.05, 95% CrI [-0.35, -0.14]) and differed based on the testing modality. For example, effect sizes were smallest for words (g = -0.28, se = 0.05, 95% CrI [-0.38, -0.18]), pictures (g = -0.38, se = 0.07, 95% CrI [-0.52, -0.24]), and figure reproduction (g = -0.49, se = 0.11, 95% CrI [-0.70, -0.27]). However, effect sizes for sentences (g = -0.59, se = 0.20, 95% CrI [-1.00, -0.21]), stories (Hedges' g = -0.54, se = 0.08, 95% CrI [-0.69, -0.38]) and staged events (g = -0.75, se = 0.10, 95% CrI [-0.95, -0.55]) were much larger. These findings suggest that ASD is associated with a small to medium reduction in scores on episodic memory tests relative to TD controls.

A robust brain signature region approach for episodic memory performance in older adults.

The brain signature concept aims to characterize brain regions most strongly associated with an outcome of interest. Brain signatures derive their power from data-driven searches that select features based solely on performance metrics of prediction or classification. This approach has important potential to delineate biologically relevant brain substrates for prediction or classification of future trajectories. Recent work has used exploratory voxel-wise or atlas-based searches, with some using machine learning techniques to define salient features. These have shown undoubted usefulness, but two issues remain. The preponderance of recent work has been aimed at categorical rather than continuous outcomes, and it is rare for non-atlas reliant voxel-based signatures to be reported that would be useful for modelling and hypothesis testing. We describe a cross-validated signature region model for structural brain components associated with baseline and longitudinal episodic memory across cognitively heterogeneous populations including normal, mild impairment and dementia. We used three non-overlapping cohorts of older participants: from the UC Davis Aging and Diversity cohort (n = 255; mean age 75.3 ± 7.1 years; 128 cognitively normal, 97 mild cognitive impairment, 30 demented and seven unclassified); from Alzheimer's Disease Neuroimaging Initiative (ADNI) 1 (n = 379; mean age 75.1 ± 7.2; 82 cognitively normal, 176 mild cognitive impairment, 121 Alzheimer's dementia); and from ADNI2/GO (n = 680; mean age 72.5 ± 7.1; 220 cognitively normal, 381 mild cognitive impairment and 79 Alzheimer's dementia). We used voxel-wise regression analysis, correcting for multiple comparisons, to generate an array of regional masks corresponding to different association strength levels of cortical grey matter with baseline memory and brain atrophy with memory change. Cognitive measures were episodic memory using Spanish and English Neuropsychological Assessment Scales instruments for UC Davis and ADNI-Mem for ADNI 1 and ADNI2/GO. Performance metric was the adjusted R2 coefficient of determination of each model explaining outcomes in two cohorts other than where it was computed. We compared within-cohort performances of signature models against each other and against other recent signature models of episodic memory. Findings were: (i) two independently generated signature region of interest models performed similarly in a third separate cohort; (ii) a signature region of interest generated in one imaging cohort replicated its performance level when explaining cognitive outcomes in each of other, separate cohorts; and (iii) this approach better explained baseline and longitudinal memory than other recent theory-driven and data-driven models. This suggests our approach can generate signatures that may be easily and robustly applied for modelling and hypothesis testing in mixed cognition cohorts.

Comparison of Education and Episodic Memory as Modifiers of Brain Atrophy Effects on Cognitive Decline: Implications for Measuring Cognitive Reserve.

OBJECTIVE: This study compared the level of education and tests from multiple cognitive domains as proxies for cognitive reserve. METHOD: The participants were educationally, ethnically, and cognitively diverse older adults enrolled in a longitudinal aging study. We examined independent and interactive effects of education, baseline cognitive scores, and MRI measures of cortical gray matter change on longitudinal cognitive change. RESULTS: Baseline episodic memory was related to cognitive decline independent of brain and demographic variables and moderated (weakened) the impact of gray matter change. Education moderated (strengthened) the gray matter change effect. Non-memory cognitive measures did not incrementally explain cognitive decline or moderate gray matter change effects. CONCLUSIONS: Episodic memory showed strong construct validity as a measure of cognitive reserve. Education effects on cognitive decline were dependent upon the rate of atrophy, indicating education effectively measures cognitive reserve only when atrophy rate is low. Results indicate that episodic memory has clinical utility as a predictor of future cognitive decline and better represents the neural basis of cognitive reserve than other cognitive abilities or static proxies like education.

A brief report: The National Adult Reading Test (NART) is a stable assessment of premorbid intelligence across disease severity in obstructive sleep apnea (OSA).

Obstructive sleep apnea (OSA) is a widely prevalent disorder that can affect cognitive function. The relationship between cognitive function and OSA is known to be affected by an individual's premorbid cognitive ability. Tools to measure premorbid intelligence across OSA disease severity have not been validated. This brief report aims to establish if the National Adult Reading Test (NART) provides a stable estimate of premorbid intelligence across levels of OSA disease severity. We examined if NART scores varied systematically across levels of untreated OSA severity (defined according to the apnea-hypopnea index [AHI]) and mean oxygen saturation in sleep clinic (n = 121) and community samples (n = 398) using regression analysis. Simple linear regression was used to predict NART scores based on the AHI. NART-estimated premorbid IQ scores without demographics did not vary systematically with AHI (F < 1; ß = 0.01) or mean SpO2 (F < 1; ß = 0.12). NART-estimated premorbid IQ scores with added demographic information also did not vary systematically with AHI (F < 1; ß = -0.01) or mean SpO2 (F < 1; ß = 0.15). This preliminary examination shows that the NART provides a stable estimate of premorbid intelligence across untreated OSA disease severity, as demarcated by AHI or mean nocturnal SpO2 .

Effects of Media Sensationalization on Cognitive Performance and Post Concussive Symptoms.

OBJECTIVES: The current study aimed to examine if televised media about mild traumatic brain injury (mTBI) framed in a sensationalized manner had a negative impact on cognitive functioning and persistent mTBI symptoms. METHODS: One hundred two participants (M Age=37.16; SD=22.61) with a history of post-acute mTBI, recruited through a community research registry and an undergraduate recruitment system, were included in this study. Participants were assessed with a measure of health literacy, the Short Test of Functional Health Literacy in Adults (S-TOFHLA), and randomized to watch either a sensationalized or non-sensationalized news clip focused on mTBI. They were then assessed with the Paced Auditory Serial Addition Test (PASAT), Rivermead Post Concussion Symptoms Questionnaire (RPQ), Patient Reported Outcome Measures Information System (PROMIS) Depression scale, and the Posttraumatic Stress Disorder Checklist for the Diagnostic and Statistical Manual of Mental Disorders 5th edition (PCL-5). RESULTS: Bayesian analyses indicated that sensationalized media-alone (ß PASAT=-0.08; ß RPQ=-0.08) or in the context of covariates (ß PASAT=-0.11; ß RPQ=-0.14)-was not a strong predictor of PASAT score or post-concussion syndrome symptom severity. CONCLUSIONS: Although media sensationalization of mTBI symptoms is not desirable, this study suggests that one brief exposure to sensationalized information may not have a meaningful immediate impact on the cognitive functioning or symptom reporting of individuals with a history of mTBI. Future research should examine long-term and downstream effects of sensationalized media reporting in samples with greater diversity of TBI history. (JINS, 2019, 25, 90-100).

The Differential Effects of Alzheimer's Disease and Lewy Body Pathology on Cognitive Performance: a Meta-analysis.

Differential diagnosis of Alzheimer's disease (AD) from normal aging and other dementia etiologies is imperative for disease specific treatment options and long-term care planning. Neuropathological confirmation is the gold standard for neurodegenerative disease diagnosis, yet most published studies examining the use of neuropsychological tests in the differential diagnosis of dementia rely upon clinical diagnostic outcomes. The present study undertook a meta-analytic review of the literature to identify cognitive tests and domains that allow for the differentiation of individuals with AD pathology from individuals with dementia with Lewy Bodies (DLB) pathology and pathology-free individuals. A comprehensive literature search yielded 14 studies that met the inclusion criteria for the present meta-analysis. Six studies comprised 222 decedents with AD compared to 433 normal controls, and eight studies comprised 431 cases of AD compared to 155 decedents with DLB. Results revealed that the effect of having neuropathologically confirmed AD versus DLB lowered performance in the memory domain, and having DLB decreased performance in the visuospatial domain. No single test differed significantly across the AD and DLB groups. For the AD and pathology free comparison, results indicated that that AD was associated with poorer performance on the memory and language domains. With respect to specific cognitive tests, AD produced lower scores on list learning tests, category fluency, and the Digit Symbol substitution test. The limited number of studies meeting inclusion criteria warrants formulation of guidelines for reporting in clinico-pathological studies; suggested guidelines are provided.

Office-Based Assessment of At-Risk Driving in Older Adults With and Without Cognitive Impairment.

BACKGROUND: A multitest approach is optimal for the identification of at-risk driving among older adults. This study examined the predictive validity of a combination of office-based screening tests for on-road driving performance in older adults with and without mild cognitive impairment (MCI)/dementia. METHODS: Forty-four normal control, 20 participants with MCI, and 20 participants with dementia completed a battery of office-based assessments. On-road driving evaluation classified participants as not at-risk (n = 65) or at-risk drivers (n = 19). RESULTS: Logistic regression revealed age and 2 tests of visual attention abilities (Useful Field of View [UFOV] Divided Attention and Neuropsychological Assessment Battery [NAB] Driving Scenes) best predicted at-risk drivers ( C statistic = 0.90); no cutoff score had both sensitivity and specificity >80%. CONCLUSIONS: Future research on larger and more clinically representative neurological samples will improve understanding of the utility of the UFOV Divided Attention and NAB Driving Scenes in detecting at-risk older adult drivers in the clinic.

The value of Bayes' theorem for interpreting abnormal test scores in cognitively healthy and clinical samples.

The base rates of abnormal test scores in cognitively normal samples have been a focus of recent research. The goal of the current study is to illustrate how Bayes' theorem uses these base rates--along with the same base rates in cognitively impaired samples and prevalence rates of cognitive impairment--to yield probability values that are more useful for making judgments about the absence or presence of cognitive impairment. Correlation matrices, means, and standard deviations were obtained from the Wechsler Memory Scale--4th Edition (WMS-IV) Technical and Interpretive Manual and used in Monte Carlo simulations to estimate the base rates of abnormal test scores in the standardization and special groups (mixed clinical) samples. Bayes' theorem was applied to these estimates to identify probabilities of normal cognition based on the number of abnormal test scores observed. Abnormal scores were common in the standardization sample (65.4% scoring below a scaled score of 7 on at least one subtest) and more common in the mixed clinical sample (85.6% scoring below a scaled score of 7 on at least one subtest). Probabilities varied according to the number of abnormal test scores, base rates of normal cognition, and cutoff scores. The results suggest that interpretation of base rates obtained from cognitively healthy samples must also account for data from cognitively impaired samples. Bayes' theorem can help neuropsychologists answer questions about the probability that an individual examinee is cognitively healthy based on the number of abnormal test scores observed.

Reliable Change on Neuropsychological Tests in the Uniform Data Set.

Longitudinal normative data obtained from a robust elderly sample (i.e., believed to be free from neurodegenerative disease) are sparse. The purpose of the present study was to develop reliable change indices (RCIs) that can assist with interpretation of test score changes relative to a healthy sample of older adults (ages 50+). Participants were 4217 individuals who completed at least three annual evaluations at one of 34 past and present Alzheimer's Disease Centers throughout the United States. All participants were diagnosed as cognitively normal at every study visit, which ranged from three to nine approximately annual evaluations. One-year RCIs were calculated for 11 neuropsychological variables in the Uniform Data Set by regressing follow-up test scores onto baseline test scores, age, education, visit number, post-baseline assessment interval, race, and sex in a linear mixed effects regression framework. In addition, the cumulative frequency distributions of raw score changes were examined to describe the base rates of test score changes. Baseline test score, age, education, and race were robust predictors of follow-up test scores across most tests. The effects of maturation (aging) were more pronounced on tests related to attention and executive functioning, whereas practice effects were more pronounced on tests of episodic and semantic memory. Interpretation of longitudinal changes on 11 cognitive test variables can be facilitated through the use of reliable change intervals and base rates of score changes in this robust sample of older adults. A Web-based calculator is provided to assist neuropsychologists with interpretation of longitudinal change.

Geriatric Anxiety Scale: item response theory analysis, differential item functioning, and creation of a ten-item short form (GAS-10).

BACKGROUND: The Geriatric Anxiety Scale (GAS; Segal et al. (Segal, D. L., June, A., Payne, M., Coolidge, F. L. and Yochim, B. (2010). Journal of Anxiety Disorders, 24, 709-714. doi:10.1016/j.janxdis.2010.05.002) is a self-report measure of anxiety that was designed to address unique issues associated with anxiety assessment in older adults. This study is the first to use item response theory (IRT) to examine the psychometric properties of a measure of anxiety in older adults. METHOD: A large sample of older adults (n = 581; mean age = 72.32 years, SD = 7.64 years, range = 60 to 96 years; 64% women; 88% European American) completed the GAS. IRT properties were examined. The presence of differential item functioning (DIF) or measurement bias by age and sex was assessed, and a ten-item short form of the GAS (called the GAS-10) was created. RESULTS: All GAS items had discrimination parameters of 1.07 or greater. Items from the somatic subscale tended to have lower discrimination parameters than items on the cognitive or affective subscales. Two items were flagged for DIF, but the impact of the DIF was negligible. Women scored significantly higher than men on the GAS and its subscales. Participants in the young-old group (60 to 79 years old) scored significantly higher on the cognitive subscale than participants in the old-old group (80 years old and older). CONCLUSIONS: Results from the IRT analyses indicated that the GAS and GAS-10 have strong psychometric properties among older adults. We conclude by discussing implications and future research directions.

The Neuropsychological Assessment Battery Driving Scenes Test in a Dementia Clinic.

OBJECTIVE: In dementia research, the Driving Scenes test from the Neuropsychological Assessment Battery has been shown to relate to memory, dementia diagnosis, and functional impairment. The aim of the current study was to examine Driving Scenes and its component scores, and their relationships with cognition and daily functioning, in a mixed dementia clinic sample. METHOD: One hundred U.S. military veterans between the ages of 55 and 88 were administered a full neuropsychological protocol that included Driving Scenes. RESULTS: The Driving Scenes score and its subscores were strongly related to memory skills, and there were additional subscore associations with language and visuospatial functions. Driving Scenes uniquely predicted reported bill payment difficulties and tendency to get lost while driving, which were not predicted by other performances across cognitive domains. CONCLUSION: Driving Scenes is a clinically and functionally relevant measure of memory. Although the Driving Scenes total score remains useful in dementia evaluations, component scores and error scores contribute additional practical information.

Associations between personality and psychological characteristics and cognitive outcomes among older adults.

Prior research has shown that some personality traits are associated with cognitive outcomes and may confirm risk or protection against cognitive decline. The present study expands on previous work to examine the association between a more comprehensive set of psychological characteristics and cognitive performance in a diverse cohort of older adults. We also examine whether controlling for brain atrophy influences the association between psychological characteristics and cognitive function. A total of 157 older adults completed a battery of psychological questionnaires (Openness to Experience, Conscientiousness, Agreeableness, Neuroticism, Extraversion, positive affect, negative affect-sadness, negative affect-anger, sense of purpose, loneliness, grit, and self-efficacy). Cognitive outcomes were measured across multiple domains: episodic memory, semantic memory, executive function, and spatial ability. Baseline brain (MRI) variables included gray matter, hippocampus, and total white matter hyperintensity volume. Parallel process, multilevel models yielded intercept (individual cognitive domain scores) and linear slope (global cognitive change) random effects for the cognitive outcomes. Positive affect (ß = 0.013, SE = 0.005, p = .004) and Openness (ß = 0.018, SE = 0.007, p = .009) were associated with less cognitive change, independent of baseline brain variables and covariates. Greater sadness predicted more cognitive decline when controlling for covariates, but not brain atrophy. A variety of psychological characteristics were associated with the cross-sectional measures of cognition. This study highlights the important impact of positive and negative affect on reducing or enhancing the risk of longitudinal cognitive decline. Such findings are especially important, given the available efficacious interventions that can improve affect. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Neighborhood socioeconomic status and segregation linked to cognitive decline.

Introduction: Few longitudinal studies have examined the joint impact of neighborhood segregation and neighborhood socioeconomic status (NSES) in cognitive decline over time. Methods: This study included non-Hispanic White (NHW, n = 209) and Black participants (n = 118) whose cognition was evaluated as part of an ongoing longitudinal study. Four distinct categories of segregation and NSES were evaluated for their association with cognitive outcomes (episodic memory, semantic memory, executive function, and spatial ability) using race-specific mixed-effects models. Results: Compared to Black participants living in higher segregation-lower NSES areas, Black participants living in lower segregation-lower NSES areas or higher segregation-higher NSES areas experienced slower decline in episodic memory over time. Compared to NHW participants living in higher segregation-lower NSES areas, NHWs living in lower segregation-higher NSES areas experienced faster decline in spatial ability. Discussion: Segregation and NSES are differentially associated with cognition depending on participant race. Further research is needed to replicate study results.

Harmonization of cognitive screening tools for dementia across diverse samples: A simulation study.

Introduction: Research focusing on cognitive aging and dementia is a global endeavor. However, cross-national differences in cognition are embedded in other sociocultural differences, precluding direct comparisons of test scores. Such comparisons can be facilitated by co-calibration using item response theory (IRT). The goal of this study was to explore, using simulation, the necessary conditions for accurate harmonization of cognitive data. Method: Neuropsychological test scores from the US Health and Retirement Study (HRS) and the Mexican Health and Aging Study (MHAS) were subjected to IRT analysis to estimate item parameters and sample means and standard deviations. These estimates were used to generate simulated item response patterns under 10 scenarios that adjusted the quality and quantity of linking items used in harmonization. IRT-derived factor scores were compared to the known population values to assess bias, efficiency, accuracy, and reliability of the harmonized data. Results: The current configuration of HRS and MHAS data was not suitable for harmonization, as poor linking item quality led to large bias in both cohorts. Scenarios with more numerous and higher quality linking items led to less biased and more accurate harmonization. Discussion: Linking items must possess low measurement error across the range of latent ability for co-calibration to be successful. HIGHLIGHTS: We developed a statistical simulation platform to evaluate the degree to which cross-sample harmonization accuracy varies as a function of the quality and quantity of linking items.Two large studies of aging-one in Mexico and one in the United States-use three common items to measure cognition.These three common items have weak correspondence with the ability being measured and are all low in difficulty.Harmonized scores derived from the three common linking items will provide biased and inaccurate estimates of cognitive ability.Harmonization accuracy is greatest when linking items vary in difficulty and are strongly related to the ability being measured.