Plasma Alzheimer's biomarkers and brain amyloid in Hispanic and non-Hispanic older adults.

INTRODUCTION: Alzheimer's disease studies often lack ethnic diversity. METHODS: We evaluated associations between plasma biomarkers commonly studied in Alzheimer's (p-tau181, GFAP, and NfL), clinical diagnosis (clinically normal, amnestic MCI, amnestic dementia, or non-amnestic MCI/dementia), and Aß-PET in Hispanic and non-Hispanic older adults. Hispanics were predominantly of Cuban or South American ancestry. RESULTS: Three-hundred seventy nine participants underwent blood draw (71.9 ± 7.8 years old, 60.2% female, 57% Hispanic of which 88% were Cuban or South American) and 240 completed Aß-PET. P-tau181 was higher in amnestic MCI (p = 0.004, d = 0.53) and dementia (p < 0.001, d = 0.97) than in clinically normal participants and discriminated Aß-PET[+] and Aß-PET[-] (AUC = 0.86). P-tau181 outperformed GFAP and NfL. There were no significant interactions with ethnicity. Among amnestic MCI, Hispanics had lower odds of elevated p-tau181 than non-Hispanic (OR = 0.41, p = 0.006). DISCUSSION: Plasma p-tau181 informs etiological diagnosis of cognitively impaired Hispanic and non-Hispanic older adults. Hispanic ethnicity may relate to greater likelihood of non-Alzheimer's contributions to memory loss. HIGHLIGHTS: Alzheimer's biomarkers were measured in Hispanic and non-Hispanic older adults. Plasma p-tau181 related to amnestic cognitive decline and brain amyloid burden. AD biomarker associations did not differ between Hispanic and non-Hispanic ethnicity. Hispanic individuals may be more likely to have non-Alzheimer causes of memory loss.

Declarative Learning, Priming, and Procedural Learning Performances comparing Individuals with Amnestic Mild Cognitive Impairment, and Cognitively Unimpaired Older Adults.

OBJECTIVE: While declarative learning is dependent on the hippocampus, procedural learning and repetition priming can operate independently from the hippocampus, making them potential targets for behavioral interventions that utilize non-declarative memory systems to compensate for the declarative learning deficits associated with hippocampal insult. Few studies have assessed procedural learning and repetition priming in individuals with amnestic mild cognitive impairment (aMCI). METHOD: This study offers an overview across declarative, conceptual repetition priming, and procedural learning tasks by providing between-group effect sizes and Bayes Factors (BFs) comparing individuals with aMCI and controls. Seventy-six individuals with aMCI and 83 cognitively unimpaired controls were assessed. We hypothesized to see the largest differences between individuals with aMCI and controls on declarative learning, followed by conceptual repetition priming, with the smallest differences on procedural learning. RESULTS: Consistent with our hypotheses, we found large differences between groups with supporting BFs on declarative learning. For conceptual repetition priming, we found a small-to-moderate between-group effect size and a non-conclusive BF somewhat in favor of a difference between groups. We found more variable but overall trivial differences on procedural learning tasks, with inconclusive BFs, in line with expectations. CONCLUSIONS: The current results suggest that conceptual repetition priming does not remain intact in individuals with aMCI while procedural learning may remain intact. While additional studies are needed, our results contribute to the evidence-base that suggests that procedural learning may remain spared in aMCI and helps inform behavioral interventions that aim to utilize procedural learning in this population.

Functional Neural Correlates of a Useful Field of View (UFOV)-Based fMRI Task in Older Adults.

Declines in processing speed performance occur in aging and are a critical marker of functional independence in older adults. Studies suggest that Useful Field of View (UFOV) training may ameliorate cognitive decline. Despite its efficacy, little is known about the neural correlates of this task. Within the current study, 233 healthy older adults completed a UFOV-based task while undergoing functional magnetic resonance imaging (fMRI). During the "stimulus" portion of this task, participants must identify a target in the center of the screen and the location of a target in the periphery, among distractors. During the "probe" portion, participants must decide if the object in the center and the location of the target in the periphery were identical to the "stimulus" screen. Widespread bilateral whole-brain activation was observed when activation patterns of the "probe" contrast were subtracted from the "stimulus" contrast. Conversely, the subtraction of "stimulus" from "probe" was associated with discrete activation patterns consisting of 13 clusters. Additionally, when evaluating the variance associated with task accuracy, specific subregions were identified that may be critical for task performance. Our data elucidate the functional neural correlates of a UFOV-based task, a task used in both cognitive training paradigms and assessment of function.

Repetition Priming in Individuals with Amnestic Mild Cognitive Impairment and Alzheimer's Dementia: a Systematic Review and Meta-Analysis.

The literature on repetition priming in Alzheimer's disease (AD) is inconsistent, with some findings supporting spared priming while others do not. Several factors may explain these inconsistencies, including AD severity (e.g., dementia vs. Mild Cognitive Impairment; MCI) and priming paradigm-related characteristics. This systematic review and meta-analysis provides a quantitative summary of repetition priming in AD. We examined the between-group standard mean difference comparing repetition priming in AD dementia or amnestic MCI (aMCI; presumably due to AD) to controls. Thirty-two studies were selected, including 590 individuals with AD dementia, 267 individuals with amnestic MCI, and 703 controls. Our results indicated that both individuals with aMCI and AD dementia perform worse on repetition priming tasks than cognitively older adults. Paradigm-related moderators suggested that the effect size between studies comparing the combined aMCI or AD dementia group to cognitively healthy older adults was the highest for paradigms that required participants to produce, rather than identify, primes during the test phase. Our results further suggested that priming in AD is impaired for both conceptual and perceptual priming tasks. Lastly, while our results suggested that priming in AD is impaired for priming tasks that require deep processing, we were unable to draw firm conclusions about whether priming is less impaired in aMCI or AD dementia for paradigms that require shallow processing.

Independent Contributions of Dorsolateral Prefrontal Structure and Function to Working Memory in Healthy Older Adults.

Age-related differences in dorsolateral prefrontal cortex (DLPFC) structure and function have each been linked to working memory. However, few studies have integrated multimodal imaging to simultaneously investigate relationships among structure, function, and cognition. We aimed to clarify how specifically DLPFC structure and function contribute to working memory in healthy older adults. In total, 138 participants aged 65-88 underwent 3 T neuroimaging and were divided into higher and lower groups based on a median split of in-scanner n-back task performance. Three a priori spherical DLPFC regions of interest (ROIs) were used to quantify blood-oxygen-level-dependent (BOLD) signal and FreeSurfer-derived surface area, cortical thickness, and white matter volume. Binary logistic regressions adjusting for age, sex, education, and scanner type revealed that greater left and right DLPFC BOLD signal predicted the probability of higher performing group membership (P values<.05). Binary logistic regressions also adjusting for total intracranial volume revealed left DLPFC surface area that significantly predicted the probability of being in the higher performing group (P = 0.017). The left DLPFC BOLD signal and surface area were not significantly associated and did not significantly interact to predict group membership (P values>.05). Importantly, this suggests BOLD signal and surface area may independently contribute to working memory performance in healthy older adults.

Procedural Learning in Individuals with Amnestic Mild Cognitive Impairment and Alzheimer's Dementia: a Systematic Review and Meta-analysis.

The notion that procedural learning and memory is spared in Alzheimer's disease (AD) has important implications for interventions aiming to build on intact cognitive functions. However, despite these clinical implications, there are mixed findings in the literature about whether or not procedural learning remains intact. This meta-analysis examines the standard mean difference of all published studies regarding procedural learning in AD dementia or amnestic Mild Cognitive Impairment (aMCI) compared to cognitively healthy older adults. Additionally, we conducted statistical equivalence analyses. Our systematic review showed that only a limited number of studies (k = 17) have compared procedural learning between individuals with aMCI or AD dementia and healthy controls. Our meta-analysis, which synthesized these studies, demonstrated that while procedural learning performance was not statistically equivalent between individuals with aMCI or AD dementia, and healthy older adults, the difference was clinically and statistically trivial. Although larger studies are needed, the present findings suggest that procedural learning does appear to remain spared in aMCI and AD dementia.

Multi-group multi-time point confirmatory factor analysis of the triadic structure of temperament: A nonhuman primate model.

Attempts to describe the latent structure of human infant temperament have led some to suggest the existence of three major dimensions. An earlier exploratory factor analysis (EFA) supported a triadic structure of temperament in week-old rhesus monkey infants, paralleling the structure in human infants. This study sought to confirm the latent triadic structure of temperament across the first month of life in a larger sample of rhesus monkey infants (N = 668), reared by their mothers or in a neonatal nursery. A weekly behavioral assessment was obtained during the first month of life using a subset of items from the widely utilized Infant Behavioral Assessment Scale (IBAS), an instrument designed to measure temperament in infant monkeys. Using the latent constructs proposed by the earlier EFA (Orienting/Regulation, Negative Affectivity, Surgency/Extraversion), multi-group, multi-time point confirmatory factor analyses were conducted to confirm the latent temperament structure across rearing groups at each time point (weeks 1-4). Results confirm and extend those of the earlier EFA: latent Orienting/Regulation,  Negative Affectivity, and Surgency/Extraversion constructs were present across the rearing groups at each time point, with the IBAS items consistently loading onto the latent factors to a similar degree across rearing groups at each time point. These findings suggest foundational evolutionary roots for the triadic structure of human infant temperament, but that its behavioral manifestations vary across maturation and rearing condition. Similarities in latent temperament structure in humans and a representative nonhuman primate highlights the potential for utilizing translational nonhuman primate models to increase understanding of human temperament.

Effects of Brief Behavioral Treatment for Insomnia on Daily Associations between Self-Reported Sleep and Objective Cognitive Performance in Older Adults.

OBJECTIVE: Behavioral treatments for insomnia improve sleep in older adults, but research documenting their effects on cognitive performance is mixed. We explored whether a brief behavioral treatment for insomnia (BBTi) impacts daily associations between sleep parameters and next day cognition. METHODS: Sixty-two older adults (Mage = 69.45 years, SD = 7.71) with insomnia completed either 4 weeks of BBTi or self-monitoring control (SMC). At baseline, post-treatment, and 3 month follow-up, participants completed 14 days of diaries measuring sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency (SE), as well as daily cognitive tests measuring processing speed (i.e., symbol digit modalities test, SDMT), and reasoning (i.e., letter series). At each time period, associations between sleep parameters and daily cognition, controlling for age, education, insomnia duration, use of sleep medications, and depression (i.e., Beck Depression Inventory-2nd Edition scores), were examined through multilevel modeling. RESULTS: At post-treatment, we observed an interactive fixed effect of treatment condition (i.e., BBTi/SMC) and TST on daily SDMT and letter series performance. For BBTi, longer TST was associated with better letter series performance, and did not predict SDMT performance. For SMC, longer TST was associated with worse SDMT, and was not associated with letter series performance. Greater WASO (regardless of group) was associated with better SDMT performance at post-treatment. Associations were not maintained at follow-up. CONCLUSIONS: Sleep duration may play an important role in BBTi-related improvements in daily higher order cognition. Maintenance of these associations may be facilitated by booster sessions following post-treatment. CLINICAL TRIAL IDENTIFIER: NCT02967185.

Anxiety and executive functions in mid-to-late life: the moderating role of sleep.

Objectives: The goal of the study was to examine the influence of sleep efficiency on the relationship between anxiety and executive functions.Method: Secondary data analyses of 82 community-dwelling middle-aged and older adults were performed (M age = 63.00, SD = 8.64). Anxiety was measured using the trait anxiety subscale of the State-Trait Anxiety Inventory. Sleep efficiency was measured using one-week of sleep diary data. Two executive functions, cognitive flexibility and inductive reasoning, were measured using the Trail-Making Test and Letter Series task, respectively. SPSS PROCESS macro software version 2 was used to assess the moderating role of sleep efficiency in the relationship between anxiety and executive functions.Results: Sleep significantly moderated the relationship between anxiety and inductive reasoning. Among middle-aged and older adults with high anxiety, those with good sleep efficiency displayed significantly better inductive reasoning than those with poor sleep efficiency after controlling for age, gender, and education (ΔR2 = .05, p = .017). Sleep efficiency did not significantly moderate the relationship between anxiety and cognitive flexibility.Conclusion: Sleep efficiency weakened the association between anxiety and inductive reasoning in middle-aged and older adults. Evidence from the study suggests better sleep may limit the negative effects of anxiety on executive functions in mid-to-late life. Further research is needed to elucidate the impact of anxiety and sleep on executive functions in clinical populations with anxiety.

Discriminative Ability of Montreal Cognitive Assessment Subtests and Items in Racial and Ethnic Minority Groups.

INTRODUCTION: The Montreal Cognitive Assessment (MoCA) is a popular screening tool for Mild Cognitive Impairment (MCI). The psychometric properties of the MoCA have not been widely examined in minority groups. We aimed to analyze the discriminate ability of subtests and items by race and ethnicity given gold-standard clinical diagnosis of cognitive status. METHODS: We analyzed data from the National Alzheimer Coordinating Center Uniform Data Set March 2018 data freeze. Stepwise regression was used to determine which subtests predicted cognitive status (normal cognition, MCI, or dementia), by race/ethnicity. Item discrimination and difficulty was calculated by race/ethnicity and cognitive status. RESULTS: In our sample (n=3895), with an average age of 69.7, 80.7% were non-Hispanic white, 15.0% were non-Hispanic black, and 4.2% were Hispanic. Among non-Hispanic whites all subtests, education, and age predicted clinician diagnosis, while visuospatial/executive, attention, language, delayed recall, and orientation subtests were predictive among non-Hispanic blacks and visuospatial/executive, delayed recall, and orientation subtests and education were predictive among Hispanics. Item discrimination and difficulty varied by race/ethnicity and cognitive status. CONCLUSIONS: By understanding the psychometric properties of MoCA subtests, we can focus on subtests that have higher discrimination and more diagnostic utility. Subtests should be further evaluated for use in screening of minority individuals.

Health literacy, sociodemographic factors, and cognitive training in the active study of older adults.

OBJECTIVE: Health literacy is critical for understanding information from health-care providers and correct use of medications and includes the capacity to filter other information in navigating health care systems. Older adults with low health literacy exhibit more chronic health conditions, worse physical functioning, and poorer mental health. This study examined the relationship between sociodemographic variables and health literacy, and the impact of cognitive training on change in health literacy over 10 years in older adults. METHODS: Participants (N = 2,802) aged 65 years and older completed assessments, including reading and numeracy health literacy items, as part of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study. We evaluated baseline sociodemographic variables and change in health literacy over a 10-year period in individuals exposed to cognitive training in reasoning, processing speed, memory, or a no-contact control condition. RESULTS: Age, sex, race, education level, and general cognitive functioning at baseline were all associated with baseline health literacy in older adults. Predictors of change in health literacy over the 10-year follow-up were age, race, education level, general cognitive functioning, and neighborhood income; disparities in health literacy because of race attenuated over time, while the effect of age increased over time. Health literacy was generally stable across the ACTIVE intervention groups over 10 years. CONCLUSIONS: The present study showed important disparities in health literacy level and change over 10 years. Cognitive training did not significantly impact health literacy, suggesting that alternative approaches are needed to reduce the disparities.

Analyzing Analgesic Medications in Community-Dwelling Older Adults.

Objectives: Analyzing medication data for research purposes is complex, and methods are rarely described in the literature. Our objective was to describe methods of quantifying opioid and nonopioid analgesics and to compare the utility of five different analgesic coding methods when analyzing relationships between pain, analgesic use, and clinical outcomes. In this study, we used physical function as the outcome variable for its clinical relevance and its relationship to pain in older adults. Design: Secondary analyses of baseline cross-sectional data from the Advanced Cognitive Training Interventions for Vital Elders (ACTIVE) study. Setting: Community settings in six regions of the United States. Subjects: A total of 2,802 community-residing adults older than age 65 years. Methods: A medication audit was conducted. Analgesics were coded as any pain medication, counts (total analgesics, number of opioids and nonopioids), equianalgesics (oral morphine equivalents, oral acetaminophen equivalents), and dose categories. Adjuvant medications used to treat pain (e.g., tricyclic antidepressants and anticonvulsants) and low-dose aspirin typically used for cardiovascular conditions were excluded from these analyses. To examine the utility of these various approaches, a series of hierarchical regression models were conducted with pain and analgesics as predictors and physical functioning as the dependent variable. Results: Eighty-one point nine percent of participants reported experiencing recent pain, but 26% reported analgesic use. Nonopioids were the most common drug class used. Models revealed that pain was significantly associated with worse physical function (ß = -0.45, P = 0.001), after controlling for demographic and analgesic variables. Two basic drug coding methods (e.g., any pain medication, number of pain medications) were equivalent in their explanatory power (ß = -0.12, P = 0.001) and were slightly stronger predictors of function than the more complex coding procedures. Conclusions: Analgesic medications are important variables to consider in community-based studies of older adults. We illustrate several methods of quantifying analgesic medications for research purposes. In this community-based sample, we found no advantage of complex equianalgesic coding methods over simple counts in predicting physical functioning. The results may differ depending on the research question or clinical outcome studied. Thus, methods of analyzing analgesic drug data warrant further research.

Pain inconsistency and sleep in mid to late-life: the role of depression.

Objectives: Inconsistency in pain may lead to depression, which may then influence sleep. Thus, the purpose of this study was to examine whether depression mediates the relationship between day-to-day inconsistency in pain and sleep in middle aged to older adults. Methods: Baseline measures from the Active Adult Mentoring Project were used for secondary data analysis. Participants included 82 adults in mid- to late-life. Pain was assessed for seven consecutive days on an 11-point Likert-scale, with pain inconsistency defined as the seven-day individual standard deviation. A self-report daily diary was used to assess sleep efficiency (SE), total wake time (TWT), total sleep time (TST), and sleep quality (SQ), and depression was assessed using the BDI-II. Results: Mediation analyses revealed that depression partially mediated the relationship between pain inconsistency and SE, TWT, and SQ but not TST. Conclusions: Results indicate that depression may be an important factor through which pain inconsistency influences sleep. Although further research is warranted, these preliminary findings suggest that intervening on both pain inconsistency and depression may be one way to improve sleep in older adults.

Self-perceived Difficulties in Everyday Function Precede Cognitive Decline among Older Adults in the ACTIVE Study.

OBJECTIVES: Careful characterization of how functional decline co-evolves with cognitive decline in older adults has yet to be well described. Most models of neurodegenerative disease postulate that cognitive decline predates and potentially leads to declines in everyday functional abilities; however, there is mounting evidence that subtle decline in instrumental activities of daily living (IADLs) may be detectable in older individuals who are still cognitively normal. METHODS: The present study examines how the relationship between change in cognition and change in IADLs are best characterized among older adults who participated in the ACTIVE trial. Neuropsychological and IADL data were analyzed for 2802 older adults who were cognitively normal at study baseline and followed for up to 10 years. RESULTS: Findings demonstrate that subtle, self-perceived difficulties in performing IADLs preceded and predicted subsequent declines on cognitive tests of memory, reasoning, and speed of processing. CONCLUSIONS: Findings are consistent with a growing body of literature suggesting that subjective changes in everyday abilities can be associated with more precipitous decline on objective cognitive measures and the development of mild cognitive impairment and dementia. (JINS, 2018, 24, 104-112).

Health Self-Empowerment Theory: Predicting Health Behaviors and BMI in Culturally Diverse Adults.

Health Self-Empowerment Theory asserts that 5 controllable psychological variables predict engagement in health-promoting behaviors. This study tests the theoretical integrity of Health Self-Empowerment Theory and its usefulness in predicting health-promoting behaviors and body mass index. Results from surveying 189 predominantly low-income, overweight/obese, and culturally diverse adults showed that most Health Self-Empowerment Theory variables were positively correlated. Structural equation modeling showed that 4 variables significantly predicted engagement in health-promoting behaviors, which mediated the relationships between body mass index and (a) motivation, (b) health self-efficacy, and (c) self-praise. Results support creating psychologically informed interventions to increase engagement in health-promoting behaviors and decrease body mass index among low-income adults, particularly racial/ethnic minorities, at risk for obesity-related health problems.

The ACTIVE conceptual framework as a structural equation model.

Background/Study Context: Conceptual frameworks are analytic models at a high level of abstraction. Their operationalization can inform randomized trial design and sample size considerations. METHODS: The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) conceptual framework was empirically tested using structural equation modeling (N=2,802). ACTIVE was guided by a conceptual framework for cognitive training in which proximal cognitive abilities (memory, inductive reasoning, speed of processing) mediate treatment-related improvement in primary outcomes (everyday problem-solving, difficulty with activities of daily living, everyday speed, driving difficulty), which in turn lead to improved secondary outcomes (health-related quality of life, health service utilization, mobility). Measurement models for each proximal, primary, and secondary outcome were developed and tested using baseline data. Each construct was then combined in one model to evaluate fit (RMSEA, CFI, normalized residuals of each indicator). To expand the conceptual model and potentially inform future trials, evidence of modification of structural model parameters was evaluated by age, years of education, sex, race, and self-rated health status. RESULTS: Preconceived measurement models for memory, reasoning, speed of processing, everyday problem-solving, instrumental activities of daily living (IADL) difficulty, everyday speed, driving difficulty, and health-related quality of life each fit well to the data (all RMSEA < .05; all CFI > .95). Fit of the full model was excellent (RMSEA = .038; CFI = .924). In contrast with previous findings from ACTIVE regarding who benefits from training, interaction testing revealed associations between proximal abilities and primary outcomes are stronger on average by nonwhite race, worse health, older age, and less education (p < .005). CONCLUSIONS: Empirical data confirm the hypothesized ACTIVE conceptual model. Findings suggest that the types of people who show intervention effects on cognitive performance potentially may be different from those with the greatest chance of transfer to real-world activities.

Sleep and Pain in Mid- to Late-Life: An Exploration of Day-to-Day Pain Inconsistency.

OBJECTIVES: This study examined how different quantifications of pain (average vs. day-to-day inconsistency) are related to sleep in older adults beyond known predictors. METHODS: Baseline measures from the Active Adult Mentoring Project were used for secondary analyses. Participants included 82 adults in mid- to late-life. Depression was assessed with the BDI-II. Pain intensity was assessed over seven days on a 11-point Likert-scale, while sleep efficiency (SE), total sleep time (TST), and total wake time (TWT) were assessed using a self-report diary. RESULTS: Regression analyses revealed that pain inconsistency was associated with both SE and TWT and accounted for significant variance over age, gender, and depression. In contrast, average pain was not associated with SE, TST, or TWT. CONCLUSIONS: The findings indicate that pain inconsistency may be a more meaningful predictor of sleep disturbance than average pain level, suggesting that one's ability to regulate pain may be related to one's ability to engage in optimal sleep in mid- to late-life. CLINICAL IMPLICATIONS: Pain inconsistency appears to contribute more to sleep disturbance than average pain. Pain inconsistency in late-life warrants greater attention and may be an area of clinical intervention through activity-pacing or coping skills training.

Age trajectories of everyday cognition in African American and White older adults under prompted and unprompted conditions.

We investigated how race and verbal prompting interacted with age to predict age trajectories on a performance-based measure of everyday cognition. African American (n = 727) and White (n = 2052) older adults from the ACTIVE clinical trial were given the Observed Tasks of Daily Living (OTDL; a performance-based measure of medication management/finances/telephone use) at baseline and 1-, 2-, 3-, 5-, and 10-year follow-ups. When participants said "I don't know" or did not respond, they received a standardised verbal prompt, which served only as a cue to initiate the first step. At each occasion, unprompted (sum of items correct without prompting) and prompted (sum of correct prompted and unprompted items) scores were derived for each participant. Mixed effects models for change were used to determine the age trajectories of OTDL performance by race. When not prompted, African Americans demonstrated more rapid decline in OTDL performance than Whites, especially after age 80. When prompted, both groups had improved performance and evinced shallower decline, although African Americans continued to demonstrate a slightly more rapid decline. Simple prompting attenuated age-related changes of African Americans and Whites on a measure of everyday cognition. Prompting may be especially helpful for older African Americans.

Exercise and sleep in community-dwelling older adults: evidence for a reciprocal relationship.

Exercise behaviour and sleep are both important health indicators that demonstrate significant decreases with age, and remain modifiable well into later life. The current investigation examined both the chronic and acute relationships between exercise behaviour and self-reported sleep in older adults through a secondary analysis of a clinical trial of a lifestyle intervention. Seventy-nine community-dwelling, initially sedentary, older adults (mean age = 63.58 years, SD = 8.66 years) completed daily home-based assessments of exercise behaviour and sleep using daily diary methodology. Assessments were collected weekly and continued for 18 consecutive weeks. Multilevel models revealed a small positive chronic (between-person mean-level) association between exercise and wake time after sleep onset, and a small positive acute (within-person, day-to-day) association between exercise and general sleep quality rating. The within-person exercise and general sleep quality rating relationship was found to be reciprocal (i.e. sleep quality also predicted subsequent exercise behaviour). As such, it appears exercise and sleep are dynamically related in older adults. Efforts to intervene on either sleep or exercise in late-life would be wise to take the other into account. Light exposure, temperature regulation and mood may be potential mechanisms of action through which exercise can impact sleep in older adults.

Modelling longitudinal changes in older adults' memory for spoken discourse: findings from the ACTIVE cohort.

Episodic memory shows substantial declines with advancing age, but research on longitudinal trajectories of spoken discourse memory (SDM) in older adulthood is limited. Using parallel process latent growth curve models, we examined 10 years of longitudinal data from the no-contact control group (N = 698) of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) randomised controlled trial in order to test (1) the degree to which SDM declines with advancing age, (2) the predictors of these age-related declines and (3) the within-person relationship between longitudinal changes in SDM and longitudinal changes in fluid reasoning and verbal ability over 10 years, independent of age. Individuals who were younger, were White, had more years of formal education, were male and had better global cognitive function and episodic memory performance at baseline demonstrated greater levels of SDM on average. However, only age at baseline uniquely predicted longitudinal changes in SDM, such that declines accelerated with greater age. Independent of age, within-person decline in reasoning ability over the 10-year study period was substantially correlated with decline in SDM (r = .87). An analogous association with SDM did not hold for verbal ability. The findings suggest that longitudinal declines in fluid cognition are associated with reduced spoken language comprehension. Unlike findings from memory for written prose, preserved verbal ability may not protect against developmental declines in memory for speech.