Metabolomics and Risk of Dementia: A Systematic Review of Prospective Studies.

BACKGROUND: The projected increase in the prevalence of dementia has sparked interest in understanding the pathophysiology and underlying causal factors in its development and progression. Identifying novel biomarkers in the preclinical or prodromal phase of dementia may be important for predicting early disease risk. Applying metabolomic techniques to prediagnostic samples in prospective studies provides the opportunity to identify potential disease biomarkers. OBJECTIVE: The objective of this systematic review was to summarize the evidence on the associations between metabolite markers and risk of dementia and related dementia subtypes in human studies with a prospective design. DESIGN: We searched PubMed, PsycINFO, and Web of Science databases from inception through December 8, 2023. Thirteen studies (mean/median follow-up years: 2.1-21.0 y) were included in the review. RESULTS: Several metabolites detected in biological samples, including amino acids, fatty acids, acylcarnitines, lipid and lipoprotein variations, hormones, and other related metabolites, were associated with risk of developing dementia. Our systematic review summarized the adjusted associations between metabolites and dementia risk; however, our findings should be interpreted with caution because of the heterogeneity across the included studies and potential sources of bias. Further studies are warranted with well-designed prospective cohort studies that have defined study populations, longer follow-up durations, the inclusion of additional diverse biological samples, standardization of techniques in metabolomics and ascertainment methods for diagnosing dementia, and inclusion of other related dementia subtypes. CONCLUSIONS: This study contributes to the limited systematic reviews on metabolomics and dementia by summarizing the prospective associations between metabolites in prediagnostic biological samples with dementia risk. Our review discovered additional metabolite markers associated with the onset of developing dementia and may help aid in the understanding of dementia etiology. The protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (https://www.crd.york.ac.uk/prospero/; registration ID: CRD42022357521).

Perceived but not objective measures of neighborhood safety and food environments are associated with longitudinal changes in processing speed among urban older adults.

BACKGROUND: Although a growing body of literature documents the importance of neighborhood effects on late-life cognition, little is known about the relative strength of objective and subjective neighborhood measures on late-life cognitive changes. This study examined effects of objective and subjective neighborhood measures in three neighborhood domains (neighborhood safety, physical disorder, food environments) on longitudinal changes in processing speed, an early marker of cognitive aging and impairment. METHODS: The analysis sample included 306 community-dwelling older adults enrolled in the Einstein Aging Study (mean age = 77, age range = 70 to 91; female = 67.7%; non-Hispanic White: 45.1%, non-Hispanic Black: 40.9%). Objective and subjective measures of neighborhood included three neighborhood domains (i.e., neighborhood safety, physical disorder, food environments). Processing speed was assessed using a brief Symbol Match task (unit: second), administered on a smartphone device six times a day for 16 days and repeated annually for up to five years. Years from baseline was used as the within-person time index. RESULTS: Results from mixed effects models showed that subjective neighborhood safety (ß= -0.028) and subjective availability of healthy foods (ß= -0.028) were significantly associated with less cognitive slowing over time. When objective and subjective neighborhood measures were simultaneously examined, subjective availability of healthy foods remained significant (ß= -0.028) after controlling for objective availability of healthy foods. Associations of objective neighborhood crime and physical disorder with processing speed seemed to be confounded by individual-level race and socioeconomic status; after controlling for these confounders, none of objective neighborhood measures showed significant associations with processing speed. CONCLUSION: Subjective neighborhood safety and subjective availability of healthy foods, rather than objective measures, were associated with less cognitive slowing over time over a five-year period. Perception of one's neighborhood may be a more proximal predictor of cognitive health outcomes as it may reflect one's experiences in the environment. It would be important to improve our understanding of both objective and subjective neighborhood factors to improve cognitive health among older adults.

Momentary loneliness and intrusive thoughts among older adults: the interactive roles of mild cognitive impairment and marital status.

OBJECTIVES: Loneliness is associated with maladaptive cognitions, yet little is known about the association between loneliness and intrusive thinking during older adulthood. Links between loneliness and intrusive thoughts may be particularly strong among individuals with mild cognitive impairment (MCI), who may have greater difficulty regulating emotion and intrusive thoughts. In contrast, having close relationships (e.g. being married) may serve as a protective factor as marital status is associated with better overall well-being. METHOD: Participants were 316 older adults (recruited from the Bronx, NY, as part of a larger study) without dementia at study intake (40% Black; 13% Hispanic, Mage = 77.45 years, 67% women) who completed ecological momentary assessments five times daily for 14 consecutive days (13,957 EMAs total). Multilevel modeling was used to examine the association between momentary loneliness and intrusive thoughts and whether MCI and marital status interacted to moderate this association. RESULTS: There was a significant three-way interaction (ß = -0.17, p < 0.05), such that lagged momentary loneliness was positively associated with intrusive thoughts (3-4 h later) for those with MCI who were not married. CONCLUSION: Findings suggest that among older adults with MCI, being married may be a protective factor and being unmarried may be a risk factor for experiencing loneliness and subsequent intrusive thoughts.

Racial differences in links between perceived discrimination, depressive symptoms, and ambulatory working memory.

OBJECTIVES: Perceived discrimination is associated with racial cognitive health disparities. Links between discrimination and cognitive performance, like working memory, in everyday settings (i.e. ambulatory performance) require investigation. Depressive symptoms may be a mechanism through which discrimination relates to ambulatory working memory. METHOD: Discrimination, retrospective and momentary depressive symptoms/mood, and aggregated and momentary working memory performance among older Black and White adults were examined within the Einstein Aging Study. RESULTS: Racially stratified analyses revealed that discrimination did not relate to Black or White adults' ambulatory working memory. Among Black adults, however, more frequent discrimination was associated with greater retrospectively reported depressive symptoms, which related to more working memory errors across two weeks (indirect effect p < 0.05). This path was not significant among White adults. Links between discrimination and momentary working memory were not explained by momentary reports of depressed mood for Black or White adults. CONCLUSION: Depressive symptoms may play an important role in the link between discrimination and ambulatory working memory among Black adults across extended measurements, but not at the momentary level. Future research should address ambulatory cognition and momentary reports of discrimination and depression to better understand how to minimize cognitive health disparities associated with discrimination.

Physical activity and cognitive function: moment-to-moment and day-to-day associations.

BACKGROUND: The beneficial effect of acute physical exercise on cognitive performance has been studied in laboratory settings and in long-term longitudinal studies. Less is known about these associations in everyday environment and on a momentary timeframe. This study investigated momentary and daily associations between physical activity and cognitive functioning in the context of everyday life. METHODS: Middle-aged adults (n = 291, aged 40-70) were asked to wear accelerometers and complete ecological momentary assessments for eight consecutive days. Processing speed and visual memory were assessed three times per day and self-rated evaluations of daily cognition (memory, thinking, and sharpness of mind) were collected each night. The number of minutes spent above the active threshold (active time) and the maximum vector magnitude counts (the highest intensity obtained) before each cognitive test and at a daily level were used as predictors of momentary cognitive performance and nightly subjective cognition. Analyses were done with multilevel linear models. The models were adjusted for temporal and contextual factors, age, sex, education, and race/ethnicity. RESULTS: When participants had a more active time or higher intensity than their average level within the 20 or 60 minutes prior to the cognitive test, they performed better on the processing speed task. On days when participants had more active time than their average day, they rated their memory in the evening better. Physical activity was not associated with visual memory or self-rated thinking and sharpness of mind. CONCLUSIONS: This study provides novel evidence that outside of laboratory settings, even small increases in physical activity boost daily processing speed abilities and self-rated memory. The finding of temporary beneficial effects is consistent with long-term longitudinal research on the cognitive benefits of physical activity.

Unsupervised high-frequency smartphone-based cognitive assessments are reliable, valid, and feasible in older adults at risk for Alzheimer's disease.

OBJECTIVE: Smartphones have the potential for capturing subtle changes in cognition that characterize preclinical Alzheimer's disease (AD) in older adults. The Ambulatory Research in Cognition (ARC) smartphone application is based on principles from ecological momentary assessment (EMA) and administers brief tests of associative memory, processing speed, and working memory up to 4 times per day over 7 consecutive days. ARC was designed to be administered unsupervised using participants' personal devices in their everyday environments. METHODS: We evaluated the reliability and validity of ARC in a sample of 268 cognitively normal older adults (ages 65-97 years) and 22 individuals with very mild dementia (ages 61-88 years). Participants completed at least one 7-day cycle of ARC testing and conventional cognitive assessments; most also completed cerebrospinal fluid, amyloid and tau positron emission tomography, and structural magnetic resonance imaging studies. RESULTS: First, ARC tasks were reliable as between-person reliability across the 7-day cycle and test-retest reliabilities at 6-month and 1-year follow-ups all exceeded 0.85. Second, ARC demonstrated construct validity as evidenced by correlations with conventional cognitive measures (r = 0.53 between composite scores). Third, ARC measures correlated with AD biomarker burden at baseline to a similar degree as conventional cognitive measures. Finally, the intensive 7-day cycle indicated that ARC was feasible (86.50% approached chose to enroll), well tolerated (80.42% adherence, 4.83% dropout), and was rated favorably by older adult participants. CONCLUSIONS: Overall, the results suggest that ARC is reliable and valid and represents a feasible tool for assessing cognitive changes associated with the earliest stages of AD.

Availability of healthy foods, fruit and vegetable consumption, and cognition among urban older adults.

BACKGROUND: . Although prior studies have examined the associations between neighborhood characteristics and cognitive health, little is known about whether local food environments, which are critical for individuals' daily living, are associated with late-life cognition. Further, little is known about how local environments may shape individuals' health-related behaviors and impact cognitive health. The aim of this study is to examine whether objective and subjective measures of healthy food availability are associated with ambulatory cognitive performance and whether behavioral and cardiovascular factors mediate these associations among urban older adults. METHODS: . The sample consisted of systematically recruited, community-dwelling older adults (N = 315, mean age = 77.5, range = 70-91) from the Einstein Aging Study. Objective availability of healthy foods was defined as density of healthy food stores. Subjective availability of healthy foods and fruit/vegetable consumption were assessed using self-reported questionnaires. Cognitive performance was assessed using smartphone-administered cognitive tasks that measured processing speed, short-term memory binding, and spatial working memory performance 6 times a day for 14 days. RESULTS: . Results from multilevel models showed that subjective availability of healthy foods, but not objective food environments, was associated with better processing speed (estimate= -0.176, p = .003) and more accurate memory binding performance (estimate = 0.042, p = .012). Further, 14~16% of the effects of subjective availability of healthy foods on cognition were mediated through fruit and vegetable consumption. CONCLUSIONS: . Local food environments seem to be important for individuals' dietary behavior and cognitive health. Specifically, subjective measures of food environments may better reflect individuals' experiences regarding their local food environments not captured by objective measures. Future policy and intervention strategies will need to include both objective and subjective food environment measures in identifying impactful target for intervention and evaluating effectiveness of policy changes.

Introversion and the frequency and intensity of daily uplifts and hassles.

OBJECTIVE: There is reason to believe that introversion may relate to different patterns of negative and positive experiences in everyday life ("hassles" and "uplifts"), but there is little evidence for this based on reports made in daily life as events occur. We thus extend the literature by using data from ecological momentary assessments to examine whether introversion is associated with either the frequency or intensity of hassles and uplifts. METHOD: Participants (N = 242) were community-dwelling adults (63% Black, 24% Hispanic; ages 25-65; 65% women) who completed baseline measures of personality and mental health, followed by reports of hassles and uplifts 5x/day for 14 days. We present associations between introversion and hassles/uplifts both with and without controlling for mood-related factors (neuroticism, recent symptoms of depression, and anxiety). RESULTS: Introversion was associated with reporting less frequent and less enjoyable uplifts, but not with overall hassle frequency or unpleasantness; exploratory analyses suggest associations with specific types of hassles. CONCLUSIONS: Our results expand understanding of the role of introversion in everyday experiences, suggesting an overall association between introversion and uplifts (but not hassles, broadly) in daily life. Better understanding of such connections may inform future research to determine mechanisms by which introversion relates to health.

Ecological Momentary Assessment of Cognition in Clinical and Community Samples: Reliability and Validity Study.

BACKGROUND: The current methods of evaluating cognitive functioning typically rely on a single time point to assess and characterize an individual's performance. However, cognitive functioning fluctuates within individuals over time in relation to environmental, psychological, and physiological contexts. This limits the generalizability and diagnostic utility of single time point assessments, particularly among individuals who may exhibit large variations in cognition depending on physiological or psychological context (eg, those with type 1 diabetes [T1D], who may have fluctuating glucose concentrations throughout the day). OBJECTIVE: We aimed to report the reliability and validity of cognitive ecological momentary assessment (EMA) as a method for understanding between-person differences and capturing within-person variation in cognition over time in a community sample and sample of adults with T1D. METHODS: Cognitive performance was measured 3 times a day for 15 days in the sample of adults with T1D (n=198, recruited through endocrinology clinics) and for 10 days in the community sample (n=128, recruited from TestMyBrain, a web-based citizen science platform) using ultrabrief cognitive tests developed for cognitive EMA. Our cognitive EMA platform allowed for remote, automated assessment in participants' natural environments, enabling the measurement of within-person cognitive variation without the burden of repeated laboratory or clinic visits. This allowed us to evaluate reliability and validity in samples that differed in their expected degree of cognitive variability as well as the method of recruitment. RESULTS: The results demonstrate excellent between-person reliability (ranging from 0.95 to 0.99) and construct validity of cognitive EMA in both the sample of adults with T1D and community sample. Within-person reliability in both samples (ranging from 0.20 to 0.80) was comparable with that observed in previous studies in healthy older adults. As expected, the full-length baseline and EMA versions of TestMyBrain tests correlated highly with one another and loaded together on the expected cognitive domains when using exploratory factor analysis. Interruptions had higher negative impacts on accuracy-based outcomes (ß=-.34 to -.26; all P values <.001) than on reaction time-based outcomes (ß=-.07 to -.02; P<.001 to P=.40). CONCLUSIONS: We demonstrated that ultrabrief mobile assessments are both reliable and valid across 2 very different clinic versus community samples, despite the conditions in which cognitive EMAs are administered, which are often associated with more noise and variability. The psychometric characteristics described here should be leveraged appropriately depending on the goals of the cognitive assessment (eg, diagnostic vs everyday functioning) and the population being studied.

To BYOD or not: Are device latencies important for bring-your-own-device (BYOD) smartphone cognitive testing?

Studies using remote cognitive testing must make a critical decision: whether to allow participants to use their own devices or to provide participants with a study-specific device. Bring-your-own-device (BYOD) studies have several advantages including increased accessibility, potential for larger sample sizes, and reduced participant burden. However, BYOD studies offer little control over device performance characteristics that could potentially influence results. In particular, response times measured by each device not only include the participant's true response time, but also latencies of the device itself. The present study investigated two prominent sources of device latencies that pose significant risks to data quality: device display output latency and touchscreen input latency. We comprehensively tested 26 popular smartphones ranging in price from < $100 to $1000+ running either Android or iOS to determine if hardware and operating system differences led to appreciable device latency variability. To accomplish this, a custom-built device called the Latency and Timing Assessment Robot (LaTARbot) measured device display output and capacitive touchscreen input latencies. We found considerable variability across smartphones in display and touch latencies which, if unaccounted for, could be misattributed as individual or group differences in response times. Specifically, total device (sum of display and touch) latencies ranged from 35 to 140 ms. We offer recommendations to researchers to increase the precision of data collection and analysis in the context of remote BYOD studies.

Relationships between daily stress responses in everyday life and nightly sleep.

Stress and sleep are related, but the nature and time course of this relation is not well understood. We explored the within-person associations of three components of emotional responses to everyday stressors, indexed by negative affect, reactivity (initial response to a stressor), recovery (persistence of the post-stressor response), and pile-up (accumulation of stress episodes), with sleep indicators. We conducted coordinated analyses of data in several studies employing ecological momentary assessments, which captured naturally occurring, self-reported stress and sleep. We defined proximal reactivity as the emotional response to the stressor moment in question compared to an immediate pre-stressor state, and distal reactivity as the emotional response to the stressor moment in question compared to a typical stressor-free state for that person. Results in two of three studies showed that people reported significantly lower sleep quality following days on which they experienced higher levels of distal reactivity to stressors. Days with greater distal reactivity also predicted significantly more difficulty falling asleep in one of two studies. There was no clear association between proximal reactivity and subsequent sleep. Associations of recovery or pile-up with subsequent sleep emerged only in single studies. Poorer sleep quality was significantly related to higher next day levels of negative affect in all three studies, but there were no consistent relations between sleep and next day stress reactivity, recovery, or pile-up. These exploratory analyses suggest that distal reactivity is associated with a heightened risk of experiencing poor sleep quality the following night, and as such the former may serve as a candidate for potential targets for the remediation of the negative effects of stress on sleep.

Associations Between Enjoyable Activities and Uplifting Events: Effects on Momentary Positive Affect in Adulthood.

This study examined the effects of participation in enjoyable activities and the experience of uplifting events on individuals' momentary positive affect (PA) and tested for age differences in these effects. 176 adults (ages 25-66) completed ecological momentary assessments (EMAs) 5 times per day for 14 days. We found that individuals reported higher levels of PA at times when an uplifting event had occurred compared to times when an uplifting event had not occurred (p < 0.05), and this association was amplified among those who participated less frequently in enjoyable activities (p < 0.05). The moderating effect of participation in enjoyable activities was invariant across the sample's age range. The findings demonstrated that individuals who habitually participated in enjoyable activities experienced higher levels of PA in everyday life. In contrast, individuals who infrequently or never engaged in enjoyable activities depended upon recent uplifting events to experience higher levels of PA.

Rural Population Health and Aging: Toward a Multilevel and Multidimensional Research Agenda for the 2020s.

The unique health and aging challenges of rural populations often go unnoticed. In fact, the rural United States is home to disproportionate shares of older and sicker people, there are large and growing rural-urban and within-rural mortality disparities, many rural communities are in population decline, and rural racial/ethnic diversity is increasing.Yet rural communities are not monolithic, and although some rural places are characterized by declining health, others have seen large improvements in population health. We draw on these realities to call for new research in five areas.First, research is needed to better describe health disparities between rural and urban areas and, because rural places are not monolithic, across rural America. Second, research is needed on how trends in rural population health and aging are affecting rural communities. Third, research is needed on the ways in which economic well-being and livelihood strategies interact with rural health and aging. Fourth, we need to better understand the health implications of the physical and social isolation characterizing many rural communities. Finally, we argue for new research on the implications of local natural environments and climate change for rural population health and aging.

Memory lapses in daily life among breast cancer survivors and women without cancer history.

OBJECTIVE: Cancer-associated cognitive decline is a concern among cancer survivors. Survivors' memory lapses (eg, location of keys, names, and reason entered room) may negatively impact quality of life. This study used smartphone-based surveys to compare cancer survivors to those without cancer history on frequency of, severity of, and affective response to daily memory lapses. METHODS: For 14 evenings, breast cancer survivors (N = 47, M age = 52.9) and women without a cancer history (N = 105, M age = 51.8) completed smartphone-based surveys on memory lapse occurrence and severity and negative and positive affect. RESULTS: Survivors were nearly three times more likely to report a daily memory lapse but did not differ from comparison group on memory lapse severity. Negative affect was significantly higher on days with memory lapses associated with doing something in the future (eg, appointments) but this did not differ across groups. Positive affect was not significantly related to survivorship status or the occurrence of daily memory lapses. CONCLUSION: Survivors may be at-risk for more frequent memory lapses. Both survivors and women without a history of cancer reported greater negative affect on days when memory lapses occurred, suggesting that daily cognitive functioning may have important implications for quality of life.

Emotional Responses to Stressors in Everyday Life Predict Long-Term Trajectories of Depressive Symptoms.

BACKGROUND: Individuals' emotional responses to stressors in everyday life are associated with long-term physical and mental health. Among many possible risk factors, the stressor-related emotional responses may play an important role in future development of depressive symptoms. PURPOSE: The current study examined how individuals' positive and negative emotional responses to everyday stressors predicted their subsequent changes in depressive symptoms over 18 months. METHODS: Using an ecological momentary assessment approach, participants (n = 176) reported stressor exposure, positive affect (PA), and negative affect (NA) five times a day for 1 week (n = 5,483 observations) and provided longitudinal reports of depressive symptoms over the subsequent 18 months. A multivariate multilevel latent growth curve model was used to directly link the fluctuations in emotions in response to momentary stressors in everyday life with the long-term trajectory of depressive symptoms. RESULTS: Adults who demonstrated a greater difference in stressor-related PA (i.e., relatively lower PA on stressor vs. nonstressor moments) reported larger increases in depressive symptoms over 18 months. Those with greater NA responses to everyday stressors (i.e., relatively higher NA on stressor vs. nonstressor moments), however, did not exhibit differential long-term changes in depressive symptoms. CONCLUSIONS: Adults showed a pattern consistent with both PA and NA responses to stressors in everyday life, but only the stressor-related changes in PA (but not in NA) predicted the growth of depressive symptoms over time. These findings highlight the important-but often overlooked-role of positive emotional responses to everyday stressors in long-term mental health.

Longitudinal relationships among depressive symptoms and three types of memory self-report in cognitively intact older adults.

OBJECTIVES: The current study examined whether self-reported memory problems among cognitively intact older adults changed concurrently with, preceded, or followed depressive symptoms over time. DESIGN: Data were collected annually via in-person comprehensive medical and neuropsychological examinations as part of the Einstein Aging Study. SETTING: Community-dwelling older adults in an urban, multi-ethnic area of New York City were interviewed. PARTICIPANTS: The current study included a total of 1,162 older adults (Mage = 77.65, SD = 5.03, 63.39% female; 74.12% White). Data were utilized from up to 11 annual waves per participant. MEASUREMENTS: Multilevel modeling tested concurrent and lagged associations between three types of memory self-report (frequency of memory problems, perceived one-year decline, and perceived ten-year decline) and depressive symptoms. RESULTS: Results showed that self-reported frequency of memory problems covaried with depressive symptoms only in participants who were older at baseline. Changes in perceived one-year and ten-year memory decline were related to changes in depressive symptoms across all ages. Depressive symptoms increased the likelihood of perceived ten-year memory decline the next year; however, perceived ten-year memory decline did not predict future depressive symptoms. Additionally, no significant temporal relationship was observed between depressive symptoms and self-reported frequency of memory problems or perceived one-year memory decline. CONCLUSION: Our findings highlight the importance of testing the unique associations of different types of self-reported memory problems with depressive symptoms.

Everyday stress components and physical activity: examining reactivity, recovery and pileup.

The experience of naturally-occurring stress in daily life has been linked with lower physical activity levels. However, most of this evidence comes from general and static reports of stress. Less is known how different temporal components of everyday stress interfere with physical activity. In a coordinated secondary analysis of data from two studies of adults, we used intensive, micro-longitudinal assessments (ecological momentary assessments, EMA) to investigate how distinct components of everyday stress, that is, reactivity to stressor events, recovery from stressor events, and pileup of stressor events and responses predict physical activity. Results showed that components of everyday stress predicted subsequent physical activity especially for indicators of stress pileup. In both studies, the accumulation of stress responses over the previous 12 h was more predictive of subsequent physical activity than current stress reactivity or recovery responses. Results are compared to the effects of general measures of perceived stress that showed an opposite pattern of results. The novel everyday stress approach used here may be fruitful for generating new insights into physical activity specifically and health behaviors in general.

Understanding stress reports in daily life: a coordinated analysis of factors associated with the frequency of reporting stress.

Although stress is a common experience in everyday life, a clear understanding of how often an individual experiences and reports stress is lacking. Notably, there is little information regarding factors that may influence how frequently stress is reported, including which stress dimension is measured (i.e., stressors-did an event happen, subjective stress-how stressed do you feel, conditional stress-how stressful a stressor was) and the temporal features of that assessment (i.e., time of day, day of study, weekday vs. weekend day). The purpose of the present study was to conduct a coordinated analysis of five independent ecological momentary assessment studies utilizing varied stress reporting dimensions and temporal features. Results indicated that, within days, stress was reported at different frequencies depending on the stress dimension. Stressors were reported on 15-32% of momentary reports made within a day; across days, the frequency ranged from 42 to 76% of days. Depending on the cutoff, subjective stress was reported more frequently ranging about 8-56% of all moments within days, and 40-90% of days. Likewise, conditional stress ranged from just 3% of moments to 22%, and 11-69% of days. For the temporal features, stress was reported more frequently on weekdays (compared to weekend days) and on days earlier in the study (relative to days later in the study); time of day was inconsistently related to stress reports. In sum, stress report frequency depends in part on how stress is assessed. As such, researchers may wish to measure stress in multiple ways and, in the case of subjective and conditional stress with multiple operational definitions, to thoroughly characterize the frequency of stress reporting.

The influence of social support and perceived stress on response time inconsistency.

OBJECTIVES: Lack of social support and high levels of stress represent potentially modifiable risk factors for cognitive aging. In this study we examined the relationships between these two risk factors and response time inconsistency (RTI), or trial-to-trial variability in choice response time tasks. RTI is an early indicator of declining cognitive health, and examining the influence of modifiable psychosocial risk factors on RTI is important for understanding and promoting cognitive health during adulthood and old age. METHODS: Using data from a community sample study (n = 317; Mage = 49, range = 19-83), we examined the effects of social support, including size of network and satisfaction with support, global perceived stress, and their interactions on RTI. RESULTS: Neither size of network nor satisfaction with support was associated with RTI independent of perceived stress. Stress was positively associated with increased RTI on all tasks, independent of social support. Perceived stress did not interact with either dimension of social support to predict RTI, and perceived stress effects were invariant across age and sex. CONCLUSION: Perceived stress, but not social support, may be a unique and modifiable risk factor for normal and pathological cognitive aging. Discussion focuses on the importance of perceived stress and its impact on RTI in supporting cognitive health in adulthood and old age.

Negative and positive affect as predictors of inflammation: Timing matters.

Very little research has assessed how measures of negative and positive affect (NA and PA) derived from assessments at multiple time points per day (e.g., via ecological momentary assessment [EMA]), as opposed to questionnaires that rely on recall over a longer period, are related to levels of peripheral inflammation. We examined how different indicators of NA and PA predicted concentrations of C-reactive protein (CRP) and seven peripheral inflammatory cytokines (IL-1ß, IL-6, TNF-α, IL-8, IL-4, IL-10, and IFN-γ) that were examined in the form of an inflammatory composite. A community-based sample of 220 adults (62% Black/African-American and 25% Hispanic/Latino; aged 25-65; 65% female) completed questionnaires at baseline (including recalled affect "over the past month") and then provided EMA reports 5x/day for 14 days. Blood was drawn from each participant after completion of EMA and used to determine plasma levels of CRP and cytokines. Analyses examined if indicators of affect predicted inflammation, controlling for age, gender, body mass index, education, health conditions, and statin use. Neither recalled NA or PA nor momentary NA or PA (aggregated across the 14 days of EMA) were significantly associated with the cytokine composite or CRP. Negative mood more proximal to the blood draw (i.e., aggregated momentary NA in week 2 of EMA) was associated with the cytokine composite but not CRP. Exploratory moderation analyses revealed that the cytokine composite was also associated with PA in week 2 for men only, and with recalled NA for those with lower education. Exploratory analyses around temporal dynamics suggested that the timing of NA measurement relative to the blood draw mattered: Specifically, there were stronger trends of association between momentary NA and inflammatory cytokines when NA was assessed closer in time to blood collection. Future investigation of the relevance of temporal proximity and other measurement details may improve understanding of how affect relates to inflammation.