A systems identification approach using Bayes factors to deconstruct the brain bases of emotion regulation

Cognitive reappraisal is fundamental to cognitive therapies and everyday emotion regulation. Analyses using Bayes factors and an axiomatic systems identification approach identified four reappraisal-related components encompassing distributed neural activity patterns across two independent functional magnetic resonance imaging (fMRI) studies (n = 182 and n = 176): (1) an anterior prefrontal system selectively involved in cognitive reappraisal; (2) a fronto-parietal-insular system engaged by both reappraisal and emotion generation, demonstrating a general role in appraisal; (3) a largely subcortical system activated during negative emotion generation but unaffected by reappraisal, including amygdala, hypothalamus and periaqueductal gray; and (4) a posterior cortical system of negative emotion-related regions downregulated by reappraisal. These systems covaried with individual differences in reappraisal success and were differentially related to neurotransmitter binding maps, implicating cannabinoid and serotonin systems in reappraisal. These findings challenge 'limbic'-centric models of reappraisal and provide new systems-level targets for assessing and enhancing emotion regulation.

Similarity in evoked responses does not imply similarity in macroscopic network states

It is commonplace in neuroscience to assume that if two tasks activate the same brain areas in the same way, then they are recruiting the same underlying networks. Yet computational theory has shown that the same pattern of activity can emerge from many different underlying network representations. Here we evaluated whether similarity in activation necessarily implies similarity in network architecture by comparing region-wise activation patterns and functional correlation profiles from a large sample of healthy subjects (N = 242). Participants performed two executive control tasks known to recruit nearly identical brain areas, the color-word Stroop task and the Multi-Source Interference Task (MSIT). Using a measure of instantaneous functional correlations, based on edge time series, we estimated the task-related networks that differed between incongruent and congruent conditions. We found that the two tasks were much more different in their network profiles than in their evoked activity patterns at different analytical levels, as well as for a wide range of methodological pipelines. Our results reject the notion that having the same activation patterns means two tasks engage the same underlying representations, suggesting that task representations should be independently evaluated at both node and edge (connectivity) levels.

Stressor-evoked brain activity, cardiovascular reactivity, and subclinical atherosclerosis in midlife adults

Background

Cardiovascular responses to psychological stressors have been separately associated with preclinical atherosclerosis and hemodynamic brain activity patterns across different studies and cohorts; however, what has not been established is whether cardiovascular stress responses reliably link indicators of stressor-evoked brain activity and preclinical atherosclerosis that have been measured in the same individuals. Accordingly, the present study used cross-validation and predictive modeling to test for the first time whether stressor-evoked systolic blood pressure (SBP) responses statistically mediated the association between concurrently measured brain activity and a vascular marker of preclinical atherosclerosis in the carotid arteries.

Methods

624 midlife adults (aged 28-56 years, 54.97% female) from two different cohorts underwent two information-conflict fMRI tasks, with concurrent SBP measures collected. Carotid artery intima-media thickness (CA-IMT) was measured by ultrasonography. A mediation framework that included harmonization, cross-validation, and penalized principal component regression was then employed, while significant areas in possible direct and indirect effects were identified through bootstrapping. Sensitivity analysis further tested the robustness of findings after accounting for prevailing levels of cardiovascular disease risk and brain imaging data quality control.

Results

Task-averaged patterns of hemodynamic brain responses exhibited a generalizable association with CA-IMT, which was mediated by an area-under-the-curve measure of aggregate SBP reactivity. Importantly, this effect held in sensitivity analyses. Implicated brain areas in this mediation included the ventromedial prefrontal cortex, anterior cingulate cortex, insula and amygdala.

Conclusions

These novel findings support a link between stressor-evoked brain activity and preclinical atherosclerosis accounted for by individual differences in corresponding levels of stressor-evoked cardiovascular reactivity.

Cortical and subcortical brain networks predict prevailing heart rate

Resting heart rate may confer risk for cardiovascular disease (CVD) and other adverse cardiovascular events. While the brainstem's autonomic control over heart rate is well established, less is known about the regulatory role of higher-level cortical and subcortical brain regions, especially in humans. The present study sought to characterize the brain networks that predict variation in prevailing heart rate in otherwise healthy adults. We used machine learning approaches designed for complex, high-dimensional datasets, to predict variation in instantaneous heart period (the inter-heartbeat-interval) from whole brain hemodynamic signals measured by fMRI. Task-based and resting-state fMRI, as well as peripheral physiological recordings, were taken from two datasets that included extensive repeated measurements within individuals. Our models reliably predicted instantaneous heart period from whole brain fMRI data both within and across individuals, with prediction accuracies being highest when measured within-participants. We found that a network of cortical and subcortical brain regions, many linked to psychological stress, were reliable predictors of variation in heart period. This adds to evidence on brain-heart interactions and constitutes an incremental step towards developing clinically-applicable biomarkers of brain contributions to CVD risk.

Psychological stress and the longitudinal progression of subclinical atherosclerosis

OBJECTIVE

In a midlife sample of adults, the present study tested the extent to which changes in psychological stress relate to the progression of subclinical cardiovascular disease over multiple years and explored the potential moderating role of cardiometabolic risk.

METHOD

Participants were screened to exclude those with clinical cardiovascular, respiratory, metabolic, and other chronic illnesses, as well as those taking psychotropic, cardiovascular, lipid, and glucose control medications. At baseline (N = 331) and then again at follow-up an average of 3 years later (N = 260), participants completed the 10-item Perceived Stress Scale, underwent assessments of their cardiometabolic risk, and underwent ultrasonography to measure carotid artery intima-media thickness (IMT), which is a surrogate indicator of subclinical atherosclerosis.

RESULTS

Regression models showed that the change in psychological stress from baseline to follow-up was positively associated with the corresponding change in IMT, with covariate control for age at baseline, sex at birth, and variability in length of follow-up across participants. Cardiometabolic risk factors did not statistically moderate this longitudinal association. In exploratory analyses, cardiometabolic risk factors also did not statistically mediate this association.

CONCLUSION

These longitudinal findings suggest that increases in psychological stress in midlife relate to corresponding increases in subclinical atherosclerosis. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effects of a laboratory-based aerobic exercise intervention on brain volume and cardiovascular health markers: protocol for a randomised clinical trial

INTRODUCTION

Physical activity (PA) has beneficial effects on brain health and cardiovascular disease (CVD) risk. Yet, we know little about whether PA-induced changes to physiological mediators of CVD risk influence brain health and whether benefits to brain health may also explain PA-induced improvements to CVD risk. This study combines neurobiological and peripheral physiological methods in the context of a randomised clinical trial to better understand the links between exercise, brain health and CVD risk.

METHODS AND ANALYSIS

In this 12-month trial, 130 healthy individuals between the ages of 26 and 58 will be randomly assigned to either: (1) moderate-intensity aerobic PA for 150 min/week or (2) a health information control group. Cardiovascular, neuroimaging and PA measurements will occur for both groups before and after the intervention. Primary outcomes include changes in (1) brain structural areas (ie, hippocampal volume); (2) systolic blood pressure (SBP) responses to functional MRI cognitive stressor tasks and (3) heart rate variability. The main secondary outcomes include changes in (1) brain activity, resting state connectivity, cortical thickness and cortical volume; (2) daily life SBP stress reactivity; (3) negative and positive affect; (4) baroreflex sensitivity; (5) pulse wave velocity; (6) endothelial function and (7) daily life positive and negative affect. Our results are expected to have both mechanistic and public health implications regarding brain-body interactions in the context of cardiovascular health.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the University of Pittsburgh Institutional Review Board (IRB ID: 19020218). This study will comply with the NIH Data Sharing Policy and Policy on the Dissemination of NIH-Funded Clinical Trial Information and the Clinical Trials Registration and Results Information Submission rule.

TRIAL REGISTRATION NUMBER

NCT03841669.

Subjective Social Status and Longitudinal Changes in Systemic Inflammation

BACKGROUND

Subjective social status (SSS) refers to a person's perception of their social rank relative to others and is cross-sectionally linked to systemic inflammation independently of objective socioeconomic status.

PURPOSE

We test the extent to which SSS relates to multiyear changes in inflammation, or if associations differ by race or sex.

METHODS

Healthy adults (N = 331; 30-51 years) completed a baseline visit and 278 participants returned for a second visit 2.85 years later. At both visits, participants underwent a fasting blood draw and completed community (SSSC) and US (SSSUS) versions of the MacArthur Scale. Multiple linear regression analyses examined change in interleukin-6 (IL-6) and C-reactive protein (CRP) predicted by each type of SSS, adjusting for time between visits, sex, race, age, body mass index, smoking, baseline inflammation, and objective socioeconomic status. Additional analyses further adjusted for hopelessness and depressive symptoms. Interactions examined moderations by sex and race.

RESULTS

Lower SSSC was longitudinally associated with greater IL-6 independently of all covariates, including education and income (β = -0.06), hopelessness (β = -0.06), and depressive symptoms (β = -0.06). Lower SSSUS was longitudinally associated with greater IL-6 independently of demographic covariates including education and income (β = -0.06), but was slightly attenuated after adjusting for hopelessness (β = -0.06) and depressive symptoms (β = -0.06). There were no associations for CRP or moderation by race or sex.

CONCLUSIONS

Lower SSS may be associated with greater circulating markers of inflammation over time as suggested by increases in IL-6.

Changes in stress pathways as a possible mechanism of aerobic exercise training on brain health: a scoping review of existing studies

Physical activity (PA) in the form of aerobic exercise (AE) preserves and improves neurocognitive function across the lifespan. However, a mechanistic understanding of the pathways by which aerobic exercise impacts brain health is still lacking, particularly with respect to stress-related pathways. One mechanistic hypothesis is that AE improves neurocognitive health in part by modifying circulating levels of stress-related hormones and signaling factors associated with the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS), as commonly measured by the biomarkers cortisol (CORT) and salivary α-amylase (sAA). Thus, this hypothesis predicts that changes in stress biomarkers, such as CORT and sAA, are possible explanatory pathways mediating the positive effects of AE on neurocognitive health. In the present review article, we provide a summary of available studies examining the possibility that exercise-induced changes to stress biomarkers could partly account for exercise-related improvements in neurocognitive health. Our review indicates that despite the intuitive appeal of this hypothesis, there is insufficient evidence available to conclude that chronic and habitual AE affects neurocognitive health by altering stress biomarker pathways. The cross-sectional nature of the majority of reviewed studies highlights the need for well-controlled studies to adequately test this hypothesis.

Do trait-level emotion regulation strategies moderate associations between retrospective reports of childhood trauma and prospective changes in systemic inflammation?

Childhood trauma may confer risk for poorer adult health through changes in systemic inflammation. Emotion regulation may plausibly moderate associations between childhood trauma and adult psychological well-being, but it remains unclear whether moderation effects extend to differences in systemic inflammation. To examine whether childhood trauma and emotion regulation separately and interactively predict prospective changes in C-reactive protein (CRP) and interleukin-6 (IL-6) and whether biopsychosocial factors account for observed associations. Healthy midlife adults (N = 331) retrospectively reported on childhood trauma, current trait-level cognitive reappraisal and expressive suppression, and had their blood drawn. At baseline and then a median of 2.85 years later, 279 of the 331 participants had their blood drawn, body mass index calculated, and reported on health behaviours (smoking, sleep), psychological distress (perceived stress, depressive symptoms), and years of education. Childhood trauma predicted prospective increases in CRP (B = 0.004, p = 0.049), which were partially accounted for by differences in adiposity, psychological distress, and health behaviours. In contrast, cognitive reappraisal predicted prospective decreases in IL-6 (B = -0.007, p = 0.006), which were independent of biopsychosocial influences. Cognitive reappraisal further moderated the association between childhood trauma and prospective changes in IL-6 (B = -0.001, p = 0.012) such that childhood trauma predicted greater IL-6 increases but only among adults lower in cognitive reappraisal (B = 0.006, p = 0.007). There were no main or moderation effects of expressive suppression (ps > 0.05). Cognitive reappraisal may attenuate IL-6 changes over time and may moderate the prospective association between childhood trauma and systemic inflammation in midlife.

Beyond neighborhood disadvantage: Local resources, green space, pollution, and crime as residential community correlates of cardiovascular risk and brain morphology in midlife adults

OBJECTIVE

Residing in communities characterized by socioeconomic disadvantage confers risk for cardiometabolic diseases. Residing in disadvantaged communities may also confer risk for neurodegenerative brain changes via cardiometabolic pathways. This study tested whether features of communities - apart from conventional socioeconomic characteristics - relate not only to cardiometabolic risk, but also relative tissue reductions in the cerebral cortex and hippocampus.

METHODS

Participants were 699 adults aged 30-54 years (340 women; 22.5% non-white) whose addresses were geocoded to compute community indicators of socioeconomic disadvantage, as well as air and toxic chemical pollutant exposures, homicide rates, concentration of employment opportunities, land use (green space), and availability of supermarkets and local resources. Participants also underwent assessments of cortical and hippocampal volumes and cardiometabolic risk factors (adiposity, blood pressure, fasting glucose, and lipids).

RESULTS

Multilevel structural equation modeling demonstrated that cardiometabolic risk was associated with community disadvantage (β = 0.10, 95%CI = 0.01 to 0.18), as well as chemical pollution (β = 0.11, 95%CI = 0.02 to 0.19), homicide rates (β = 0.10, 95%CI = 0.01 to 0.18), employment opportunities (β = -0.16, 95%CI = -0.27 to -0.04), and green space (β = -0.12, 95%CI = -0.20 to -0.04). Moreover, cardiometabolic risk indirectly mediated the associations of several of these community features and brain tissue volumes. Some associations were nonlinear, and none were explained by participants' individual-level socioeconomic characteristics.

CONCLUSIONS

Features of communities other than conventional indicators of socioeconomic disadvantage may represent nonredundant correlates of cardiometabolic risk and brain tissue morphology in midlife.

The personality meta-trait of stability and carotid artery atherosclerosis

BACKGROUND

Several personality traits increase the risk for atherosclerotic cardiovascular disease. Because many of these traits are correlated, their associations with disease risk could reflect shared variance, rather than unique contributions of each trait. We examined a higher-order personality trait of Stability as related to preclinical atherosclerosis and tested whether any such relationship might be explained by correlated variation in cardiometabolic risk factors.

METHOD

Among 798 community volunteers, lower-order traits of Neuroticism, Agreeableness, and Conscientiousness were modeled as latent variables (from self- and informant ratings) and used to estimate the second-order factor, Stability. Cardiometabolic risk was similarly modeled from indicators of glycemic control, blood pressure, adiposity, and lipids. Carotid artery atherosclerosis was measured as intima-media thickness (IMT) by duplex ultrasonography.

RESULT

A structural equation model incorporating direct and indirect effects showed lower Stability associated with greater IMT, and this relationship was accounted for by the indirect pathway via cardiometabolic risk. Secondary analyses showed that: (1) Neuroticism, Agreeableness, and Conscientiousness were unrelated to IMT independent of Stability; and (2) Stability predicted variation in IMT when estimated from informant-, but not self-rated, traits.

CONCLUSION

Personality traits may associate with atherosclerotic burden through their shared, rather than unique, variance, as reflected in Stability.

Does an Online Positive Psychological Intervention Improve Positive Affect in Young Adults During the COVID-19 Pandemic?

Meta-analyses indicate that positive psychological interventions are effective at increasing positive affect, as well as reducing anxiety and depression; however, it is unclear how well these effects generalize during periods of high stress. Therefore, the current study tested whether a 2-week online positive psychological intervention delivered during the COVID-19 pandemic, a naturalistic stressor, (1) increased positive affect; (2) improved psychological well-being, optimism, life satisfaction, perceived social support, and loneliness; (3) and reduced negative affect in college students, a group known to have high pandemic distress. Participants (N = 250; 76.9% female) ages 18-45 were recruited from the University of Pittsburgh undergraduate subject pool between September and November of 2020. Participants were randomized to the online positive psychological intervention or active control condition and stratified by trait positive affect, sex, and year in college. Participants in both conditions completed one writing activity every other day for two consecutive weeks. Control participants documented their activities for that day (e.g., meals, going to gym). Intervention participants chose from six positive psychology activities. All outcome variables were assessed pre- and post-intervention by validated questionnaires. Across both conditions, positive and negative affect decreased from pre- to post-intervention. No other psychological factor differed by condition, time, or their interaction. The current null findings are in line with a more recent meta-analysis indicating that positive psychological interventions may have smaller effects on psychological well-being and depressive symptoms than was reported pre-pandemic. Study findings may suggest reduced efficacy of virtual positive psychological interventions under highly stressful circumstances.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42761-022-00148-z.

Multivariate Brain Activity while Viewing and Reappraising Affective Scenes Does Not Predict the Multiyear Progression of Preclinical Atherosclerosis in Otherwise Healthy Midlife Adults

Cognitive reappraisal is an emotion regulation strategy that is postulated to reduce risk for atherosclerotic cardiovascular disease (CVD), particularly the risk due to negative affect. At present, however, the brain systems and vascular pathways that may link reappraisal to CVD risk remain unclear. This study thus tested whether brain activity evoked by using reappraisal to reduce negative affect would predict the multiyear progression of a vascular marker of preclinical atherosclerosis and CVD risk: carotid artery intima-media thickness (CA-IMT). Participants were 176 otherwise healthy adults (50.6% women; aged 30-51 years) who completed a functional magnetic resonance imaging task involving the reappraisal of unpleasant scenes from the International Affective Picture System. Ultrasonography was used to compute CA-IMT at baseline and a median of 2.78 (interquartile range, 2.67 to 2.98) years later among 146 participants. As expected, reappraisal engaged brain systems implicated in emotion regulation. Reappraisal also reduced self-reported negative affect. On average, CA-IMT progressed over the follow-up period. However, multivariate and cross-validated machine-learning models demonstrated that brain activity during reappraisal failed to predict CA-IMT progression. Contrary to hypotheses, brain activity during cognitive reappraisal to reduce negative affect does not appear to forecast the progression of a vascular marker of CVD risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42761-021-00098-y.

Resting (Tonic) Blood Pressure Is Associated With Sensitivity to Imagined and Acute Experiences of Social Pain: Evidence From Three Studies

Social pain is a common experience that has potent implications for health. However, individuals differ in their sensitivity to social pain. Recent evidence suggests that sensitivity to social pain varies according to a biological factor that modulates sensitivity to physical pain: resting (tonic) blood pressure. The current studies extended this evidence by testing whether blood pressure relates to sensitivity to imagined (Study 1: N = 762, 51% female adults) and acute (Study 2, preregistered: N = 204, 57% female adults) experiences of social pain and whether associations extend to general emotional responding (Studies 1-3; Study 3: N = 162, 59% female adults). In line with prior evidence, results showed that higher resting blood pressure was associated with lower sensitivity to social pain. Moreover, associations regarding blood pressure and sensitivity to social pain did not appear to be explained by individual differences in general emotional responding. Findings appear to be compatible with the interpretation that social and physical pain share similar cardiovascular correlates and may be modulated by convergent interoceptive pathways.

Integrating multiple brain imaging modalities does not boost prediction of subclinical atherosclerosis in midlife adults

•

Brain measures from MRI do not improve Framingham Risk Score prediction of CA-IMT.

•

Prediction stacking is a flexible approach to determine added predictive utility.

•

Multimodal stacking can be applied to individual difference factors.

Background

Human neuroimaging evidence suggests that cardiovascular disease (CVD) risk may relate to functional and structural features of the brain. The present study tested whether combining functional and structural (multimodal) brain measures, derived from magnetic resonance imaging (MRI), would yield a multivariate brain biomarker that reliably predicts a subclinical marker of CVD risk, carotid-artery intima-media thickness (CA-IMT).

Methods

Neuroimaging, cardiovascular, and demographic data were assessed in 324 midlife and otherwise healthy adults who were free of (a) clinical CVD and (b) use of medications for chronic illnesses (aged 30–51 years, 49% female). We implemented a prediction stacking algorithm that combined multimodal brain imaging measures and Framingham Risk Scores (FRS) to predict CA-IMT. We included imaging measures that could be easily obtained in clinical settings: resting state functional connectivity and structural morphology measures from T1-weighted images.

Results

Our models reliably predicted CA-IMT using FRS, as well as for several individual MRI measures; however, none of the individual MRI measures outperformed FRS. Moreover, stacking functional and structural brain measures with FRS did not boost prediction accuracy above that of FRS alone.

Conclusions

Combining multimodal functional and structural brain measures through a stacking algorithm does not appear to yield a reliable brain biomarker of subclinical CVD, as reflected by CA-IMT.

Cortisol activity partially accounts for a relationship between community socioeconomic position and atherosclerosis

Compared to others, individuals living in communities of socioeconomic disadvantage experience more atherosclerotic cardiovascular disease (CVD) and a greater extent of preclinical atherosclerosis. Although the mechanisms underlying these associations remain unclear, it is widely hypothesized that alterations in normative cortisol release from the Hypothalamic Pituitary Adrenal (HPA) axis may play a role in linking lower community socioeconomic position (C-SEP) to CVD risk. The current study examined this hypothesis in relation to a marker of preclinical atherosclerosis among 488 healthy midlife adults (30-54 years, Mean age= 43, 52% Female, 81% White). All participants were employed and without clinical CVD. C-SEP was estimated from census tract data, and atherosclerosis was measured as intima-medial thickness of the carotid arteries (cIMT) by duplex ultrasonography. Four indicators of HPA activity [cortisol at awakening and the cortisol awakening response (CAR), rate of diurnal decline in cortisol (diurnal slope), and total output expressed as area under the curve (AUC)] were derived from salivary cortisol measurements obtained from 5 samples on each of 3 working days. Path analyses were used to examine associations of C-SEP with cIMT and HPA activity and to test whether individual differences in HPA activity could account for any association of C-SEP with cIMT using bootstrapping (5000 iterations). All models were adjusted for age, sex, race, and composite measures of both individual-level socioeconomic position (income, education, occupation), and cardiometabolic risk (systolic and diastolic blood pressure, waist circumference, fasting lipids and glucose). Lower C-SEP was related to both greater cIMT (b = -0.004, p = .021) and a flatter diurnal slope of cortisol (b = -0.001, p = .039). An indirect effect showed attenuated diurnal slope to partially mediate the relationship between C-SEP and cIMT (95% CI = -0.0018 to -0.0001), and a residual direct effect of C-SEP on cIMT remained significant (95% CI = -0.0097 to -0.004). These results suggest that low C-SEP associations with preclinical atherosclerosis may be due in part to correlated variation in adrenocortical activity.

Affective brain patterns as multivariate neural correlates of cardiovascular disease risk

This study tested whether brain activity patterns evoked by affective stimuli relate to individual differences in an indicator of pre-clinical atherosclerosis: carotid artery intima-media thickness (CA-IMT). Adults (aged 30-54 years) completed functional magnetic resonance imaging (fMRI) tasks that involved viewing three sets of affective stimuli. Two sets included facial expressions of emotion, and one set included neutral and unpleasant images from the International Affective Picture System (IAPS). Cross-validated, multivariate and machine learning models showed that individual differences in CA-IMT were partially predicted by brain activity patterns evoked by unpleasant IAPS images, even after accounting for age, sex and known cardiovascular disease risk factors. CA-IMT was also predicted by brain activity patterns evoked by angry and fearful faces from one of the two stimulus sets of facial expressions, but this predictive association did not persist after accounting for known cardiovascular risk factors. The reliability (internal consistency) of brain activity patterns evoked by affective stimuli may have constrained their prediction of CA-IMT. Distributed brain activity patterns could comprise affective neural correlates of pre-clinical atherosclerosis; however, the interpretation of such correlates may depend on their psychometric properties, as well as the influence of other cardiovascular risk factors and specific affective cues.

Cortical thickness and resting-state cardiac function across the lifespan: A cross-sectional pooled mega-analysis

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.

Long-Term Ambient Air Pollution Exposures and Circulating and Stimulated Inflammatory Mediators in a Cohort of Midlife Adults

BACKGROUND

Chronic exposure to air pollution may prime the immune system to be reactive, increasing inflammatory responses to immune stimulation and providing a pathway to increased risk for inflammatory diseases, including asthma and cardiovascular disease. Although long-term exposure to ambient air pollution has been associated with increased circulating markers of inflammation, it is unknown whether it also relates to the magnitude of inflammatory response.

OBJECTIVES

The aim of this study was to examine associations between chronic ambient pollution exposures and circulating and stimulated levels of inflammatory mediators in a cohort of healthy adults.

METHODS

Circulating interleukin (IL)-6, C-reactive protein (CRP) (n=392), and lipopolysaccharide stimulated production of IL-1β, IL-6, and tumor necrosis factor (TNF)-α (n=379) were measured in the Adult Health and Behavior II cohort. Fine particulate matter [particulate matter with aerodynamic diameter less than or equal to 2.5 μm (PM2.5)] and constituents [black carbon (BC), and lead (Pb), manganese (Mn), zinc (Zn), and iron (Fe)] were estimated for each residential address using hybrid dispersion land use regression models. Associations between pollutant exposures and inflammatory measures were examined using linear regression; models were adjusted for age, sex, race, education, smoking, body mass index, and month of blood draw.

RESULTS

There were no significant correlations between circulating and stimulated measures of inflammation. Significant positive associations were found between exposure to PM2.5 and BC with stimulated production of IL-6, IL-1β, and TNF-α. Pb, Mn, Fe, and Zn exposures were positively associated with stimulated production of IL-1β and TNF-α. No pollutants were associated with circulating IL-6 or CRP levels.

DISCUSSION

Exposure to PM2.5, BC, Pb, Mn, Fe, and Zn was associated with increased production of inflammatory mediators by stimulated immune cells. In contrast, pollutant exposure was not related to circulating markers of inflammation. These results suggest that chronic exposure to some pollutants may prime immune cells to mount larger inflammatory responses, possibly contributing to increased risk for inflammatory disease. https://doi.org/10.1289/EHP7089.

Dual impedance cardiography: An inexpensive and reliable method to assess arterial stiffness

Pulse wave velocity (PWV) is a common measure of arterial stiffness. Non-invasive methods to measure PWV are widely used in biomedical studies of aging and cardiovascular disease, but they are rarely used in psychophysiology. Barriers to wider use include the prohibitive costs of specialized equipment and need for trained technicians (e.g., ultrasonographers). Here, we describe an impedance cardiography method to measure PWV. By this method, impedance signals are dually collected from the thorax and calf. Combined with ensemble averaging of vascular signals, this dual impedance cardiography (d-ICG) method allows for the measurement of aortic flow onset and the arrival time of peripheral pulse waveforms to compute PWV. In a community sample of adults (aged 19-78 years), PWV measured with d-ICG exhibited a strong positive correlation with age. Moreover, age-specific mean PWV values were within the normative reference intervals established by large scale studies using other techniques. PWV derived from d-ICG exhibited high test-retest reliability across several days, as well as excellent inter-rater reliability. Last, PWV exhibited expected associations with known cardiovascular disease risk factors and indicators of autonomic cardiovascular control. d-ICG is an inexpensive and reliable method to assess arterial stiffness.

Is stressor-evoked cardiovascular reactivity a pathway linking positive and negative emotionality to preclinical cardiovascular disease risk?

Stressor-evoked cardiovascular reactivity, trait positive emotionality, and negative emotionality are all associated with cardiovascular disease. It is unknown, however, whether cardiovascular reactivity may constitute a pathway by which trait positive or negative emotionality relates to disease risk. Accordingly, this study modeled the cross-sectional relationships between trait positive and negative emotionality, stressor-evoked cardiovascular reactivity, and severity of a subclinical vascular marker of cardiovascular risk, carotid artery intima-media thickness (CA-IMT). The sample consisted of healthy, midlife adults free from clinical cardiovascular disease (N = 286; ages 30-54; 50% female). Trait positive and negative emotionality were measured by three questionnaires. Heart rate and blood pressure reactivity were assessed across three stressor tasks. CA-IMT was assessed by ultrasonography. Latent factors of positive and negative emotionality, blood pressure reactivity, heart rate reactivity, and CA-IMT were created using structural equation modeling. Greater negative emotionality was marginally associated with more CA-IMT (β = .21; p = .049), but lower blood pressure reactivity (β = -.19; p = .03). However, heightened blood pressure (β = .21; p = .03), but not heart rate reactivity (β = -.05; p = .75), associated with greater CA-IMT. Positive emotionality was uncorrelated with cardiovascular reactivity (blood pressure: β = -.04; p = .61; heart rate: β = .16; p = .11) and CA-IMT (β = .16; p = .07). Although trait negative emotionality associates with a known marker of cardiovascular disease risk, independent of positive emotionality, it is unlikely to occur via a stressor-evoked cardiovascular reactivity pathway.

Adiposity covaries with signatures of asymmetric feedback learning during adaptive decisions

Unhealthy weight gain relates, in part, to how people make decisions based on prior experience. Here we conducted post hoc analysis on an archival data set to evaluate whether individual differences in adiposity, an anthropometric construct encompassing a spectrum of body types, from lean to obese, associate with signatures of asymmetric feedback learning during value-based decision-making. In a sample of neurologically healthy adults (N = 433), ventral striatal responses to rewards, measured using fMRI, were not directly associated with adiposity, but rather moderated its relationship with feedback-driven learning in the Iowa gambling task, tested outside the scanner. Using a biologically inspired model of basal ganglia-dependent decision processes, we found this moderating effect of reward reactivity to be explained by an asymmetrical use of feedback to drive learning; that is, with more plasticity for gains than for losses, stronger reward reactivity leads to decisions that minimize exploration for maximizing long-term outcomes. Follow-up analysis confirmed that individual differences in adiposity correlated with signatures of asymmetric use of feedback cues during learning, suggesting that reward reactivity may especially relate to adiposity, and possibly obesity risk, when gains impact future decisions more than losses.

Relationship between Dispositional Mindfulness, Psychological Health, and Diet Quality among Healthy Midlife Adults

Mindfulness, a practice of non-judgmental awareness of present experience, has been associated with reduced eating psychopathology and emotion-driven eating. However, it remains unclear whether mindfulness relates to diet quality. Thus, the purpose of this study was to examine whether dispositional mindfulness is associated with diet quality and to explore psychological factors relating dispositional mindfulness to diet quality. Community-dwelling adults (N = 406; M_age = 43.19, SD = 7.26; M_{body mass index [BMI]} = 27.08, SD = 5.28; 52% female) completed ratings of dispositional mindfulness, depressive symptoms, perceived stress, positive affect (PA), and negative affect (NA). Dietary intake was assessed using the Block Food Frequency Questionnaire, from which the 2015 Healthy Eating Index was derived. Analyses were conducted using the "lavaan" package in R with bias-corrected bootstrapped confidence intervals (BootCI). Age, sex, race, education, and BMI were entered as covariates in all models. Higher dispositional mindfulness was associated with higher diet quality (β = 0.11, p = 0.03), and this effect was mediated through lower depressive symptoms (indirect effect β = 0.06, p = 0.02, BootCI = 0.104-1.42, p = 0.03). Dispositional mindfulness was negatively correlated with perceived stress (β = -0.31, p < 0.01) and NA (β = -0.43, p < 0.01), as well as positively correlated with PA (β = -0.26, p < 0.01). However, these factors were unrelated to diet quality. These cross-sectional data provide initial evidence that dispositional mindfulness relates to diet quality among midlife adults, an effect that may be explained in part by less depressive symptomatology. Given that lifestyle behaviors in midlife are leading determinants of risk for cardiovascular disease and neurocognitive impairment in late life, interventions to enhance mindfulness in midlife may mitigate disease risk. Additional research assessing the impact of mindfulness interventions on diet quality are warranted.

The effects of omega-3 fatty acids on neuropsychological functioning and brain morphology in mid-life adults: a randomized clinical trial

BACKGROUND

The diet of most adults is low in fish and, therefore, provides limited quantities of the long-chain, omega-3 fatty acids (LCn-3FAs), eicosapentaenoic and docosahexaenoic acids (EPA, DHA). Since these compounds serve important roles in the brain, we sought to determine if healthy adults with low-LCn-3FA consumption would exhibit improvements in neuropsychological performance and parallel changes in brain morphology following repletion through fish oil supplementation.

METHODS

In a randomized, controlled trial, 271 mid-life adults (30-54 years of age, 118 men, 153 women) consuming ⩽300 mg/day of LCn-3FAs received 18 weeks of supplementation with fish oil capsules (1400 mg/day of EPA and DHA) or matching placebo. All participants completed a neuropsychological test battery examining four cognitive domains: psychomotor speed, executive function, learning/episodic memory, and fluid intelligence. A subset of 122 underwent neuroimaging before and after supplementation to measure whole-brain and subcortical tissue volumes.

RESULTS

Capsule adherence was over 95%, participant blinding was verified, and red blood cell EPA and DHA levels increased as expected. Supplementation did not affect performance in any of the four cognitive domains. Exploratory analyses revealed that, compared to placebo, fish oil supplementation improved executive function in participants with low-baseline DHA levels. No changes were observed in any indicator of brain morphology.

CONCLUSIONS

In healthy mid-life adults reporting low-dietary intake, supplementation with LCn-3FAs in moderate dose for moderate duration did not affect neuropsychological performance or brain morphology. Whether salutary effects occur in individuals with particularly low-DHA exposure requires further study.

Cerebrovascular function in hypertension: Does high blood pressure make you old?

The majority of individuals over an age of 60 have hypertension. Elevated blood pressure and older age are associated with very similar changes in brain structure and function. We review the parallel brain changes associated with increasing age and blood pressure. This review focuses on joint associations of aging and elevated blood pressure with neuropsychological function, regional cerebral blood flow responses to cognitive and metabolic challenges, white matter disruptions, grey matter volume, cortical thinning, and neurovascular coupling. Treatment of hypertension ameliorates many of these changes but fails to reverse them. Treatment of hypertension itself appears more successful with better initial brain function. We show evidence that sympathetic and renal influences known to increase blood pressure also impact brain integrity. Possible central mechanisms contributing to the course of hypertension and aging are then suggested. An emphasis is placed on psychologically relevant factors: stress, cardiovascular reactions to stress, and diet/obesity. The contribution of some of these factors to biological aging remains unclear and may provide a starting point for defining the independent and interacting effects of aging and increasing blood pressure on the brain.

Does well-being associate with stress physiology? A systematic review and meta-analysis

OBJECTIVE

The current meta-analysis tested whether trait indicators of well-being associate with stressor-evoked physiological reactivity and recovery in healthy adults.

METHOD

Medline, PsycINFO, and PubMed were used to identify relevant articles. Articles were included if they (a) measured cardiovascular or neuroendocrine (but not immune) physiology during or after an acute laboratory stress paradigm (b) measured indicators of hedonic well-being, eudaimonic well-being, or optimism, and (c) included healthy adult participants. Laboratory stress tasks included frustrating cognitive tasks, emotional recall tasks, and tasks involving social evaluation. Physiological variables were aggregated across cardiac (heart rate and cardiac output), hemodynamic (mean arterial pressure, systolic blood pressure, and diastolic blood pressure), HPA (cortisol), and autonomic (high frequency heart rate variability, skin conductance, and catecholamines) markers. Twenty-seven studies were included (n = 3,390; 54.6% women). Effect sizes and confidence intervals were estimated using a random-effects model with pooled variance.

RESULTS

Contrary to expectations, optimism was associated with greater cardiac reactivity to cognitive stressors but did not associate with stress recovery. By contrast, hedonic well-being was associated with enhanced hemodynamic recovery following laboratory stressors but was not associated with stress reactivity.

CONCLUSIONS

Hedonic well-being, but not optimism, could potentially buffer against the effects of psychological stressors on physiological responding by relating to more complete recovery. Identifying the mechanisms contributing to these patterns of association may provide insights into psychological interventions for well-being and stress-related disease risk. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Host in the machine: A neurobiological perspective on psychological stress and cardiovascular disease

Psychological stress still attracts scientific, clinical, and public interest because of its suspected connection to health, particularly cardiovascular health. Psychological stress is thought to arise from appraisal processes that imbue events and contexts with personal significance and threat-related meaning. These appraisal processes are also thought to be instantiated in brain systems that generate and control peripheral physiological stress reactions through visceral motor (brain-to-body) and visceral sensory (body-to-brain) mechanisms. In the short term, physiological stress reactions may enable coping and adaptive action. Among some individuals, however, the patterning of these reactions may predict or contribute to pathology in multiple organ systems, including the cardiovascular system. At present, however, we lack a precise understanding of the brain systems and visceral control processes that link psychological appraisals to patterns of stress physiology and physical health. This understanding is important: A mechanistic account of how the brain connects stressful experiences to bodily changes and health could help refine biomarkers of risk and targets for cardiovascular disease prevention and intervention. We review research contributing to this understanding, focusing on the neurobiology of cardiovascular stress reactivity and cardiovascular health. We suggest that a dysregulation of visceral motor and visceral sensory processes during stressful experiences may confer risk for poor cardiovascular health among vulnerable individuals. We further describe a need for new interpretive frameworks and markers of this brain-body dysregulation in cardiovascular behavioral medicine. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

NEIGHBORHOOD SOCIOECONOMIC STATUS AND GRAY MATTER VOLUME IN OLDER ADULTS

Lower neighborhood socioeconomic status (nSES) is associated with poorer cognitive function; underlying neural correlates are unknown. Cross-sectional associations of nSES (six census-derived measures of income, education, and occupation) and gray matter volume (GMV) of eight memory-related regions (hippocampus, middle frontal gyrus, amygdala, insula, parahippocampal gyrus, anterior, middle, and posterior cingulum) were examined in 264 community-dwelling older adults (mean age=83, 56.82% female, 39.02% black). In linear mixed effects models adjusted for total brain atrophy and accounting for geographic clustering, higher nSES was associated with greater GMV of the left hippocampus, left posterior cingulum, and bilateral insula, middle frontal, and parahippocampal gyri. nSES remained associated with GMV of the right insula (β= -32.26, p=0.026, 95%CI: -60.66, -3.86) after adjusting for individual level age, gender, race, income, and education. The nSES and cognitive function association may not be due to gray matter volume differences; other behavioral and biological mediators should be explored.

Ventromedial prefrontal cortex connectivity during and after psychological stress in women

The ventromedial prefrontal cortex (vmPFC) integrates sensory, affective, memory-related, and social information from diverse brain systems to coordinate behavioral and peripheral physiological responses according to contextual demands that are appraised as stressful. However, the functionality of the vmPFC during stressful experiences is not fully understood. Among 40 female participants, the present study evaluated (a) functional connectivity of the vmPFC during exposure to and recovery following an acute psychological stressor, (b) associations among vmPFC functional connectivity, heart rate, and subjective reports of stress across individuals, and (c) whether patterns of vmPFC functional connectivity were associated with distributed brain networks. Results showed that psychological stress increased vmPFC functional connectivity with individual brain areas implicated in stressor processing (e.g., insula, amygdala, anterior cingulate cortex) and decreased connectivity with the posterior cingulate cortex and thalamus. There were no statistical differences in vmPFC connectivity to individual brain areas during recovery, as compared with baseline. Spatial similarity analyses revealed stressor-evoked increased connectivity of the vmPFC with the so-called dorsal attention, ventral attention, and frontoparietal networks, as well as decreased connectivity with the default mode network. During recovery, vmPFC connectivity increased with the frontoparietal network. Finally, individual differences in heart rate and perceived stress were associated with vmPFC connectivity to the ventral attention, frontoparietal, and default mode networks. Psychological stress appears to alter network-level functional connectivity of the vmPFC in a manner that further relates to individual differences in stressor-evoked cardiovascular and affective reactivity.

Socioeconomic disparities of depressive symptoms and cytokines in hepatocellular carcinoma

OBJECTIVE

To examine the associations among socioeconomic factors, depressive symptoms, and cytokines in patients diagnosed with hepatocellular carcinoma (HCC).

METHODS

A total of 266 patients diagnosed with HCC were administered a battery of questionnaires including a sociodemographic questionnaire and the Center for Epidemiologic StudiesDepression (CES-D) scale. Blood samples were collected to assess serum levels of cytokines using Luminex. Descriptive statistics, Mann-Whitney U, Kruskal-Wallis, linear regression, and Bonferroni corrections were performed to test the hypotheses.

RESULTS

Of the 266 patients, 24% reported depressive symptoms in the clinical range (CES-D ≥ 22). Females had higher CES-D score than males (Mann-Whitney U = 7135, P = .014, P_adj  = .028). Being unemployed/disabled (Kruskal-Wallis = 14.732, P = .001, P_adj  = .005) was found to be associated with higher depressive symptoms in males but not in females. Serum level of IL-2 (Kruskal-Wallis = 17.261, P = .001, P_adj  = .005) were found to be negatively associated with education level. Gender (β = .177, P = .035), income (β = -.252, P = .004), whether the patient's income met their basic needs (β = .180, P = .035), and IL-1β (β = -.165, P = .045) independently predicted depressive symptoms and together explained 19.4% of variance associated with depressive symptoms.

CONCLUSIONS

Sociodemographic and socioeconomic factors were predictive of inflammation and depressive symptoms. Recommendations include the development of gender-targeted interventions for patients diagnosed with HCC who have low socioeconomic status (SES) and may suffer from depressive symptoms.

The prospective relationship between prehypertension, race, and whole-brain white matter microstructure

Compared to whites, blacks develop hypertension earlier in life, progress from prehypertension to hypertension at an accelerated rate, and exhibit greater hypertension mediated organ damage (e.g., kidney disease, stroke). In this paper we tested whether the longitudinal associations between elevated systolic blood pressure and disruption of brain white matter structural integrity differs as a function of race. A community sample of 100 middle-aged adults with prehypertension underwent diffusion imaging to quantify indirect metrics of white matter structural integrity, including fractional anisotropy. Blood pressure and diffusion imaging measurements were collected at baseline and at a two-year follow-up. Regression analyses showed that higher systolic blood pressure at baseline was associated with a decrease in fractional anisotropy over two years in blacks only (β = −0.51 [95% C.I. = −0.85, −0.16], t = −2.93, p = .004, ΔR² = .09). These findings suggest that blacks are more susceptible to the impact of systolic prehypertension on white matter structural integrity.

Should heart rate variability be "corrected" for heart rate? Biological, quantitative, and interpretive considerations

Metrics of heart period variability are widely used in the behavioral and biomedical sciences, although somewhat confusingly labeled as heart rate variability (HRV). Despite their wide use, HRV metrics are usually analyzed and interpreted without reference to prevailing levels of cardiac chronotropic state (i.e., mean heart rate or mean heart period). This isolated treatment of HRV metrics is nontrivial. All HRV metrics routinely used in the literature exhibit a known and positive relationship with the mean duration of the interval between two beats (heart period): as the heart period increases, so does its variability. This raises the question of whether HRV metrics should be "corrected" for the mean heart period (or its inverse, the heart rate). Here, we outline biological, quantitative, and interpretive issues engendered by this question. We provide arguments that HRV is neither uniformly nor simply a surrogate for heart period. We also identify knowledge gaps that remain to be satisfactorily addressed with respect to assumptions underlying existing HRV correction approaches. In doing so, we aim to stimulate further progress toward the rigorous use and disciplined interpretation of HRV. We close with provisional guidance on HRV reporting that acknowledges the complex interplay between the mean and variability of the heart period.

Neural Mechanisms Linking Emotion with Cardiovascular Disease

PURPOSE OF REVIEW

The present review discusses brain circuits that are engaged by negative emotions and possibly linked to cardiovascular disease risk. It describes recent human brain imaging studies that relate activity in these brain circuits to emotional processes, peripheral physiology, preclinical pathophysiology, as well as clinical outcomes.

RECENT FINDINGS

Negative emotions and the regulation of negative emotions reliably engage several brain regions that cross-sectional and longitudinal brain imaging studies have associated with CVD risk markers and outcomes. These brain regions include the amygdala, anterior cingulate cortex, medial prefrontal cortex, and insula. Other studies have applied advanced statistical techniques to characterize multivariate patterns of brain activity and brain connectivity that associate with negative emotion and CVD-relevant peripheral physiology. Brain imaging studies on emotion and cardiovascular disease risk are expanding our understanding of the brain-body bases of psychosocial and behavioral risk for cardiovascular disease.

Associations of immunometabolic risk factors with symptoms of depression and anxiety: The role of cardiac vagal activity

OBJECTIVES

This study examined 1) the cross-sectional relationships between symptoms of depression/anxiety and immunometabolic risk factors, and 2) whether these relationships might be explained in part by cardiac vagal activity.

METHODS

Data were drawn from the Adult Health and Behavior registries (n = 1785), comprised of community dwelling adults (52.8% women, aged 30-54). Depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale (CES-D) and the Beck Depression Inventory-II (BDI-II), and anxious symptoms with the Trait Anxiety scale of the State-Trait Anxiety Inventory (STAI-T). Immunometabolic risk factors included fasting levels of triglycerides, high-density lipoproteins, glucose, and insulin, as well as blood pressure, waist circumference, body mass index, C-reactive protein, and interleukin-6. Measures of cardiac autonomic activity were high- and low-frequency indicators of heart rate variability (HRV), standard deviation of normal-to-normal R-R intervals, and the mean of absolute and successive differences in R-R intervals.

RESULTS

Higher BDI-II scores, in contrast to CES-D and STAI-T scores, were associated with increased immunometabolic risk and decreased HRV, especially HRV likely reflecting cardiac vagal activity. Decreased HRV was also associated with increased immunometabolic risk. Structural equation models indicated that BDI-II scores may relate to immunometabolic risk via cardiac vagal activity (indirect effect: β = .012, p = .046) or to vagal activity via immunometabolic risk (indirect effect: β = -.015, p = .021).

CONCLUSIONS

Depressive symptoms, as measured by the BDI-II, but not anxious symptoms, were related to elevated levels of immunometabolic risk factors and low cardiac vagal activity. The latter may exhibit bidirectional influences on one another in a meditational framework. Future longitudinal, intervention, an nonhuman animal work is needed to elucidate the precise and mechanistic pathways linking depressive symptoms to immune, metabolic, and autonomic parameters of physiology that predispose to cardiovascular disease risk.

Increased stressor-evoked cardiovascular reactivity is associated with reduced amygdala and hippocampus volume

Exaggerated cardiovascular reactivity to acute psychological stress is associated with an increased risk of developing cardiovascular disease. The amygdala and hippocampus have been implicated in centrally mediating stressor-evoked cardiovascular reactivity. However, little is known about the associations of amygdala and hippocampus morphology with stressor-evoked cardiovascular reactivity. Forty (M_age = 19.05, SD = 0.22 years) healthy young women completed two separate testing sessions. Session 1 assessed multiple parameters of cardiovascular physiology at rest and during a validated psychological stress task (Paced Auditory Serial Addition Test), using electrocardiography, Doppler echocardiography, and blood pressure monitoring. In Session 2, 1 year later, structural MRI was conducted. Brain structural volumes were computed using automated segmentation methods. Regression analyses, following Benjamini-Hochberg correction, showed that greater heart rate and cardiac output reactivity were associated with reduced amygdala and hippocampus gray matter volume. Systolic blood pressure reactivity was associated with reduced hippocampus volume. In contrast, no associations between diastolic blood pressure, mean arterial blood pressure, stroke volume, or total peripheral resistance reactivity with amygdala or hippocampus volumes were apparent. Comparison analyses examining insula volume found no significant associations. Some indicators of greater stressor-evoked cardiovascular reactivity associate with reduced amygdala and hippocampus gray matter volume, but the mechanisms of this association warrant further study.

Perceived discrimination and cardiovascular health disparities: a multisystem review and health neuroscience perspective

There are distinct racial disparities in cardiovascular disease (CVD) risk, with Black individuals at much greater risk than White individuals. Although many factors contribute to these disparities, recent attention has focused on the role of discrimination as a stress-related factor that contributes to racial disparities in CVD. As such, it is important to understand the mechanisms by which discrimination might affect CVD. Recent studies have examined these mechanisms by focusing on neurobiological mediators of CVD risk. Given this increase in studies, a systematic review of perceived discrimination and neurobiological mediators of CVD risk is warranted. Our review uses a multisystem approach to review studies on the relationship between perceived discrimination and (1) cardiovascular responses to stress, (2) hypothalamic-pituitary-adrenocortical axis function, and (3) the immune system, as well as (4) the brain systems thought to regulate these parameters of peripheral physiology. In addition to summarizing existing evidence, our review integrates these findings into a conceptual model describing multidirectional pathways linking perceived discrimination with a CVD risk.

Functional neuroanatomy of peripheral inflammatory physiology: A meta-analysis of human neuroimaging studies

Communication between the brain and peripheral mediators of systemic inflammation is implicated in numerous psychological, behavioral, and physiological processes. Functional neuroimaging studies have identified brain regions that associate with peripheral inflammation in humans, yet there are open questions about the consistency, specificity, and network characteristics of these findings. The present systematic review provides a meta-analysis to address these questions. Multilevel kernel density analysis of 24 studies (37 statistical maps; 264 coordinates; 457 participants) revealed consistent effects in the amygdala, hippocampus, hypothalamus, striatum, insula, midbrain, and brainstem, as well as prefrontal and temporal cortices. Effects in some regions were specific to particular study designs and tasks. Spatial pattern analysis revealed significant overlap of reported effects with limbic, default mode, ventral attention, and corticostriatal networks, and co-activation analyses revealed functional ensembles encompassing the prefrontal cortex, insula, and midbrain/brainstem. Together, these results characterize brain regions and networks associated with peripheral inflammation in humans, and they provide a functional neuroanatomical reference point for future neuroimaging studies on brain-body interactions.

Socioeconomic Position and Age-Related Disparities in Regional Cerebral Blood Flow Within the Prefrontal Cortex

OBJECTIVE

Socioeconomic position (SEP) is associated with cerebrovascular health and brain function, particularly in prefrontal cortex and medial temporal lobe regions that exhibit plasticity across the life course. However, it is unknown whether SEP associates with resting cerebral blood flow (CBF), an indicator of baseline brain function, in these regions in midlife, and whether the association is (a) period specific, with independent associations for childhood and adulthood SEP, or driven by life course SEP, and (b) explained by a persistent disparity, widening disparity, or the leveling of disparities with age.

METHODS

To address these questions, we analyzed cerebral perfusion derived by magnetic resonance imaging in a cross-sectional study of healthy adults (N = 443) who reported on childhood and adult SEP. Main effects were examined as an index of persistent disparity and age by SEP interactions as reflecting widening or leveling disparities.

RESULTS

Stable high SEP across the lifespan was associated with higher global CBF and regional CBF (rCBF) in inferior frontal gyrus. However, childhood SEP was associated with rCBF in middle frontal gyrus, as moderated by age (β = 0.04, p = .035): rCBF was inversely associated with age only for those whose parents had a high school education or below. No associations were observed for the hippocampus or amygdala.

CONCLUSIONS

Life course SEP associations with rCBF in prefrontal cortex are suggestive of persistent disparities, whereas the age by childhood SEP interaction suggests that childhood disadvantage relates to a widening disparity, independent of global differences. These differential patterns in midlife may relate to disparities in later-life cerebrovascular and neurocognitive outcomes.

A population neuroscience approach to the study of cerebral small vessel disease in midlife and late life: an invited review

Aging in later life engenders numerous changes to the cerebral microvasculature. Such changes can remain clinically silent but are associated with greater risk for negative health outcomes over time. Knowledge is limited about the pathogenesis, prevention, and treatment of potentially detrimental changes in the cerebral microvasculature that occur with advancing age. In this review, we summarize literature on aging of the cerebral microvasculature, and we propose a conceptual framework to fill existing research gaps and advance future work on this heterogeneous phenomenon. We propose that the major gaps in this area are attributable to an incomplete characterization of cerebrovascular pathology, the populations being studied, and the temporality of exposure to risk factors. Specifically, currently available measures of age-related cerebral microvasculature changes are indirect, primarily related to parenchymal damage rather than direct quantification of small vessel damage, limiting the understanding of cerebral small vessel disease (cSVD) itself. Moreover, studies seldom account for variability in the health-related conditions or interactions with risk factors, which are likely determinants of cSVD pathogenesis. Finally, study designs are predominantly cross-sectional and/or have relied on single time point measures, leaving no clear evidence of time trajectories of risk factors or of change in cerebral microvasculature. We argue that more resources should be invested in 1) developing methodological approaches and basic science models to better understand the pathogenic and etiological nature of age-related brain microvascular diseases and 2) implementing state-of-the-science population study designs that account for the temporal evolution of cerebral microvascular changes in diverse populations across the lifespan.

Community Socioeconomic Disadvantage in Midlife Relates to Cortical Morphology via Neuroendocrine and Cardiometabolic Pathways

Residing in communities of socioeconomic disadvantage confers risk for chronic diseases and cognitive aging, as well as risk for biological factors that negatively affect brain morphology. The present study tested whether community disadvantage negatively associates with brain morphology via 2 biological factors encompassing cardiometabolic disease risk and neuroendocrine function. Participants were 448 midlife adults aged 30-54 years (236 women) who underwent structural neuroimaging to assess cortical and subcortical brain tissue morphology. Community disadvantage was indexed by US Census data geocoded to participants' residential addresses. Cardiometabolic risk was indexed by measurements of adiposity, blood pressure, glucose, insulin, and lipids. Neuroendocrine function was indexed from salivary cortisol measurements taken over 3 days, from which we computed the cortisol awakening response, area-under-the-curve, and diurnal cortisol decline. Community disadvantage was associated with reduced cortical tissue volume, cortical surface area, and cortical thickness, but not subcortical morphology. Moreover, increased cardiometabolic risk and a flatter (dysregulated) diurnal cortisol decline mediated the associations of community disadvantage and cortical gray matter volume. These effects were independent of age, sex, and individual-level socioeconomic position. The adverse risks of residing in a disadvantaged community may extend to the cerebral cortex via cardiometabolic and neuroendocrine pathways.

Childhood maltreatment moderates the effect of combat exposure on cingulum structural integrity

Limbic white matter pathways link emotion, cognition, and behavior and are potentially malleable to the influences of traumatic events throughout development. However, the impact of interactions between childhood and later life trauma on limbic white matter pathways has yet to be examined. Here, we examined whether childhood maltreatment moderated the effect of combat exposure on diffusion tensor imaging measures within a sample of military veterans (N = 28). We examined five limbic tracts of interest: two components of the cingulum (cingulum, cingulate gyrus, and cingulum hippocampus [CGH]), the uncinate fasciculus, the fornix/stria terminalis, and the anterior limb of the internal capsule. Using effect sizes, clinically meaningful moderator effects were found only within the CGH. Greater combat exposure was associated with decreased CGH fractional anisotropy (overall structural integrity) and increased CGH radial diffusivity (perpendicular water diffusivity) among individuals with more severe childhood maltreatment. Our findings provide preliminary evidence of the moderating effect of childhood maltreatment on the relationship between combat exposure and CGH structural integrity. These differences in CGH structural integrity could have maladaptive implications for emotion and memory, as well as provide a potential mechanism by which childhood maltreatment induces vulnerability to later life trauma exposure.

Brain Regional Blood Flow and Working Memory Performance Predict Change in Blood Pressure Over 2 Years

Hypertension is a presumptive risk factor for premature cognitive decline. However, lowering blood pressure (BP) does not uniformly reverse cognitive decline, suggesting that high BP per se may not cause cognitive decline. We hypothesized that essential hypertension has initial effects on the brain that, over time, manifest as cognitive dysfunction in conjunction with both brain vascular abnormalities and systemic BP elevation. Accordingly, we tested whether neuropsychological function and brain blood flow responses to cognitive challenges among prehypertensive individuals would predict subsequent progression of BP. Midlife adults (n=154; mean age, 49; 45% men) with prehypertensive BP underwent neuropsychological testing and assessment of regional cerebral blood flow (rCBF) response to cognitive challenges. Neuropsychological performance measures were derived for verbal and logical memory (memory), executive function, working memory, mental efficiency, and attention. A pseudo-continuous arterial spin labeling magnetic resonance imaging sequence compared rCBF responses with control and active phases of cognitive challenges. Brain areas previously associated with BP were grouped into composites for frontoparietal, frontostriatal, and insular-subcortical rCBF areas. Multiple regression models tested whether BP after 2 years was predicted by initial BP, initial neuropsychological scores, and initial rCBF responses to cognitive challenge. The neuropsychological composite of working memory (standardized beta, -0.276; se=0.116; P=0.02) and the frontostriatal rCBF response to cognitive challenge (standardized beta, 0.234; se=0.108; P=0.03) significantly predicted follow-up BP. Initial BP failed to significantly predict subsequent cognitive performance or rCBF. Changes in brain function may precede or co-occur with progression of BP toward hypertensive levels in midlife.

A Brain Phenotype for Stressor-Evoked Blood Pressure Reactivity

Background

Individuals who exhibit large‐magnitude blood pressure (BP) reactions to acute psychological stressors are at risk for hypertension and premature death by cardiovascular disease. This study tested whether a multivariate pattern of stressor‐evoked brain activity could reliably predict individual differences in BP reactivity, providing novel evidence for a candidate neurophysiological source of stress‐related cardiovascular risk.

Methods and Results

Community‐dwelling adults (N=310; 30–51 years; 153 women) underwent functional magnetic resonance imaging with concurrent BP monitoring while completing a standardized battery of stressor tasks. Across individuals, the battery evoked an increase systolic and diastolic BP relative to a nonstressor baseline period (M ∆systolic BP/∆diastolic BP=4.3/1.9 mm Hg [95% confidence interval=3.7–5.0/1.4–2.3 mm Hg]). Using cross‐validation and machine learning approaches, including dimensionality reduction and linear shrinkage models, a multivariate pattern of stressor‐evoked functional magnetic resonance imaging activity was identified in a training subsample (N=206). This multivariate pattern reliably predicted both systolic BP (r=0.32; P<0.005) and diastolic BP (r=0.25; P<0.01) reactivity in an independent subsample used for testing and replication (N=104). Brain areas encompassed by the pattern that were strongly predictive included those implicated in psychological stressor processing and cardiovascular responding through autonomic pathways, including the medial prefrontal cortex, anterior cingulate cortex, and insula.

Conclusions

A novel multivariate pattern of stressor‐evoked brain activity may comprise a phenotype that partly accounts for individual differences in BP reactivity, a stress‐related cardiovascular risk factor.

Systemic inflammation and resting state connectivity of the default mode network

The default mode network (DMN) encompasses brain systems that exhibit coherent neural activity at rest. DMN brain systems have been implicated in diverse social, cognitive, and affective processes, as well as risk for forms of dementia and psychiatric disorders that associate with systemic inflammation. Areas of the anterior cingulate cortex (ACC) and surrounding medial prefrontal cortex (mPFC) within the DMN have been implicated specifically in regulating autonomic and neuroendocrine processes that relate to systemic inflammation via bidirectional signaling mechanisms. However, it is still unclear whether indicators of inflammation relate directly to coherent resting state activity of the ACC, mPFC, or other areas within the DMN. Accordingly, we tested whether plasma interleukin (IL)-6, an indicator of systemic inflammation, covaried with resting-state functional connectivity of the DMN among 98 adults aged 30-54 (39% male; 81% Caucasian). Independent component analyses were applied to resting state fMRI data to generate DMN connectivity maps. Voxel-wise regression analyses were then used to test for associations between IL-6 and DMN connectivity across individuals, controlling for age, sex, body mass index, and fMRI signal motion. Within the DMN, IL-6 covaried positively with connectivity of the sub-genual ACC and negatively with a region of the dorsal medial PFC at corrected statistical thresholds. These novel findings offer evidence for a unique association between a marker of systemic inflammation (IL-6) and ACC and mPFC functional connectivity within the DMN, a network that may be important for linking aspects of immune function to psychological and behavioral states in health and disease.

Body-Brain Connections: The Effects of Obesity and Behavioral Interventions on Neurocognitive Aging

Obesity is a growing public health problem in the United States, particularly in middle-aged and older adults. Although the key factors leading to a population increase in body weight are still under investigation, there is evidence that certain behavioral interventions can mitigate the negative cognitive and brain (“neurocognitive”) health consequences of obesity. The two primary behaviors most often targeted for weight loss are caloric intake and physical activity. These behaviors might have independent, as well as overlapping/synergistic effects on neurocognitive health. To date obesity is often described independently from behavioral interventions in regards to neurocognitive outcomes, yet there is conceptual and mechanistic overlap between these constructs. This review summarizes evidence linking obesity and modifiable behaviors, such as physical activity and diet, with brain morphology (e.g., gray and white matter volume and integrity), brain function (e.g., functional activation and connectivity), and cognitive function across the adult lifespan. In particular, we review evidence bearing on the following question: Are associations between obesity and brain health in aging adults modifiable by behavioral interventions?