Self-reported experiences of discrimination in older black adults are associated with insula functional connectivity

Racial Discrimination-Related Interoceptive Network Disruptions: A Pathway to Disconnection

BACKGROUND

Racial discrimination (RD) disrupts regulatory systems in minoritized individuals, particularly systems that govern attention, including attention to visceral signals (interoception). RD frequency is linked to physiological shutdown responses, characterized clinically by dissociation. We examined associations between RD frequency and functional connectivity of attention and interoceptive networks in a sample of trauma-exposed Black women, investigating potential links between connectivity and dissociation severity.

METHODS

Seventy-two Black women who were recruited as part of two trauma studies underwent magnetic resonance imaging during performance of an affective Stroop (AS) task and completed dissociation and RD measures. Generalized psychophysiological interaction analyses were used to examine seed-to-voxel (seeds: bilateral amygdala and insula) functional connectivity with RD as a regressor; connectivity was examined during presentation of threat-relevant versus neutral AS distractor images. Connectivity values were extracted from significant clusters and examined in association with dissociative symptoms. We also investigated connectivity in association with posttraumatic stress disorder (PTSD) symptoms for comparison analyses.

RESULTS

During attention to threat-relevant AS trials, greater RD frequency was associated with less insula connectivity to several medial prefrontal cortex (mPFC) clusters (false discovery rate-corrected ps < .05). Insula-mPFC connectivity was significantly and negatively associated with derealization symptoms (r = -0.31, p = .009), but not PTSD (r = -0.16, p = .182).

CONCLUSIONS

RD frequency was linked to reduced functional connectivity between the insula and mPFC, 2 interoceptive network nodes, during attention to threat, and diminished connectivity was linked to more severe dissociation. RD may interrupt interoceptive network functioning, and these network alterations may, in turn, influence mind-body disconnection, or physiological shutdown response in Black individuals.

Racial Discrimination, Neural Connectivity, and Epigenetic Aging Among Black Women

Importance

Racial discrimination increases the risk of adverse brain health outcomes, potentially via neuroplastic changes in emotion processing networks. The involvement of deep brain regions (brainstem and midbrain) in these responses is unknown. Potential associations of racial discrimination with alterations in deep brain functional connectivity and accelerated epigenetic aging, a process that substantially increases vulnerability to health problems, are also unknown.

Objective

To examine associations of racial discrimination with brainstem and midbrain resting-state functional connectivity (RSFC) and DNA methylation age acceleration (DMAA) among Black women in the US.

Design, Setting, and Participants

This cohort study was conducted between January 1, 2012, and February 28, 2015, and included a community-based sample of Black women (aged ≥18 years) recruited as part of the Grady Trauma Project. Self-reported racial discrimination was examined in association with seed-to-voxel brain connectivity, including the locus coeruleus (LC), periaqueductal gray (PAG), and superior colliculus (SC); an index of DMAA (Horvath clock) was also evaluated. Posttraumatic stress disorder (PTSD), trauma exposure, and age were used as covariates in statistical models to isolate racial discrimination-related variance. Data analysis was conducted between January 10 and October 30, 2023.

Exposure

Varying levels of racial discrimination exposure, other trauma exposure, and posttraumatic stress disorder (PTSD).

Main Outcomes and Measures

Racial discrimination frequency was assessed with the Experiences of Discrimination Scale, other trauma exposure was evaluated with the Traumatic Events Inventory, and current PTSD was evaluated with the PTSD Symptom Scale. Seed-to-voxel functional connectivity analyses were conducted with LC, PAG, and SC seeds. To assess DMAA, the Methylation EPIC BeadChip assay (Illumina) was conducted with whole-blood samples from a subset of 49 participants.

Results

This study included 90 Black women, with a mean (SD) age of 38.5 (11.3) years. Greater racial discrimination was associated with greater left LC RSFC to the bilateral precuneus (a region within the default mode network implicated in rumination and reliving of past events; cluster size k = 228; t85 = 4.78; P < .001, false discovery rate-corrected). Significant indirect effects were observed for the left LC-precuneus RSFC on the association between racial discrimination and DMAA (β [SE] = 0.45 [0.16]; 95% CI, 0.12-0.77).

Conclusions and Relevance

In this study, more frequent racial discrimination was associated with proportionately greater RSFC of the LC to the precuneus, and these connectivity alterations were associated with DMAA. These findings suggest that racial discrimination contributes to accelerated biological aging via altered connectivity between the LC and default mode network, increasing vulnerability for brain health problems.

Discrimination and Cognition in Midlife Black Women: The Roles of Social Support and Spirituality

OBJECTIVES

Black women are at high risk for discrimination and cognitive impairment in late life. It is not known if discrimination is a risk factor for cognitive decline in Black women and if so, what factors are protective against the adverse cognitive effects of discrimination. Using the biopsychosocial model of gendered racism, we determined if discrimination is associated with poorer cognition in midlife Black women and if social support and/or spirituality would protect against the deleterious effects of discrimination on cognition.

METHODS

Participants were midlife Black women (N = 669) from the Study of Women's Health Across the Nation. Discrimination was measured by the Everyday Discrimination scale. Cognitive outcomes included episodic memory, processing speed, and working memory. Total social support, emotional support, instrumental support, and spirituality were assessed as protective factors.

RESULTS

Contrary to expectations, structural equation modeling indicated that discrimination was associated with better immediate recall. For women with more emotional support, greater discrimination was associated with better immediate recall than for women with lower emotional support. Spirituality was not a significant moderator in the association between discrimination and cognition.

DISCUSSION

Discrimination had unexpected positive associations with learning and attention-based cognitive skills for midlife Black women. Discrimination might enhance vigilance, which could be facilitated by higher levels of emotional support. There is an opportunity for clinical and public health interventions for cognitive health and discrimination focused on Black women to better incorporate emotional support as a coping resource.

Sound-localization-related activation and functional connectivity of dorsal auditory pathway in relation to demographic, cognitive, and behavioral characteristics in age-related hearing loss

Background

Patients with age-related hearing loss (ARHL) often struggle with tracking and locating sound sources, but the neural signature associated with these impairments remains unclear.

Materials and methods

Using a passive listening task with stimuli from five different horizontal directions in functional magnetic resonance imaging, we defined functional regions of interest (ROIs) of the auditory "where" pathway based on the data of previous literatures and young normal hearing listeners (n = 20). Then, we investigated associations of the demographic, cognitive, and behavioral features of sound localization with task-based activation and connectivity of the ROIs in ARHL patients (n = 22).

Results

We found that the increased high-level region activation, such as the premotor cortex and inferior parietal lobule, was associated with increased localization accuracy and cognitive function. Moreover, increased connectivity between the left planum temporale and left superior frontal gyrus was associated with increased localization accuracy in ARHL. Increased connectivity between right primary auditory cortex and right middle temporal gyrus, right premotor cortex and left anterior cingulate cortex, and right planum temporale and left lingual gyrus in ARHL was associated with decreased localization accuracy. Among the ARHL patients, the task-dependent brain activation and connectivity of certain ROIs were associated with education, hearing loss duration, and cognitive function.

Conclusion

Consistent with the sensory deprivation hypothesis, in ARHL, sound source identification, which requires advanced processing in the high-level cortex, is impaired, whereas the right-left discrimination, which relies on the primary sensory cortex, is compensated with a tendency to recruit more resources concerning cognition and attention to the auditory sensory cortex. Overall, this study expanded our understanding of the neural mechanisms contributing to sound localization deficits associated with ARHL and may serve as a potential imaging biomarker for investigating and predicting anomalous sound localization.

Exploring the impact of immersive virtual reality on depression knowledge and stigma reduction: a cross-over RCT fMRI study

The stigma of mental illness is a form of negative judgmental knowledge and is a barrier to individual seeking treatment. Contact-based educational interventions with first-person perspective (1PP) combined with immersive virtual reality (IVR) is promising as an anti-stigma intervention. This study aims to investigate the effectiveness of 1PP anti-stigma IVR intervention compared to video in enhancing depression knowledge and reducing stigma, as well as to examine the corresponding depression knowledge brain activity change using functional magnetic resonance imaging (fMRI). Participants engaged in a 1PP anti-stigma intervention using both IVR and conventional video, focusing on the daily life and recovery of a patient with mild depression. The change in depression knowledge, stigma-related behavioral, and brain activity using fMRI were measured at pre- and post-interventions. Depression knowledge improved for both interventions; however, only the IVR intervention reduced stigma. In the IVR intervention, depression knowledge score was positively associated with neural response in the right superior frontal gyrus activation, indicative of empathic concern. Conversely, the video intervention correlated with increased activity in the right anterior insula, suggesting a distress-related response. The findings demonstrate that the immersive nature of IVR can reduce stigma more effectively than video intervention. This effectiveness is underpinned by the change in depression knowledge on neural activity, with IVR fostering empathy-related behavioral responses. The results highlight the potential of IVR in enhancing empathic understanding and reducing stigma towards mental illness, emphasizing the need for further exploration into immersive technologies for mental health education.

C-reactive protein moderates associations between racial discrimination and ventromedial prefrontal cortex activation during attention to threat in Black American women

Prior research has shown that racial discrimination (RD) impacts activation in threat network regions, including the ventromedial prefrontal cortex (vmPFC) and middle occipital cortex during attention to threat-relevant stimuli. However, little is known about the biological mechanisms that may modulate these effects; inflammation may be a pathway linking RD and threat network activation. As such, the current study aimed to explore whether systemic inflammation, measured by C-reactive protein (CRP) levels, may moderate the relationship between RD and activation in the vmPFC and middle occipital cortex during attention to threat. Blood samples for inflammatory marker (CRP) assays were obtained from forty Black American women (mean [SD] age, 39.93 [9.97] years; range, 22-58 years) recruited from an ongoing trauma study; participants also viewed threat-relevant stimuli as part of an attention task during fMRI. We found that CRP moderated the relationship between RD and vmPFC activation during attention to threat, such that participants with relatively higher concentrations of CRP ( ≥ 23.97 mg/L) demonstrated significant positive associations between RD and vmPFC activation [β = 0.18, CI (0.04, 0.32), t = 2.65, p = 0.01]. No significant associations were observed for participants who showed moderate (10.89 mg/L) or low (0.20 mg/L) CRP concentrations. CRP did not moderate the relationship between RD and middle occipital cortex activation. Our data present a mechanism through which RD may influence immune system activation and, in turn, threat network activation. Inflammation may contribute to brain health vulnerabilities in Black Americans via its effects on threat circuits; this merits further investigation in large-scale studies.

Looking Upstream to Understand Race/Ethnicity as a Moderator for Poststroke Neuroinflammation and a Social Determinant for Poststroke Aphasia Outcomes

INTRODUCTION

Over the past decade, the stroke literature has begun to acknowledge and explore explanations for longstanding racial/ethnic differences in stroke outcomes. Poststroke cognitive impairment (PSCI) and poststroke aphasia are two such negative poststroke outcomes where racial/ethnic differences exist. Physiological differences, such as stroke type and lesion size, have been used to partially explain the variation in PSCI and aphasia. However, there is some evidence, although limited, that suggests neuroinflammatory processes as part of allostatic load may be a key contributor to the observed disparities.

METHOD

In this tutorial, we explore the influence of race differences in inflammation on poststroke cognitive outcomes. We suggest lifetime stress and other external determinants of health such as neighborhood environment and discriminatory practices through "weathering" explain differences in inflammation. While using an allostatic load framework, we explore the literature focusing specifically on the role of neuroinflammation on poststroke outcomes.

CONCLUSIONS

Examination of the immune response poststroke provides a foundation for understanding the mechanisms of PSCI and poststroke aphasia and the potential contributions of neuroinflammatory processes on poststroke cognitive outcomes. Furthermore, understanding of racial differences in those processes may contribute to a better understanding of racial disparities in general stroke outcomes as well as poststroke aphasia.

Association of polygenic risk for bipolar disorder with resting-state network functional connectivity in youth with and without bipolar disorder

Little is known regarding the polygenic underpinnings of anomalous resting-state functional connectivity (rsFC) in youth bipolar disorder (BD). The current study examined the association of polygenic risk for BD (BD-PRS) with whole-brain rsFC at the large-scale network level in youth with and without BD. 99 youth of European ancestry (56 BD, 43 healthy controls [HC]), ages 13-20 years, completed resting-state fMRI scans. BD-PRS was calculated using summary statistics from the latest adult BD genome-wide association study. Data-driven independent component analyses of the resting-state fMRI data were implemented to examine the association of BD-PRS with rsFC in the overall sample, and separately in BD and HC. In the overall sample, higher BD-PRS was associated with lower rsFC of the salience network and higher rsFC of the frontoparietal network with frontal and parietal regions. Within the BD group, higher BD-PRS was associated with higher rsFC of the default mode network with orbitofrontal cortex, and altered rsFC of the visual network with frontal and occipital regions. Within the HC group, higher BD-PRS was associated with altered rsFC of the frontoparietal network with frontal, temporal and occipital regions. In conclusion, the current study found that BD-PRS generated based on adult genetic data was associated with altered rsFC patterns of brain networks in youth. Our findings support the usefulness of BD-PRS to investigate genetically influenced neuroimaging markers of vulnerability to BD, which can be observed in youth with BD early in their course of illness as well as in healthy youth.

Transgender Adults From Minoritized Ethnoracial Groups in the U.S. Report Greater Subjective Cognitive Decline

OBJECTIVES

Investigate subjective cognitive decline (SCD) among 4 study groups consisting of cisgender and transgender adults who are from minoritized ethnoracial groups (i.e., minoritized ethnoracial transgender, minoritized ethnoracial cisgender) and White cisgender and transgender adults aged 45+ (i.e., White transgender, White cisgender) to determine the odds of SCD by group and to test for group differences.

METHODS

Data from the 2015-2020 Behavioral Risk Factor Surveillance System were used in a modified case-control approach to perform an intercategorical intersectional study. Each transgender participant was matched to 2 cisgender men and 2 cisgender women, on state, ethnoracial identity, and age. Multivariable logistic regressions modeled SCD odds by group and post hoc contrasts estimated pairwise odds ratios comparing the SCD odds for each combination of groups.

RESULTS

SCD prevalence was highest among minoritized ethnoracial transgender (21.6%), followed by White transgender (15.0%), minoritized ethnoracial cisgender (12.0%), and White cisgender (9.0%). After accounting for age, education, and survey year, the odds of SCD were higher in minoritized ethnoracial transgender when compared to White cisgender (adjusted odds ratio [aOR] = 2.51, 95% confidence interval [CI]: 1.59-3.96) and minoritized ethnoracial cisgender (aOR = 1.89, 95% CI: 1.16-3.09). The odds of SCD were higher in White transgender compared to White cisgender (aOR = 1.66, 95% CI: 1.20-2.30).

DISCUSSION

When considering the intersection of transgender and ethnoracial identities, we found that transgender adults from minoritized ethnoracial groups reported higher odds of SCD when compared to cisgender adults from minoritized ethnoracial groups. Additional studies are needed to understand the relationship between racialized and gendered inequities in cognitive impairment and how specific mechanisms of systemic transphobia and racism may contribute to this inequity.

Aging brain shows joint declines in brain within-network connectivity and between-network connectivity: a large-sample study (N > 6,000)

Introduction

Numerous studies have shown that aging has important effects on specific functional networks of the brain and leads to brain functional connectivity decline. However, no studies have addressed the effect of aging at the whole-brain level by studying both brain functional networks (i.e., within-network connectivity) and their interaction (i.e., between-network connectivity) as well as their joint changes.

Methods

In this work, based on a large sample size of neuroimaging data including 6300 healthy adults aged between 49 and 73 years from the UK Biobank project, we first use our previously proposed priori-driven independent component analysis (ICA) method, called NeuroMark, to extract the whole-brain functional networks (FNs) and the functional network connectivity (FNC) matrix. Next, we perform a two-level statistical analysis method to identify robust aging-related changes in FNs and FNCs, respectively. Finally, we propose a combined approach to explore the synergistic and paradoxical changes between FNs and FNCs.

Results

Results showed that the enhanced FNCs mainly occur between different functional domains, involving the default mode and cognitive control networks, while the reduced FNCs come from not only between different domains but also within the same domain, primarily relating to the visual network, cognitive control network, and cerebellum. Aging also greatly affects the connectivity within FNs, and the increased within-network connectivity along with aging are mainly within the sensorimotor network, while the decreased within-network connectivity significantly involves the default mode network. More importantly, many significant joint changes between FNs and FNCs involve default mode and sub-cortical networks. Furthermore, most synergistic changes are present between the FNCs with reduced amplitude and their linked FNs, and most paradoxical changes are present in the FNCs with enhanced amplitude and their linked FNs.

Discussion

In summary, our study emphasizes the diversity of brain aging and provides new evidence via novel exploratory perspectives for non-pathological aging of the whole brain.

Brain-body pathways linking racism and health

Racial disparities in health are a major public health problem in the United States, especially when comparing chronic disease morbidity and mortality for Black versus White Americans. These health disparities are primarily due to insidious anti-Black racism that permeates American history, current culture and institutions, and interpersonal interactions. But how does racism get under the skull and the skin to influence brain and bodily processes that impact the health of Black Americans? In the present article, we present a model describing the possible neural and inflammatory mechanisms linking racism and health. We hypothesize that racism influences neural activity and connectivity in the salience and default mode networks of the brain and disrupts interactions between these networks and the executive control network. This pattern of neural functioning in turn leads to greater sympathetic nervous system signaling, hypothalamic-pituitary-adrenal axis activation, and increased expression of genes involved in inflammation, ultimately leading to higher levels of proinflammatory cytokines in the body and brain. Over time, these neural and physiological responses can lead to chronic physical and mental health conditions, disrupt well-being, and cause premature mortality. Given that research in this area is underdeveloped to date, we emphasize opportunities for future research that are needed to build a comprehensive mechanistic understanding of the brain-body pathways linking anti-Black racism and health. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Radically reframing studies on neurobiology and socioeconomic circumstances: A call for social justice-oriented neuroscience

Socioeconomic circumstances are associated with symptoms and diagnostic status of nearly all mental health conditions. Given these robust relationships, neuroscientists have attempted to elucidate how socioeconomic-based adversity "gets under the skin." Historically, this work emphasized individual proxies of socioeconomic position (e.g., income, education), ignoring the effects of broader socioeconomic contexts (e.g., neighborhood socioeconomic disadvantage) which may uniquely contribute to chronic stress. This omission represented a disconnect between neuroscience and other allied fields that have recognized health is undeniably linked to interactions between systems of power and individual characteristics. More recently, neuroscience work has considered how sociopolitical context affects brain structure and function; however, the products of this exciting line of research have lacked critical sociological and historical perspectives. While empirical evidence on this topic is burgeoning, the cultural, ethical, societal, and legal implications of this work have been elusive. Although the mechanisms by which socioeconomic circumstances impact brain structure and function may be similar across people, not everyone is exposed to these factors at similar rates. Individuals from ethnoracially minoritized groups are disproportionally exposed to neighborhood disadvantage. Thus, socioeconomic inequities examined in neuroscience research are undergirding with other forms of oppression, namely structural racism. We utilize a holistic, interdisciplinary approach to interpret findings from neuroscience research and interweave relevant theories from the fields of public health, social sciences, and Black feminist thought. In this perspective piece, we discuss the complex relationship that continues to exist between academic institutions and underserved surrounding communities, acknowledging the areas in which neuroscience research has historically harmed and/or excluded structurally disadvantaged communities. We conclude by envisioning how this work can be used; not just to inform policymakers, but also to engage and partner with communities and shape the future direction of human neuroscience research.

Proximal improvement and higher-order resting state network change after multidomain cognitive training intervention in healthy older adults

Prior randomized control trials have shown that cognitive training interventions resulted in improved proximal task performance, improved functioning of activities of daily living, and reduced dementia risk in healthy older adults. Neural correlates implicated in cognitive training include hub brain regions of higher-order resting state networks including the default mode network, dorsal attention network, frontoparietal control network, and cingulo-opercular network. However, little is known about resting state network change after cognitive training, or the relation between functional brain changes and improvement in proximal task performance. We assessed the 1) change in proximal task performance, 2) change in higher-order resting state network connectivity via functional magnetic resonance imaging, and 3) association between these variables after a multidomain attention/speed-of-processing and working memory randomized control trial in a sample of 58 healthy older adults. Participants in the cognitive training group improved significantly on seven out of eight training tasks immediately after the training intervention with the largest magnitude of improvement in a divided attention/speed-of-processing task, the Double Decision task. Only the frontoparietal control network had significantly strengthened connectivity in the cognitive training group at the post-intervention timepoint. Lastly, higher frontoparietal control network connectivity was associated with improved Double Decision task performance after training in the cognitive training group. These findings show that the frontoparietal control network may strengthen after multidomain cognitive training interventions, and this network may underlie improvements in divided attention/speed-of-processing proximal improvement.

A systematic review of the neural correlates of sexual minority stress: towards an intersectional minority mosaic framework with implications for a future research agenda

BACKGROUND

Systemic oppression, particularly towards sexual minorities, continues to be deeply rooted in the bedrock of many societies globally. Experiences with minority stressors (e.g. discrimination, hate-crimes, internalized homonegativity, rejection sensitivity, and microaggressions or everyday indignities) have been consistently linked to adverse mental health outcomes. Elucidating the neural adaptations associated with minority stress exposure will be critical for furthering our understanding of how sexual minorities become disproportionately affected by mental health burdens.

METHODS

Following PRISMA-guidelines, we systematically reviewed published neuroimaging studies that compared neural dynamics among sexual minority and heterosexual populations, aggregating information pertaining to any measurement of minority stress and relevant clinical phenomena.

RESULTS

Only 1 of 13 studies eligible for inclusion examined minority stress directly, where all other studies focused on investigating the neurobiological basis of sexual orientation. In our narrative synthesis, we highlight important themes that suggest minority stress exposure may be associated with decreased activation and functional connectivity within the default-mode network (related to the sense-of-self and social cognition), and summarize preliminary evidence related to aberrant neural dynamics within the salience network (involved in threat detection and fear processing) and the central executive network (involved in executive functioning and emotion regulation). Importantly, this parallels neural adaptations commonly observed among individuals with posttraumatic stress disorder (PTSD) in the aftermath of trauma and supports the inclusion of insidious forms of trauma related to minority stress within models of PTSD.

CONCLUSIONS

Taken together, minority stress may have several shared neuropsychological pathways with PTSD and stress-related disorders. Here, we outline a detailed research agenda that provides an overview of literature linking sexual minority stress to PTSD and insidious trauma, moral affect (including shame and guilt), and mental health risk/resiliency, in addition to racial, ethnic, and gender related minority stress. Finally, we propose a novel minority mosaic framework designed to inform future directions of minority stress neuroimaging research from an intersectional lens.

Racism and Older Black Americans' Health: a Systematic Review

We reviewed research that examines racism as an independent variable and one or more health outcomes as dependent variables in Black American adults aged 50 years and older in the USA. Of the 43 studies we reviewed, most measured perceived interpersonal racism, perceived institutional racism, or residential segregation. The only two measures of structural racism were birth and residence in a "Jim Crow state." Fourteen studies found associations between racism and mental health outcomes, five with cardiovascular outcomes, seven with cognition, two with physical function, two with telomere length, and five with general health/other health outcomes. Ten studies found no significant associations in older Black adults. All but six of the studies were cross-sectional. Research to understand the extent of structural and multilevel racism as a social determinant of health and the impact on older adults specifically is needed. Improved measurement tools could help address this gap in science.

Higher-order resting state network association with the useful field of view task in older adults

Speed-of-processing abilities decline with age yet are important in performing instrumental activities of daily living. The useful field of view, or Double Decision task, assesses speed-of-processing and divided attention. Performance on this task is related to attention, executive functioning, and visual processing abilities in older adults, and poorer performance predicts more motor vehicle accidents in the elderly. Cognitive training in this task reduces risk of dementia. Structural and functional neural correlates of this task suggest that higher-order resting state networks may be associated with performance on the Double Decision task, although this has never been explored. This study aimed to assess the association of within-network connectivity of the default mode network, dorsal attention network, frontoparietal control network, and cingulo-opercular network with Double Decision task performance, and subcomponents of this task in a sample of 267 healthy older adults. Multiple linear regressions showed that connectivity of the cingulo-opercular network is associated with visual speed-of-processing and divided attention subcomponents of the Double Decision task. Cingulo-opercular network and frontoparietal control network connectivity is associated with Double Decision task performance. Stronger connectivity is related to better performance in all cases. These findings confirm the unique role of the cingulo-opercular network in visual attention and sustained divided attention. Frontoparietal control network connectivity, in addition to cingulo-opercular network connectivity, is related to Double Decision task performance, a task implicated in reduced dementia risk. Future research should explore the role these higher-order networks play in reduced dementia risk after cognitive intervention using the Double Decision task.

Racial Discrimination and Resting-State Functional Connectivity of Salience Network Nodes in Trauma-Exposed Black Adults in the United States

Importance

For Black US residents, experiences of racial discrimination are still pervasive and frequent. Recent empirical work has amplified the lived experiences and narratives of Black people and further documented the detrimental effects of racial discrimination on both mental and physical health; however, there is still a need for further research to uncover the mechanisms connecting experiences of racial discrimination with adverse health outcomes.

Objective

To examine neurobiological mechanisms that may offer novel insight into the association of racial discrimination with adverse health outcomes.

Design, Setting, and Participants

This cross-sectional study included 102 Black adults who had recently experienced a traumatic injury. In the acute aftermath of the trauma, participants underwent a resting-state functional magnetic resonance imaging scan. Individuals were recruited from the emergency department at a Midwestern level 1 trauma center in the United States between March 2016 and July 2020. Data were analyzed from February to May 2021.

Exposures

Self-reported lifetime exposure to racial discrimination, lifetime trauma exposure, annual household income, and current posttraumatic stress disorder (PTSD) symptoms were evaluated.

Main Outcomes and Measures

Seed-to-voxel analyses were conducted to examine the association of racial discrimination with connectivity of salience network nodes (ie, amygdala and anterior insula).

Results

A total of 102 individuals were included, with a mean (SD) age of 33 (10) years and 58 (57%) women. After adjusting for acute PTSD symptoms, annual household income, and lifetime trauma exposure, greater connectivity between the amygdala and thalamus was associated with greater exposure to discrimination (t(97) = 6.05; false discovery rate (FDR)-corrected P = .03). Similarly, racial discrimination was associated with greater connectivity between the insula and precuneus (t(97) = 4.32; FDR-corrected P = .02).

Conclusions and Relevance

These results add to the mounting literature that racial discrimination is associated with neural correlates of vigilance and hyperarousal. The study findings extend this theory by showing that this association is apparent even when accounting for socioeconomic position, lifetime trauma, and symptoms of psychological distress related to an acute trauma.

Informant-Reported Discrimination, Dementia, and Cognitive Impairment in Older Brazilians

BACKGROUND

Self-reported discrimination is a source of psychosocial stress that has been previously associated with poor cognitive function in older African Americans without dementia.

OBJECTIVE

Here, we examine the association of discrimination with dementia and cognitive impairment in racially diverse older Brazilians.

METHODS

We included 899 participants 65 years or older (34.3% Black) from the Pathology, Alzheimer's and Related Dementias Study (PARDoS), a community-based study of aging and dementia. A structured interview with informants of the deceased was conducted. The interview included the Clinical Dementia Rating (CDR) Scale for the diagnosis of dementia and cognitive impairment proximate to death and the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) as a second measure of cognitive impairment. Informant-reported discrimination was assessed using modified items from the Major and Everyday Discrimination Scales.

RESULTS

Discrimination was reported by informants of 182 (20.2%) decedents and was more likely reported by informants of Blacks than Whites (25.3% versus 17.6%, p = 0.006). Using the CDR, a higher level of informant-reported discrimination was associated with higher odds of dementia (OR: 1.24, 95% CI 1.08 -1.42, p = 0.002) and cognitive impairment (OR: 1.21, 95% CI: 1.06 -1.39, p = 0.004). Similar results were observed using the IQCODE (estimate: 0.07, SE: 0.02, p = 0.003). The effects were independent of race, sex, education, socioeconomic status, major depression, neuroticism, or comorbidities.

CONCLUSION

Higher level of informant-reported discrimination was associated with higher odds of dementia and cognitive impairment in racially diverse older Brazilians.

Parental Education, Household Income, Race, and Children's Working Memory: Complexity of the Effects

Background. Considerable research has linked social determinants of health (SDoHs) such as race, parental education, and household income to school performance, and these effects may be in part due to working memory. However, a growing literature shows that these effects may be complex: while the effects of parental education may be diminished for Blacks than Whites, household income may explain such effects. Purpose. Considering race as sociological rather than a biological construct (race as a proxy of racism) and built on Minorities' Diminished Returns (MDRs), this study explored complexities of the effects of SDoHs on children's working memory. Methods. We borrowed data from the Adolescent Brain Cognitive Development (ABCD) study. The total sample was 10,418, 9- and 10-year-old children. The independent variables were race, parental education, and household income. The primary outcome was working memory measured by the NIH Toolbox Card Sorting Test. Age, sex, ethnicity, and parental marital status were the covariates. To analyze the data, we used mixed-effect regression models. Results. High parental education and household income were associated with higher and Black race was associated with lower working memory. The association between high parental education but not household income was less pronounced for Black than White children. This differential effect of parental education on working memory was explained by household income. Conclusions. For American children, parental education generates unequal working memory, depending on race. This means parental education loses some of its expected effects for Black families. It also suggests that while White children with highly educated parents have the highest working memory, Black children report lower working memory, regardless of their parental education. This inequality is mainly because of differential income in highly educated White and Black families. This finding has significant public policy and economic implications and suggests we need to do far more than equalizing education to eliminate racial inequalities in children's cognitive outcomes. While there is a need for multilevel policies that reduce the effect of racism and social stratification for middle-class Black families, equalizing income may have more returns than equalizing education.

Subjective Socioeconomic Status and Children's Amygdala Volume: Minorities' Diminish Returns

Considerable research has suggested that low socioeconomic status (SES) negatively influences brain structure, including but not limited to decreased amygdala volume. Considering race and ethnicity as sociological rather than biological constructs, this study was built on minorities' diminished returns (MDRs) to test if the effects of family SES on the total amygdala volume is weaker for black and Latino children than white and non-Latino children. We borrowed data from the Adolescent Brain Cognitive Development (ABCD) study, a national multi-center brain imaging investigation of childhood brain development in the US. The total sample was 9380 9-10-year-old children. The independent variables were subjective family SES and parental education. The primary outcome was total amygdala volume. High subjective SES and parental education were independently associated with larger total amygdala size. The association between high subjective SES and larger total amygdala volume was less pronounced for black and Latino children than white and non-Latino children. For American children, family SES has unequal effects on amygdala size and function, a pattern that is consistent with MDRs. This result suggests that SES loses some of its expected effects for racial and ethnic minority families.

Parental Education and Nucleus Accumbens Response to Reward Anticipation: Minorities' Diminished Returns

Background

Considerable research has documented the effects of race and socioeconomic status (SES) on reward-seeking behaviors; however, less is known about the multiplicative effects of race and family SES on brain response to reward anticipation. Marginalization-related Diminished Returns (MDRs) suggest that family SES would show weaker effects on brain development of children in non-White families than in White families.

Objective

To test race by SES variation in Nucleus Accumbens (NAcc) response to reward anticipation (NAcc-RA) among American children.

Methods

For this cross-sectional analysis, data came from the Adolescent Brain Cognitive Development (ABCD) study which included 6,419, 9-10 year old children. The independent variable was parental education. The moderator was race. The primary outcome was the right NAcc-RA. Age, sex, ethnicity, household income, and family structure were the covariates. We used mixed effects regression models that adjusted for the nested nature of the ABCD data.

Results

While high parental education was associated with a higher amount of right NAcc-RA, this effect was stronger for White than non-White children. This finding was evident in the observed interactions between race and parental education on the right NAcc-RA.

Discussion

For American children, NAcc-RA is not shaped by race or family SES, but by their intersection. As a result of the interaction between race and SES (diminished return of SES for non-Whites), middle-class racial minority children may remain susceptible to high-risk behaviors. Disparities in high-risk behaviors in children should not be reduced to economic disparities. Structural inequalities may reduce the return of SES resources for non-White families.