Indira Carlene Turney

• Doctor of Philosophy
• Principal Investigator at National Institutes of Health

Previous memory research has exploited the perceptual similarities between lures and targets in order to evoke false memories. Nevertheless, while some studies have attempted to use lures that are objectively more similar than others, no study has systematically controlled for perceptual overlap between target and lure items and its role in account...

Distinctive encoding is greatly influenced by gist-based processes and has been shown to suffer when highly similar items are presented in close succession. Thus, elucidating the mechanisms underlying how presentation format affects gist processing is essential in determining the factors that influence these encoding processes. The current study ut...

The growing population of older adults emphasizes the need to develop interventions that prevent or delay some of the cognitive decline that accompanies aging. In particular, as memory impairment is the foremost cognitive deficit affecting older adults, it is vital to develop interventions that improve memory function. This study addressed the prob...

Background Parental education is an important determinant of late-life cognition, but the extent to which intervening on midlife risk factors, such as hypertension, mitigates the impact of early-life factors is unclear. Novel methodological approaches, such as causal decomposition, facilitate the assessment of contributors to health inequities thro...

Background Greater adherence to the Mediterranean Diet (MeDi) is associated with lower risk for cardiovascular disease, slower cognitive decline, and reduced risk for Alzheimer’s Disease (AD). However, its association with AD biomarkers is not well known. We hypothesized that greater MeDi adherence is associated with reduced amyloid and tau PET bur...

Background White matter hyperintensities (WMHs) are areas of increased signal on T2‐weighted MRI scans. They vary in size, location, and intensity, suggesting different underlying conditions like small vessel disease and inflammation. This variation potentially links WMH to outcomes ranging from normal aging to severe neurological disorders. We use...

Background High glycemic levels, indexed by hemoglobin A1c (HbA1c), heighten risk for Alzheimer’s Disease and Related Dementias (ADRD). Previous studies suggest that high HbA1c and low socioeconomic status (SES) may be associated with MRI markers of ADRD risk, including lower cortical thickness and greater white matter hyperintensities (WMH). The w...

Background Moderate alcohol use may be associated with brain and cognitive benefits compared to heavy alcohol use. However, results have varied. We hypothesized that the relationship between alcohol use and cognition is mediated by neurodegenerative and cerebrovascular measures in a diverse middle‐aged sample of non‐alcohol dependent community‐dwel...

Background Moderate alcohol use may be associated with brain and cognitive benefits compared to heavy alcohol use. However, results have varied. We hypothesized that the relationship between alcohol use and cognition is mediated by neurodegenerative and cerebrovascular measures in a diverse middle‐aged sample of non‐alcohol dependent community‐dwel...

Background High glycemic levels, indexed by hemoglobin A1c (HbA1c), heighten risk for Alzheimer’s Disease and Related Dementias (ADRD). Previous studies suggest that high HbA1c and low socioeconomic status (SES) may be associated with MRI markers of ADRD risk, including lower cortical thickness and greater white matter hyperintensities (WMH). The w...

Background Greater adherence to the Mediterranean Diet (MeDi) is associated with lower risk for cardiovascular disease, slower cognitive decline, and reduced risk for Alzheimer’s Disease (AD). However, its association with AD biomarkers is not well known. We hypothesized that greater MeDi adherence is associated with reduced amyloid and tau PET bur...

Background White matter hyperintensities (WMHs) are areas of increased signal on T2‐weighted MRI scans. They vary in size, location, and intensity, suggesting different underlying conditions like small vessel disease and inflammation. This variation potentially links WMH to outcomes ranging from normal aging to severe neurological disorders. We use...

Existing studies examining the predictive ability of biomarkers for cognitive outcomes do not account for variance due to measurement error, which could lead to under-estimates of the proportion of variance explained. We used data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) (N = 1084) to estimate the proportion of variance explained...

INTRODUCTION Loneliness has a rising public health impact, but research involving neuropathology and representative cohorts has been limited. METHODS Inverse odds of selection weights were generalized from the autopsy sample of Rush Alzheimer's Disease Center cohorts (N = 680; 89 ± 9 years old; 25% dementia) to the US‐representative Health and Ret...

Objectives: On average, adults racialized as non-Hispanic Black and Hispanic sleep more poorly than adults racialized as non-Hispanic White (hereafter, Black, Hispanic, White), but associations between factors that may moderate sleep-memory associations in these groups, such as neighborhood conditions, are unclear. Poorer neighborhood conditions (...

Introduction: Older adults racialized as Black experience higher rates of dementia than those racialized as White. Structural racism produces socioeconomic challenges, described by artist Marvin Gaye as “hang ups, let downs, bad breaks, setbacks” that likely contribute to dementia disparities. Robust dementia literature suggests socioeconomic facto...

Background Structural racism has concentrated Americans racialized as Black in under‐resourced and disinvested neighborhoods. These same Americans experience higher rates of Alzheimer’s disease and related dementias (ADRD). Differences in socioeconomic opportunities structured by racism is a potential contributor to ADRD disparities. To investigate...

Background Cerebrovascular dysfunction and vascular brain injury are associated with risk and progression of clinical Alzheimer’s disease (AD), but it is unclear whether they contribute directly to disease pathogenesis. Animal models of small vessel cerebrovascular disease suggest that transient cerebral hypoperfusion may promote tau pathology inde...

Background Poor sleep quality, a modifiable risk factor for dementia, that is prevalent in non‐Hispanic Black and Hispanic adults, is associated with greater memory complaints and smaller hippocampal volumes in predominantly non‐Hispanic White samples. These associations among sleep quality, memory complaints, and hippocampal volumes are understudi...

Background Minoritized groups experience higher stress due to structural racism and discrimination. These exposures have been linked to lower cognitive test scores and inflammation is a potential biological pathway underlying this association. Yet studies with multiple inflammatory markers in diverse populations remain limited. Method We assessed...

Background White matter hyperintensities (WMH) are areas of increased signal visualized on T2‐weighted FLAIR magnetic resonance imaging (MRI), thought to reflect macrostructural damage due to small vessel cerebrovascular disease. Previous work established an association of WMH severity, particularly in posterior regions, with risk and progression o...

Background Moderate alcohol use may provide later life cognitive benefits compared to heavy alcohol use. However, results have been mixed, with reports of both increased and decreased gray and white matter volumes with moderate drinking. Additionally, alcohol use on brain health may differ by sex and race/ethnicity. Understanding the association be...

Background A recent study showed that middle‐aged Black participants exhibited the magnitude of brain aging observed during late life, suggesting accelerated brain aging. Lifecourse socioeconomic status (SES) is an important predictor of health status, like cognition and Alzheimer’s disease (AD), and may help us understand some of the underlying me...

Background Cerebrovascular disease is associated with risk for dementia and possibly Alzheimer’s disease (AD) pathogenesis. Most people diagnosed with AD have mixed pathology, including plaques, tangles, and cerebrovascular disease. Because parental history of dementia is a strong risk factor for AD, studying the extent to which markers of cerebrov...

Background Small vessel cerebrovascular disease, often visualized as white matter hyperintensities (WMH) on T2‐weighted MRI scans, contributes to risk, progression, and, possibly, pathogenesis of Alzheimer’s disease (AD). When considered in the context of previous neuroimaging biomarker work in AD, WMH appear to colocalize with other markers of dis...

Background Moderate alcohol use may provide later life cognitive benefits compared to heavy alcohol use. However, results have been mixed, with reports of both increased and decreased gray and white matter volumes with moderate drinking. Additionally, alcohol use on brain health may differ by sex and race/ethnicity. Understanding the association be...

Objective Multiple sclerosis (MS) has historically been considered a syndrome that primarily affects White persons of northern European ancestry. This has been strongly disproven in recent decades with prevalence/incidence studies showing that MS impacts individuals from diverse backgrounds. The few studies available investigating clinical characte...

Objective Cardiovascular disease (CVD) is a well-known risk factor for cognitive impairment and dementia, particularly among minoritized groups that have experienced a history of low childhood socioeconomic status (SES). Although previous literature has linked all levels of SES to varying degrees of stress exposure, children raised in higher SES ho...

Dementia represents a growing public health burden with large social, racial, and ethnic disparities. The etiology of dementia is poorly understood, and the lack of robust biomarkers in diverse, population-representative samples is a barrier to moving dementia research forward. Existing biomarkers and other measures of pathology—derived from neurop...

Introduction: With the rapid expansion of the aging population, the burden of Alzheimer's disease related dementias (ADRD) is anticipated to increase in racialized and minoritized groups who are at disproportionately higher risk. To date, research emphasis has been on further characterizing the existence of racial disparities in ADRD through compa...

Background While studies have shown that Non‐Latinx Black and Latinx adults sleep less and more poorly than Non‐Latinx White adults, the cognitive consequences of poor sleep in Non‐Latinx Black and Latinx adults are understudied. Moreover, it is unclear if negative factors that disproportionately affect racial/ethnic minorities, including discrimin...

Introduction On average, minoritized racial and ethnic groups, including non-Hispanic Black and Hispanic adults, sleep more poorly than non-Hispanic White adults (hereafter, Black and White). Although racial and ethnic sleep disparities have been well-documented, few studies have investigated factors that may contribute to sleep disparities, such a...

Socioeconomic status (SES) is associated with white matter hyperintensities (WMHs) and contributes to racial and ethnic health disparities. However, traditional measures of SES may not accurately represent individual financial circumstances among non-Latinx Black and Latinx older adults due to longstanding structural inequities. This study examined...

Alzheimer’s disease and related dementias (ADRD) represent a growing public health burden with large social, racial, and ethnic disparities. The etiology of dementia is poorly understood, and the lack of robust biomarkers in diverse and population-representative samples is a barrier to moving dementia research forward. Existing biomarkers, derived...

Lower lifecourse socioeconomic status (SES) is associated with worse cognition and greater risk for Alzheimer’s disease (AD). Parental level of educational attainment is one indicator of childhood SES, which predicts myriad health outcomes throughout the lifespan. It is unclear whether midlife SES moderates the impact of childhood SES on midlife ou...

Alzheimer’s disease (AD) and cerebrovascular disease are the two most common pathologies underlying dementia. Loneliness is associated with faster cognitive decline and greater AD risk independent of pathology. Risk reduction efforts would benefit from knowing whether loneliness exacerbates the cognitive impact of pathology. Our objective was to ch...

Memory Complaints (MCs) are a risk factor for dementia, but research in this area has largely been limited to non-Latinx White adults. Previous studies have shown that Latinx/Hispanic individuals are at higher risk for Alzheimer’s Disease and Related Disorders (ADRD). The mechanisms underlying this disparity in ADRD are multidimensional and can inc...

State‐level socioeconomic opportunity disparities have been linked to health outcomes. We examined whether early‐life exposure to state‐level socioeconomic opportunity disparities between women and men influences the pattern of sex/gender inequalities in cognitive decline. Participants were 2,394 U.S.‐born non‐Latinx Black and non‐Latinx White wome...

Inclusive ADRD research should consider social and structural forces as potential sources of cognitive reserve and resilience. Characterization of neuropathology is critical for cognitive reserve research, but few cohorts have AD biomarker data in concert with sufficient sample size, population representativeness, and multi‐level, lifecourse measur...

Importance Neuroimaging studies have documented racial and ethnic disparities in brain health in old age. It remains unclear whether these disparities are apparent in midlife. Objective To assess racial and ethnic disparities in magnetic resonance imaging (MRI) markers of cerebrovascular disease and neurodegeneration in midlife and late life. Des...

The growing population of older adults emphasizes the need to develop interventions that prevent or delay some of the cognitive decline that accompanies aging. In particular, as memory impairment is the foremost cognitive deficit affecting older adults, it is vital to develop interventions that improve memory function. This study addressed the prob...

Biologic aging reflects the genetic, molecular, and cellular changes underlying the development of morbidity and mortality with advancing chronological age. As several potential mechanisms have been identified, there is a growing interest in developing robust measures of biologic age that can better reflect the underlying biology of aging and predi...

Background and Objectives Exposure to socioeconomic disadvantage is associated with early-onset cognitive aging. Biological aging, the progressive loss of system integrity that occurs as we age is proposed as a modifiable process mediating this health inequality. We examined whether socioeconomic disparities in cognitive aging in mid-to late-life a...

Background As global populations age, cross-national comparisons of cognitive health and dementia risk are increasingly valuable. It remains unclear, however, whether country-level differences in cognitive function are attributable to population differences or bias due to incommensurate measurement. To demonstrate an effective method for cross-nati...

Biological aging is a proposed mechanism through which social determinants drive health disparities. We conducted proof-of-concept testing of eight DNA-methylation and blood-chemistry quantifications of biological aging as mediators of disparities in healthspan between Black and White participants in the 2016 wave of the United States Health and Re...

Background The effect of family history on risk of developing late‐onset AD differs across race/ethnicity; however, the mechanisms underlying AD risk or resilience through heritability of genetic, environmental, and health factors are not well understood. Few large‐scale cohort studies have prospectively‐collected data of both parental and offsprin...

Importance: Exposure to socioeconomic disadvantage is associated with rapid cognitive aging. Biological aging, the progressive loss of system integrity that occurs as we age is proposed as a modifiable process mediating this health inequality. Objective: To test the hypothesis that socioeconomic disparities in cognitive aging in older adults is exp...

Healthy aging is accompanied by increased false remembering in addition to reduced successful remembering in older adults. Neuroimaging studies implicate age-related differences in the involvement of medial temporal lobe and fronto-parietal regions in mediating highly confident false recollection. However, no studies have directly examined the rela...

Biological aging is a proposed mechanism through which social determinants drive health disparities. We conducted proof-of-concept testing of eight DNA-methylation and blood-chemistry quantifications of biological aging as mediators of disparities in healthspan between Black and White participants in the United States Health and Retirement Study (H...

A family history of Alzheimer's disease (AD) increases risk for AD in an individual by 1.5-to 3-fold. Heritability of AD risk may be due in part to the aggregation of neurodegeneration and cerebrovascular changes with cognitive endophenotypes within families. The purpose of this study was to determine the extent to which cognitive functioning in mi...

INTRODUCTION: Numerous neuroimaging studies demonstrated racial and ethnic disparities in brain health at older ages. It remains unclear whether racial and ethnic disparities increase with aging and whether they are already apparent in midlife. METHODS: We investigated differences in MRI markers of aging and cerebrovascular disease in 969 participa...

Quality of social relations have increasingly been recognized as an important factor in cognitive health in later adulthood. Less is known about the association of relationship quality with executive functioning (EF) and memory; and whether the links differ by race/ethnicity. In this paper, we investigated the associations between positive and nega...

Examining the neural correlates underlying racial differences in cognitive functioning is necessary to help clarify mechanisms and to improve the generalizability of findings related to brain-behavior relationships. This systematic review aimed to determine whether there are racial differences in structural markers of brain aging among community-dw...

We compared verbal list learning, verbal memory, animal fluency, and letter fluency in 1407 education-matched participants from two community-based, intergenerational studies of cognitive aging and dementia. WHICAP participants are sampled from Medicare-eligible people aged 65+ and the Offspring cohort includes their middle-aged children. WHICAP pa...

Background Alzheimer’s disease and related disorders (ADRD) disproportionately affect African American, Hispanic, and American Indian older adults. Previous studies report racial/ethnic differences in markers of aging and neurodegeneration, but results are inconsistent due to small, non‐representative samples. We hypothesized that accelerated aging...

Introduction: Numerous neuroimaging studies demonstrated an association between the apolipoprotein E (APOE) ε4 allele and resting-state functional connectivity (rsFC) of regions within the default mode network (DMN), both in healthy populations and patients with AD. It remains unclear whether the APOE ε4 allele differentially affects the brain's f...

The Offspring Study of Racial and Ethnic Disparities in Alzheimer’s Disease began in 2017 to identify biological and sociocultural mechanisms of disparities in cognitive function among middle-aged people with and without a parent with Alzheimer's Disease (AD). This article outlines the objectives and design of this prospective cohort study aimed at...

Introduction: We examined whether educational attainment differentially contributes to cognitive reserve (CR) across race/ethnicity. Methods: A total of 1553 non-Hispanic Whites (Whites), non-Hispanic Blacks (Blacks), and Hispanics in the Washington Heights-Inwood Columbia Aging Project (WHICAP) completed structural magnetic resonance imaging. M...

Overall social network size, often the sum of common lifetime relationships, including children, family, and friends, has been linked to cognitive impairment and Alzheimer's Disease. However, little research has examined the association between network size composition and cognitive function in middle-aged and older adults in the context of race/et...

Socioeconomic disadvantages in childhood has been linked to dementia in late life. However, the underlying pathways through which childhood socioeconomic status (CSES) affects health in old age is unclear. CSES has been linked to age-related differences in regions affected by Alzheimer’s disease (AD; e.g., hippocampus). CSES varies across race/ethn...

Previous false memory research has suggested that older adults' false memories are based on an overreliance on gist processing in the absence of item-specific details. Yet, false memory studies have rarely taken into consideration the precise role of item-item similarity on the cognitive and neural mechanisms underlying perceptual false memories in...

Associative memory is considered to be resource-demanding, requiring individuals to learn individual items and the specific relationships between those items. Previous research has shown that prior studying of items aids in associative memory for pairs composed of those same items, as compared to pairs of items that have not been prelearned (e.g.,...