Person-specific and precision neuroimaging: Current methods and future directions.

Most neuroimaging studies of brain function analyze data in normalized space to identify regions of common activation across participants. These studies treat interindividual differences in brain organization as noise, but this approach can obscure important information about the brain's functional architecture. Recently, a number of studies have adopted a person-specific approach that aims to characterize these individual differences and explore their reliability and implications for behavior. A subset of these studies has taken a precision imaging approach that collects multiple hours of data from each participant to map brain function on a finer scale. In this review, we provide a broad overview of how person-specific and precision imaging techniques have used resting-state measures to examine individual differences in the brain's organization and their impact on behavior, followed by how task-based activity continues to add detail to these discoveries. We argue that person-specific and precision approaches demonstrate substantial promise in uncovering new details of the brain's functional organization and its relationship to behavior in many areas of cognitive neuroscience. We also discuss some current limitations in this new field and some new directions it may take.

Health insurance coverage moderates the relationship between metabolic syndrome and baseline memory outcomes in Latino older adults.

Objective: Latino adults are at increased risk of metabolic syndrome (MetS) and have lower rates of health insurance (HI) coverage. Although inadequate HI coverage and MetS have been independently linked to poor cognition, their potential interactive effects have not yet been examined. The present study explored whether HI moderated the association between MetS and cognition. We hypothesized that Latinos with MetS that did not have HI would demonstrate poorer cognition than those with HI, whereas there would be minimal differences in cognition across HI status in those without MetS. Methods: Cross-sectional data from 805 Latino older adults enrolled in the Health and Aging Brain Study-Health Disparities was utilized. Analysis of covariance adjusting for sociodemographics examined MetS x HI interactions on memory and attention/executive functions composites. Results: Results revealed a significant MetS x HI interaction on memory (F = 4.33, p = 0.037, ηp2 = .01); Latino adults with MetS and no HI coverage had worse memory performance than those with MetS who had HI coverage (p = 0.022, ηp2 = .01), whereas there was no significant difference in memory between HI coverage groups in those without MetS (p > .05, ηp2 = .002). No MetS x HI interaction was observed for the attention/executive functions composite (F = 0.29, p = 0.588, ηp2 < .001). Conclusion: Latino older adults with MetS that do not have HI coverage may be at risk for poorer memory outcomes. Increasing the accessibility of HI coverage may help reduce cognitive health disparities in Latino older adults with vascular health comorbidities.

Cerebral blood flow, tau imaging, and memory associations in cognitively unimpaired older adults.

Objective: Cerebral blood flow (CBF) has been independently linked to cognitive impairment and traditional Alzheimer's disease (AD) pathology (e.g., amyloid-beta [Aß], tau) in older adults. However, less is known about the possible interactive effects of CBF, Aß, and tau on memory performance. The present study examined whether CBF moderates the effect of Aß and tau on objective and subjective memory within cognitively unimpaired (CU) older adults. Methods: Participants included 54 predominately white CU older adults from the Alzheimer's Disease Neuroimaging Initiative. Multiple linear regression models examined meta-temporal CBF associations with (1) meta-temporal tau PET adjusting for cortical Aß PET and (2) and cortical Aß PET adjusting for tau PET. The CBF and tau meta region was an average of 5 distinct temporal lobe regions. CBF interactions with Aß or tau PET on memory performance were also examined. Covariates for all models included age, sex, education, pulse pressure, APOE-ε4 positivity, and imaging acquisition date differences. Results: CBF was significantly negatively associated with tau PET (t = -2.16, p = .04) but not Aß PET (t = 0.98, p = .33). Results revealed a CBF by tau PET interaction such that there was a stronger effect of tau PET on objective (t = 2.51, p = .02) and subjective (t = -2.67, p = .01) memory outcomes among individuals with lower levels of CBF. Conclusions: Cerebrovascular and tau pathologies may interact to influence cognitive performance. This study highlights the need for future vascular risk interventions, which could offer a scalable and cost-effective method for AD prevention.

Social engagement and its links to cognition differ across non-Hispanic Black and White older adults.

OBJECTIVE: Racial inequalities in dementia have been linked to disparities in socioeconomic status, chronic diseases, and psychosocial stress. Less focus has been given to psychosocial protective factors. Previous studies suggest that social engagement promotes better cognitive aging, but few have examined whether social engagement or its associations with cognition vary across non-Hispanic Whites (NHW) and Blacks (NHB). METHOD: Participants included 465 adults (53% NHB) from the Michigan Cognitive Aging Project (Mage = 63.59 ± 3.15) who completed a comprehensive neuropsychological battery. Social engagement was operationalized as network size, frequency of social activity participation, and social support. Cognition was operationalized using factor scores corresponding to five domains: episodic memory, executive functioning, processing speed, language, and visuospatial functioning. Cross-sectional associations between social engagement and cognitive outcomes were examined using race-stratified regressions controlling for age, sex/gender, education, wealth, marital status, depressive symptoms, and chronic diseases. RESULTS: There were no racial differences in social network size or social support. NHB participants reported less social activity participation than NHW participants. Social activity participation was positively associated with memory in NHW, but not NHB. CONCLUSIONS: These findings may suggest a threshold effect whereby NHB older adults are less likely to participate in social activities at the level needed to yield cognitive benefits. Lower social activity participation among NHB may reflect structural barriers and/or cultural differences in patterns of social engagement. This study highlights the need to improve measurement of and access to culturally relevant social activities for NHB to combat racial inequalities in cognitive aging. (PsycInfo Database Record (c) 2022 APA, all rights reserved).