Brain Connectivity and Neurocognitive Health in Older Adults: The Baltimore Experience Corps Trial Brain Health Study

cognitive aging;task positive network;task negative network;functional connectivity;brain networks;fMRI;executive functions;memory;dementia;Experience Corps;older adults;Public Health Studies

Khasawinah, SarahCaffo, Brian S. ;

Johns Hopkins University

关键词: cognitive aging;    task positive network;    task negative network;    functional connectivity;    brain networks;    fMRI;    executive functions;    memory;    dementia;    Experience Corps;    older adults;    Public Health Studies;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/37873/KHASAWINAH-DISSERTATION-2015.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Background: Cognitive aging is associated with cognitive decline and poor functional connectivity in the brain; however, the lengthening of life also presents additional potential to contribute to society. Addressing both these challenges and opportunities, we studied brain networks and cognitive functions within a randomized controlled trial of a senior service volunteer program, Experience Corps (EC).Methods: Data are from the Brain Health Study (BHS), a longitudinal trial nested within the Baltimore Experience Corps Trial, randomizing 123 socio-demographically diverse community-dwelling adults over the age of 60. At Baseline, 12-month Follow-Up, and24-month Follow-Up, functional magnetic resonance imaging (fMRI) brain data and neuropsychological test data were collected. We investigated two brain networks whose coupling is known to be associated with cognitive aging and dementia risk, the TaskNegative Network (TNN) and the Task Positive Network (TPN). We studied the associations between these biologic measures and the cognitive domains of executive function and memory, which are also known to be important to dementia risk. In particular, we investigated (Aim 1) TNN-TPN functional connectivity at baseline; (Aim 2) how the connectivity between and within the TNN and TPN were associated with dementia-linked cognitive functions; and (Aim 3) how these connectivity scores and cognitive functions changed longitudinally in the EC and Control Groups.Results: In Aim 1, we found that, the TPN and TNN were not strongly anti-correlated. In Aim 2, we found heterogeneous relations between functional connectivity and cognitivefunctions. In Aim 3, we found that these brain networks remained remarkably stable, and intervention effects were not statistically significant. Additionally, the EC group demonstrated an improvement in the executive functions domain of cognition compared to the Control group.Implications: The BHS is the first of its kind, to have investigated cognitive aging with biological markers in the brain and cognitive measures in a randomized controlled trialdesign of a volunteer intervention. These results contribute to a better understanding of functional connectivity in older adults, its relations to cognitive functions, and how these outcomes can be modified by senior service. We also developed analytic methodologies that can be standardized and applied to other fMRI studies.