Executive function (EF) performance in older adults has been linked with functional and structural profiles within the executive control network (ECN) and default mode network (DMN), white matter hyperintensities (WMH) burden and levels of Alzheimer's disease (AD) pathology. Here, we simultaneously explored the unique contributions of these factors to baseline and longitudinal EF performance in older adults. Thirty-two cognitively normal (CN) older adults underwent neuropsychological testing at baseline and annually for three years. Neuroimaging and AD pathology measures were collected at baseline. Separate linear regression models were used to determine which of these variables predicted composite EF scores at baseline and/or average annual change in composite ΔEF scores over the three-year follow-up period. Results demonstrated that low DMN deactivation, high ECN activation and WMH burden were the main predictors of EF scores at baseline. In contrast, poor DMN and ECN WM microstructure and higher AD pathology predicted greater annual decline in EF scores. Subsequent mediation analysis demonstrated that DMN WM microstructure uniquely mediated the relationship between AD pathology and ΔEF. These results suggest that functional activation patterns within the DMN and ECN and WMHs contribute to baseline EF while structural connectivity within these networks impact longitudinal EF performance in older adults.
|Number of pages
|Published - Jul 15 2019
Bibliographical noteFunding Information:
This study was supported by the National Institute on Aging and National Center for Advancing Translational Sciences of the National Institutes of Health (grant numbers R01AG033036 , R01AG055449 , P30AG028383 , P01AG030128 , TL1TR001997 ). The content is solely the responsibility of the authors and does not necessarily represent the official views of these granting agencies. The authors declare no competing financial interests. The authors thank, Dr. Gregory Jicha for performing some of the lumbar punctures, Drs. Jon Trojanowski and Leslie Shaw for CSF analysis, Beverly Meacham for conducting some of the MRI scans, and Drs. Erin Abner and Richard Kryscio for providing biostatistics consultation.
© 2019 The Authors
ASJC Scopus subject areas
- Cognitive Neuroscience