Changes In Cerebral White Matter, Vascular Risk And Cognition Across The Adult Lifespan

CHANGES IN CEREBRAL WHITE MATTER, VASCULAR RISK ANDCOGNITION ACROSS THE ADULT LIFESPANbyANDREW R. BENDERMay 2014Advisor: Dr. Naftali RazMajor: Psychology (Behavioral and Cognitive Neuroscience)Degree: Doctor of PhilosophyNumerous studies over the past decade have used diffusion tensor imaging (DTI) toexamine the associations between age, diffusion and anisotropy measures of cerebral whitematter (WM), and cognitive performance. However, few have examined relationshipsbetween intra-individual change in DTI measures of WM and cognitive function. It ispossible that the extant cross-sectional findings are a poor representation of age-relatedchange in WM and cognition. The present study used latent difference-score modeling (LDM)to assess change over two years in DTI indices fractional anisotropy (FA), radial diffusivity (DR), axial diffusivity (DA) and mean diffusivity (MD). In addition, we examined the effectsof WM change on concomitant change in age-sensitive cognitive domains, while controllingfor individual differences in duration of hypertension treatment, a common marker ofvascular risk. A sample of 96 healthy participants spanning the adult lifespan underwent DTIscanning and cognitive testing at baseline and following a two-year delay. Univariate latentdifference score model (LDM) analyses showed cross-sectional associations between DTImeasures and age did not accurately describe actual change in WM. Regions including the