title: Cognitive reserve moderates the relationship between neuropsychological performance and white matter fiber bundle length in healthy older adults.
abstract: Recent work using novel neuroimaging methods has revealed shorter white matter fiber bundle length (FBL) in older compared to younger adults. Shorter FBL also corresponds to poorer performance on cognitive measures sensitive to advanced age. However, it is unclear if individual factors such as cognitive reserve (CR) effectively moderate the relationship between FBL and cognitive performance. This study examined CR as a potential moderator of cognitive performance and brain integrity as defined by FBL. Sixty-three healthy adults underwent neuropsychological evaluation and 3T brain magnetic resonance imaging. Cognitive performance was measured using the Repeatable Battery of Assessment of Neuropsychological Status (RBANS). FBL was quantified from tractography tracings of white matter fiber bundles, derived from the diffusion tensor imaging. CR was determined by estimated premorbid IQ. Analyses revealed that lower scores on the RBANS were associated with shorter whole brain FBL (p = 0.04) and lower CR (p = 0.01) CR moderated the relationship between whole brain FBL and RBANS score (p < 0.01). Tract-specific analyses revealed that CR also moderated the association between FBL in the hippocampal segment of the cingulum and RBANS performance (p = 0.03). These results demonstrate that lower cognitive performance on the RBANS is more common with low CR and short FBL. On the contrary, when individuals have high CR, the relationship between FBL and cognitive performance is attenuated. Overall, CR protects older adults against lower cognitive performance despite age-associated reductions in FBL.
authors.affiliation: Department of Psychological Sciences, University of Missouri - Saint Louis, One University Boulevard, Stadler Hall 327, Saint Louis, MO, 63121, USA. lauriebaker@umsl.edu.
authors.forename: Laurie M
authors.initials: LM
authors.lastname: Baker
authors.affiliation: Computer Science Department, Brown University, Providence, RI, 02912, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Laidlaw
authors.affiliation: Computer Science Department, Brown University, Providence, RI, 02912, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Cabeen
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
authors.forename: Erbil
authors.initials: E
authors.lastname: Akbudak
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Conturo
authors.affiliation: Division of Biology and Medicine, Brown Medical School, Providence, RI, 02912, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Correia
authors.affiliation: Missouri Institute of Mental Health, St. Louis, MO, 63134, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Tate
authors.affiliation: Missouri Institute of Mental Health, St. Louis, MO, 63134, USA.
authors.forename: Jodi M
authors.initials: JM
authors.lastname: Heaps-Woodruff
authors.affiliation: Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Brier
authors.affiliation: Missouri Institute of Mental Health, St. Louis, MO, 63134, USA.
authors.forename: Jacob
authors.initials: J
authors.lastname: Bolzenius
authors.affiliation: Department of Psychological Sciences, University of Missouri - Saint Louis, One University Boulevard, Stadler Hall 327, Saint Louis, MO, 63121, USA.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Salminen
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Lane
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: McMichael
authors.affiliation: Department of Psychological Sciences, University of Missouri - Saint Louis, One University Boulevard, Stadler Hall 327, Saint Louis, MO, 63121, USA.|Missouri Institute of Mental Health, St. Louis, MO, 63134, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Paul
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D058245:Cognitive Reserve; D056324:Diffusion Tensor Imaging; D005260:Female; D000073656:Healthy Aging / Q000473:pathology* / Q000523:psychology*; D006801:Humans; D007360:Intelligence; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D009483:Neuropsychological Tests; D012044:Regression Analysis; D012737:Sex Factors; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology*
keywords: Aging; Cognition; Diffusion tensor imaging; Neuropsychological assessment; RBANS