Paper Info
Title
Differential age-dependent associations of gray matter volume and white matter integrity with processing speed in healthy older adults.
Abstract
Slower processing speed (PS), a highly robust feature of cognitive aging, is associated with white matter (WM) deterioration and gray matter volume (GMV) loss. Traditional linear regression models assume a constant relationship between brain structure and cognition over time. To probe for variation in the association between WM and GMV and PS over time, we used a novel sparse varying coefficient model on data collected from 126 relatively healthy older adults (67 females, aged 58–85years) evaluated with MRI and a standardized neuropsychological test-battery. We found that WM microstructural differences indexed by fractional anisotropy values in the fronto-striatal tracts (internal and external capsule) showed a stronger association with PS before the age of 70years. Contrastingly, GMV values of the left putamen and middle occipital gyrus were more strongly correlated with PS after 70years. Additionally, within GM and WM compartments, there was heterogeneity in the temporal sequence in which different cortical and subcortical elements were most strongly associated with PS. Together, these observations provide a more nuanced account of the relationships between different structural components of the aging brain and processing speed, a key cognitive domain affected in relatively healthy older adults.
Year
DOI
Venue
2015
10.1016/j.neuroimage.2015.08.034
NeuroImage
Field
DocType
Volume
Developmental psychology,Neuroscience,White matter,Fractional anisotropy,Psychology,Cognition,Aging brain,External capsule,Neuropsychology,Linear regression,Gray (unit)
Journal
123
ISSN
Citations 
PageRank 
1053-8119
2
0.40
References 
Authors
14
8
Name
Order
Citations
PageRank
Zhaoping Hong120.40
Kwun Kei Ng2252.14
Sam K. Y. Sim330.79
Mei Yi Ngeow420.40
Hui Zheng5195.74
June C. Lo6181.62
Michael W. L. Chee727926.13
Juan Zhou8834.71