Potential Diffusion Tensor Imaging Biomarkers for Elucidating Intra-Individual Age-Related Changes in Cognitive...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Cognitive aging research often relies on cross-sectional data, potentially missing individual aging trajectories.
• White matter (WM) integrity is implicated in cognitive aging, but its role in intra-individual changes requires further investigation.

Purpose of the Study:

• To compare age-related differences (cross-sectional) and changes (longitudinal) in cognitive control and processing speed.
• To investigate the relationship between WM integrity metrics and intra-individual cognitive aging.

Main Methods:

• Acquired diffusion-weighted imaging (DTI) data from 114 participants over 1-2 years.
• Assessed cognitive control and processing speed using neuropsychological and computerized tasks.
• Analyzed DTI metrics (FA, MD, RD, AxD) and their correlation with cognitive changes.

Main Results:

• Cross-sectional age effects on cognitive control diminished in longitudinal analyses.
• Longitudinal data showed MD, RD, and AxD (especially in anterior thalamic radiation) strongly correlated with aging.
• Processing speed was the most prominent cognitive function reflecting DTI-related effects longitudinally.

Conclusions:

• Intra-individual cognitive aging is better reflected by longitudinal white matter changes, particularly axonal/myelin damage (MD, RD, AxD).
• Processing speed is a sensitive indicator of these age-related white matter changes.
• Specific DTI measures may serve as neuroimaging biomarkers for intra-individual cognitive aging.