Age-related Differences in Response Inhibition Are Mediated by Frontoparietal White Matter but Not Functional
Shireen Parimoo1,2, Cheryl Grady1,2, Rosanna Olsen1,2
1University of Toronto.
Journal of Cognitive Neuroscience
|April 5, 2024
Summary
Frontal white matter integrity, not brain network activity, drives age-related declines in cognitive control. Reduced frontal white matter "disconnection" impacts performance on response inhibition tasks in older adults.
Area of Science:
- Neuroscience
- Cognitive Neuroscience
- Neuroimaging
Background:
- Healthy aging is associated with altered cognitive control, often characterized by reduced performance and increased frontoparietal network activity.
- The cortical disconnection hypothesis posits that age-related white matter degradation impairs neural communication, impacting behavior.
Purpose of the Study:
- To investigate the contribution of white matter microstructure to frontoparietal network recruitment and behavioral performance during a go/no-go task across the adult lifespan.
- To determine if age-related white matter changes underlie cognitive control differences.
Main Methods:
- Functional magnetic resonance imaging (fMRI) and diffusion-weighted imaging (DWI) were employed in a lifespan sample (n=145).
- Participants completed a go/no-go task assessing response inhibition.
Main Results:
- Older and female participants exhibited slower reaction times (RTs) on go trials.
- Frontoparietal network recruitment did not vary with age or correlate with white matter fractional anisotropy (FA).
- Frontal white matter FA and go RTs jointly mediated the relationship between age and no-go accuracy.
Conclusions:
- Frontal white matter microstructural integrity, or "disconnection," is a key factor in age-related cognitive control deficits.
- White matter FA may be a more critical determinant of cognitive aging than task-related functional activation in the frontoparietal network.
