Executive control function, brain activation and white matter hyperintensities in older adults
Vijay K Venkatraman1, Howard Aizenstein, Jack Guralnik
1Department of Bioengineering, School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Neuroimage
|November 20, 2009
Summary
Older adults with higher executive control function (ECF) performance show greater brain activation. This increased activation, particularly in the posterior parietal cortex, may help maintain accuracy despite brain structural abnormalities like white matter hyperintensities.
Area of Science:
- Neuroscience
- Cognitive Aging
- Neuroimaging
Background:
- Older adults often exhibit increased brain activation during executive control function (ECF) tasks.
- It remains unclear if this heightened activation compensates for brain structural abnormalities to maintain performance.
Purpose of the Study:
- To investigate the relationship between fMRI activation patterns, ECF task performance, and brain structural abnormalities in older adults.
Main Methods:
- Cross-sectional analysis of 25 community-dwelling older adults.
- Assessed fMRI activation, accuracy on the Digit Symbol Substitution Test (ECF task), and volumes of white matter hyperintensities (WMH) and brain atrophy.
Main Results:
- Higher accuracy on the ECF task correlated with greater fMRI activation in ECF-related regions (e.g., frontal and parietal cortex).
- Increased WMH volume was associated with reduced activation in accuracy-related areas.
- A significant interaction indicated that WMH volume influenced posterior parietal activation differently based on accuracy levels.
Conclusions:
- Greater brain activation and recruitment of additional areas in older adults are linked to better performance on ECF tasks.
- Posterior parietal activation appears crucial for maintaining accuracy, especially when structural brain abnormalities (e.g., WMH) are present.
