PMC

Examples of the extent of WMH from individual subjects in this study. WMH load is expressed as percent of total cranial volume.

Group-averaged activations. (A) Episodic retrieval task and (B) High-load working memory task (p < .001 uncorrected, 10 voxel cluster threshold).

Global WMH volume is negatively correlated with activity in the dorsal prefrontal cortex during the high-load working memory task. Parameter estimates, indexing magnitude of activity during episodic retrieval relative to baseline, were averaged over each ROI for each subject. Global WMH volume is expressed as the log transform of total WMH load.

Behavioral tasks. (A) Episodic retrieval task. Participants first studied 36 objects (18 red/18 green). After a 1-hr delay, during scanning, participants viewed all 36 pictures again in black and white during the experimental blocks and indicated the color at study with a left or right button press. The control condition was a visual size-discrimination task. (B) The high-load working memory task is depicted here. The low-load condition was the same except that the study set contained four letters.