The mind decays in characteristic ways, and researchers are making inroads in linking the symptoms to the specific physical causes: "Advanced aging is associated with reduced attentional control and less flexible information processing. ... Older adults often perform poorly in situations where multiple goals and response rules must be maintained and coordinated ... Here, we explored age differences in recruitment of brain systems associated with attentional control and their relationship to behavior and markers of neuropathology. ... Examining 2 markers of preclinical pathology in older adults revealed that white matter hyperintensities (WMHs), but not high amyloid burden, were associated with failure to modulate activity in response to changing task demands. In contrast, high amyloid burden was associated with alterations in default network activity. ... These results, in addition to the rarity of co-occurrence between amyloid and white matter pathology among our sample of clinically normal adults, suggest that age-related cognitive failures may arise from multiple distinct pathologies. ... Age-related failures of dynamic allocation of attention may be an early consequence of disrupted neural integrity within prefrontal-parietal networks."