Cognitive decline is mediated by gray matter changes during middle age
Date
2014Abstract
The present theoretical framework of Alzheimer’s disease proposes that pathophysiological changes
occur 10e20 years before the diagnosis of dementia. We addressed the question of how age-related
changes in gray matter mediate the cognitive performance during middle age. Eighty-two participants
(40e50 years, 2) were assessed with a comprehensive neuropsychological battery covering a broad
spectrum of cognitive domains and components. Mediation effects were studied with hierarchical
regression and bootstrapping analysis. Results showed that more vulnerable cognitive components were
related to executive functioning and in a lesser degree to processing speed. Age-related differences in
gray matter mainly involved the frontal lobes. Moreover, age-related differences in visuoconstructive,
visuospatial functions, reaction time, and mental flexibility and executive control were mediated by
several gray matter regions. It is important to increase the knowledge of the impact of brain changes on
cognitive function during middle age. To define the early stages of the aging process may allow early
detection of pathologic changes and therapeutic interventions.