Abstract
Aging is characterized by a decline of cognitive control. In semantic cognition, this leads to the paradox that older adults usually show poorer task performance than young adults despite their greater semantic knowledge. So far, the underlying neural changes of these behavioral differences are poorly understood. In the current neuroimaging study, we investigated the interplay of domain-specific and domain-general networks in young and older adults during a verbal semantic fluency task. In both age groups, task processing was characterized by a strong interaction between the domain-general multiple-demand and the default mode system during semantic fluency. However, the behavioral relevance of strengthened connectivity differed between groups: While within- and between-network functional connectivity predicted better performance in young adults, these increases were associated with a performance decline in older adults. Our findings lend novel support to the notion of reduced efficiency in the aging brain, due to neural dedifferentiation in semantic cognition.
Competing Interest Statement
The authors have declared no competing interest.