A non-unitary view of aging: Behavioral and neural variability during working memory performance in younger and older adults

Researcher: Emi Saliasi, PhD
Thesis defense: 2014
Second promotor: Monicque M. Lorist, PhD (Exp. Psychology, RuG)
Funding: BCN-BRAIN

Aging is not a unitary process; rather the trajectory and degree of age-related changes vary not only considerably across older individuals but also across cognitive domains. In this thesis, we have showed that some older adults are able to maintain a relatively high level of cognitive functioning while others show overall performance decline across a variety of cognitive domains. In addition to changes in overall cognitive performance, we investigated age- and performance-related effects on brain activity. We focused specifically on working memory, one of the cognitive functions most affected by aging. One consistent finding in our studies was the presence of more activity in frontal regions of the aging brain. Enhanced activation in brain regions previously associated with working memory processes was related to more efficient performance in the elderly. On the other hand, enhanced activation in several brain regions related to working memory as well as other cognitive functions seems to be related to less efficient performance in the elderly. The results in this thesis emphasize that the relationship between performance efficiency and neural activity is complex and is affected by aging, the task at hand and individual differences.