Date of Award
Doctor of Philosophy (PhD)
Cognitive motivation is a feature of everyday experience with important consequences for decision-making across the adult life span. Yet, despite its hypothesized importance, very little is understood about what factors contribute to age-related changes in cognitive motivation (i.e., cognitive effort costs), how the measures used to assess cognitive motivation in the laboratory relate to daily life, and what neural mechanisms help to support decision-making when weighing the costs and benefits of engaging in cognitively effortful activities. To examine these questions, the current project employed a multimethod research strategy to assess cognitive effort decision-making in younger and older adults, and how this relates to daily life activities, working memory capacity, and relevant neurobiological substrates. Specifically, the Cognitive Effort Discounting Paradigm (Cog-ED) was used to precisely quantify individual differences in the valuation (or costs) of cognitive effort with multiple incentive types (e.g., monetary gains, losses). In addition, Ecological Momentary Assessment (EMA) was used to measure the mental demand of daily life activities in both older and younger adults. Data were aggregated across multiple projects indexing individual differences in working memory capacity to better understand the contribution of cognitive ability on the relationship between cognitive motivation and daily life decision-making. Finally, in a subset of younger adult participants, simultaneous PET-fMRI was utilized to examine the neural mechanisms underlying cognitive effort costs by assessing both brain activity during decision-making and individual differences in dopamine receptor availability. The findings provide strong support for increased cognitive effort costs in older adults across both gain and loss incentive framing and further demonstrate the ecological validity of these costs in both younger and older adults. Critically, participants who had lower effort costs in the gain frame tended to report engaging in more mentally demanding daily life activities, but the opposite pattern was observed in the loss frame. On the other hand, there was no evidence that working memory capacity was related to either cognitive effort costs or daily life mental demand. Moreover, the neuroimaging data provide initial support for the contribution of both brain activity during effort valuation and individual differences in dopamine receptor availability on cognitive effort costs and daily life mental demand. Taken together, these results suggest cognitive effort costs, as measured through behavioral choice patterns in a neuroeconomic decision-making task, can be used to explain engagement in mentally demanding activities during daily life and that individual differences in brain activity and striatal dopamine availability help to further explain this choice behavior across the laboratory and daily life.
Chair and Committee
Deanna Barch, Tammy English, Sarah Eisenstein, Jason Hassenstab,
Crawford, Jennifer, "Aging and the Costs of Cognitive Effort" (2022). Arts & Sciences Electronic Theses and Dissertations. 2792.
Available for download on Tuesday, December 21, 2027