UC Irvine

Negative emotional states are frequently associated with declines in cognitive performance. However, the mechanisms and pathways underlying the relationship between emotion and cognition are not well understood. In a three-study series, this dissertation examined associations between affect, perceived stress, and cognitive functioning and how unconstructive repetitive thinking (URT), and inflammatory markers may underlie the association between emotion and cognition. The first two studies focused on the association between fluctuations in momentary affective experiences and cognitive functioning. Study 1 examined how high arousal negative and positive emotional states relate to working memory across different age groups. Findings indicated that both high negative and positive affect were linked to poorer working memory performance, with younger adults experiencing more pronounced negative effects when positive affect increased. Study 2 explored the impact of momentary unconstructive repetitive thinking (URT), such as worry and rumination, on cognitive function throughout the day. Contrary to expectations, greater URT was associated with improved working memory, especially in younger adults, although this relationship was moderated by negative affect, which suppressed the cognitive benefits of URT. Study 3 investigated the effects of chronic perceived stress on cognitive performance and its potential mediation by inflammatory cytokines among adults in midlife. Results revealed that higher perceived stress was directly related to poorer cognitive function and elevated levels of certain inflammatory markers; however, inflammation did not mediate the perceived stress–cognition link. These studies underscore the nuanced interactions between affective states, stress, and cognitive performance, highlighting age-related differences and the complex role of physiological stress responses in cognitive aging. Overall, in moments when positive and negative affect were heightened, cognitive function worsened, but only for younger and middle-aged adults. Across younger and middle-aged adults, moments of increased URT were related to better cognitive performance; and, when negative affect was accounted for during moments of greater URT, cognition was more affected by momentary URT. The momentary relationships between affect and age on cognition, as well as greater URT and better cognition, provide notable contributions to the area of emotion and cognition research focused on understanding the differences in state versus trait emotional processes. The findings demonstrate that cognition is sensitive to both state and trait emotional processes, which has important implications for understanding when and how cognitive function improves or when interference occurs.