Prospective memory (PM) and executive functions (EF) are interconnected cognitive processes of particular importance in cognitive aging, given their central role in goal-oriented activities, planning, and executing everyday tasks — ranging from managing medication to regulating behavior. These tasks are essential to the functional autonomy and health-related quality of life for older adults. Both PM and EF are supported by the prefrontal regions of the brain and are fundamental contributors to an individual's overall well-being.
Different factors influencing EF and PM have been investigated, but demonstrated certain inconsistencies and it remains unresolved which factors are worth further investigations. The interplay between affect and metacognition can be of interest for cognition in older adults. Indeed, affect has been demonstrated to significantly influence different cognitive domains (e.g., retrospective memory), but the picture is not as detailed in the context of EF and PM, where inconsistent results have been demonstrated. These inconsistencies suggest that other factors may be at play such as metacognition, which has been linked to affect in healthy and clinical populations (e.g., depression). The main aim of this thesis is to investigate the interplay between affect, metacognition and cognitive performance in older age.
Previous studies indicated that the influence of neuroticism – emotional instability – on EF is inconsistent in cross-sectional studies and largely unexplored in longitudinal studies. In fact, a deeper understanding of the underlying mechanisms is lacking, which is an important knowledge gap considering that personality changes precede cognitive decline in older age. Thus, Study 1 investigated in a six-year longitudinal design the dynamics between neuroticism and EF through Bayesian analyses, with a focus on 768 older adults (Mage = 73.51 years; SD = 6.09 at Wave 1). A cross-lagged analysis was used to examine the data. Wave 1 revealed no correlation between neuroticism and Trail Making Test (TMT) scores. Interestingly, Wave 1 neuroticism did predict TMT performance in the at Wave 2, indicating that the more neurotic participants were, the lower they performed on the TMT six years later. Further examination indicated that this association was fully mediated by individuals’ perceived stress. These findings indicate that higher neuroticism in older adults may amplify perceived stress over time, which adversely affects their EF performance. Thus, the study uncovers a potential causal path where neuroticism can impair EF over a span of six years, highlighting perceived stress as a key mediating factor. The study concludes by exploring potential interventions that could mitigate these negative outcomes.
Neuroticism increases risk of developing psychological affective disorders, such as depression, which is one of the most common mental health issues experienced by older adults. Unfortunately, the relationship between depressive symptoms and PM in older adults has only been investigated in two studies which demonstrated inconsistencies, not allowing to draw solid conclusions. These inconsistencies may stem from the neglection of underlying factors such as metamemory representations, as depressive individuals experience distorted metaco
