Understanding cognitive ageing: From unraveling inter-individual variability in cognitive functioning to advancing research

Cognitive functioning is a key determinant of healthy ageing, and exhibits marked variability across both normal and pathological ageing. The present thesis used this heterogeneity to increase our understanding of cognitive ageing, focusing on the interplay between cognitive functions, brain health, and potentially modifiable factors contributing to risk and resilience (socio-behavioural or lifestyle-related factors). Additionally, this thesis aimed to further advance research on cognitive ageing. An open dataset was introduced to study the underlying mechanisms of risk and resilience in cognitive ageing, an innovative method was employed to better utilize inter-individual variability in the context of fMRI studies, and the standardized reporting of memory interventions was facilitated with an online tool. Reflecting the multifaceted nature of cognitive ageing research, the presented studies considered various study populations (e.g., normal ageing vs. Alzheimer’s disease dementia), and applied a wide range of methods (e.g., qualitative content analysis vs. quantitative MRI). The insights and developments presented in this dissertation contribute to a better understanding of cognitive aging and provide directions for future research and interventions aimed at preserving cognitive  functioning in later life.