Cognition, brain, and aging (COBRA): A longitudinal multimodal imaging study
Memory functions and other cognitive abilities (such as attention and executive functions) decline for many elderly persons. Globally, major efforts are taken to investigate if this kind of decline can be reduced, for example through systematic training. These actions, if they are successful, could be of great importance for both individuals and society in general. However, there is still missing a lot of knowledge concerning how cognitive decline is connected to age-related changes in the brain.
In particular, there are very few longitudinal studies in which individuals are followed over time that maps changes in the brain in relation to changes in cognitive abilities. This is a critical shortage since the existing results, for example from the Swedish Betula-project, clearly shows that longitudinal data can strongly deviate from attempts to estimate age-related changes from cross-sectional studies (that are comparing individuals of different ages).
The purpose with this project is that for a decade to follow, and on three occasions examine a group of about 190 people between 63 and 67 years of age. The study's design and the thorough measurements have been developed to maximize the chances of capturing subtle patterns of change over time, and the participating researchers specific expertise ensures that the study is carried out in an optimal way. Participants undergo a thorough cognitive examination, brain structure and functional activation patterns are examined with MRI and functionality of the brain's dopamine system is mapped with positron emission tomography (PET). The latter is a unique contribution to the international research community and is highly topical because different studies show that dopamine function is not only critical for our motor skills, but also cognition.
We expect that some of the participants will demonstrate impaired cognitive ability, which can be related to the different brain recordings. In addition, lifestyle habits will be identified, such as physical activity, diet and sleep, which can further illustrate why deterioration is seen in some but not other individuals. Such knowledge can inform theory and practice about the aging brain's constraints and opportunities.
Cognitive impairments in aging compromise the well-being of individuals and make independent living difficult. Such impairments come with major individual and societal costs. Hence, developing means of preserving functioning in old age is of great importance. However, current knowledge of the brain mechanisms underlying age-related cognitive decline is insufficient to inform design of effective intervention programs. Few studies have comprehensively integrated age-related brain changes as measured by different in vivo imaging modalities and linked such changes to cognitive decline, and hardly any previous multi-modal imaging studies used a longitudinal design. This is a noteworthy omission as inferences of change from cross-sectional comparisons may significantly deviate from inferences based on actually measured longitudinal change.
We will follow a large representative cohort of 63-67 year-old healthy individuals over one decade, and at multiple measurement points assess dopamine availability, structural integrity of white and grey matter, functional brain integrity, cognitive performance, and engagement in relevant life-style activities. Thereby, we will yield crucial and novel information on brain mechanisms of cognitive decline in aging as well as on how life-style choices may induce protective effects on brain functions and related cognitive operations. This information will pave the road for successful design and implementation of intervention and prevention programs.
The study will follow a large cohort (n = 190) of 63-67 year-old healthy individuals randomly selected from the population registry in Umeå over a 10 year period. Cognitive performance, functional and structural brain integrity, and relevant lifestyle-related factors will be assessed at three measurement points, each separated by 4.5 years.