Lifebrain: Breaking new ground in Lifespan Cognitive Neuroscience

The project has a lifespan perspective with the goal of explaining, predicting, and improving cognitive function from birth to old age. Our cognitive functioning affects all aspects of life, and to understand health and disease development at all ages, it is important to understand the entire lifespan. The project investigates both normal variation, risk groups, and disease development. The project is based on four principles of the brain's lifespan and what regulates its development: 1. The brain changes throughout life. 2. There are significant individual differences, combined with age-typical traits. 3. Early-life factors influence the brain and our mental abilities throughout the lifespan. 4. The boundary between health and disease is dimensionally defined for some brain diseases. The project has examined the role of these overarching principles in explaining variations in the brain's lifespan. This has provided new knowledge about both general and individual factors that affect cognitive functioning, which can be used in prevention and treatment strategies. These issues require the examination of large samples of research participants using a variety of methods. Particularly important in this project are neuropsychological and cognitive examinations combined with brain imaging using MRI. Currently, we have collected data from over 4,000 examinations of around 2,000 participants aged between 4 and 90+. In addition, we use large international databases to test whether the findings are consistent across groups. In some of these analyses, we have included more than 500,000 participants, with over 50,000 having MRI scans of the brain. We have focused on the effect of cognitive training on memory function and brain structure, studied factors that influence brain plasticity, examined brain changes throughout life that are relevant to cognitive function, and identified factors that co-vary with these changes, such as genetics, sleep quality, and social factors like education and income. For example, we find that poorer self-reported sleep is associated with some increase in brain tissue loss over time, but the relationships are not strong. We have also focused extensively on how individual differences in brain activity relate to our ability to encode, store, and retrieve memories, in other words, what constitutes good memory function. We observe that both young and old individuals with good memory function use their brains in a similar way when learning information, whereas older individuals with slightly poorer function do not show the same pattern of brain activity as young individuals. We have also examined the relationship between the brain, cognition, and socio-economic factors, and how these vary across different samples and countries in Europe and the USA. We find, among other things, that associations between socio-economic factors, the brain, and cognition seem to be established early in life and vary greatly among the different cohorts we have studied from various countries in Europe and the USA. For example, there are differences in brain structure between participants with higher and lower education, but these differences remain stable throughout adulthood, so aging-related brain changes, such as higher or lower levels of change over time, are not influenced. We have also shown that stable relationships exist between general cognitive function and brain structure, primarily remaining stable over time, but participants with high function tend to show tendencies for the brain to change less in old age than participants with lower function.

Prosjektet har bidratt med ny kunnskap om både generelle og individuelle faktorer som påvirker kognitiv fungering. Denne kunnskapen kan brukes i forebyggings- og behandlingsstrategier for hjernehelse og ikke-optimal kognitiv fungering. Resultatene har vist hvordan målrettet ikke-medikamentelle intervensjoner kan påvirke kognitiv funksjon, spesielt hukommelse, og hvilke individuelle faktorer som påvirker dette. Dette er kunnskap som er nyttig ved utvikling av individtilpassede intervensjons og prevensjonsprogrammer. Prosjektet har også demonstrert at faktorer i livet har stor betydning for senere kognitiv funksjon, også i høy alder. Dette betyr at tiltak for å bedre helse under svangerskap og i nyfødtperioden vil kunne ha stor betydning for kognitiv funksjon resten av livet. Resultatene gir dermed viktig kunnskap om når i livet tiltak vil kunne ha størst effekt på hjernehelse og kognitiv funksjon. Prosjektet har også sett på sammenhenger mellom ulike faktorer som ofte regnes som modifiserbare livsstilsfaktorer og hjernehelse. Kunnskap om slike relasjoner og størrelsen på dem er viktig for individtilpasset og generelle hjernehelseråd. Vi har f eks funnet at selv om det er sammenhenger mellom ulike søvnproblemer og hjerneatrofi, er disse forholdene svake, spesielt for søvnlengde. Resultatene tyder derfor på at intervensjoner med formål å endre søvnlengde neppe vil ha stor betydning for hjernehelse i voksne. Vi har ikke undersøkt dette i barn og ungdom.

Cognitive functioning affects every aspect of human life. Lifebrain`s primary objective is to explain, predict and promote cognitive function from birth to old age. Genetic and experiential factors interact at all times throughout life to shape brain and cognition. A key knowledge challenge is thus that to understand health and disease at any given age, we need to take into account the entire life course. We propose a multidisciplinary approach, investigating brain and cognition longitudinally in individuals at all ages of the lifespan, in large community samples, along with neurocognitive at-risk and disorder Groups. We use brain imaging, genotyping, standardized and experimental cognitive data as well as registry information. Lifebrain will be implemented through 1) The existing longitudinal "in-house" LCBC sample of 1500 participants aged 4to 90+ years, and a total of about 3000 examinations. 2) The addition of 1100 new examinations as part of Lifebrain. 3) Samples available through collaborators and international databases (n > 10 000) to replicate, compare and extend the findings. We hypothesize that 1) Change is continuously ongoing, in part governed by genetic and evolutionary organization, 2) While age trends can thus be identified, there is substantial individual variation, reflective of genetic and environmental factors affecting offset, slope or their interaction, 3) Early life factors exert influence through the entire life course, necessitating long term studies and linkage to registry data on pre-, neonatal and other early variables, and 4) Differences in health and disease of brain and cognition may in several instances be found along a continuum, i.e. be of dimensional nature. Hence, investigating normal variation along with the borders of disease is key to understand both. Lifebrain will enable novel understanding of determinants of general as well as individual trajectories, which can be utilized in strategies for prevention and intervention.