Our brains change as we age. For instance, the availability of the neurotransmitter dopamine drops, as does the volume of gray and white matter. However, we lack data on average long-term changes in these measures and on how these changes are related to cognitive performance. We thus have incomplete knowledge on aging, the brain, and cognition.
The Cognition, Brain, and Aging (COBRA) study aims to help fill these crucial gaps in our basic knowledge with data on approximately 180 people, gathered over a decade. Baseline data were collected between 2012 and 2014 when participants were 63-67 years old. The first follow-up begins now, in September 2017, and the second in 2022. In all waves, positron emission tomography and magnetic resonance imaging are used to assess multiple brain measures, including dopamine D2 receptors, markers of grey- and white-matter integrity, and functional networks. Cognition is evaluated using measures of working memory, episodic memory, and speed, and a comprehensive lifestyle questionnaire is administered.
The study has several aims. One is to increase our understanding of the shared and unique contributions of changes in dopamine, grey matter, and white matter to changes in cognitive performance in old age. Another is to explore the sequence of change; that is, to determine which change occurs first and how that might affect subsequent changes in other brain variables. A third is to better understand the connections between lifestyle and the observed age-related changes in the brain and cognition.
COBRA involves scientists from ARC, Umeå University, and the Max Planck Institute for Human Development in Berlin. It is funded by the af Jochnick Foundation, the Wallenberg Foundation, and a Leibniz Research Award.

COBRA retreat 26 October 2016. Photo: Johanna Bylund