1. Laboratory of Epidemiology and Population Sciences; National Institute on Aging, National Institutes of Health; Bethesda MD
2. Aging Research Center, Department of Neurobiology; Care Sciences, and Society, Karolinska Institutet-Stockholm University; Stockholm Sweden
3. Icelandic Heart Association; Kopavogur Iceland
4. Faculty of Psychology; University of Iceland; Reykjavik Iceland
5. Departments of Neurology and Radiology; Landspitali University Hospital; Reykjavik Iceland
6. Department of Radiology; Leiden University Medical Center; Leiden the Netherlands
7. Faculty of Medicine; University of Iceland; Reykjavik Iceland