Cognitive functioning in aging and dementia:: The Kungsholmen Project

The Kungsholmen Project (KP) is a community-based longitudinal study of aging and dementia targeting the 75+ population. In this article, we review empirical studies with a cognitive focus from the KP. The main findings indicate that (a) there is an age-related decline for some cognitive domains (e.g., episodic memory, verbal fluency, visuoconstructive skill, psychomotor speed), but not for others (e.g., primary memory, visuoperceptive skill, motor-hand coordination), (b) multiple individual-difference variables within demographic (e.g., sex, education) life-style (e.g., activity levels), genetic (e.g., apolipoprotein E genotype), and health-related (e.g., vitamin B deficiency, depression, diabetes) domains are related to late-life cognitive functioning, (c) a potential for improving cognitive performance - a reserve capacity - is present also among very old adults, (d) the 2 most common dementia diseases, Alzheimer's disease (AD) and vascular dementia (VaD), affect cognition in a strikingly similar manner, (e) the role of individual-difference variables in cognitive functioning is markedly reduced in dementia - the pathogenesis itself may overshadow the influence of other variables, and (f) there is a long preclinical period in dementia during which cognitive deficits are detectable. As is true with the other projects represented in this issue, the KP portrays a rather diversified picture of cognitive aging, although systematic patterns are evident with regard to the variability of late-life cognitive functioning.