Cognitive functioning of 75- and 80-year-old people and changes during a 5-year follow-up

The aim of the study was to analyze cognitive functioning among two cohorts of elderly people, aged 75 and 80 years at baseline, and changes in the functioning during a five-year period. Cognitive functioning was assessed using psychometric tests, neuropsychological tasks, metacognitive self-evaluations, cognitive screening tests and reaction time tasks. The objective methods correlated significantly with each other, and only one general factor was clearly produced by the factor analyses. However, the speed of cognitive processing was concluded to have a central meaning in the kind of assessments used in this study. Selective attrition affected the results of psychometric and neuropsychological methods; subjects with better cognitive functioning participating in the follow-up assessments. Among those retested, the cognitive level decreased significantly, but the magnitude of the decline was usually low. Differences between the men and the women were mostly nonsignificant. The retest correlations were high in the psychometric tests but lower in many of the neuropsychological and metacognitive methods. Connections between the metamemory scores and the objective test scores were variable.