Cognitive functioning in centenarians: a coordinated analysis of results from three countries

Area of Science:

• Gerontology
• Cognitive Neuroscience
• Comparative Psychology

Background:

• Centenarians represent a unique population for studying cognitive aging.
• Cross-cultural comparisons of cognitive function in extreme old age are limited.
• Understanding cognitive reserve and its relation to longevity is crucial.

Purpose of the Study:

• To compare dementia prevalence and cognitive performance in centenarians across Japan, Sweden, and the United States.
• To examine age-related changes in cognitive abilities, focusing on crystallized and fluid intelligence.
• To investigate interindividual variability in cognitive performance among the oldest old.

Main Methods:

• Comparative analysis of existing longitudinal and cross-sectional studies.
• Assessment of dementia prevalence using standardized diagnostic criteria.
• Evaluation of cognitive performance across various domains, including semantic memory and processing speed.

Main Results:

• Dementia prevalence in centenarians ranged from 40% to 63%, with higher rates in women, varying by country.
• Centenarians exhibited lower overall cognitive performance compared to younger groups.
• Wider performance variability was observed in centenarians for crystallized abilities, narrower for fluid abilities.

Conclusions:

• Cognitive differentiation generally increases with age, particularly in crystallized intelligence.
• Cognitive function appears robust across different countries in centenarian populations.
• Cognitive abilities play a significant role in achieving extreme longevity.