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Updated: Jun 8, 2026

Assessment of Age-related Changes in Cognitive Functions Using EmoCogMeter, a Novel Tablet-computer Based Approach
Published on: February 14, 2014
Propositional density and cognitive function in later life: findings from the Precursors Study.
Michal Engelman1, Emily M Agree, Lucy A Meoni
1Department of Population, Family, and Reproductive Health, Johns Hopkins Bloomberg School of Pubic Health, 615 North Wolfe Street, Room E4647, Baltimore, MD 21205, USA. mengelma@jhsph.edu
Written propositional density in early adulthood is a predictor of Alzheimer's disease (AD) later in life. Lower density in essays suggests a higher risk, highlighting its potential as a cognitive reserve marker.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Linguistics
Background:
- Alzheimer's disease (AD) is a progressive neurodegenerative disorder.
- Previous research (Nun Study) suggested a link between early-life writing and later dementia.
- The Johns Hopkins Precursors Study provides longitudinal data to re-examine this association.
Purpose of the Study:
- To test the hypothesis that lower written propositional density in early adulthood predicts Alzheimer's disease (AD).
- To re-examine the association in a cohort with diverse demographics.
Main Methods:
- Longitudinal data from the Johns Hopkins Precursors Study.
- Case-control study: 18 AD patients matched with 36 controls.
- Linguistic analysis of medical school admission essays (age 22) using Computerized Propositional Idea Density Rater 3.
- Conditional logistic regression to calculate adjusted odds ratios.
Main Results:
- Mean propositional density was significantly lower in AD cases (4.70) compared to controls (4.99).
- Higher propositional density substantially reduced the odds of developing AD (OR = 0.16).
Conclusions:
- Early-life written propositional density is a potential predictor of AD in later life for both men and women.
- Propositional density may serve as a marker of cognitive reserve in life-course studies of cognition.
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