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The association between personality and longitudinal cognitive trajectories is independent of baseline brain variables
Author(s) -
De Leon Fransia S,
Mungas Dan M,
Gavett Brandon E,
Fletcher Evan M,
Farias Sarah Tomaszewski
Publication year - 2021
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.056461
Subject(s) - psychology , extraversion and introversion , brain size , neuroticism , agreeableness , conscientiousness , longitudinal study , personality , developmental psychology , clinical psychology , big five personality traits , medicine , social psychology , radiology , pathology , magnetic resonance imaging
Background Previous work has shown that select personality and other interpersonal characteristics influence late‐life cognitive outcomes. However, it is not well understood whether these associations are dissociable from the effects of late‐life brain integrity. The current study examines whether personality characteristics are associated with cross‐sectional and longitudinal cognitive variables in a diverse cohort of older adults and whether these associations are independent of brain integrity as measured by structural MRI. Method 157 participants (mean age 73.1±6.3 years) from the UC Davis ADC longitudinal Diversity Cohort were evaluated using the Spanish and English Neuropsychological Assessment Scales (SENAS) to assess verbal episodic memory, semantic memory, executive function, and spatial ability. The Big 5 personality measures were used to assess openness, conscientiousness, agreeableness, neuroticism, and extraversion as well as positive affect, sadness, meaning in life, and self‐efficacy. Baseline brain (MRI) variables including total gray matter volume, hippocampus volume and total white matter hyperintensity volume were also measured (n = 131). A parallel process, multi‐level model of the four longitudinal cognitive outcomes yielded intercept and linear slope random effects for each outcome. Slope random effects were highly correlated and summarized by a global slope second order factor. Global slope and individual intercepts were regressed on personality variables, covariates (age, gender, education, race/ethnicity, and recruitment source), and baseline brain variables. Result Positive affect (p=0.004) and openness to new experience (p=0.009) demonstrated positive associations with longitudinal change in cognition that were independent of baseline brain variables and covariates (Table 2). Other personality variables, including conscientiousness, extraversion, neuroticism, agreeableness, sadness, meaning in life, and self‐efficacy did not demonstrate significant associations with cognitive change. Lower neuroticism and higher conscientiousness were associated with higher spatial ability intercepts, and lower sadness was associated with a higher episodic memory intercept, independent of covariates and brain variables. Conclusion Positive affect and openness are significantly associated with longitudinal cognitive trajectories, independent of demographics and cross‐sectional brain variables, including total gray matter volume, hippocampal volume, and total white matter hyperintensity volume. Future research will help to delineate how individual differences in personality and behavior relate to late‐life brain and cognitive changes.