The Ups and Downs of Cognitive Function: Neuroticism and Negative Affect Drive Performance Inconsistency.

<p><b>OBJECTIVES: </b>Response time inconsistency (RTI)-or trial-to-trial variability in speeded performance-is increasingly recognized as an indicator of transient lapses of attention, cognitive health status, and central nervous system integrity, as well as a potential early indicator of normal and pathological cognitive aging. Comparatively, little research has examined personality predictors of RTI across adulthood.</p><p><b>METHODS: </b>We evaluated the association between the personality trait neuroticism and RTI in a community-dwelling sample of 317 adults between the ages of 19-83 and tested for two indirect pathways through negative affect (NA) and cognitive interference (CI).</p><p><b>RESULTS: </b>The personality trait neuroticism predicted greater RTI independent of mean response time performance and demographic covariates; the results were age-invariant. Furthermore, NA (but not CI) accounted for this association and moderated mediation model results indicated that older adults were more vulnerable to the adverse effects of NA.</p><p><b>DISCUSSION: </b>Neuroticism predicts greater RTI irrespective of mean performance and this effect is driven largely by heightened negative emotionality that may be particularly detrimental for older adults.</p>