Within-person trial-to-trial variability precedes and predicts cognitive decline in old and very old age: Longitudinal data from the Berlin Aging Study

Neurocomputational modeling and empirical evidence suggest that losses in neuronal signaling fidelity cause senescent changes in behavior. We appliedstructural equation modelingto five-occasion 13-yearlongitudinal datafrom the Berlin Aging Study (n=447; age range at t1=70–102 years) to test whether trial-to-trial reaction time variability in perceptual speed (identical pictures) antecedes and signals longitudinal decline in levels of performance on perceptual speed (digit letter and identical pictures) and ideational fluency (category fluency). Higher trial-to-trial variability preceded and predicted greater cognitive decline in perceptual speed and ideational fluency. We conclude that trial-to-trial variability signals impending decline in cognitive performance, and that theories of neurocognitive aging need to postulate developmental cascades between senescent changes in variability and central tendency