Broadscale dampening of uncertainty adjustment in the aging brain

Abstract

AbstractThe ability to prioritize task-relevant inputs enables efficient behavior across the human lifespan. However, contexts in which feature relevance is ambiguous require dynamic exploration rather than stable selectivity. Although both cognitive flexibility and stability generally decline with ageing, it is unknown whether the aging brain differentially adjusts to changing uncertainty. Here, we comprehensively assess the dynamic range of uncertainty adjustments across the adult lifespan (N = 100) via behavioral modelling and a theoretically informed set of human neuroimaging signatures (EEG-, fMRI-, and pupil-based). As a group, older adults show a broadscale dampening of neuro-computational uncertainty adjustments. In support of a “maintenance” account of brain aging, older individuals with more young-like neural recruitment were better able to select task-relevant features, also in a Stroop task with low perceptual demands. Our results highlight neural mechanisms whose maintenance plausibly enables flexible task set, perception, and decision computations across the adult lifespan.