Lifespan differences in adapting to cognitive and motor uncertainties

Adaptive behavior in uncertain environments requires joint cognitive and motor functions, which change across the lifespan. We developed a touchscreen-based task combining reinforcement learning and rapid reaching to test children (6–9), adolescents (13–16), young adults (18–30), and older adults (65–80). Participants predicted a butterfly’s location before rapidly reaching toward it as moving target. Consistent with an inverted‑u-shaped relationship with age, children and older adults showed reduced cognitive performance and weaker adaptation to uncertainty. During rapid reaching, they performed less well during initial movement but, unexpectedly, exhibited stronger adaptation to uncertainty. Cross‑domain effects included impaired motor spatial efficiency under cognitive uncertainty and enhanced cognitive performance under motor uncertainty. Cross‑domain correlations were most pronounced in children and young adults under high cognitive uncertainty. These findings advance a cross‑domain framework for lifespan adaptation and highlight the importance of integrating cognitive and motor processes in uncertain environments.