Older adults update internal predictions about their environment more slowly than younger adults, and this reduced belief updating corresponds with impaired adaptive step initiation. When conditions change unexpectedly, the delay in revising expectations degrades the anticipatory motor adjustments that precede a step — a mechanism relevant to fall risk and the loss of independent mobility with age.
Key Points
- Belief updating slows with age, delaying revision of movement expectations
- Impaired prediction degrades anticipatory adjustments preceding step initiation
- Cognitive inference, not muscle strength alone, shapes mobility decline
Longevity Analysis
Mobility loss in later life is routinely attributed to muscle mass, joint integrity, and reaction speed, yet the limiting factor here is how quickly the brain revises its model of the ground ahead. Gait and balance training that only loads the body misses the inferential layer — unpredictable, variable-surface, and dual-task conditions force the nervous system to update predictions rather than rehearse a fixed pattern. Measuring how a patient responds to perturbation, rather than how they walk under stable conditions, yields a more useful early signal of decline.
Original published by Nature - npj Aging, by Alan Bince Jacob.