Age-related decline in vestibulo-ocular reflex gain is associated with an increase in EVS-evoked postural sway, consistent with an increase in central neural gain to compensate for age-related peripheral vestibular loss.
VOR gain showed a significant age-related reduction across the lifespan.
EVS-evoked postural sway responses increased significantly with age.
VOR gain and EVS gain were inversely correlated across participants.
The inverse correlation between VOR and EVS gain persisted after controlling for age, suggesting a general CNS property of tuning neural gain to match interpersonal differences in peripheral vestibular input.
VOR phase lead increased with age, which may limit the extent of central compensation for peripheral vestibular loss.
The study provides evidence for partial, but not complete, neural compensation for age-related peripheral vestibular loss.
This research suggests that as people age, the inner ear loses sensory cells that detect head movement — up to 40% of these cells can be gone by age 70. Despite this significant loss, eye and balance movements remain relatively functional in older adults, raising the question of how the brain compensates. This study tested 62 people aged 20 to 87 years using two methods: a spinning chair to measure how well the eyes stabilize during head movement (the vestibulo-ocular reflex, or VOR), and mild electrical stimulation of the vestibular nerve behind the ear to estimate how strongly the brain responds to vestibular signals (bypassing the damaged sensors). The researchers found that older adults had weaker VOR responses but stronger reactions to the electrical stimulation, suggesting the brain turns up its internal 'volume' to amplify weakened signals from aging ears. Interestingly, this compensation appears to be only partial — VOR function still declined with age even though the brain was amplifying signals more. The study also found that older adults showed a timing irregularity (called phase lead) in their VOR responses, which may reduce the accuracy of the eye movement reflex and limit how much the brain's compensation can help. Importantly, even after statistically removing the effects of age, individuals with lower VOR responses tended to have stronger reactions to electrical stimulation, suggesting the brain continuously fine-tunes its sensitivity to match each person's unique level of peripheral vestibular input, regardless of age. This research suggests that the human brain has an ongoing, adaptive mechanism for compensating for vestibular sensory loss — not just in response to aging, but potentially as a general feature of how the nervous system calibrates itself across individuals. Understanding this compensation process could have implications for diagnosing balance disorders and for developing interventions that support vestibular function in older adults.
Osler C, Reynolds R. (2026). Age-related decline in vestibulo-ocular reflex gain is associated with an increased sway response to electrical vestibular stimulation.. Journal of neurophysiology. https://doi.org/10.1152/jn.00110.2026