Dynamic and static subjective visual vertical with aging

Objective: Our vestibular function is gradually deteriorating during aging, although, its behavioral consequences are not easily recognized due to a substitution process by other sensory modalities as visual or proprioceptive inputs. Methods: To reveal such a hidden substitution process by visual signals, the measurement of the static as well as the dynamic subjective visual vertical (SVV) was performed among 63 healthy subjects of different age. Results: The static SVV was found to be stable among all subjects, whereas the shift of the dynamic SVV during rotation of a background scene gradually increased with age. Conclusion: This result indicates that the substitution process identified as a function of age in a perceptual test may have its counterpart in postural stabilizing reflex.