Abstract
The visual, vestibular, and oculomotor systems are tightly linked, with vestibular responses calibrated to the fovea. Studies in healthy young adults have also shown that gaze orientation impacts body stabilization and control: whole-body adaptations occur to enhance gaze/body stability during visual tasks, and postural responses are gaze-direction dependent. Central visual field loss (CFL, e.g., due to macular degeneration) is very common in older age causing high-acuity vision loss, mobility difficulties, and increased fall risk. Those with binocular CFL often adopt eccentric viewing strategies, but how these adaptations interact with low vision and other sensory-motor signals for body coordination and control remains unclear. We begin addressing this by examining how eccentric viewing impacts body stabilization and postural control in young and older adults with and without CFL.
In one experiment, participants stepped in place with and without a visual search task. In another, participants viewed a fixation target with or without the presence of a full-field (58°x48°) laterally oscillating optic flow stimulus while standing under different gaze-to-screen orientations.
Preliminary data suggest that postural adaptations driven by the demands of the search task persist in older adults with and without CFL, e.g. through modulations in step width. In the standing task, we observe an interaction in the effects of optic flow and gaze eccentricity, e.g. on center of pressure velocity, that vary between individual profiles. These findings highlight how CFL affects integration across sensorimotor systems, while the preserved adaptations we observe suggests avenues for training that exploit ecological relationships between these systems.