The current study examined the role of vision in spatial updating and
its potential contribution to an increased risk of falls in older
adults. Spatial updating was assessed using a path integration task in
fall-prone and healthy older adults. Specifically, participants
conducted a triangle completion task in which they were guided along two
sides of a triangular route and were then required to return, unguided,
to the starting point. During the task, participants could either
clearly view their surroundings (full vision) or visuo-spatial
information was reduced by means of translucent goggles (reduced
vision). Path integration performance was measured by calculating the
distance and angular deviation from the participant's return point
relative to the starting point. Gait parameters for the unguided walk
were also recorded. We found equivalent performance across groups on all
measures in the full vision condition. In contrast, in the reduced
vision condition, where participants had to rely on interoceptive cues
to spatially update their position, fall-prone older adults made
significantly larger distance errors relative to healthy older adults.
However, there were no other performance differences between fall-prone
and healthy older adults. These findings suggest that fall-prone older
adults, compared to healthy older adults, have greater difficulty in
reweighting other sensory cues for spatial updating when visual
information is unreliable.