Abstract
Purpose: :
The study objective was to obtain point of gaze during indoor wayfinding in older adults with and without mild dementia. Wayfinding problems (e.g., an inability to find or recognize a destination) are common among older adults especially those with mild cognifive loss and are related to falls. Wayfinding problems are person-environment problems from deficits in spatial orientation making it difficult to maintain a cognitive map of the route to a desired location, as well as with deficits that impact abilities to plan and carry out goal-directed travel and to ignore irrelevant and distracting stimuli. Optimal wayfinding has the potential to positively impact the independence, safety, and QOL of older adults.
Methods: :
58 participants (age 65 to 92, 44 with MMSE of 24 or higher, and independent in mobility) followed a 120 ft indoor route marked with content-free, high contrast signs. The signs were placed at 3 heights - near the floor, above the handrail, and just above the existing signage. Participants were instructed to look for and follow the signs. Point of gaze, time, and path errors were recorded. A wireless mobile eye tracking system (ISCAN ETL-410) was used to measure 30 points of gaze per second. Point of gaze was calibrated for each participant before and then validated after each testing session. Participants were screened for visual acuity, contrast sensitivity, visual fields and Mattis Dementia Rating Scale (DRS). How many and which of the test signs subjects looked at was also recorded.
Results: :
All participants had normal age-related visual function. Participant hallway performance included: 1) 49 / 12.1 (mean / SD) seconds to complete the route; 2) looked least often at the upper areas of the hallway walls, the locations for existing signage; 3) Looking down the hallway and at the floor accounted for almost 47% of the point of gaze locations; and 4) looked to the left and right hallway walls below the existing signage about as often as they looked directly down the hall. The hallway walls below the handrail and at the floor directly in front of them accounted for 54% of the point of gaze locations. Few subjects swept their gaze from left to right and back. Participants looked at bottom signs more often (53%) than middle or top signs combined. Participants who had lower MMSE scores (below 24) had more errors/redirects during wayfinding and took longer to complete the route.
Conclusions: :
Our results provide evidence that wayfinding information is not located where older adults most often look while wayfinding. The findings suggest that providing wayfinding information that is easy to see and placing it in locations they routinely look at while ambulating can improve wayfinding performance.
Keywords: eye movements • aging: visual performance • scene perception