Abstract
BACKGROUND: Human spatial navigation can be conceptualized as egocentric or exocentric, depending on the navigator's perspective. Navigational impairment is known to occur in individuals with cognitive impairment, but less is known about navigational abilities in nondemented older adults. Our objective was to develop tests of navigation and study their cognitive correlates in nondemented older adults. METHODS: We developed a Local Route Recall Test (LRRT) to examine egocentric navigation and a Floor Maze Test (FMT) to assess exocentric navigation in 127 older adults without dementia or amnestic Mild Cognitive Impairment (MCI). Factor analysis was used to reduce neuropsychological test scores to three cognitive factors representing Executive Function/Attention, Verbal Ability, and Memory. We examined relationships between navigational tests and cognitive function (using both cognitive factors and the highest loading individual test on each factor) in a series of regression analyses adjusted for demographic variables (age, sex, and education), medical illnesses, and gait velocity. RESULTS: The tests were well tolerated, easy to administer, and reliable in this nondemented and non-MCI sample. Egocentric skills on the LRRT were associated with Executive Function/Attention (B = -0.650; 95% confidence interval [CI], -0.535 to -0.139) and Memory (B = -0.518; 95% CI, -4.893 to -0.063) factors. Exocentric navigation on the FMT was related to Executive Function/Attention (B = -8.542; 95% CI, -13.357 to -3.727). CONCLUSIONS: Our tests appear to assess egocentric and exocentric navigation skills in cognitively normal older adults, and these skills are associated with specific cognitive processes such as executive function and memory.