- This study applied a virtual rendition of the Morris water maze, which is commonly used for assessing spatial memory in rodents, to an examination of age-related differences in spatial learning among 42 younger (18-30 years) and older (>60 years) male human participants. Virtual Morris water maze performance was measured by cumulative proximity to the goal corrected for start position across 44 learning trials. After controlling for age differences in visible trial pathlength, older adults exhibited greater cumulative proximity to the goal than younger adults. When older participants were categorized into good and poor performers based on a median split of their performance across hidden trials, poor older performers searched away from the hidden platform more than young adults. fMRI scanning was conducted during the final, well-learned phase of water maze trials. Greater activation was witnessed in young adults in the cerebellum compared to older adults, and older good performers displayed greater activation in the middle and superior frontal gyrus than older poor performers. These findings suggest that older adults may be poorer at acquiring spatial memories and show functional differences when performing spatial memory tasks, calling for further investigation into the neural mechanisms of age-related differences in spatial memory formation.
Key Words: spatial memory, fMRI, Morris water maze, cognitive aging, navigation