[Effect of aging on real route memorization: the role of working memory and episodic memory]

This research investigates the role of different memory components in the age-related decline of new route learning. Few studies have considered real route learning, for which the situation can be more complex, and the richness greater than with simple mazes. In this experiment, the memory of a route in a real city has been assessed considering visual scene recognition, directions recognition, and temporal order memorization. Thirty young adults (m=25 years old) and 30 older adults (m=70 years old) have watched the video of the route twice before performing the three recognition tasks. Various cognitive abilities (episodic memory, verbal and visuo-spatial working memory, short-term binding, inhibition, flexibility, and mental rotation ability) have then been assessed through different neuropsychological tests. The results demonstrate that older adults have poorer performance than younger in the three route learning tasks: visual scene recognition task, direction recognition task, and temporal order recognition task. Moreover, mediation analyses indicate that episodic memory performance partly explains the effect of aging on visual scene recognition, while working memory capacity performance (measured with Corsi's block test, digit span test, and multimodal span test) partly explains the effect of aging on direction recognition. Spatial memory involved in real navigation and route learning is thus impaired in normal aging, which is partly due to the decline of episodic and working memory components.