Separable cognitive and motor decline tracked across adult life-span for goal-directed navigation

Abstract

Spatial navigation is a fundamental cognitive skill, yet our understanding of the strategies people employ in real-world navigation remains incomplete. This study investigates navigation strategies using data from the large-scale Sea Hero Quest (SHQ) game, in which participants face navigational problems consisting in controlling a boat to reach a series of goal locations, within maps having different shapes. By using a combination of behavioral and computational modeling approaches, we report three key findings: First, participants predominantly use goal-directed strategies compared to visibility-based strategies. Second, participants show signatures of sequential planning, both during memorization -- as they spend more time looking at difficult levels -- and during navigation -- as they show primacy effects, suggesting that they remember better the first navigational goal. Third, our results show a significant age-related decline in navigation performance, which depends both on reduced motor skill -- as indexed by poorer control of the boat -- and decreased cognitive strategy -- as indexed by a loss of goal-directedness during spatial navigation. Unexpectedly, the loss of goal-directedness with age is not associated with a shift to visibility-based strategy or to an incorrect sequencing of goals. Taken together, our findings offer a nuanced understanding of spatial navigation strategies in naturalistic conditions and their decline with age. Our computational approach permits distinguishing motoric and cognitive variables, showing that both decline with age. These results align with and extent previous research on spatial memory decline with age, including potential links to neurodegenerative diseases like Alzheimer's. The computational models developed in this study provide a robust framework for analyzing navigation strategies, applicable to other virtual environments and video games.