Structured route learning mitigates age-related interference between overlapping spatial representations during virtual wayfinding

Age-related declines in spatial navigation are often attributed to impairments in executive control, particularly cognitive flexibility and task switching. However, it remains unclear to what extent these deficits reflect age-related limitations and/or sensitivity to task structure and interference. The present study investigated how switching demands between competing route representations shape spatial knowledge acquisition in older (OA) and younger (YA) adults during complex wayfinding in a virtual environment. Participants learned two partially overlapping routes under either a high-interference alternating condition (A–B–A–B–A–B) or a low-interference sequential condition (A–A–A–B–B–B). Spatial knowledge was assessed using route retracing performance, navigation errors, landmark recognition, and directional estimation between landmarks. OA showed lower overall performance than YA across all measures. Critically, however, OA who learned routes sequentially exhibited substantial improvements in route retracing accuracy and landmark recognition compared to those exposed to alternating learning, thereby markedly reducing age-related performance differences under identical task demands. In contrast, alternating learning disproportionately impaired OA, consistent with elevated switching-related effects between competing route representations. These findings demonstrate that age-related differences in spatial navigation are strongly modulated by learning structure. Reducing switching between competing route representations and stabilizing representational demands mitigates interference-related costs, enabling more efficient encoding and integration of spatial information in older adults. The results suggest that structured, low-interference learning environments may serve as an effective compensatory scaffold for age-related declines in cognitive flexibility, highlighting the importance of task design in supporting navigation and learning across the adult lifespan.