Linking visual and spatial exploration dynamics during free navigation in a large-scale virtual city

Abstract

Balancing exploration and exploitation is a fundamental challenge for adaptive behavior, yet it remains unclear whether visual sampling and spatial locomotion reflect a single cross-domain trait or operate independently. We addressed this question by recording head-mounted eye-tracking and full-body motion tracking while 26 participants freely navigated "Westbrook", a large-scale virtual city for a total of 150 min across five sessions. From the movement trajectories we derived three spatial descriptors: median walking speed, occupancy entropy, and the proportion of explorative route choices. From the gaze data, we computed 38 robust visual descriptors encompassing fixation dynamics, pupil size, saccadic amplitude, gaze-head alignment, and transition entropy. Principal-component analysis reduced the visual descriptors to three components that captured 58 % of variance, with the first component (PC1) reflecting "gaze dynamism" (frequent shifts, larger saccades, higher transition entropy). Canonical correlation analysis revealed a strong coupling between spatial and visual behaviours: the first pair of canonical variates correlated at r = 0.68 (cross-validated r = 0.45), driven primarily by the association of high walking speed and occupancy entropy with elevated gaze dynamism. In contrast, the proportion of explorative route choices contributed little to this coupling. These findings demonstrate that individual differences in low-level locomotor speed and spatial coverage co-vary with an exploratory visual style, supporting the existence of a domain-general "exploration" factor that shapes both how people move through, and attend to, complex environments.