Eyes on the prize: Mice deploy task-driven saccades during naturalistic foraging
Active sensing allows organisms to shape incoming sensory information through self-generated actions, and saccadic eye movements provide a key readout of this process in vision. In primates, saccades are strongly modulated by cognitive variables such as uncertainty, value, and behavioural goals, particularly in complex, naturalistic settings. In rodents, by contrast, saccades have largely been interpreted as reflexive or compensatory, and evidence that they are modulated by cognitive state, such as trial outcome, expectation, or task demands, has remained sparse. Here, we examined how mice use saccades during a vision-dependent foraging task in a traversable immersive virtual environment with naturalistic stimuli. We correlated their saccade dynamics with behavioural strategies observed within the virtual environment. Target-directed saccades emerged specifically when informative sensory evidence was available, but also occurred anticipatorily when animals could rely on previously learned spatial contingencies, indicating that saccades were guided not only by immediate visual input but also by internal representations. Strikingly, the temporal structure of inter-saccade intervals resembled signatures previously reported in primates and lengthened with increased processing demand following changes in task contingencies. Together, these findings show that mouse saccades are not merely reflexive gaze corrections, but form part of a cognitively modulated active sampling strategy. More broadly, they suggest that key principles of active visual sensing may be conserved across species and establish mouse oculomotor behaviour as a tractable readout of internal cognitive state.