Brain-wide gaze-dependent activity during eyes-closed rest and sleep

Gaze behavior and brain activity are tightly coupled during perception and mental imagery. Whether this coupling extends to eyes-closed states remains largely unknown, primarily because measuring eye movements alongside brain activity is difficult when the eyes are closed. Here, we used a scalable MR-based eye-tracking approach to reconstruct gaze behavior from fMRI data during eyes-closed rest and sleep. We found widespread coupling between inferred gaze behavior and brain activity distributed through much of the cerebral cortex and cerebellum, including many regions typically associated with vision. These dynamics largely persisted across the two states. Additionally, accounting for gaze systematically altered functional connectivity estimates of large-scale brain organization. Together, these results underscore the importance of considering gaze as a hidden behavioral dimension of intrinsic fMRI signals, even in eyes-closed states. More broadly, our findings suggest that eye-brain dynamics may provide a window into eyes-closed states of consciousness.