Data from: Active vision in freely moving marmosets using head-mounted eye tracking

Our understanding of how vision functions as primates actively navigate
the real-world is remarkably sparse. As most data have been limited to
chaired and typically head-restrained animals, the synergistic
interactions of different motor actions/plans inherent to active
sensing—e.g., eyes, head, posture, movement, etc.—on visual perception are
largely unknown. To address this considerable gap in knowledge, we
developed an innovative wireless head-mounted eye-tracking system that
performs Chair-free Eye-Recording using Backpack mounted micROcontrollers
(CEREBRO) for small mammals, such as marmoset monkeys. Because eye
illumination and environment lighting change continuously in natural
contexts, we developed a segmentation artificial neural network to perform
robust pupil tracking in these conditions. Leveraging this innovative
system to investigate active vision, we demonstrate that although freely
moving marmosets exhibit frequent compensatory eye movements equivalent to
other primates, including humans, the predictability of the visual
behavior (gaze) is higher when animals are freely moving relative to when
they are head-fixed. Moreover, despite increases in eye/head-motion during
locomotion, gaze stabilization remains steady because of an increase in
vestibularocular reflex gain during locomotion. These results demonstrate
the efficient, dynamic visuomotor mechanisms and related behaviors that
enable stable, high-resolution foveal vision in primates as they explore
the natural world.