Where we look, what we know: how hippocampal predictions shape, and are shaped by, eye movements.

As we interact with our environment, information from hippocampal representations guides further cognition and action on a moment-to-moment basis. We propose that eye movements modulate the organization of neural dynamics in humans and other primates with advanced visual systems, allowing reciprocal encoding and retrieval of information in service of predictive action. Gaze fixations and saccades allow the hippocampus to generate, test and update predictions about the external world in real time. Integrating evidence from computational modelling, neurophysiology and neuroimaging, we highlight viable anatomical and functional connections between the hippocampus and oculomotor control systems that support this bidirectional flow of information. We synthesize findings across spatial and temporal scales-from intracranial recordings showing saccade-related modulation in hippocampal and visuo-oculomotor neurons, to electrophysiological studies linking oscillatory dynamics to predictive processing, to functional magnetic resonance imaging work revealing network-level coupling shaped by viewing behaviour. Together, these converging results suggest that eye movements not only guide ongoing perceptual processing but also structure the neural dynamics underlying memory and prediction. We conclude by identifying open questions about how gaze modulates different types of hippocampally mediated predictions and under what conditions eye movements both reflect and update internal models of the world. This article is part of the theme issue 'The role of hippocampal predictions in cognition: bridging perception and memory'.