Abstract
It has been proposed that the hippocampal formation (HF) supports cognitive map-like representations of both navigational and visual spaces (i.e., where one is looking) (Nau, et al., 2018, TiCS), raising the question of whether the same neural mechanisms support both domains. If so, we would expect the HF visual mapping system to undergo a relatively protracted developmental trajectory, as it does in the navigational domain (Julian et al., 2018, Dev. Sci.). To address this question, we focused on grid cell-like representations of visual space in the entorhinal cortex (EC) in a large cohort of children (ages 5–18 years old). FMRI data were acquired while the children freely viewed a movie (Alexander et al. 2017, Sci. Data). We measured grid-cell-like fMRI responses as a function of gaze movement direction, using an analysis procedure previously used to identify this visual grid signal in adults (Nau et al., 2018, Nat. Neurosci; Julian et al., 2018, Nat. Neurosci.). There was significant reliable grid-cell-like modulation in EC as a function of gaze movement direction. Critically, the magnitude of EC visual grid coding increased with age, due to developmental changes in the temporal stability of visual grid-like representations. This change in visual grid coding across the early lifetime could not be explained by developmental changes in eye movement behavior. Our results support the idea that visual and navigable space are represented using the same neural mechanisms, and help to elucidate how cognitive maps emerge during development.