Abstract
INTRODUCTION Where the role of the cerebellum has long been suggested to be only sensorimotor, this view has changed to the involvement in a broader set of functioning, including visual processing. Previously we identified 3 retinotopically organized clusters in the cerebellum using a population receptive field (pRF) approach. Since this model uses a simple bar mapping stimulus with fixation task, it is hard to translate these results to natural vision. In this study, we use functional connectivity, as modeled using connective field mapping, to investigate the retinotopic organization in the cerebellum in different cognitive situations. METHODS We used 7T fMRI of 174 subjects, who participated in Movie Watching (MW) and Resting State (RS) experiments of the Human Connectome Project (HCP). The retinotopic connective field (CF) model combines the logic of the pRF-model with functional connectivity. The pRF-model estimates for every voxel the region of visual space that it responds to. For every voxel in the cerebellum a best-fitting CF is estimated: a Gaussian patch on the surface of V1. In effect, the retinotopic connective field model projects the visual field map of V1 into the cerebellum. We derived for every CF the parameters for visual field position from the underlying pRFs of the CF. RESULTS & CONCLUSION We show how different cognitive states reveal differences in retinotopic organization in the cerebellum. In the MW experiment, we find a new retinotopically organized cluster in Crus II. Here we see a reversal of an eccentricity gradient on the cerebellar surface. Furthermore, the oculomotor vermis shows a gradient in eccentricity, particularly striking in the MW condition. This result fits with the known role of OMV in eye-movements and spatial attention. These findings arise only during MW’s naturalistic visual behavior, and show the importance of using naturalistic conditions for studying the cerebellar retinotopic organization.