From Contrasts to Representations: Rethinking fMRI Approaches for Cortico-Cerebellar Networks

The relationship between the cerebellum and cerebrum remains poorly understood in the neuroimaging literature, despite decades of functional magnetic resonance (fMRI) research. In this opinion article, we argue that this gap reflects fundamental methodological constraints rather than merely a lack of scientific interest. We first discuss challenges in acquiring fMRI data and analysis, with an emphasis on the cerebellum. We then critically evaluate the most common analysis approaches including functional connectivity, univariate contrasts, multivariate pattern analysis, and encoding models, examining the contributions and limitations of each to identify and quantify cortico-cerebellar networks. Through the lens of language processing, we briefly review how these approaches have been applied to characterize cortico-cerebellar networks underlying cognitive function. We conclude by proposing that encoding model frameworks, combined with ecologically valid naturalistic paradigms, offer advantages that can help resolve longstanding debates about cortico-cerebellar network function and organization.