Abstract
While fMRI studies have documented cerebellar activity across a wide array of tasks, the functional contribution of the cerebellum within these task domains remains unclear. Here we present a new framework to address this problem, asking if neocortical inputs to the cerebellum are gated in a task-dependent manner. We tested this idea in the context of finger movements, where the integrity of the cerebellum has been shown to be essential for the coordination of rapid alternating movements but not grip force generation. While neocortical and cerebellar activity both increased with increasing speed and force, the changes in cerebellar activity associated with speed were larger than predicted by an optimized cortico-cerebellar connectivity model. This suggests a task-specific recruitment of the cerebellum through gating of information between the cerebellum and neocortex. More generally, this framework offers a new approach to identify cerebellar contributions to function using fMRI.
Significance statement Previous functional imaging studies have shown the cerebellum is activated across a large range of tasks. However, drawing specific inferences about cerebellar function from this work has been difficult because activation patterns in the cerebellum are strongly constrained by its anatomical connectivity with the neocortex. As activity in the neocortex increases, corresponding changes should be expected in the cerebellum, regardless of whether the cerebellum is functionally involved in the task or not. We present a new framework to address this problem, comparing cerebellar activations with that predicted by a task-general cortico-cerebellar connectivity model. Applying this approach in the motor domain, we show that the input to the cerebellum is preferentially upregulated for the coordination of rapid, alternating finger movements.
Competing Interest Statement
R.I. is a co-founder with equity in Magnetic Tides, Inc. The other authors declare no competing interests.
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