Humans are adept at predicting what will happen next and when precisely it will occur. An activity as everyday as walking at a steady pace through a busy city while talking to a friend can only happen as smoothly as it does because the human brain has predicted most of the sensory feedback it will receive. It is only when the sensory feedback does not match what was expected, say, a sudden slippery spot on the pavement, that one becomes aware of the sensory feedback. The cerebellum is known to

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... e involved in these predictions, but not much is known about the precise timing of them due to the scarcity of time-sensitive cerebellar neuroimaging studies, such as ones conducted with magnetoencephalography. We here investigated the timing of sensory expectations as they are expressed in the cerebellum using magnetoencephalography. We did this by comparing the cerebellum's response to somatosensory omissions from regular trains of stimulation to its response to omissions from irregular trains of stimulation. This revealed that omissions following regular trains of stimulation showed higher cerebellar power in the beta band than those following irregular trains of stimulation, precisely when the omitted stimulus should have appeared. We also found evidence of cerebellar theta band activity encoding the rhythm of new sequences of stimulation. Our results furthermore strongly suggest that the putamen and the thalamus mirror the cerebellum in showing higher beta band power when omissions followed regular trains of stimulation compared to when they followed irregular trains of stimulation. We interpret this as the cerebellum functioning as a clock that precisely encodes and predicts upcoming stimulation, perhaps in tandem with the putamen and thalamus. Relative to less predictable stimuli, perfectly predictable stimuli induce greater cerebellar power. This implies that the cerebellum entrains to rhythmic stimuli for the purpose of catching any deviations from that rhythm.