Behavioral/Cognitive Generalized Role for the Cerebellum in Encoding Internal Models: Evidence from Semantic Processing

The striking homogeneity of cerebellar microanatomy is strongly suggestive of a corresponding uniformity of function. Consequently, theoreticalmodels of the cerebellum’s role inmotor control should offer important clues regarding cerebellar contributions to cognition. One such influential theory holds that the cerebellum encodes internal models, neural representations of the context-specific dynamic properties of anobject, to facilitate predictive controlwhenmanipulating theobject. Thepresent study examinedwhether this theoretical construct can shed light on the contribution of the cerebellum to language processing.We reasoned that the cerebellummight perform a similar coordinative functionwhen the contextprovidedby the initial part of a sentence canbehighlypredictiveof the endof the sentence. Using functional MRI in humans we tested two predictions derived from this hypothesis, building on previous neuroimaging studies of internal models in motor control. First, focal cerebellar activation–reflecting the operation of acquired internal models–should be enhanced when the linguistic context leads terminal words to be predictable. Second, more widespread activation should be observed when such predictions are violated, reflecting the processing of error signals that can be used to update internalmodels. Both predictions were confirmed, with predictability and prediction violations associated with increased blood oxygenation level-dependent signal in the posterior cerebellum (Crus I/II). Our results provide further evidence for cerebellar involvement in predictive language processing and suggest that the notion of cerebellar internal models may be extended to the language domain. Key words: cerebellum; cognition; fMRI; internal models; languag