The cognitive neuropsychology of the cerebellum

We review evidence from neuropsychological studies of patients with damage to the cerebellum that suggests cerebellar involvement in four general cate gories of cognition: (1) speech and language; (2) temporal processing; (3) implicit learning and memory; (4) visuospatial processing and attention. A relatively strong case can be made for cerebellar contributions to language (including speech perception, lexical retrieval, and working memory) and t o temporal processing. However, the evidence concerning cerebellar involvem ent in non-motor implicit learning and visuospatial processing is more equi vocal. We argue that cerebellar contributions to cognition are computationa lly plausible, given its reciprocal connectivity with the cerebral cortex, and suggest that this function of the cerebellum may be an example of an ev olutionary process by which mechanisms originally evolved for one function (in this case, motor control) are adapted to other functions (cognition).