Cerebellum and verbal fluency (phonological and semantic)

Verbal fluency indicates the rate at which one produces words. It is measured by tasks that assess phonological or semantic associative processes and strategic abilities in retrieving words from a lexicon under forced conditions. Impairments in verbal fluency tasks are common in adult patients who are affected by cerebellar pathology. Despite conflicting results with regard to the laterality and specificity of cerebellar involvement in verbal fluency, the ability to generate lists of words per the phonemic rule has been reported to be more affected than under the semantic rule, with specific damage to phonemic clustering and switching. Phonemic verbal fluency requires the use of an unusual and novel search strategy to process sequenced information correctly. Thus, we propose that the prevalent impairment in phonological verbal fluency tasks is consistent with the sequence detection model, which has been advanced as the basic operational mode of the cerebellum