THE CEREBELLUM’S ROLE IN LANGUAGE PROCESSING AND GRAMMAR ACQUISITION Deficits in language functioning in the chronic phase after cerebellar stroke and the relationship between implicit learning of grammar and motor control

Abstract

To investigate the role of the cerebellum in language functioning and the relationship between implicit motor learning and implicit grammar learning, an extensive neuropsychological test battery was conducted among 13 patients who were in the chronic phase after cerebellar stroke, and 28 healthy controls who were matched with regard to age, gender and education. The project was divided into two separate studies. The first study aimed to investigate the cerebellum’s role in language functioning by comparing patients to healthy controls on a number of language tests (NADL, NWRT, TAK Verteltaak, Verbal Fluency, RAN, EMT, Klepel and six PALPA subtests). A better performance of healthy controls was expected on all tasks in comparison to cerebellar stroke patients. Also, it was expected that patients with left cerebellar damage (n=6) would perform better than patients with right cerebellar damage (n=5). In the second study, the correlation between an implicit grammar learning task (NADL) and an implicit learning serial reaction time task (ILSRT) was measured in order to investigate the relationship between implicit motor learning and implicit grammar learning. A positive correlation was expected, in which better discrimination ability between grammatical and ungrammatical sentences would correlate significantly with greater differences in reaction time between learnt motor sequences and novel motor sequences. None of the hypotheses were confirmed, although a relationship was found between fine motor skills and phonological memory and processing. Language disorders do not seem to be prominent after cerebellar stroke, which suggests either a good functional outcome after cerebellar stroke due to cerebellar plasticity, or a minor involvement of the cerebellum in language functioning.