CONDITIONAL ASSOCIATIVE LEARNING IS IMPAIRED IN CEREBELLAR DISEASE INHUMANS

Eight patients with lesions restricted to the cerebellum were compared with a total of 25 age-matched controls on a reaction time (RT) task allowing the recording of simple and choice RTs as well as RTs to abst ract visual patterns signifying the particular movement to be performe d. In all conditions the actual movements required (either a left or a right button press) remained the same, but the cognitive requirements of the task varied. In the abstract patterns condition, the significa nce of the various patterns with regard to the required movement had t o be learned by the subjects. The patients with cerebellar lesions wer e particularly impaired in this condition. It is concluded that the ce rebellum is involved not just in the timing of movements but also in t he decision process as to which movement should be performed under par ticular circumstances.