Acquisition of simple auditory and visual sequences in cerebellar patients.

Previous studies suggest a role of the cerebellum in detecting and recognizing event sequences. In the present study sequences of two acoustic tones of different frequencies and sequences of two visual stimuli with different colours were presented with short, long and very long durations. Thirteen cerebellar patients and 13 controls were required to indicate whether the order of stimuli was identical or opposite to a reference by saying 'yes' or 'no'. To minimize motor requirements no time restrictions were given. In none of the test conditions a significant difference between patients and controls was observed. The results suggest that the cerebellum is not essential for acquisition of simple sensory sequences. Differences in findings between previous and the present study may be explained by differences in motor demands and the explicit nature of the tasks.