Following complex rhythmical acoustical patterns by tapping.

Rhythmic acoustical sequences consisting of patterns of various complexity (number of intervals in pattern) were generated and subjects were asked to synchronize with them by finger tapping. Deviations between onset of stimuli and onset of response were measured. It has been confirmed that tapping precedes the onset of stimuli by about 20-30 ms. The duration of this anticipatory period increased with an increase in stimulus complexity to the limit of three intervals in pattern. This finding points to a systematic error in timing of rhythmic motor reactions during acoustical following. Its degree depends to a certain limit on the nature of the stimuli. Subjects are subjectively aware of this error.