Influences of metrical structure and grouping on the kinematics of rhythmic finger tapping

We investigated whether metrical accentuation has obligatory effects on the kinematics of rhythmic finger tapping. Auditory rhythmic patterns were repeated cyclically, and participants first synchronized with each pattern and then reproduced it 10 times on a MIDI keyboard, which yielded measures of the timing and velocities of key depression and release. Experiment 1 used strongly and weakly metrical patterns from Povel and Essens (1985). Experiment 2 varied metrical structure independently of grouping structure by adding an explicit beat in different phases to rhythmic patterns. Strongly metrical sequences were produced with more precise and less variable timing (Exp. 1), and syncopation had some unexpected effects on timing (Exp. 2). However, metrically accented taps were similar in most respects to unaccented taps; only key release velocities tended to be faster for accented taps (Exp. 2). By contrast, grouping structure had strong effects on all movement parameters. The results suggest that, unlike rhythmic grouping, metrical structure (and metrical accentuation in particular) is not necessarily reflected in action. Repp & Saltzman: Meter and grouping 3