Dual-finger preferred-speed tapping: Effects of coordination mode and anatomical finger and limb pairings

Interlimb and interfinger coordination were examined in a dual-finger tappi ng paradigm in which 16 subjects performed at preferred frequencies. Three bimanual finger combinations, in random order (2 index; 2 middle; and 1 ind ex and 1 middle), were performed in in-phase and antiphase coordination mod es, in addition to 1 unimanual combination (antiphase index-middle). Relati ve phase means were within 3% accuracy for all conditions. A lower tapping frequency was found in all antiphase vs. in-phase conditions, accompanied b y lower phasing variability and lower intrafinger consistency in the antiph ase. When frequency was changed from the preferred rate, the 2 coordination modes became more alike in variability and, within the same frequency rang e, demonstrated no significant differences. The bimanual mixed-fingers tapp ing tended to have significantly lower phasing values (a small fixed point drift) and higher tapping frequencies than the symmetric conditions. The un imanual task was similar to all other antiphase conditions. Changes in pref erred frequency with different coordination modes may be related to differi ng perceptual informational constraints. Current models addressing natural frequencies of coupled oscillators do not account for the present data.