ANTICIPATORY AND SEQUENTIAL MOTOR CONTROL IN PIANO PLAYING

Pianists were asked to play short excerpts from several pieces on an e lectronic keyboard. In each piece, there were two phrases whose first few notes were played identically with the right hand. Thereafter, the two phrases were played differently. The aim of the investigation was to ascertain whether or not hand and finger kinematics diverged prior to the depression of the last common note. Such a divergence would im ply an anticipatory modification of sequential movements of the hand, akin to the phenomenon of coarticulation in speech. The lack of such a divergence would imply a strictly serial organization of movement seq uences with one hand, as was found previously to be the case for typin g. The time at which each key was depressed and released and the speed with which the key was depressed was recorded via a MIDI interface to a laboratory computer. The motion of the right wrist and of the finge rs of the right hand was recorded optoelectronically. Piano playing ca n invoke anticipatory modifications of hand and finger kinematics. The time at which two patterns of movements diverged varied considerably from piece to piece. Playing an ascending scale with the requirement o f a ''thumb-under'' maneuver could evoke an anticipatory modification as much as 500 ms in advance of the last common note. In another piece , keypresses appeared to be executed in a strict serial ordering and a third piece gave results intermediate between these two extremes. We interpret the results to suggest that a strict serial execution of a m ovement sequence is favored as long as this is compatible with the dem ands of the task.