Bimanual Synchronization in Pentachord Performance Effects of Finger Homology and Movement Direction

Resumen

ABSTRACT

Research Question/Problem

Temporal synchronization between the hands constitutes a fundamental component of piano performance (Goebl & Palmer, 2013), as it relates to motor organization, fingering choices, and the precision of sound onset. Although the literature widely acknowledges the relevance of bimanual coordination (Goebl, Flossmann, & Widmer, 2010; Swinnen & Wenderoth, 2004; Jabusch, 2006; Furuya & Altenmüller, 2013; Ito et al., 2023), the implications of the anatomical constraints of the fingers for temporal synchronization remain insufficiently investigated. Due to the tendinous organization of the extensor muscles, the fingers do not operate fully independently and are subject to mechanical and neuromuscular dependencies, particularly in tasks requiring extension and force production. In the context of piano performance, the motor challenge lies in developing functional dissociation between the fingers while maintaining temporal precision.

Objectives

To investigate the effects of homologous and non-homologous fingering on bimanual synchronization during F major pentachord performance, comparing parallel and contrary motion.

Method

Two pianists (P1 and P2) participated in the study and performed an F major pentachord under two conditions: parallel and contrary motion. In each condition, 12 repetitions were performed, from which the mean temporal asynchrony was calculated, resulting in a single value per condition and participant. Data were collected via MIDI, allowing for the calculation of asynchrony between the note onsets of the two hands. A script developed for this research identified note attacks and the temporal difference between the hands. Performances were conducted on a digital piano connected to a computer and recorded using Reaper software. Data analysis was performed in MATLAB, and differences between conditions were compared using a t-test, with p < 0.05 adopted as the significance level.

Results

The results indicated that hand synchronization in P1 varied systematically as a function of movement type and note-finger combinations, suggesting distinct motor organizations in parallel and contrary motion. In parallel motion, a predominant anticipation of the left hand and a smaller magnitude of asynchrony were observed, indicating greater temporal stability. In contrary motion, in addition to a shift in leadership to the right hand in most combinations, a consistent increase in the magnitude of asynchrony was observed, reflecting greater temporal reorganization.
For P2, the results also indicated greater temporal stability in parallel motion, with smaller magnitudes of asynchrony. In contrast, contrary motion showed an increase in asynchrony magnitude, accompanied by greater variability and alternation of leadership between the hands. These findings suggest that the demands of bimanual coordination modulate not only the direction but also the magnitude of temporal offset between the hands, depending on the note-finger combination.

Implications
Combinations involving homologous fingers did not yield better synchronization in either participant, suggesting that anatomical factors alone may not determine temporal precision. Factors related to the direction of musical motion, fingering, and motor familiarity with parallel motion may have influenced the results, indicating that different motor organizations can support bimanual synchronization within the same task.