Investigating Brain Connectivity Patterns in Varying Degrees of Bimanual Task Asymmetry

Bimanual coordination is essential for daily activities, ranging from simple tasks like buttoning a shirt to complex actions such as playing musical instruments. While symmetric bimanual tasks, which involve mirrored movements of both hands, are well-understood in terms of neural synchronization, the mechanisms underlying asymmetric bimanual coordination remain comparatively unclear. This study investigated the influence of varying degrees of task asymmetry on both motor performance and functional brain connectivity using electroencephalography (EEG). We designed a coin-collecting game that systematically manipulated task asymmetry through different coin patterns and alignments, allowing participants to control movements with both hands using a game controller. Behavioral results revealed that task complexity significantly affected performance, with symmetric tasks yielding the best results and highly asymmetric tasks yielding the worst. The EEG-based connectivity analysis identified distinct neural patterns associated with different levels of asymmetry, particularly in the alpha and theta frequency bands. Our findings suggest that asymmetric tasks exhibit stronger connectivity than symmetric tasks do. These insights contribute to a deeper understanding of bimanual motor control and have implications for motor skill training, rehabilitation, and human-computer interface design.