Handedness and brain lateralization: A nonlinear motor approach combined with EEG

This study explores handedness through a multidisciplinary approach, integrating biomechanical analysis and electroencephalography (EEG) to uncover differences in motor strategies and brain lateralization among right-handed, left-handed, and ambidextrous individuals. Seventy participants were assessed using motion capture and EEG during writing and drawing tasks performed with both dominant and non-dominant hands. Biomechanical data were analyzed through the lens of motion optimization, using the Movement Element Decomposition (MED) method, while EEG data focused on event-related synchronization/desynchronization (ERD/S) patterns. Results highlight that right-handers demonstrate stronger lateralization for fine motor tasks, with optimized neural and biomechanical adaptations favoring the right hand. In contrast, left-handers exhibit specialization for impedance control with their right hand, suggesting distinct motor planning strategies. EEG findings corroborate these behaviors, showing that right-handers require less cognitive effort when using their dominant hand for writing, whereas left-handers show heightened parietal activity associated with sensorimotor integration during similar tasks. The study reveals an asymmetry in motor skill acquisition, possibly related to left-handed adaptations to right-hand-dominated environments. These insights contribute to understanding handedness's role in motor control and brain organization, with implications for neurorehabilitation.