Externally cued inphase bimanual training enhances preparatory premotor activity

OBJECTIVE: Previous studies have demonstrated that cortical potentials representing motor preparation for visually-cued movements are enhanced following a single session of visually-cued bimanual movement training (BMT). The neuroanatomical sources that contribute to these rapid training-induced adaptations were unclear. To address this, we compared cortical potentials associated with motor preparation for visually-cued (movement-related potential, MRP) and self-paced (Bereitschaftspotential, BP) movements and investigated adaptations of these following BMT. METHODS: EEG recorded the cued MRP and self-paced BP during two experiments. In experiment one, pre and post self-paced unimanual trials were interspersed with cued inphase BMT. In experiment two, self-paced and visually-cued movement trials were performed to assess the differences between and the contributing neural sources to the cued MRP and self-paced BP. RESULTS: Inphase BMT does not affect the early BP. Source localization analysis revealed that the preparatory portion of the cued MRP and self-paced BP are generated by the lateral premotor cortex and the supplementary motor area, respectively. CONCLUSIONS: The early cued MRP and self-paced BP have unique cortical generators and are independently modulated by specific training types. SIGNIFICANCE: These novel findings have implications for interpreting rapid, single-session, training adaptations previously observed. These cortical potentials may also be useful measurement tools to gauge within-session cortical modulations in response to specific modes of rehabilitative training in the stroke population.