Dynamic involvement of premotor and supplementary motor areas in bimanual pinch force control

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2023-08, Vol.276, p.120203-120203, Article 120203
• Main Authors: Karabanov, Anke Ninija, Chillemi, Gaetana, Madsen, Kristoffer Hougaard, Siebner, Hartwig Roman
• Format: Article
• Language: English
• Subjects: Activities of daily living; Asymmetry; Coordination; Cortex (premotor); Cortex (somatosensory); Feedback; Functional magnetic resonance imaging; Motor task performance; Neuroimaging; Supplementary motor area; Transcranial magnetic stimulation
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2023.120203

Many activities of daily living require quick shifts between symmetric and asymmetric bimanual actions. Bimanual motor control has been mostly studied during continuous repetitive tasks, while little research has been carried out in experimental settings requiring dynamic changes in motor output generated by both hands. Here, we performed functional magnetic resonance imaging (MRI) while healthy volunteers performed a visually guided, bimanual pinch force task. This enabled us to map functional activity and connectivity of premotor and motor areas during bimanual pinch force control in different task contexts, requiring mirror-symmetric or inverse-asymmetric changes in discrete pinch force exerted with the right and left hand. The bilateral dorsal premotor cortex showed increased activity and effective coupling to the ipsilateral supplementary motor area (SMA) in the inverse-asymmetric context compared to the mirror-symmetric context of bimanual pinch force control while the SMA showed increased negative coupling to visual areas. Task-related activity of a cluster in the left caudal SMA also scaled positively with the degree of synchronous initiation of bilateral pinch force adjustments, irrespectively of the task context. The results suggest that the dorsal premotor cortex mediates increasing complexity of bimanual coordination by increasing coupling to the SMA while SMA provides feedback about motor actions to the sensory system. •PMd activity and functional PMd-to-SMA coupling increases during more demanding bimanual movements.•SMA activity does not show a general task dependent modulation but scales with synchronicity of bimanual movement onset.•Functional SMA connectivity is modulated by bimanual movemnt context: The right SMA shows stronger negative coupling with visual areas during complex bimanual movements.•Together these findings suggest that the dorsal premotor cortex mediates increasing complexity of bimanual coordination by increasing coupling to the SMA while SMA provides feedback about motor actions to the sensory system.