Lateralised Transmission of Beta Oscillations From Cortex to Muscle During Movement Cancellation Reflects Selective Motor Inhibition

Beta oscillations in the sensorimotor cortex are modulated across various stages of motor control, including movement preparation and cancellation, and are known to project to the motor neuron pool and muscles during Go/No-Go tasks. While these oscillations have been linked to motor inhibition, the specificity of their transmission to end-effector muscles during movement cancellation remains unclear. We investigated the selectivity of beta-band activity using a lateralised Go/No-Go paradigm. Participants maintained steady bimanual wrist extensor contractions and either executed a unilateral ballistic wrist extension (Go) or cancelled the planned movement (No-Go). Concurrent electroencephalographic and electromyographic recordings were measured throughout. Successful movement cancellation was characterised by contralateral cortical beta modulation accompanied by stronger and more clearly lateralised peripheral beta synchronisation in the muscle associated with the suppressed movement. Peripheral beta activity exhibited greater magnitude and clearer separability between left- and right-sided conditions than cortical signals. These findings demonstrate effector-specific brain-to-muscle beta transmission during movement cancellation and highlight the potential of peripheral measures to provide enhanced resolution of motor cortical dynamics.