Cortico-motor control dynamics orchestrates visual sampling

Movements overtly sample sensory information, making sensory analysis an active-sensing process. In this study, we show that visual information sampling is not just locked to the (overt) movement dynamics, but it is structured by the internal (covert) dynamics of cortico-motor control. We asked human participants to perform an isometric motor task - based on proprioceptive feedback - while detecting unrelated near-threshold visual stimuli. The motor output (Force) shows zero-lag coherence with brain activity (recorded via electroencephalography) in the beta-band, as previously reported. In contrast, cortical rhythms in the alpha-band systematically forerun the motor output by 200ms. Importantly, visual detection is facilitated when cortico-motor alpha (not beta) synchronization is enhanced immediately before stimulus onset, namely at the optimal phase relationship for sensorimotor communication. These findings demonstrate an automatic gating of visual inputs by the ongoing motor control processes, providing evidence of an internal and alpha-cycling visuomotor loop.