Alpha and Beta Corticomotor Phase Dynamics Shape Visuomotor Control on a Single-Trial Basis

A central question in sensorimotor neuroscience is how sensory inputs are mapped onto motor outputs to enable swift and accurate responses, even in the face of unexpected environmental changes. Here, we leverage corticomotor coherence as a window into the dynamics of sensorimotor loops and explore how it relates to online visuomotor control. We recorded brain activity using electroencephalography, while human participants (of either sex) performed an isometric tracking task involving transient, unpredictable visual perturbations. Our results show that coherence between cortical activity and motor output (force) in the alpha band (8-13 Hz) is associated with faster motor responses, while beta-band coherence (18-30 Hz) promotes more accurate control, which is in turn linked to a higher likelihood of obtaining rewards. Both effects are most pronounced near the onset of the perturbation, underscoring the predictive value of corticomotor coherence for sensorimotor performance. Single-trial analyses further reveal that deviations from the preferred corticomotor phase relationship are associated with longer reaction times and larger errors, and these phase effects are independent of power effects. Thus, beta-band coherence may reflect a cautious, reward-efficient control strategy, while alpha-band coherence enables quicker, though not necessarily efficient, motor responses, indicating a complementary, reactive control mode. These results highlight the finely tuned nature of sensorimotor control, where different aspects of sensory-to-motor transformations are governed by frequency-specific neural synchronization on a moment-to-moment basis. By linking neural dynamics to motor output, this study sheds light on the spectrotemporal organization of sensorimotor networks and their distinct contribution to goal-directed behavior.