Evolution of cerebral cortico-cortical communication during visuomotor adaptation to a cognitive-motor executive challenge.

Cortical dynamics were examined during a cognitive-motor adaptation task that required inhibition of a familiar motor plan. EEG coherence between the motor planning (Fz) and left hemispheric region was progressively reduced over trials (low-beta, high-beta, gamma bands) along with faster, straighter reaching movements during both planning and execution. The major reduction in coherence (delta, low/high-theta, low/high-alpha bands) between Fz and the left prefrontal region during both movement planning and execution suggests gradual disengagement of frontal executive following its initial role in the suppression of established visuomotor maps. Also, change in the directionality of phase lags (delta, high-alpha, high-beta, gamma bands) reflects a progressive shift from feedback to feedforward motor control. The reduction of cortico-cortical communication, particularly in the frontal region, and the strategic feedback/feedforward mode shift translated as higher quality motor performance. This study extends our understanding of the role of frontal executive beyond purely cognitive tasks to cognitive-motor tasks.