Chan et al show that the prefrontal cortex (PFC) may exert top-down influences on the superior colliculus (SC) via oscillatory synchrony.  Animals performed both pro- and anti-saccade trials.  Anti-saccades are highly dependent on the PFC because they involve inhibiting a highly prepotent response (a pro-saccade).  Bilateral deactivation of the PFC attenuated beta and gamma power in the SC around the time the animals were preparing to respond.   The gamma power was correlated with spiking activity whereas beta was tonic (and reduced after PFC deactivation) and may facilitate communication between the PFC and SC.