Randoph Helfrich and Robert Knight review evidence that the infrastructure of cognitive control is rhythmic. The general idea is that the prefrontal cortex controls large-scale oscillatory dynamics in the cortex and subcortex. But there is much more. Do yourself a favor: Read it.
Helfrich, R. F., & Knight, R. T. (2016). Oscillatory Dynamics of Prefrontal Cognitive Control. Trends in Cognitive Sciences.