Rhythmic coupling across the cortex underlies perception.

Randolph F. Helfrich, Melody Huang, Guy Wilson, and Robert T. Knight
Prefrontal cortex modulates posterior alpha oscillations during top-down guided visual perception
PNAS 2017 114 (35) 9457-9462; published ahead of print August 14, 2017, doi:10.1073/pnas.1705965114