The basic “activity packet” building blocks defined by distinct frequencies can give rise to more complex regulatory structure through interactions between different frequency bands, a phenomenon termed cross-frequency coupling (CFC). In particular, phase-amplitude CFC provides an effective means to integrate activity across different spatial and temporal scales. Phase-amplitude CFC describes the statistical dependence between the phase of a low-frequency brain rhythm and the amplitude (or power) of the high-frequency component of electrical brain activity.
