It is possible that phase-amplitude CFC exists but is unrelated to functional activity, computation or communication. However, recent research has shown that low frequency activity can be entrained by rhythmic external sensory and motor events [56–58], as well as internal cognitive processes related to learning and memory [59]. Therefore, low frequency phase entrainment combined with the presence of phase-amplitude CFC implies that the modulation of high-frequency power by CFC will be entrained and coordinated with the occurrence of slower, behaviorally-relevant internal and external events.
