The phase diagram option is used to analyze phase differences between coherent channels. This can give an insight into a possible
coupling of brain regions which may be necessary e.g. to integrate input from various specialized neurons to a common perception.
However, the measured coupling is also influenced by volume conduction effects (scalp coherence) or the modeling parameters
(source coherence). If brain regions show oscillatory coupling in the same frequency range, the phase relationship should be
constant over some time.