Fig. 4

Algorithm flowchart for the implemented PPC method. For each channel (\(S1\) and \(S2\)), m windows of time are determined, and the Morlet wavelet transform is calculated for each window in both channels. For each time window, n frequency windows are determined, and their phases are calculated. The difference between the two phases is measured for every time–frequency epoch and this is used to calculate the phase-coherence value, which is represented in an n by m matrix