Fig. 1.

Schematic overview of the processing steps required to apply the GLM. First of all, the instantaneous amplitude and phase for the intended frequencies need to be extracted using bandpass filtering and Hilbert transformation. Z-transformation of these time series ensures that PAC and AAC estimates are normalised and comparable to other existing measures. The β-coefficients of the GLM are estimated in two ways: (1) using the entire data length available; (2) by first dividing the continuous data into shorter epochs and re-estimating the β-coefficients for each epoch. The latter estimates are subsequently used to assess the significance of the overall coupling values in the indicated way.