Gamma power (40 and 45 Hz) in two brain dipoles was modulated by a theta wave from a third dipole. Activity from these three dipoles was projected, along with correlated 1/f noise from 2,001 other dipoles, to 64 scalp EEG channels (top row of (A) shows the signal-dipole projections). gedCFC was able to recover these three components ((A), bottom row) by comparing broadband covariance matrices between theta peaks and troughs. (B) shows the time-frequency power spectra of the components time series time-locked to theta peaks and theta troughs. (C) shows power spectra of the three component time series. For comparison, the power spectrum from POz (the channel with maximum power) is shown. (D) shows CFC modulation defined as the average peak-trough distances per frequency. (E) shows a 2 s snippet of data from the theta component and the power time courses from the theta-peak and theta-trough components. The lower panel shows data from POz bandpass filtered around theta, 40 Hz, and 45 Hz. Note that the continuous gamma power time series closely matched the theta wave from which they were simulated, although the covariance matrices were taken only from peaks and troughs.