After applying this method to every trial for the frequencies between 3 and 7 Hz at Fz, Cz, and Pz, the phase-locking factor was calculated as 1 minus the phase variance. This calculation is identical to that used by others (Ford et al. 2008; Tallon-Baudry et al. 1997). High phase-locking at a specific frequency and within a specific time window indicates that oscillations have become phase-synchronized across trials with respect to event onset.
