The PLI was calculated to measure phase variability in relation to stimulus onset, as previously described (Schack and Klimesch, 2002; Klimesch et al., 2004). The PLI, which ranges between zero and one, is a measure of phase resetting (Schack and Klimesch, 2002). An increased PLI indicates less phase variability and stronger phase locking to the onset, whereas a reduced PLI indicates higher phase variability and weaker phase locking (Schack and Klimesch, 2002).
