We examined task-related changes in the synchronization of neural oscillations by means of phase synchronization within (PLI) and between (PC) the electrodes during four different task conditions in the continuous performance task. As expected, both synchronization measures were increased in Go and NoGo conditions as compared with Warning or Neutral stimuli. The main findings concerning Go versus NoGo differences can be summarized as follows: (a) both synchronization measures (PLI and PC) showed strongest effects in the delta frequency band; (b) both measures showed also strong modulations by scalp topography, frequency and time course related to Go/NoGo differences; whereas PLI and PC in Go trials reach their maxima in the first post-stimulus time interval (0–300 ms), these synchronization measures in NoGo trials showed strongest effect in the second post-stimulus time interval (300–600 ms). Although phase synchronization (especially, measured by PLI) was in general highest at centro-parietal sites, phase synchronization in Go trials was stronger than in NoGo trials in the first time interval at centro-parietal sites, phase synchronization in NoGo trials was stronger than in Go trials in the second time interval at frontal and central sites.
