Frontoparietal phase synchronization of the p300 ERP component in an oddball task

P300, also known as P3, is a component of event-related potential (ERP), a positive peak appearing 300ms after target stimulus onset. P300 consists of two sub-components, P3a and P3b, where P3a is an early component and pronounced in the frontal area and P3b is induced following P3a and pronounced in the parietal area. This time difference between P3a and P3b can be evaluated by a phase difference. Hence, it seems plausible that a phase difference between frontal and parietal areas would remain consistent during the P300 period in response to a target stimulus. To address this conjecture, the present study analyzed phase locking value (PLV) of P300 between frontal and parietal areas and examined differences between the target and non-target ERPs. The oddball paradigm was used to elicit P300, in which a target to non-target ratio was 1:3. Thirty subjects participated in the experiment and each subject completed 50 blocks. 12-channel EEG on frontal area as well as 11-channel EEG on parietal area were collected for the analysis. PLV was estimated within the time interval from 150 ms to 500 ms after stimulus onset. The PLV analysis revealed significantly higher PLVs between frontal and parietal channels in the target ERP than in the non-target ERP (p < 0.05). It suggests that the recognition of a target stimulus may enhance long-range connections of P300-related brain responses between frontal and parietal areas