Simulation results based on referential, corrected, and bipolar EEGs showed that the reference signal may have a significant effect on the correlation, phase synchrony, and MSC. For this particular patient, we found that the reference signal with smaller amplitude compared with scalp EEG may decrease correlation and phase-synchrony values [see, e.g., the referential T7*F7 of smaller values and corrected T7*F7 of larger values in Fig. 5(B) and (C)]. On the contrary, the reference signal with larger amplitude compared with iEEG may increase correlation and phase-synchrony values [see, e.g., the referential LTD4*LTD5 of larger values and corrected LTD4*LTD5 of smaller values in Figs. 3(H) and 4(C)]. The reference signal with larger power compared with iEEG may increase MSC values [see, e.g., the referential LTD4*LTD5 of larger values and corrected LTD4*LTD5 of smaller values in Fig. 4(F)]. Hence, the reference signal may change the observed correlation, phase-synchrony, and MSC values significantly and thus lead to an incorrect interpretation of EEG.
