2017 Volume 16 Issue 2 Pages 245-252
Interictal paroxysmal rhythmic activity can appear in electroencephalography (EEG) in patients with mental disorders. The abnormal EEG were analyzed by wavelet-crosscorrelation analysis. The EEG were categorized as following: 2-4 seconds (A) and 0-2 seconds (B) before the appearance of the abnormal EEG; 2 seconds during the abnormal EEG (C); 0-2 seconds (D) and 2-4 seconds (E) after the abnormal EEG. Wavelet-crosscorrelation coefficients (WCC) in the theta and alpha bands for each segment were calculated in all patients. The results in the theta band showed that the abnormal connections between the sites in the brain could continue although the EEG seemingly recovered from the interictal paroxysmal rhythmic activity. The results in the alpha band showed that the normal connections between the sites in the brain could be weakened in the 2 seconds prior to the beginning of the interictal paroxysmal rhythmic activity in the EEG.