where * represents a complex conjugate, and < > represents an expected value. ImC was calculated by dividing the calculated cross-spectral value by the product of the power spectral values of each electrode. f represents frequency, Sij represents a cross-spectrum value of electrodes i and j, and Sii(f) and Sjj(f) represent power spectrum values. ImC has a value between 0 and 1, and values closer to 1 indicate full phase coherence. Fisher’s z transformation was performed on these calculated values, and the independent t-test was used to compare the FCs of the theta, lower-alpha, and upper alpha bands between the BD and non-BD groups. A total of 44 electrodes were analyzed after excluding the electrodes used for removing noise caused by eye or body movement (FP2, FP1, AF7, and AF8), the electrodes attached to the skin (T9, T10, P9, P10, PO7, PO8, F9, F10, 62, and 63), and the electrodes in which artifacts were recorded (F1, C1, FT7, CP5, and P1).
