Fig. 7. (  A ) Bicoherence peak frequencies (○) and bicoherence value (□) regarding the third peak, in relation to one side of paired biphasic frequency matching the basal α frequency (7 ≤α frequency ≤12). Significant difference in these bicoherence data compared with the value at: * 7 Hz; # 8 Hz; ** 9 Hz. (  B ) Simple regression analysis among pair frequencies, describing third peaks in relation to basal α frequencies. The regression line is shown with 95% confidence limits. Two biphasic pair frequencies make a third peak, displaying a linear relation, and frequency of the other side was twice as high as in α harmonics.