Figure 4From: Time-varying bispectral analysis of visually evoked multi-channel EEGPhase-coupled and random phase sinusoids. (a) time domain signal. This corresponds to a window of length 128 samples centred around 0.315s, (b) power spectrum, (c) bicoherence. Note that the triad (8, 8, 16Hz) is phase-coupled and shows up with high bicoherence around (8, 8) while the triad (20, 20, 40Hz) is random phase and the bicoherence at (20, 20) is not significantly high. The power spectrum is unable to reveal this difference.Back to article page