Preictal conditional mutual information (CMI, top plots) and interaction information (II, bottom plots) as a function of channels, at frequencies ≤100 Hz (left plots) and >100 Hz (right plots) is shown. For each channel, information parameters were averaged over all pairwise values between that channel and all others. Inter-patient variability is superimposed. Values prior to noise perturbation (black dashed line), and following addition of white noise with amplitudes 0.1 (red), 0.5 (cyan), 1 (green), 2 (blue), 4(black) times the maximum amplitude of the signal are superimposed. Noise was added to each signal at the time interval of maximum mean CMI.