Figure 1

Signal processing steps used to compute the EEG spectro-temporal signal representation. Subplots on the top right illustrate the five subband EEG signals (gray) and their respective Hilbert temporal envelopes (black). The subplots on the bottom depict the average modulation spectrograms for the beta frequency and m-delta modulation bands (i.e., ${\overline{\mathcal{E}}}_{4,1}$, where only a part of the m-delta band is depicted for visualization purposes) for healthy control (left subplot) and AD (right subplot) patients.