A new method for quantifying EEG event-related desynchronization:amplitude envelope analysis

Amplitude modulation (AM) analysis defines precisely the EEG signal envelope changes at sampling frequency. Here we demonstrate mathematically that event-related desynchronization (ERD) corresponds to the integration of AM-EEG. We applied this new approach to a group of 12 healthy human volunteers hearing repeated auditory stimuli and statistically compared the results from ERD to those from AM-EEG. The results indicate that AM-EEG characterized more precisely a specific evoked EEG cortical activation event and may be a powerful method for studying the time-course of functional dynamic brain EEG mapping with improved time resolution.