EEG recordings were acquired at a sampling frequency of 173.61 Hz using a 12-bit analog to digital (A/D) converter, band-pass filtered from 0.5 to 85 Hz (12 dB/oct.) and with a 50-Hz notch filter, and referenced against the common average of the non-focal recording contacts. Mean recording time per patient was 130 min (range 15–420 min, typically recorded over several days). All recordings were performed during the seizure-free interval while patients were awake and at rest with eyes opened. Only EEG recordings from the MTL contralateral to the zone of seizure origin were analyzed in the present study to reduce poorly controllable effects introduced by the epileptic process (Grunwald et al., 1995).
