P3 and ERD/ERS in a Visual Oddball Paradigm

Abstract: Objective: The present study investigates intracerebrally the concurrent occurrence of event-related potentials (ERPs) and event-related desynchronization/synchronization phenomena (ERD/ERS) in subjects performing a visual oddball task. Methods: Evoked (P3) and induced ERD/ERS changes were studied in six subjects with drug-resistant epilepsy. Depth EEG activity from the mesiotemporal limbic structures (amygdala, hippocampus, and parahippocampal gyrus) was analyzed. We used an averaging of raw data to obtain ERPs, and an averaging of the amplitude/power envelope (complex demodulation) in five frequency bands: theta, α 1, α 2, beta, and gamma to obtain ERD/ERS. The P3 component of ERP and ERD/ERS in response to target and nontarget stimuli were evaluated. Results: Even though both P3 and ERD/ERS phenomena were observed in all of the investigated mesiotemporal regions, the most pronounced findings were revealed in the hippocampus. A P3 component of ERP was repeatedly observed in the hippocampus aft...