Phase 3a of the project will comprise of an EEG-registration with the different types of electrodes in epilepsy patients with prominent interictal epileptiform discharges (IEDs) on EEG. For each epilepsy patient the EEG-recording with dry electrodes will be compared to the EEG-recordings with conventionally used wet electrodes (bridge and cup electrodes). Each EEG-recording will take approximately 10 minutes.