Event - Related Potentials

11 Electroencephalography is one of the most popular psychophysiological methods in clinical and 12 preclinical research and provides a recording that reflects the global electrical activity of the 13 brain – the EEG. A limitation of the EEG is that it represents the summation of all the electrical 14 activity at a given moment in time, making it difficult to isolate the activity associated with 15 individual neurocognitive processes. A more powerful method for the study of isolated 16 neurocognitive processes focuses on the specific EEG responses to particular sensory, cognitive, 17 or motor events. Such specific responses are called event-related potentials (ERPs), to denote the fact 18 that they are associated with specific events. The ERP is difficult to see in the EEG recorded for 19 a single event. To isolate an ERP, one must collect the EEG of a large number of trials with the event 20 of interest, time-lock the corresponding signals to the onset of this event, and then average the 21 signals. The averaging process filters out all EEG activity that is not related to the event of interest 22 and isolates the ERP – the systematic response of the EEG to the event (Luck 2005).